Titanium
<p>Titanium is a mineral commodity that is essential to the smooth functioning of modern industrial economies. Most of the titanium produced is refined into…
Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.
Titanium Chapter T of Critical Mineral Resources of the United States—Economic and Environmental Geology and Prospects for Future Supply Photograph of Ilmenite Open Pit Mine at Tellnes, Sokndal, Norway Photograph of Space Component Photograph of Open Pit Mining of Heavy Mineral Sands Photograph of Paint Buckets Professional Paper 1802–T U.S. Department of the Interior U.S. Geological Survey
Periodic Table of Elements Ta bl e El em en ts Modified from Los Alamos National Laboratory Chemistry Division; available at ://periodic.lanl.gov/images/periodictable.pdf. Cover. Upper left, Ilmenite open pit mine at Tellnes, Sokndal, Norway. Photograph courtesy of Mike Norton/CC-BY-SA-3 at ://en.wikipedia.org/ wiki/File:Tellnes.jpg. Lower left, open pit mining of heavy mineral sands at the Maxville deposit on Trail Ridge near Starke, Florida. Photograph by Andrew Romeo, The Chemours Co., used with permission. Upper right, because of titanium’s high strength-to-weight ratio, it is used for many spacecraft components. For example, the Hubble Space Telescope’s primary mirror is made of titanium silicate glass. Photograph courtesy of NASA. Lower right, most of the world’s titanium output is refined into titanium dioxide (TiO2), which is used to give a durable white color to many products, including paint, paper, rubber, and wallboard. Photograph ©2012 Tronox Ltd. All rights reserved.
Titanium By Laurel G. Woodruff, George M. Bedinger, and Nadine M. Piatak Chapter T of Critical Mineral Resources of the United States—Economic and Environmental Geology and Prospects for Future Supply Edited by Klaus J. Schulz, John H. DeYoung, Jr., Robert R. Seal II, and Dwight C. Bradley Professional Paper 1802–T U.S. Department of the Interior U.S. Geological Survey
U.S. Department of the Interior RYAN K. ZINKE, Secretary U.S. Geological Survey William H. Werkheiser, Acting Director U.S. Geological Survey, Reston, Virginia: 2017 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit ://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit ://store.usgs.gov/. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Woodruff, L.G., Bedinger, G.M., and Piatak, N.M., 2017, Titanium, chap. T of Schulz, K.J., DeYoung, J.H., Jr., Seal, R.R., II, and Bradley, D.C., eds., Critical mineral resources of the United States—Economic and environmental geology and prospects for future supply: U.S. Geological Survey Professional Paper 1802, p. T1– T23, ://doi.org/10.3133/ pp1802T. ISSN 2330-7102 (online)
Contents Abstract T1 Introduction T1 Titanium Commodities T1 Settings for Titanium Oxide Mineral Occurrences T2 Uses and Applications T2 Strategic and Critical Resource Issues T4 Geology T4 Geochemistry T4 Mineralogy T4 Deposit Types T6 Titanium Deposits Related to Igneous Rock T6 Titanium Deposits Related to Metamorphic Rocks T8 Titanium Deposits Related to Coastal Shorelines and Dunes, and Older Equivalent Rocks T9 Resources and Production T11 Identified Resources T11 Undiscovered Resources T12 Exploration for New Deposits T15 Environmental Considerations T15 Sources and Fate in the Environment T15 Mine Waste Characteristics T16 Human Health Concerns T16 Ecological Health Concerns T16 Mine Closure T17 Problems and Future Research T18 References Cited T18
Figures
T1. Chart showing common titanium-bearing oxide minerals and common titanium-bearing silicate minerals with their approximate titanium content T5
T2. Reflected-light photographs showing lamellae of hematite in ilmenite in hemo-ilmenite from the magmatic Lac Tio hemo-ilmenite deposit; and titaniferous magnetite and ilmenite from the magmatic La Blache iron-titanium-oxide deposit T5
T3. World map showing global distribution of titanium deposits, by size and type of depost T7
T4. Bar chart comparing approximate titanium dioxide content in titanium deposits of different deposit types T8
T5. Plot of titanium dioxide grade and tonnage for selected igneous, metamorphic, and sedimentary deposits in the world, by deposit type T10
T6. Pie charts showing percentage of estimated 2012 world mine production of ilmenite and rutile, and percentage of global reserves of ilmenite and rutile, by country T11 Tables
T1. Classification of selected titanium mineral deposits based on their geologic setting and the processes through which they were formed T3
T2. Titanium resources of the United States T13
T3. Titanium mineral resources of the world (excluding the United States) for ilmenite (including titanomagnetite and leucoxene) and rutile (including anatase and brookite). T14
Conversion Factors International System of Units to Inch/Pound Multiply By To obtain Length angstrom (Å) (0.1 nanometer) microinch angstrom (Å) (0.1 nanometer) 0.000003937 mil micrometer (µm) [or micron] mil millimeter (mm) inch (in.) centimeter (cm) inch (in.) meter (m) foot (ft) meter (m) yard (yd) kilometer (km) mile (mi) Area hectare (ha) acre square kilometer (km2) acre square meter (m2) square foot (ft2) square centimeter (cm2) square inch (ft2) square kilometer (km2) square mile (mi2) Volume milliliter (mL) ounce, fluid (fl. oz) liter (L) ounce, fluid (fl. oz) liter (L) quart (qt) liter (L) gallon (gal) cubic meter (m3) gallon (gal) cubic centimeter (cm3) cubic inch (in3) cubic meter (m3) cubic yard (yd3) cubic kilometer (km3) cubic mile (mi3) Mass microgram (μg) 0.00000003527 ounce, avoirdupois (oz) milligram (mg) 0.00003527 ounce, avoirdupois (oz) gram (g) ounce, avoirdupois (oz) gram (g) 0.03215075 ounce, troy kilogram (kg) ounce, troy kilogram (kg) pound avoirdupois (lb) ton, metric (t) ton, short [2,000 lb] ton, metric (t) ton, long [2,240 lb] Deposit grade gram per metric ton (g/t) 0.0291667 ounce per short ton (2,000 lb) (oz/T) Pressure megapascal (MPa) bar gigapascal (GPa) 10,000 bar Density gram per cubic centimeter (g/cm3) pound per cubic foot (lb/ft3) milligram per cubic meter (mg/m3) 0.00000006243 pound per cubic foot (lb/ft3) Energy joule (J) 0.0000002 kilowatthour (kWh) joule (J) 6.241 × 1018 electronvolt (eV) joule (J) calorie (cal) kilojoule (kJ) 0.0002388 kilocalorie (kcal)
International System of Units to Inch/Pound—Continued Multiply By To obtain Radioactivity becquerel (Bq) 0.00002703 microcurie (μCi) kilobecquerel (kBq) microcurie (μCi) Electrical resistivity ohm meter (Ω-m) ohm inch (Ω-in.) ohm-centimeter (Ω-cm) ohm inch (Ω-in.) Thermal conductivity watt per centimeter per degree Celsius (watt/cm °C) International British thermal unit inch per hour per square foot per degree Fahrenheit (Btu in/h ft2 °F) watt per meter kelvin (W/m-K) International British thermal unit inch per hour per square foot per degree Fahrenheit (Btu in/h ft2 °F) Inch/Pound to International System of Units Length mil micrometer (µm) [or micron] inch (in.) centimeter (cm) inch (in.) millimeter (mm) foot (ft) meter (m) mile (mi) kilometer (km) Volume ounce, fluid (fl. oz) milliliter (mL) ounce, fluid (fl. oz) liter (L) Mass ounce, avoirdupois (oz) 28,350,000 microgram ounce, avoirdupois (oz) 28,350 milligram ounce, avoirdupois (oz) gram (g) ounce, troy 31.10 348 gram (g) ounce, troy 0.03110348 kilogram (kg) pound, avoirdupois (lb) kilogram (kg) ton, short (2,000 lb) ton, metric (t) ton, long (2,240 lb) ton, metric (t) Deposit grade ounce per short ton (2,000 lb) (oz/T) 34.285714 gram per metric ton (g/t) Energy kilowatthour (kWh) 3,600,000 joule (J) electronvolt (eV) 1.602 × 10–19 joule (J) Radioactivity microcurie (μCi) 37,000 becquerel (Bq) microcurie (μCi) kilobecquerel (kBq) Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:
°F (1.8 × °C) + 32 Temperature in degrees Celsius (°C) may be converted to kelvin (K) as follows:
K °C + 273.15 Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:
°C (°F – 32) / 1.8
Datum Unless otherwise stated, vertical and horizontal coordinate information is referenced to the World Geodetic System of 1984 (WGS 84). Altitude, as used in this report, refers to distance above the vertical datum. Supplemental Information Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C). Concentrations of chemical constituents in soils and (or) sediment are given in milligrams per kilogram (mg/kg), parts per million (ppm), or parts per billion (ppb). Concentrations of chemical constituents in water are given in milligrams per liter (mg/L), micrograms per liter (µg/L), nanogams per liter (ng/L), nanomoles per kilogram (nmol/kg), parts per million (ppm), parts per billion (ppb), or parts per trillion (ppt). Concentrations of suspended particulates in water are given in micrograms per gram (µg/g), milligrams per kilogram (mg/kg), or femtograms per gram (fg/g). Concentrations of chemicals in air are given in units of the mass of the chemical (milligrams, micrograms, nanograms, or picograms) per volume of air (cubic meter). Activities for radioactive constituents in air are given in microcuries per milliliter (μCi/mL). Deposit grades are commonly given in percent, grams per metric ton (g/t)—which is equivalent to parts per million (ppm)—or troy ounces per short ton (oz/T). Geologic ages are expressed in mega-annum (Ma, million years before present, or 10 6 years ago) or giga-annum (Ga, billion years before present, or 10 9 years ago). For ranges of years, “to” and (or) the en dash (“–”) mean “up to and including.” Concentration unit Equals milligram per kilogram (mg/kg) part per million microgram per gram (µg/g) part per million microgram per kilogram (μg/kg) part per billion (109) Equivalencies part per million (ppm): 1 ppm 1,000 ppb 1,000,000 ppt 0.0001 percent part per billion (ppb): 0.001 ppm 1 ppb 1,000 ppt 0.0000001 percent part per trillion (ppt): 0.000001 ppm 0.001 ppb 1 ppt 0.0000000001 percent Metric system prefixes tera- (T-) 1 trillion giga- (G-) 1 billion mega- (M-) 1 million kilo- (k-) 1 thousand hecto- (h-) 1 hundred deka- (da-) 1 ten deci- (d-) 10–1 1 tenth centi- (c-) 10–2 1 hundredth milli- (m-) 10–3 1 thousandth micro- (µ-) 10–6 1 millionth nano- (n-) 10–9 1 billionth pico- (p-) 10–12 1 trillionth femto- (f-) 10–15 1 quadrillionth atto- (a-) 10–18 1 quintillionth
Abbreviations and Symbols °C degree Celsius µg/L microgram per liter µm micrometer EPA U.S. Environmental Protection Agency Ga giga-annum kg kilogram km2 square kilometer m meter mg/L milligram per liter ng/m3 nanogram per cubic meter WHO World Health Organization
Titanium By Laurel G. Woodruff, George M. Bedinger, and Nadine M. Piatak Abstract Titanium is a mineral commodity that is essential to the smooth functioning of modern industrial economies. Most of the titanium produced is refined into titanium dioxide, which has a high refractive index and is thus able to impart a durable white color to paint, paper, plastic, rubber, and wallboard. Because of their high strength-to-weight ratio and corrosion resistance, titanium metal and titanium metal alloys are used in the aerospace industry as well as for welding rod coatings, biological implants, and consumer goods. Ilmenite and rutile are currently the principal titaniumbearing ore minerals, although other minerals, including anatase, perovskite, and titanomagnetite, could have economic importance in the future. Ilmenite is currently being mined from two large magmatic deposits hosted in rocks of Proterozoic-age anorthosite plutonic suites. Most rutile and nearly one-half of the ilmenite produced are from heavymineral alluvial, fluvial, and eolian deposits. Titanium-bearing minerals occur in diverse geologic settings, but many of the known deposits are currently subeconomic for titanium because of complications related to the mineralogy or because of the presence of trace contaminants that can compromise the pigment production process. Global production of titanium minerals is currently dominated by Australia, Canada, Norway, and South Africa; additional amounts are produced in Brazil, India, Madagascar, Mozambique, Sierra Leone, and Sri Lanka. The United States accounts for about 4 percent of the total world production of titanium minerals and is heavily dependent on imports of titanium mineral concentrates to meet its domestic needs. Titanium occurs only in silicate or oxide minerals and never in sulfide minerals. Environmental considerations for titanium mining are related to waste rock disposal and the impact of trace constituents on water quality. Because titanium is generally inert in the environment, human health risks from titanium and titanium mining are minimal; however, the processes required to extract titanium from titanium feedstock can produce industrial waste. Introduction Titanium is an abundant element that has become an important industrial commodity only within the past 150 years. Ilmenite (FeTiO3 ) and rutile (which is the most common form of titanium dioxide [TiO2 ]) are the two principal minerals that are sources of titanium. Pure titanium metal was first isolated in 1910, but the metal was not commercially available until the development of the Kroll process by William Kroll in 1938. In this process, titanium is produced by reduction of titanium tetrachloride with magnesium. Titanium is now considered essential for modern industrial technology production as well as to meet other needs of modern affluent societies. Many of the uses for titanium in modern industry, including in pigments for paints and paper and in manufacturing by the aerospace industry, are described by Gambogi (2012) and Murphy and Frick (2006). Although the United States is dependent on imports of titanium mineral concentrates and titanium sponge, the United States continues to be a net exporter of TiO2 pigment and titanium wrought-metal products. Titanium Commodities The major titanium commodities and their industrial uses are described in Murphy and Frick (2006). Titanium commodity sources include both titanium-bearing oxide minerals extracted from natural sources and synthetic titaniumbearing materials processed from these minerals. Some 93 percent of the world’s titanium resources are accounted for by the mineral ilmenite; the remaining percentage is mainly from rutile and leucoxene. Leucoxene is not a true mineral but is, rather, a finely crystalline aggregate of rutile, anatase, or brookite with greater than 70 percent TiO2 that is created by the weathering of ilmenite. Rutile, anatase, and brookite are TiO2 polymorphs; that is, minerals that share the same chemical composition of TiO2 but have different crystal forms. Ilmenite, rutile, and leucoxene are processed mainly into titanium-rich slag or synthetic rutile and then further processed for use in pigments and as titanium metal. Titanium slag, which
T2 Critical Mineral Resources of the United States—Titanium is derived by smelting ilmenite, contains about 75 to 86 percent TiO2; with further processing by high-pressure acid leaching, titanium slag can be upgraded to about 94.5 percent TiO2 (Guéguin and Cardarelli, 2007). Synthetic rutile is produced by removing iron from secondary ilmenite feed, which increases its TiO2 content to about 90 to 95 percent TiO2 from about 50 to 55 percent TiO2 (Mackey, 1994). Synthetic rutile can be used as a substitute for natural rutile. Two main industrial processes—a sulfate process and a chloride process—are currently used to convert the raw materials of ilmenite and rutile into pure white TiO2 for use in pigment or into titanium metal (Mackey, 1994). The sulfate process is the older of the two processes; it was perfected in 1916 by two Norwegian chemists (Korneliussen and others, 2000a). In the sulfate process, finely ground ilmenite or high-TiO2 slag is digested with concentrated sulfuric acid. In the chloride process, high titanium-content feedstock, such as natural and synthetic rutile, high-TiO2 slag, or high-TiO2 ilmenite sands, is converted into titanium chlorides at high temperature. As of 1992, the sulfate and chloride processes produced about equal amounts of product; however, because it produces a superior TiO2 pigment product and fewer waste products, the chloride process has largely supplanted the sulfate process. This shift from the sulfate process to the chloride process for TiO2 pigment production has increased demand for a high-grade titanium feedstock, such as rutile, upgraded titanium-rich slag, and synthetic rutile. Settings for Titanium Oxide Mineral Occurrences The diverse types of economic and potentially economic titanium deposits originally categorized by rock type and environment by Force (1991) have been updated in table T1 and are described in the geology section of this chapter. Major deposit types listed in table T1 include (a) magmatic deposits in igneous and related rocks with ilmenite as the primary ore mineral; (b) metamorphic deposits with rutile as the primary ore mineral; (c) rutile in hydrothermal porphyry deposits, and (d) heavy-mineral concentrations in unconsolidated and lithified sand deposits that may include rutile, ilmenite, and alteration products, such as leucoxene. Most deposit types (for example, those in the I–8 and S–4 classes) can be further altered by weathering, at times upgrading the titanium content of the ilmenite, if present. Ilmenite accounts for about 92 percent of the world’s consumption of titanium minerals. The world’s two active magmatic titanium mines—the Tellnes Mine in Norway and the Lac Tio Mine in the Province of Quebec, Canada— together produce an estimated 32 percent of the world’s titanium (Gross, 1996; Schiellerup and others, 2003). The remaining 68 percent comes from high-grade ilmenite and rutile heavy-mineral deposits in unconsolidated heavy-mineral shoreline and dune deposits, fluvial placers (surface mineral deposits formed by mechanical concentration of minerals from weathered rock), and older lithified equivalents. Magmatic iron-titanium-oxide-rich deposits are hosted by a complex suite of mafic rocks that includes anorthosite, gabbro, and norite. The principal ore minerals are ilmenite and hemo-ilmenite, which is ilmenite that has extensive hematite (Fe2O3) exsolution lamellae, so that hematite occurs as small parallel plates within larger ilmenite crystals. Titaniferous magnetite, which is a complex oxide made up primarily of magnetite (Fe3O4) with iron-titanium-oxide exsolution lamellae, can also occur in these rocks in high concentrations, but it is of less economic importance because of its low titanium content. Heavy-mineral deposits contain concentrations of iron-titanium-oxide minerals that are denser than quartz and so lag behind during erosion and weathering as lighter minerals are more rapidly transported away or broken down. A typical mineral assemblage in heavy-mineral deposits can include rutile and ilmenite (and minerals produced from the weathering of ilmenite, such as anatase, leucoxene, and pseudorutile), as well as other high-density, erosion-resistant minerals, including chromite, garnet, kyanite, monazite, staurolite, tourmaline, and zircon. Heavy-mineral deposits develop when relatively resistant iron-titanium-oxide minerals and other heavy minerals, such as monazite and zircon, are eroded from the parent rocks, transported and sorted, and finally deposited in fluvial, alluvial, or eolian settings. Many productive heavy-mineral provinces, such as the East Coast of the United States, the east and west coasts of South Africa, and the east and west coasts of Australia, are located on passive continental margins that are usually backed by elevated and often highly weathered high-grade metamorphic or mafic igneous hinterlands (Force, 1991). Uses and Applications About 93 percent of the world’s titanium is refined into TiO2 for pigment; consequently, trends in the TiO2 pigment industry exert a large influence on the development of titanium resources (Towner and others, 1988; Murphy and Frick, 2006). Titanium dioxide has properties of whiteness, opacity, and chemical inertness that make it especially suitable for use as pigment to impart a durable white color to paints, paper, plastic, sunscreen, toothpaste, and wallboard (Miller, 1957; Stamper, 1970). The leading uses of TiO2 pigment in the United States in 2012 were paint (59 percent), plastics (28 percent), paper (9 percent), and other (4 percent) (Bedinger, 2013). Titanium is different than most other metallic elements in that it is mined primarily to satisfy demands for a chemical product (TiO2 for pigment) rather than for the metal itself (Murphy and Frick, 2006). The high cost of extracting titanium metal from ore curtails broader use of titanium metal and alloys. About 2.5 percent of the world’s titanium is used for the production of corrosion-resistant titanium metal (Murphy and Frick, 2006). Titanium metal alloys are desirable for their high strength-to-weight ratio and corrosion resistance,
Introduction T3 Table T1. Classification of selected titanium mineral deposits based on their geologic setting and the processes through which they were formed. [Modified from Force (1991). The relative economic importance of each deposit type, which is subjective, is indicated as follows: 1, of great current impor tance; 2, of probable great importance in the near future; 3, of possible importance; 4, of moderate importance; and 5, of minor importance. Locality abbrevia tions: Ark., Arkansas; Colo., Colorado; Fla., Florida; Md., Maryland; Minn., Minnesota; N.Y., New York; Va., Virginia] Deposit class Deposit type1 Typical mineralogy Level of economic importance Example deposits Magmatic (igneous and igneous related) I–1 Massif anorthosite Hemo-ilmenite Lac Tio, Quebec; Tellnes, Norway I–2 Anorthosite-gabbro Ilmenite, titanomagnetite Sanford Lake district, N.Y. I–3 Layered mafic intrusion Ilmenite, titanomagnetite Magpie, Quebec; Panzihuia, China I– 4 Troctolite/ultramafic Ilmenite, titanomagnetite Longnose, Minn. I–5 Albititic/metasomatized Rutile Kragerø, Norway; Roseland, Va. (in part) I–6 Alkalic/metasomatized Perovskite, brookite, rutile Iron Hill, Colo.; Magnet Cove, Ark. I–7 Weathered alkalic rocks Anatase Catalão, Salitre, and Tapira, Brazil I–8 Weathered anorthositic rocks Ilmenite, rutile Roseland, Va. (in part) Metamorphic M–1 Eclogite-hosted Rutile Engebøfjellet, Norway; Piampaludo, Italy M–2 Amphibolite-hosted Rutile Daixian, China M–3 Greenschist-hosted Rutile Dinning, Md. M– 4 Contact metasomatized anorthosite Ilmenite, rutile Roseland, Va. (in part) M–5 Metasomatized aluminum-rich schist Rutile Evergreen, Colo. Hydrothermal (igneous and [or] metamorphic) I/M Hydrothermal porphyry ore deposits Rutile Bingham, Utah; El Teniente, Chile Sedimentary-related S–1 Fluvial Rutile, ilmenite Mogbwemo and Sherbo River, Sierra Leone S–2 Beach (strandline) and (or) coastal dune Ilmenite, altered ilmenite, rutile, leucoxene North Stradbroke Island, eastern Australia; Richards Bay, South Africa; Trail Ridge, Fla. (in part) S–3 Lithified paleo-placers (fluvial and [or] beach) Ilmenite, altered ilmenite, rutile, leucoxene Bothaville, South Africa S – 4 Weathered sedimentary deposits Altered ilmenite, leucoxene Trail Ridge, Fla. (in part) 1Individual deposit types are further classified and described more fully in the text. and they are used widely in the manufacturing of aircraft. In general, production of titanium mill products precedes aircraft deliveries by about 1 year. In 2010, mill product shipments increased by 62 percent because of increased aircraft build rates and higher inventory levels throughout the titanium supply chain (Gambogi, 2012). The aerospace industry (67 percent) was the leading end user of mill products. Titanium has other important end uses. For example, titanium is used in welding-rod coatings, where it protects the surfaces of a weld from unwanted reaction with the atmosphere during welding, as well as in the manufacture of mineral fibers; it is used in ceramic components for electronic equipment, and in carbides and other titanium chemicals. Because of titanium’s resistance to corrosion in saltwater, it is used in shipbuilding, deep-sea petroleum exploration and production, and geothermal power-generating facilities. A significant quantity of titanium in the form of ferrotitanium, scrap, and sponge (a porous form of titanium created during the first stage of processing) is consumed in the steel and nonferrous metal alloy industries. In the steel industry, titanium is used for deoxidation, grain size control, and controlling and stabilizing carbon and nitrogen content. Titanium-intensive steels include interstitial-free, stainless, and high-strength low-alloy steels. Titanium has the property of osseointegration, which means that it can be structurally accepted by bone, and because titanium is nonreactive, it is increasingly used to make medical devices, such as hip and knee joints, bone screws and plates, and dental implants.
T4 Critical Mineral Resources of the United States—Titanium Strategic and Critical Resource Issues Titanium is considered a critical and strategic mineral because of the unique properties of both titanium metal (and its alloys) and TiO2 pigment. There are no completely satisfactory substitutes for titanium, especially titanium metal (Towner and others, 1988). Titanium metal’s combination of corrosion resistance, excellent weight-to-strength ratio, and very high melting point is not found with other metals. Substitutes for TiO2 pigment, such as zinc oxide, lithopone (a mixture of barium sulfate and zinc sulfide), and calcium carbonate, generally result in an inferior product and are less environmentally safe. Although lead has similar whitening properties, titanium dioxide pigment replaced lead as a whitener because of public health issues related to lead toxicity. Consumption of titanium mineral concentrates in the United States exceeds domestic production (Gambogi, 2012). From 2008 to 2012, U.S. consumption of titanium concentrates averaged about 1,400,000 metric tons. The net import reliance for the United States in that same time period, as a percentage of apparent consumption, was between 65 and 78 percent. The primary sources of U.S. imports of titanium mineral concentrates, which include ilmenite, rutile, synthetic rutile, and titanium slag, were Australia, Canada, Mozambique, and South Africa. The titanium feedstock industry is dominated by a relatively few companies at both ends of the supply chain; consequently, the actions of a few industry leaders can have implications for the entire industry (Murphy and Frick, 2006). Titanium resources are located in relatively few countries, which means that many industrial nations are dependent on titanium imports (Towner and others, 1988). In addition, the influence of China is an important strategic issue for the tita nium industry, as increased economic growth in that nation will likely increase its consumption of titanium minerals, pigments, and metal in the long term (Gambogi, 2012). Increasing demand in China for titanium will be paced by increasing demand in the United States as the U.S. economy recovers from the recession that began in 2008 and as aerospace, defense, and industrial uses grow. For example, new lighter and fuel-efficient aircraft and ground vehicles will require significantly more titanium in their structures to reduce weight and increase durability. Global consumption of titanium by the defense industry alone was expected to increase by slightly more than 30 percent between 2010 and 2015 (Gambogi, 2012). Improving global economic conditions resulted in a 7 percent increase in domestic TiO2 pigment production from 2009 to 2010 (Gambogi, 2012). Thus, the dynamics of the global titanium industry are a complex interdependence of supply and demand, industry activities, and environmental regulations, all of which could be highly influenced by the discovery of new uses for titanium and by technological advances in the extraction and production of titanium metal and TiO2 pigment. Geology Geochemistry Titanium is the ninth most abundant element in Earth’s crust, with an average TiO2 abundance of 0.7 weight percent (Rudnick and Fountain, 1995). Titanium can be found in nearly all rocks and sediments, often at contents greater than 1 weight percent, and thus, unlike many other elements of economic interest, it is considered to be a major element rather than a trace element. Titanium is a transition element with atomic number 22 and an atomic mass of 47.867 atomic mass units. Titanium’s chemistry has similarities to the chemistries of silicon and zirconium. The main oxidation state is Ti4+, although Ti2+ and Ti3+ are known to exist. Titanium is a lithophile element with a strong affinity for oxygen, and it typically forms oxide minerals. It is not found as a pure metal in nature, and processing is required to produce a low-density, high-strength metal. Titanium metal has excellent corrosion resistance, and it is as strong as steel but 45 percent lighter. Mineralogy The most economically important titanium oxides are ilmenite (FeTiO3 ) and the titanium dioxide (TiO2 ) polymorphs rutile, anatase, and brookite. Only some titanium-bearing oxide minerals currently have economic value. Less common, subeconomic minerals include pseudobrookite (Fe2TiO5 ), perovskite (CaTiO3 ), geikielite ((Mg,Fe)TiO3 ), pyrophanite (MnTiO3 ), and titanite or sphene (CaTiSiO5 ). The titanium content in titanomagnetite ranges between about 2 percent and about 20 percent, and titaniferous magnetite as a group of iron-titanium-oxide ore minerals contains between about 1 percent and about 15 percent titanium (fig. T1; Rose, 1969). The mineralogy of iron-titanium oxides in magmatic deposits is dependent on several factors, including the initial magma composition, the magma oxygen fugacity, and the cooling history. At magmatic temperatures (>700 degrees Celsius [°C]), iron-titanium-rich liquids are in a single, homogenous phase after which, during cooling, the liquids will separate into two or more oxide minerals. In a hightemperature titanium-rich magma, a small amount of hematite (Fe2O3 ) will separate out of the cooling oxide phase to form thin lamellae within ilmenite crystals. Deposits dominated by the composite mineral hemo-ilmenite (fig. T2A) are the largest and most economically important magmatic deposits. In more iron-rich magmas under varying magmatic condi tions, a titanium-rich phase (usually ilmenite or ulvöspinel [Fe2TiO4 ]) will separate from magnetite (Fe3O4 ) to form (a) titanomagnetite, which is a complex mixture of irontitanium oxides with thin exsolution lamellae of ilmenite or ulvöspinel in magnetite, or (b) granular, interlocking discrete grains of ilmenite, ulvöspinel, and magnetite (fig. T2B). Titaniferous magnetite is a general mining term applied to low-temperature aggregations of hematite, ilmenite,
Geology T5 T1 - Chart Showing Common Titanium-Bea ri ng O d e Minerals Figure T1. Chart showing common titanium-bearing oxide minerals (black text) and common titanium-bearing silicate minerals (red text) with their approximate titanium content (in weight percent). The blue shaded boxes represent the range of titanium content for the mineral species in the boxes. magnetite, titanomagnetite, and other intermediate members of the iron-titanium-oxide solid solution series (Rose, 1969). With current technologies, deposits dominated by titaniferous magnetite are generally too high in titanium to mine for iron ore yet too low in titanium to mine for titanium; however, if metallurgical problems with extraction and separation could be resolved, then deposits containing very large resources of titaniferous magnetite could be economically viable for both elements (Rose, 1969). Substitution of aluminum, calcium, chromium, copper, magnesium, manganese, silicon, vanadium, and zinc in the ilmenite crystal structure can lower the quality of ilmenite concentrate, as these elements decrease the TiO2 grade and may affect pigment color (Chernet, 1999). Ilmenite also is a common detrital mineral, being somewhat resistant to erosion processes. Weathering of ilmenite typically involves progressive leaching of iron from its mineral structure, thereby enriching the altered ilmenite in titanium and potentially forming pseudorutile (Fe2Ti3O9), leucoxene, and rutile (fig. T1). Because of this upgrading in titanium content, altered ilmenite is a preferred ore target. T Photograph of Reflected Light Figure T2. Reflected-light photographs showing A, lamellae of hematite (light-pink) in ilmenite (dark pink) in hemo-ilmenite from the magmatic Lac Tio hemo-ilmenite deposit, and B, titaniferous magnetite (Ti-Mte) and ilmenite (Ilm) from the magmatic La Blache iron-titanium-oxide deposit. Scale bar is 0.5 millimeters in length. Photographs courtesy of Serge Perreault, SOQUEM, Inc. Rutile is the most common of the TiO2 polymorphs. It has a high index of refraction and thus a high degree of opacity, which accounts for rutile’s desirability for use in pigments. Rutile occurs as an accessory mineral in many igneous rocks and in all grades of metamorphic rocks. With increasing metamorphic grade, the breakdown of ilmenite and silicates will release titanium, which then crystallizes into rutile. Rutile is highly stable across most geologic environments, which explains its presence in a wide range of rock types and as a common detrital mineral. Rutile can be a major host mineral for niobium, tantalum, tungsten, uranium, zirconium, and ferric iron. The presence of trace elements is in part dependent on the availability of trace constituents during rutile formation. Anatase and brookite are low-temperature alteration products of ilmenite or titanite.
T6 Critical Mineral Resources of the United States—Titanium Deposit Types Table T1 shows the classification of titanium mineral deposit types. These classifications can have considerable overlap. For example, magmatic concentrations of iron- and titanium-bearing silicates and oxides can be metamorphosed to form rutile, weathered from parent rocks to subsequently reside in place within weathered zones, or transported and sorted by wind or water to form heavy-mineral deposits. A common thread among all the deposit types described in table T1 is their ultimate origin from rocks somewhat enriched in titanium by geologic processes. The worldwide distribution of titanium deposits is shown in figure T3. The economic value and mining potential of a titanium deposit is highly dependent on its mineralogy rather than its overall titanium content. Although there are very large global resources of ilmenite and rutile combined, there is a worldwide lack of high-grade, high-quality ilmenite deposits as well as of high-quality rutile deposits (Korneliussen and others, 2000a). Mineral assemblage, grain size, morphology, texture, and type and quantity of included trace elements all contribute to the economic potential of a deposit. Qualitative differences in the approximate TiO2 content of different deposit types are shown in figure T4. In sedimen tary deposits, titanium-bearing minerals have been released from their parent rock; thus, low-grade deposits of this type may be mined if the titanium minerals are of sufficiently high quality, either through alteration of ilmenite or by the presence of rutile. Brooks (1976, p. 149), in postulating that the ultimate “cut-off grade” for each metal is its crustal abundance, acknowledges former U.S. Geological Survey Director Vincent McKelvey for pointing out that the titanium content of ilmenite beach placers mined in Florida is below the crustal abundance of titanium. The presence or absence of discrete crystals of ilmenite is a key factor that determines the economic value of most magmatic oxide deposits. In magmatic hemo-ilmenite deposits, such as the deposit at Tellnes (Norway), ore has to be mined and crushed and the ilmenite separated from the waste rock; therefore, ore grades in these types of deposits must be high (Korneliussen and others, 2000a). Deposits with uncon ventional titanium ore minerals, such as Iron Hill (Colorado; also called Powderhorn in the literature), which host perovskite, are currently uneconomic; likewise, the anatase deposits in Brazil (the Catalão, Salitre, and Tapira deposits) are not being exploited for titanium at this time. Titanium Deposits Related to Igneous Rock Mafic intrusions of various age and rock types can contain significant iron-titanium-oxide deposits. Deposits dominated by ilmenite and hemo-ilmenite are hosted by discordant and layered bodies in Proterozoic-age massif anorthosite plutonic complexes. These unique rock suites are restricted in time, from about 0.5 to 2.5 Ga (giga-annum, or billion years ago); the majority that contain significant titanium resources were emplaced from about 1.0 to 1.8 Ga (Ashwal, 2010). The plutonic suites are dominated by different and often unusual mafic rock types. These rocks are called, for example, anorthosite, charnockite, jotunite, gabbro, norite, or troctolite. The different names distinguish among rocks with various proportions and compositions of plagioclase and pyroxene. Anorthosite plutonic suites of the Grenville Province in eastern Canada and parts of the Northeastern United States and the Rogaland anorthosite province in Norway contain numerous iron-titanium-oxide deposits (Rose, 1969; Krause and others, 1985; Corriveau and others, 2007). Hemo-ilmenite (with little or no magnetite) is currently being mined at Lac Tio in Quebec Province, Canada, and is hosted by the Allard Lake anorthosite in the Havre-Saint-Pierre anorthosite plutonic suite (Gross, 1996). Hemo-ilmenite is also being mined at Tellnes, which is a hemo-ilmenite-bearing norite lens in the Åna-Sira anorthosite pluton in Norway (Wilmart and others, 1989). A deposit model for titanium deposits hosted by Proterozoic-age massif anorthosite plutonic suites was completed by Woodruff and others (2013). Deposits dominated by titaniferous magnetite with minor amounts of ilmenite are hosted in layered and massive intrusions of gabbro, leucogabbro (light-colored gabbro), and norite, which can include, but are not restricted to, Proterozoic-age massif anorthosites (Gross, 1996). These types of deposits have somewhat different characteristics than the magmatic deposits typified by Lac Tio or Tellnes, including differences in host rock form, dominant ore mineralogy, and proposed magmatic history. Examples include numerous deposits in layered and discordant anorthositenorite-gabbro intrusions in the Grenville Province, such as Magpie Mountain and Lac la Blache (Canada) and Sanford Lake district in the Adirondacks (New York), and large layered mafic intrusions of various ages, such as the Bushveld Complex (South Africa), which is currently being exploited for vanadium from titaniferous magnetite. Titanomagnetite and ilmenite are mined for iron, titanium, and vanadium from several deposits in the Permian-age Panzhihua layered mafic intrusion in China (Zhou and others, 2005). Other magmatic occurrences are somewhat enigmatic. For example, in the Duluth Complex of Minnesota, small bodies of ilmenite and titanomagnetite hosted by ultramafic rocks that cross-cut gabbroic rocks are a significant (but presently subeconomic) titanium resource. The origin of these deposits remains under debate (Hauck and others, 1997). In Finland, the relatively small Koivusaarenneva gabbro intrusion contains layers of ilmenite (with minor amounts of magnetite) that are interpreted as iron-titanium-oxides deposited in a flow-through magmatic system that has created a large resource in a small-volume intrusion (Kärkkäinen and Bornhorst, 2003). Formation of iron-titanium-oxide deposits in mafic intrusions requires favorable combinations of composition, oxygen fugacity, and crystallization history, which determine if a deposit is dominated by ilmenite or titaniferous magnetite (Woodruff and others, 2013). Massive hemo-ilmenite
Geology T7 Worl d Ma p S how in g G lob al D istr ibu tio n o f T ita niu m described more fully in World map showing global distribution of titanium deposits, by size and type of depost. Deposit types are from table T1 and are ize is denoted by the relative size of each into-Madagascar Government joint venture to extract ilmenite from sands
Figure T3. the text. D, district; S, State; numbers in parentheses indicate the number of deposits included in a single symbol. Deposit s owner and others (1988) and Force (1991). circle and descriptive text. QMM stands for QIT Madagascar Minerals, which is a Rio T around Fort Dauphin. Deposit information was compiled primarily from T
T8 Critical Mineral Resources of the United States—Titanium Figure T4. Bar chart comparing approximate titanium 2 ) content in titanium deposits of different deposit types (modified from Korneliussen and others, 2000a). The sources of ore given here as examples are average crustal abundance (Rudnick and Fountain, 1995); average rutile and ilmenite sands (sedimentary) (Force, 1991); rutile in eclogite from the Engebøfjellet deposit in Norway (metamorphic) (Korneliussen and others, 2000a); perovskite in pyroxenite at the Iron Hill (Powderhorn) deposit in Colorado (igneous) (Van Gosen, 2009); hemoilmenite in anorthosite at the Tellnes deposit in Norway (igneous) (Korneliussen and others, 2000a); and anatase in weathered rocks from the Catalão, the Salitre, and the Tapira deposits in Brazil (Force, 1991). dioxide (TiO T4 - Bar Ch art Compari ng Appr oxmate Ti ta ni um D io de deposits, such as those at Lac Tio and Tellnes, are thought to have formed by early magmatic crystallization of ilmenite (Duchesne, 1999; Charlier and others, 2010). Deposits dominated by titaniferous magnetite in layered intrusions may represent late-stage concentrations of iron and titanium in magmatic liquids following extensive silicate crystallization. When rocks are affected by metasomatism (a process that changes the chemical composition of rocks by the introduction of external fluids), titanium minerals in the host rock may be altered. For example, at the Bamble-Arendal iron-titanium province of Norway, Proterozoic-age mafic rocks were affected by local and regional alkali-metasomatism during which original ilmenite was converted to rutile by the removal of iron (Korneliussen and others, 2000a). In this district, rutile was mined at Kagerø from a rutile-rich vein (Force, 1991). At Roseland, Va., rutile that occurs in metasomatized shear zones along complex contacts of anorthosite/ferrogabbro intrusions and dikes with adjacent country rocks was mined from 1900 to 1949 (Herz and Force, 1987). Concentrations of titanium minerals also occur in carbon atites (unusual rocks of magmatic or metasomatic origin dominated by carbonate minerals) and alkali igneous rocks. The Iron Hill (Powderhorn) carbonatite complex in Colorado is a series of successively intruded alkali rocks, including such rock types as carbonatite, nepheline, pyroxenite, and syenite (Temple and Grogan, 1965). Mainly because it contains abundant amounts of perovskite (a calcium-titanium oxide), the pyroxenite ranges from 1.9 to 9.6 weight percent TiO2 (with an average of about 5.3 weight percent TiO2) and significant amounts of rare-earth elements, thorium, niobium, and vanadium (Van Gosen, 2009). In another carbonatite-hosted setting, extensive titanium (plus vanadium and niobium) mineralization is related to intrusion of the Magnet Cove carbonatite-alkalic ring dike complex in Arkansas, and accompanying metasomatic events (Fryklund and Holbrook, 1950; Flohr, 1994). At the Magnet Cove deposit, rutile occurs in feldspar-carbonate veins. Other deposits at Magnet Cove that formed by contact metasomatism include the Christy titanium-niobium-vanadium deposit and the Hardy-Walsh prospect. Both deposits contain brookite in novaculite (chert) where country rock was intruded by and reacted with titanium-, vanadium-, and niobium-bearing fluids from adjacent alkali-rich rocks (Erickson and Blade, 1963; Flohr, 1994). Brookite at the Christy deposit can contain exceptionally high amounts of niobium and vanadium (Flohr, 1994). Highly weathered rocks, such as bauxites (white-gray rock dominated by aluminum-rich oxides and hydroxides) and laterites (reddish rock dominated by iron- and aluminum-rich oxides and clays), can contain significant titanium resources. The titanium deposits at Catalão, Salitre, and Tapira (Brazil) formed by weathering of perovskite, magnetite, and titanite in titaniferous carbonatite, resulting in development of anatase in an about 200-meter (m)-thick laterite cap (Gomes and others, 1990; Force, 1991). Significant amounts of rutile and ilmenite occur in saprolite (weathered rock) over mineralized contacts of the ilmenite-bearing Roseland anorthosite pluton (Virginia), with minor transport and accumulation of both minerals in streams that cut through the saprolite (Fish, 1962). Titanium Deposits Related to Metamorphic Rocks Rutile is the most economically valuable mineral for titanium, but rutile sand ores are limited in volume, and, given that there are inadequate supplies of high-grade (>55 percent TiO2 ) ilmenite sands, much of the recent search for high-grade ore has focused on rutile potential from metamorphic rocks (Korneliussen and others, 2000a). The main exploration focus is on high-grade metamorphic rocks, such as eclogite (a rock composed primarily of garnet and pyroxene, with lesser amounts of rutile, and typically formed under highpressure conditions). Based on surveys of eclogite in Norway, Korneliussen and others (2000b) state that metamorphism of titanium-rich protoliths (the unmetamorphosed rock from
Geology T9 which a metamorphic rock forms) is a requirement to generate sufficient rutile to be of economic interest. Complications for exploitation of eclogite include highly variable rutile concentrations and grain sizes, retrograde alteration of high-grade metamorphic rutile back to ilmenite or titanite, and the possible presence of impurities, such as calcium, magnesium, iron, and aluminum in trace silicates in rutile concentrates (Korneliussen and others, 2000b). For example, in northern Italy, the Piampaludo eclogite has high TiO2 content (about 6 weight percent), but during later metamor phism, some rutile was replaced by secondary ilmenite and titanite (Liou and others, 1998), making this resource less economically attractive. The only currently active rutile mines in metamorphic rocks are the Daixian rutile deposits in east-central China, which consist of lenses and layers of rutile-bearing high-grade metamorphic rocks that average about 2 weight percent TiO2 (Shi and others, 2012). Intense alteration by hydrothermal fluids reacting with large volumes of rock can result in profound changes in the original bulk rock composition, creating aluminum-rich rocks depleted in most other elements. Metamorphism of these hydrothermally altered rocks can create a rock rich in the minerals kyanite (Al2SiO5) and quartz and containing trace amounts of rutile (Marsh and Sheridan, 1976; Owens and Pasek, 2007). In addition, metamorphism of deeply weathered rocks, such as laterites and bauxites, can also result in rutile-bearing aluminum-rich rocks. Because these aluminum-rich rocks are stripped of many other elements, they potentially create a low-grade (about 1 percent or less rutile) and commonly low-tonnage but high-quality TiO2 resource that is generally free of other contaminants (Force, 1991). Rutile in such deposits can be a valuable byproduct of primary industrial commodities, such as alumina, andalusite, kaolinite, or kyanite. Rutile also commonly occurs in mineralized zones and alteration halos of many hydrothermal and metamorphosed mineral deposits (Czamanske and others, 1981; Force, 1991; Clark and Williams-Jones, 2004). Large bodies of igneous rock that contain disseminated chalcopyrite and other sulfides are known as porphyry copper deposits. In the alteration zones around some porphyry copper deposits, such as Bingham Canyon (United States) or El Teniente (Chile), rutile can form from the breakdown of titanium-bearing silicates and oxides by the introduction of high-temperature hydrothermal fluids into the surrounding rock (Czamanske and others, 1981; Rabbia and others, 2009). Titanium Deposits Related to Coastal Shorelines and Dunes, and Older Equivalent Rocks Much of the high-grade ilmenite and rutile used today is extracted from unconsolidated heavy minerals (minerals that typically have a specific gravity higher than 2.85 grams per cubic centimeter) in shoreline beach placers and concen trations in sand dunes. Heavy-mineral sand deposits develop when relatively resistant titanium-bearing minerals and other heavy minerals are eroded from primary parent rocks, then transported and sorted, and finally deposited in fluvial, beach, or eolian settings. In addition to rutile and ilmenite (and minerals produced from weathering of ilmenite, such as anatase, leucoxene, and pseudorutile), other heavy minerals may enhance or detract from a deposit’s value. For example, zircon is a valuable commodity for the ceramics industry, whereas monazite (a phosphate mineral that can contain rare-earth elements and thorium) can make a deposit more problematic because of potential radioactivity issues with waste disposal. Fluvial deposits, as used here, consist of heavy minerals deposited by streams and rivers above sea level, including deltaic deposition in rivers and lakes. Fluvial heavy-mineral deposits in old drainage courses in the Ghangbama district in Sierra Leone (for example, Mogbwemo and Sherbo River) are dominated by rutile, and contain lesser amounts of zircon and ilmenite; the deposits have been eroded from deeply weathered garnet amphibolite and leucocratic garnet granulite highlands (Force, 1991). Many fluvial deposits are small and geologically young and have a heavy-mineral assemblage that closely resembles that of the unaltered source rock (Force, 1991). The abundance and distribution of heavy minerals in active and older (mostly Pleistocene) beach placer and eolian deposits are related to the area’s geology, physiography, and coastal dynamics. Many productive heavy-mineral sand provinces have the following characteristics: (a) deposits are located on passive continental margins that almost always are backed by elevated (typically highly weathered) high-grade metamorphic or mafic igneous hinterlands that supply detritus to the sands; (b) shoreline regions are dominated by sea-level changes and relatively low rates of sedimentation; (c) sands have been repeatedly reworked during marine transgressions and (or) by high-energy waves and littoral drifting; and (d) many sand bodies form topographic highs that represent former barrier island and (or) eolian dunes (Force, 1991; Hamilton, 1995; Roy, 1999; Pirkle and others, 2007; Hou and others, 2017). Iron-titanium oxides in older, lithified heavy-mineral sand deposits may have undergone extensive post-depositional altera tion, which diminishes the proportion of nonheavy minerals and enhances the conversion of ilmenite to leucoxene, causing an upgrade of the titanium content (Force, 1991). Ilmenite-rich layers of the Tertiary Cohansey Formation in New Jersey were mined at the Lakehurst deposit from 1962 until 1978 (Puffer and Cousminer, 1982). The Bothaville deposit in Late Paleozoic sandstones of the Ecca Group in the Karoo basin, South Africa, is a lithified paleo-beach deposit that contains (in order of abundance) ilmenite, rutile, and anatase (Hamilton, 1995). Heavy-mineral placers in shorelines of the Eocene-Pliocene Eucla basin (Hou and others, 2011) and the Pliocene Murray basin (Roy and Whitehouse, 2003) along the southern coast of Australia are major heavy-mineral sand provinces.
T10 Critical Mineral Resources of the United States—Titanium A grade-and-tonnage model for shoreline placer titanium was developed by Attanasi and DeYoung (1992). Titanium grade and tonnage data for these deposits were combined with grade and tonnage data for titanium deposits related to both igneous and metamorphic rocks to create figure T5. The data for figure T5 are taken from disparate sources and represent a wide variety of deposit types and settings. Many of the deposits depicted in figure T5 are not economic. The high-grade and low-tonnage igneous deposits are typically characterized by the presence of abundant ilmenite and hemoilmenite (for example, Coulombe East and West, Bignel, and Lac Brûlé, all in the Grenville Province, Canada). Low-grade and high-tonnage igneous deposits are dominantly titano magnetite (for example, Magpie Mountain and Panzhihua). Anatase is the titanium mineral at Salitre and Tapira, and perovskite is the titanium mineral at Iron Hill (Powderhorn), Colorado. Manavalakurichi is a heavy-mineral deposit in the State of Tamil Nadu, India. T5 P lot of T itaniu m D io de Grade and Tonnage Figure T5. Plot of titanium dioxide grade and tonnage for selected igneous, metamorphic, and sedimentary deposits in the world, by deposit type. Data were compiled from Towner and others (1988), Attanasi and DeYoung (1992), Corriveau and others (2007), and the Fennoscandian Ore Deposit Database (FODD), which is maintained by the Geological Survey of Finland (2013). Deposits extracted from the FODD have titanium, titanium and vanadium, or iron and titanium listed as their main metals. Some of the major deposits discussed in the text are labeled.
Resources and Production T11 Resources and Production Identified Resources Figure T6 shows world ilmenite and rutile mine produc tion and reserves for 2012 (based on the data available), which are reported as titanium mineral concentrates by the U.S. Geological Survey (Bedinger, 2013). A major difficulty in quantifying titanium resources is the range of standards that individual countries and companies apply to the categorization of resources (Murphy and Frick, 2006). Resource calculations also depend on complex mineralogical factors, such as ore mineralogy, grain size, and trace element concentrations, which are all critical to a determination of whether a deposit can be mined economically or not. Because of the widespread distribution of titanium minerals in many geologic environ ments, development of new technologies to extract titanium from nonconventional ore minerals and deposit types has great potential to open up large, currently untapped resources. T6 - Pie Char ts Show P ercentage of Estima ted 2012 World Mine P roducts Figure T6. Pie charts showing percentage of estimated 2012 world mine production of A, ilmenite, and B, rutile, and percentage of global reserves of C, ilmenite, and D, rutile, by country. Total world mine production and reserves are also shown. Ilmenite data from the United States include rutile to avoid disclosing company proprietary data. Ilmenite reserves for Sri Lanka are not available. Data are from Bedinger (2013). Percentages are rounded and may not add to 100. The term reserves as used here is defined as that part of the reserve base that would be economically extracted or produced at the time of determination (U.S. Bureau of Mines and U.S. Geological Survey, 1980).
T12 Critical Mineral Resources of the United States—Titanium The United States has large resources of ilmenite and perovskite, as well as the potential for rutile resources. Table T2 lists the titanium mineral resources (including mineral reserves) of the United States. The East Coast of the United States is part of the eastern North America titanium province, as described by Stanaway (1996). Although deposits in the region include titanium oxides related to anorthosite and gabbro in New York (Sanford Lake district) and Virginia (Piney River [Roseland] anorthosite complex), the bulk of the resource is contained in heavy-mineral concentrations in beach, bar, dune, and stream sands along the Atlantic Coastal Plain and in large parts of the Gulf Coastal Plain (fig. T3; Pirkle and others, 2007). Nonetheless, the estimated amount of more than 100 million metric tons of contained TiO2 resources in the United States given in table T2 represents less than 10 percent of the world’s titanium resources. The low grade of some U.S. resources, the possible presence of unfavorable trace constituents in ore, challenges with mineral separation and beneficiation of such nonconventional ore minerals as titaniferous magnetite and perovskite, anticipated high costs of permitting and production, and competition from foreign sources continue to curtail domestic production. Total world resources of anatase, ilmenite, and rutile are estimated to be more than 2 billion metric tons (Bedinger, 2013). Compiled world resource estimates given in table T3 total more than this amount but that is because they include hypothetical and speculative resources in addition to identified resources. Rose (1969), Towner and others (1988), and Force (1991) provide detailed geologic and location information for a number of deposits included in the estimates in table T3. Important points from table T3 are (a) the predominance of ilmenite resources versus rutile resources, and (b) the relative proportions of heavy-mineral sand resources compared with igneous and metamorphic sources. Discounting the speculative estimate of greater than 2,000 million metric tons of ilmenite resources in Canada, which is largely based on estimates from Gross (1996), heavy-mineral sand deposits represent the largest resource type for worldwide titanium supplies. Undiscovered Resources Undiscovered (hypothetical and speculative) resources of titanium are considered to be very large but difficult to quantify. Ilmenite is a common mineral in mafic and ultra mafic rocks, and rutile is a highly stable mineral in meta morphic rocks. Many of the resources identified in table T3 include hypothetical and speculative titanium resources that await technological advances or favorable economics before they are likely to be exploited. For example, Rose (1969) states that high-grade magmatic ilmenite and titaniferous magnetite resources in Canada are measurable in hundreds of millions of tons, whereas low-grade deposits are potentially available in billions of tons. The Alberta oil sands also represent a very large speculative source of titanium (Towner and others, 1988). Although heavy minerals do not occur in large concentrations in these sands, the large quantity of sand processed for hydrocarbons creates a potentially significant titanium resource. The hot-water extraction process that recovers bitumen from the oil sands concentrates heavy minerals in treatment tailings, which contain on average about 11.5 percent TiO2 (Liu and others, 2006). Attempts to isolate a high-grade titanium concentrate from these tailings have met with only limited success, however (Kaminsky and others, 2008). About 500 million metric tons of black sands on the North Island of New Zealand contain titanomagnetite (which averages about 23 percent of the raw sand) with a TiO2 content of 7 to 8 weight percent (Christie and Braithwaite, 1998). The North Island black sands are currently mined for iron with vanadium as a byproduct, but they are not yet considered economic for titanium (Christie and others, 2000). Magmatic iron-titanium-vanadium deposits in layered anorthosite-gabbro rocks that contain abundant titaniferous magnetite but only minor amounts of ilmenite represent another very large potential source of titanium. Among numerous examples are the Magpie Mountain deposits (Canada) (which hosts an estimated 1.5 billion metric tons of titaniferous magnetite ore containing 45.37 weight percent iron and 10.8 weight percent titanium; Gross, 1996) and the large Suwalki district (Poland), which contains significant resources in terms of tonnage that are not economic at this time (Charlier and others, 2009). As with perovskite at Iron Hill (Powderhorn), however, titanium mineralogy rather than the titanium content determines the economic value of the deposit. Other speculative resources include very large but very low-grade rutile deposits in porphyry copper systems, which Force (1991) suggests have great potential because of the purity and ubiquitous nature of rutile in altered rock. In addi tion, shallow underwater offshore placers paralleling known exposed coastal placers are sparsely developed and largely unexplored but in some areas are known to contain commer cially exploitable heavy minerals. Offshore placers represent large speculative titanium resources (Grosz and others, 1986).
Resources and Production T13 Table T2. Titanium resources of the United States. [Values are from Force and Lynd (1984) with some updates from Force and Creely (2000), except that the Virginia heavy-mineral sands estimate is from Newton and Romeo (2006). Deposit classes are taken from table T1; —, none reported, or negligible; ?, identification uncertain] State District, deposit, or deposit type Deposit class Contained titanium dioxide, by primary ore mineral (thousand metric tons) Rutile Ilmenite Perovskite Alabama Cretaceous sands S–3 — — Arizona Porphyry copper ore I/M 4,000 Arkansas Magnet Cove I–7 — — California San Gabriel Mountains I–2 — 4,800 — California Ione placer S–1 — 4,000 — California White Mountains M–5 — — Colorado Iron Hill (Powderhorn) I–7 — — 20,000 Colorado Evergreen M–5 — — Florida Old beach sands S–2/S–4 1,100 9,700 — Georgia Heavy-mineral sands S–2 2,400 — Maryland Dinning M–3? — — Minnesota Duluth Complex I–2 — 10,000 — Mississippi Ship Island S–2 — — New Jersey Lakehurst S–3 — 10,100 — New Mexico Cretaceous sands S–3 — — New York Sanford Lake district I–2 — 8,600 — New York Port Leyden S–1 — 6,300 — North Carolina Yadkin Valley M–2? — — North Carolina Heavy-mineral sands S–2 — — Oklahoma Wichita Mountains S–1 — — — South Carolina Heavy-mineral sands S–2 1,400 — Tennessee Cretaceous sands S–3 1,300 8,400 — Utah Porphyry copper ore I/M 4,000 — — Utah Escalante S–3 — — Virginia Heavy-mineral sands S–2 2,200 — Virginia Roseland I–5/I–8 1,000 5,500 — Virginia Willis Mountain kyanite M–5 — — Wyoming Laramie Range I–2 — 2,700 — Wyoming Cretaceous sands S–3 — — Total1 14,000 77,900 20,000 1The U.S. resource total for titanium dioxide contained in the three primary ore minerals (rutile, ilmenite, and perovskite) is about 112 million metric tons of titanium dioxide. Totals have been rounded.
T14 Critical Mineral Resources of the United States—Titanium Table T3. Titanium mineral resources of the world (excluding the United States) for ilmenite (including titanomagnetite and leucoxene) and rutile (including anatase and brookite). [Numbers are estimates. Deposit classes are taken from table T1; S, sedimentary, primarily heavy-mineral sands; I, igneous, primarily ilmen ite and (or) titanomagnetite in mafic rocks; M, metamorphic, primarily rutile in eclogite; —, none reported or negligible; ?, amount uncertain; approximately. Values for heavy-mineral sand resources (deposit class S), with the exceptions of New Zealand and Russia, are from Elsner (2010); deposit class S values for New Zealand from Christie and Braithwaite (1998) are for ilmenite on the South Island and do not include titanium in the 500-million-metric-ton titanomagnetite iron sand resources of the North Island; deposit class I values for Brazil, Italy, and Mexico are from Force (1991); deposit class I values for Canada are generalized from Rose (1969); deposit class I values for China are calculated from China Mining Association (2006); deposit class M values for China are from Shi and others (2012); deposit classes I and M values for Norway are from Korneliussen and others (2000a); deposit classes I and S values for Russia are from Bykhovskii and Tigunov (2011)] Country Deposit type Deposit class Contained titanium dioxide, by primary ore mineral (million metric tons) Rutile Ilmenite/ titanomagnetite Australia Heavy-mineral sands S Brazil Heavy-mineral sands S Brazil Anatase in weathered rock — Cameroon Heavy-mineral sands S — Canada Heavy minerals in oil sands S — 183? Canada Gabbro/anorthosite — China Heavy-mineral sands S China Titanomagnetite in layered mafic intrusions — ~52 China Rutile in anthophyllite M — Egypt Heavy-mineral sands S — India Heavy-mineral sands S Italy Rutile in eclogite M — Kazakhstan Heavy-mineral sands S
Kenya Heavy-mineral sands S Madagascar Heavy-mineral sands S — Malawi Heavy-mineral sands S >13 Malaysia Heavy-mineral sands S — ~10 Mexico Metasomatized anorthositic rocks — Mozambique Heavy-mineral sands S Namibia Heavy-mineral sands S New Zealand Heavy-mineral sands S — Norway Gabbro/anorthosite — Norway Rutile in metamorphic/metasomatic rocks M — Russia Titanomagnetite/ilmenite/titanite — Russia Heavy-mineral sands S Senegal Heavy-mineral sands S Sierra Leone Rutile/ilmenite in fluvial deposits S South Africa Heavy-mineral sands S Sri Lanka Heavy-mineral sands S ~12 Ukraine Heavy-mineral sands S ~14 Vietnam Heavy-mineral sands S — Total1 1The world resource total for rutile and ilmenite combined is about 4.3 billion metric tons, which includes hypothetical and speculative resources in addition to identified resources.
Environmental Considerations T15 Exploration for New Deposits Heavy-mineral analysis is an effective exploration guide for titanium-bearing heavy-mineral concentrations (Hou and others, 2017). In addition to high levels of titanium, geochemical signatures include high levels of zirconium, rareearth elements, thorium, and uranium (Grosz and Schruben, 1994). For example, data indicating anomalously high levels of hafnium, rare-earth elements, titanium, and zirconium for streambed sediments collected for the U.S. Department of Energy’s National Uranium Resource Evaluation program helped locate major heavy-mineral deposits in an area between the Piedmont and the Atlantic Coastal Plain in Virginia and North Carolina (Grosz and Schruben, 1994). Exploration for fluvial placer deposits is best focused on source rock lithology, as many deposits are proximal and reflect the mineralogy of their source rocks (Force, 1991). Thus, a rutile source is more promising than an ilmenite source. More recent exploration for heavy-mineral deposits has relied on increasingly sophisticated radiometric methods and on stratigraphic and sedimentological modeling (Hou and others, 2017). Multichannel gamma-ray spectrometers coupled with geologic and land-use and landcover data have allowed recognition of anomalies that could be tied to thorium radiation from monazite (Pirkle and others, 2007). In the Eucla basin in southern Australia, high-resolution satellite nighttime thermal imagery and detailed elevation data were combined with geologic data to identify beach-barrier facies and favorable heavy-mineral assemblages (Hou and others 2011, 2017). In most cases, modern beaches or inter preted older beaches must be cored to determine the presence of heavy minerals, and samples have to be characterized by mineralogy, grain size, and titanium content (Pirkle and others, 2007). The large induced polarization response of ilmenite permits exploration for offshore marine heavy-mineral deposits using shipborne geophysical methods (Wynn, 1988). Innovative and modern exploration marine exploration methods, such as induced polarization, could cover a large swath of the continental shelf (Wynn, 1988). Exploration for magmatic iron-titanium-oxide deposits is not only focused on grade and tonnage, but also on finding ilmenite suitable for pigment processing (for example, chromium- and magnesium-poor ilmenite). Suitable mineralogy and chemistry depend on relationships among magmatic evolution, major- and trace-element chemistry, and low temperature re-equilibration. Geophysical methods have been used for exploration and to extend known deposits. Prospecting for workable and chemically suitable ilmenite resources relies in part on aeromagnetic signatures of iron-titanium-oxides that record ore microtextures that can be related back to ore chemistry (McEnroe and others, 2000). Aeromagnetic maps over favorable terranes may have a spectacular range of positive and negative anomalies because of highly contrasting rocks and possible deposit types (McEnroe and others, 2001). Concentrations of nonmagnetic hemo-ilmenite commonly have distinctive negative magnetic anomalies or mixed patterns of positive and negative magnetic anomalies. Strong positive anomalies related to magnetite content may point toward large titanomagnetite concen trations. Because of contrasting physical properties compared to silicates, iron-titanium-deposits commonly have higher gravity anomalies than surrounding anorthositic, granitic, or gneissic country rock (Gross, 1996). Exploration for rutile in metamorphic rocks, specifi cally eclogite, depends on recognition of favorable geologic circumstances that would create high-grade and high-quality rutile concentrations. These favorable circumstances include (a) high-grade metamorphism of large volumes of titaniumbearing gabbroic protoliths; (b) favorable mineralogical factors, such as grain size, mineral intergrowths, modal variations, and degree of retrograde mineral alteration; (c) favorable locations with regard to deposit development, shipping, and waste treatment; and (d) potential byproducts (for example, garnet) that could enhance the economics of a deposit (Korneliussen and others, 2000b). Environmental Considerations Sources and Fate in the Environment The behavior of titanium in the environment is dominated by its low solubility and the limited reactivity of titanium minerals. The main sources of anthropogenic titanium in the environment are from the combustion of fossil fuels and, to a lesser extent, incineration of titaniumcontaining products (International Programme on Chemical Safety, 1982). The mean concentration of titanium in soils worldwide is 0.33 weight percent titanium (Kabata-Pendias and Mukherjee, 2007); the average and range in titanium concentrations for soils in the conterminous United States are 0.29 weight percent and 0.007 to 2.0 weight percent, respectively (Shacklette and Boerngen, 1984). Titanium in stream waters worldwide ranges from 12 to 926 micrograms per liter (µg/L) (Reimann and de Caritat (1998). River waters in North America contain between 2 and 107 µg/L titanium, and drinking waters in the United States contain from 0.5 to 15 µg/L titanium (International Programme on Chemical Safety, 1982). The average concentration of titanium in suspended sediments in rivers worldwide is 0.44 weight percent (Viers and others, 2009). In the atmosphere, titanium ranges from 0.5 to 2.5 nanograms per cubic meter (ng/m3) for remote areas and from 15 to 25 ng/m3 for urban areas (Kabata-Pendias and Mukherjee, 2007). Atmospheric concentrations of titanium in urban areas of the United States are typically below 100 ng/m3, but values of up to 1,000 ng/m3 have been reported in some industrial regions (International Programme on Chemical Safety, 1982). A significant amount of the titanium manufactured as a metal is recycled. For TiO2 used for pigment, however, there is no role for recycling because the compound is so profoundly
T16 Critical Mineral Resources of the United States—Titanium incorporated into the end product that it cannot be recovered with today’s technology (Murphy and Frick, 2006). Because the bulk of the world’s titanium is used for pigment, recycling currently plays little or no role in titanium consumption or pricing trends. Mine Waste Characteristics Magmatic ilmenite and sedimentary-related titanium deposits produce very different volumes and types of mine waste. The open pit methods used to extract ore from massive magmatic ilmenite deposits produce large volumes of waste rock and tailings. The Storgangen Mine (Norway), which operated from 1917 to 1965, produced more than 10 million metric tons of ore (Schiellerup and others, 2003) and more than 8 million metric tons of tailings (Ettner, 1999). Annual production (1999) from the Tellnes open pit mine (Norway) is about 2 million metric tons of ore and 1.6 million metric tons of waste rock (Norges Geologiske Undersøkelse, 2012). Tailings from the Tellnes Mine are composed predominantly of feldspar, ilmenite, and pyroxene with a size range of 10 to 200 micrometers (µm) (Olsgard and Hasle, 1993). Mining of the Lac Tio deposit (Quebec, Canada) began in the early 1950s. Waste-rock piles at Lac Tio are estimated to be more than 72 million metric tons and to cover approximately 100 hectares of land, and they are between 20 and 80 m in height (Pepin and others, 2008). Waste rock at Lac Tio is dominantly plagioclase, followed by lesser amounts of hemo-ilmenite and trace sulfides (Pepin and others, 2008). Pyrite is the main sulfide (1 to 2 weight percent) in waste rock with only trace amounts (<1 weight percent) of chalcopyrite (Plante and others, 2011). Laboratory tests on the Lac Tio Mine waste to approximate weathering produced neutral to slightly alkaline leachate (pH 6.5 to 9.0), which is consistent with the near-neutral natural drainage from the waste piles (Plante and others, 2011). Field monitoring of experimental mine-waste cells produced drainage with a pH of between 4 and 8, which mimicked the pH of rain water (Pepin and others, 2008). Thus, any acid generated by sulfides in mine waste from the Lac Tio Mine is neutralized by silicates; the net neutralization potentials range from – 6.0 to 3.1 kilograms (kg) of calcium carbonate (CaCO3 ) per metric ton of ore, all within the uncertainty zone of ±20 kg of CaCO3 per metric ton of ore for the test method (Plante and others, 2011). Mining and milling methods for heavy-mineral sand deposits involve physical separation of a bulk concentrate and quartz-rich tailings by mechanical means, typically magnetic or electrostatic methods or density separation. During further concentration, the mineral-bearing sand fraction is separated from finer textured slimes (clays, silts, very fine sand), which is mixed with a flocculent to aid settling, and then pumped back as a slurry into a reclamation pit (Daniels and others, 2003). The average grain size of heavy minerals and the percentage of slimes in a deposit are variable, which results in different amounts and types of waste material. For example, two mineral-sand blocks in India (Kuttam and Sattankulam) contain up to 10 percent heavy minerals and 15 percent slimes (Murty and others, 2007). The sands in these blocks are very homogeneous—85 percent of the sands range from millimeters to 63 µm in size. Heavy-mineral sands on the northeastern coast of Sri Lanka (Pulmoddai sands) are very high grade; 71 percent of the beach sands are smaller than 355 µm, and more than 99 percent of the titanium content is in this size fraction (Premaratne and Rowson, 2003). The two blocks in India cover approximately 120 square kilometers (km2) and contain an estimated 400 million metric tons of raw sand and 30 million metric tons of ilmenite (Murty and others, 2007). Pulmoddai sands cover an area of only 3.2 km2 with an even thickness of 6 m (Premaratne and Rowson, 2003); thus, the amount and type of waste generated by the two deposits in India would be very different than the waste generated at Pulmoddai. Human Health Concerns Human health concerns related to titanium are minimal. Titanium can enter the human body by ingestion or inhalation, but most ingested titanium is eliminated unabsorbed. An exception to this is some industrial inhalation exposures to high amounts of dust during titanium processing (KabataPendias and Mukherjee, 2007). Mining processes conducted on ilmenite ore or heavy-mineral sands may create high amounts of airborne dust, and control measures are needed to reduce workers’ exposure. The U.S. Environmental Protection Agency (EPA) has not found any human or animal studies that are useful for developing toxicity values for titanium (U.S. Environmental Protection Agency, 2010). The processing of heavy-mineral sands at mine sites may expose workers to minor amounts of radiation. The radiation levels in heavy-mineral concentrates are usually too low to be classified as radioactive; however, when radioactive minerals, such as monazite or xenotime, are separated at the dry processing stage, precautions may need to be taken to protect employees from low levels of ionizing radiation (Abuodha, 2002). The EPA and the World Health Organization (WHO) have not established drinking water guidelines for titanium nor has the EPA established soil screening levels for industrial or residential land use for remediation purposes. In fact, TiO2 replaced lead carbonate and lead oxide as the whiteners in paints in the United States because of its low toxicity to humans. Ecological Health Concerns The EPA also has not established water-quality criteria for the protection of aquatic life for titanium because titanium minerals are generally insoluble and not bioaccessible.
Environmental Considerations T17 Recent findings do suggest that TiO2 nanoparticles, commonly defined as particles smaller than 100 nanometers in at least two dimensions, may be toxic to some aquatic and terrestrial organisms (Federici and others, 2007; Wang and others, 2008; Sharma, 2009). Titanium dioxide nanoparticles are used in a range of products, including sunscreen, cosmetics, paint, and building materials, and have been shown to behave differently in the environment than larger particles of the same composition (Sharma, 2009). Applications for nanoparticles are increasing and, consequently, this form of titanium may be of increasing environmental concern in the future. Titanium deposits and related waste products are usually sulfide-poor and generally generate near-neutral pH drainage after interacting with rain, surface water, or groundwater. Therefore, acid mine drainage, which is a common potential problem for many types of ore deposits, is not a significant concern at titanium mines. Although titanium may not be an environmental concern, other metals found in trace sulfides may be deleterious to the environment. Some metals, such as cobalt, nickel, and zinc, will remain in solution even at neutral pH. Drainage water with near-neutral pH and some quantity of dissolved metals is termed “contaminated neutral drainage.” Nickel values greater than 0.5 milligram per liter (mg/L) have been reported from waters draining waste piles at the Lac Tio Mine, at times exceeding U.S. and Canadian water-quality guidelines for the protection of aquatic life (Plante and others, 2010). Initially, nickel was adsorbed by residual ilmenite and plagioclase in fresh waste rock, but as mine waste weathered, adsorption sites filled and a lowered adsorptive capacity resulted in increased nickel in drainage waters, creating contaminated neutral drainage (Plante and others, 2010). This interpretation is consistent with field observations on mine waste experimental cells at Lac Tio that produced drainage with higher concentrations of nickel (0.1 to 0.4 mg/L) from approximately 25-year-old mine waste compared with drainage concentrations of nickel (<0.05 mg/L) from freshly blasted waste rock (Pepin and others, 2008). These studies suggest that ecosystem health concerns from high nickel concentrations in mine drainage waters may increase as mine wastes weather. Approximately 750,000 cubic meters of water drains annually from a tailings impoundment for the closed Storgangen Mine (Norway) (Ettner, 2007). Runoff from the former mine that subsequently reaches the North Sea at a distance of about 5 kilometers downstream has a neutral pH and nickel concentrations of up to 6 mg/L (Ettner, 2007). An anaerobic passive treatment system was installed in 2003 to remove nickel, and initially it had variable efficacy because of the immaturity of the system and extreme rain storms; since 2007, however, the system has successfully removed nickel from the tailings runoff (Ettner, 2007). Mine tailings from Tellnes are almost inert and are nontoxic to marine life (Olsgard and Hasle, 1993). Disposal of tailings underwater can lead to increased water turbidity, however, and, depending on the sedimentation rate, to the smothering of organisms living in bottom sediment. At Tellnes, about 2 million metric tons per year of tailings were deposited into a local fjord throughout the 1980s, which resulted in the reduction in number and diversity of species. After underwater tailings deposition ceased in 1994, bottom fauna in the fjord began to recover. Although there was a reduction in species richness compared with that of unaffected background locations for several years after tailings deposition ceased, within 4 years, all the main macrobenthic phyla were represented (Olsgard and Hasle, 1993). Some of the waste rock at the Lac Tio Mine is adjacent to a water body called Lac Petit Pas. A study by the operating company of the Lac Tio Mine showed that there were elevated concentrations of some metals in the first several centimeters of sediment within the lake but concluded that the sediments act as a retention medium (Rio Tinto, 2009). Mine Closure The post-mining landscape at titanium mines depends on the type of deposit exploited and the mining methods employed. Pit lakes remaining from open pit magmatic titanium deposits could contain low concentrations of trace elements typically found in ores, such as cobalt, chromium, nickel, vanadium, and zinc. In the Sanford Lake district of New York, the pit lake at the McIntyre Mine, which was closed in 1982, has a neutral pH of 8 and low to nondetectable concentrations of trace elements (Woodruff and others, 2013; S. Hollmeyer, undergraduate student, University of Vermont, unpub. data, December 2003). Titanium minerals from heavy-mineral sand deposits are most commonly mined using surface methods, including wet dredging and dry mining techniques. Pits are backfilled with tailings and slimes. Commonly, topsoil initially removed at a site is stored during active mining and later mixed with tailings and slimes to facilitate the return of vegetation. Daniels and others (2003) examined soil profiles within reclamation pits at the Old Hickory Mine site (Virginia). Soils were a mixture of dewatered slimes and tailings with added soil amendments, such as biosolids, fertilizer, and lime. Amended surface soils from reclaimed pits had near neutral pH values and up to 1.5 percent organic matter. Reclaimed mine soils from the Green Cove Springs Mine in Florida are similar, with organic-rich topsoil-amended surface layers and quartz-rich tailings in the subsurface (Daniels and others, 1992). Surface mining of mineral sands has the potential to disturb prime agricultural farmlands along the eastern coast of the United States (Daniels and others, 1992). Orndorff and others (2011) and Zimmerman and others (2008), however, suggest that disturbed lands around such sites could be successfully returned to local regional agricultural levels if best agricultural and science-based practices, such as replace ment of topsoil, pH adjustments with lime, and addition of fertilizers and biosolids, are applied.
T18 Critical Mineral Resources of the United States—Titanium Problems and Future Research Titanium is an abundant element; it is found at concen trations higher than 20 percent in many minerals (see fig. T1). It is currently not possible to extract a high-grade titanium product from titanite and perovskite, however, and largescale recovery of titanium from low-titanium oxides, such as titanomagnetite, is mainly in the research stage. A role for future research for titanium resources revolves around the ability to develop cost-effective extraction methods for titanium minerals other than anatase, brookite, ilmenite, and rutile. Depletion of rutile resources and the shift from the sulfate process to the chloride process, which requires higher-grade TiO2 feedstock compared with the older sulfate process, increases the need to develop low-cost, energyefficient hydrometallurgical processes to, in effect, upgrade the more abundant ilmenite (Zhang and others, 2011). If these issues of mineralogy could be resolved, there are many large titanium resources—some of which are in advanced stages of exploration—that could become economic. Rutile is in high demand, so the search for additional resources is likely to focus on exploration for large, high-grade domestic rutile resources. Increased examination of the myriad geologic environments where rutile occurs (see, for example, Meinhold, 2010) might make it possible to discover previ ously unrecognized or underutilized rutile sources, such as porphyry systems, metamorphic terranes, or highly weathered rock. Rutile as a magmatic mineral is described for some massif anorthosite ilmenite deposits in the Saint-Urbain and Lac Allard anorthosite plutonic suites (Quebec). Morisset and others (2010) attribute this occurrence to an exceptionally high alumina content of parent magmas and the subsequent oxide crystallization path. Rutile also occurs along the metasomatized margins of the Roseland anorthosite (Virginia) and in the Pluma Hidalgo anorthosite district (Mexico), where swarms of anorthosite dikes and sills cut country rock (Force, 1991). In these two deposits, anorthosite has a more alkali composition than is typical for most other anorthositehosted magmatic deposits, which Force (1991) links to the relative abundance of rutile. Thus, research into a possible relation between host anorthosite chemistry and occurrences of abundant rutile with ilmenite in magmatic deposits could result in delineation and identification of favorable environ ments for higher grade rutile-bearing magmatic deposits. Recent research in anorthosite plutonic terranes that host ilmenite-dominated magmatic systems, such as Lac Tio and Tellnes, has led to recognition of the role that magmatic processes, such as contamination, mineral fractionation, and flow dynamics, play in the development of world-class titanium orebodies (Wilmart and others, 1989; Charlier and others, 2010). An updated deposit model for the formation of these types of titanium deposits (Woodruff and others, 2013) could guide exploration for this type of mineralization as either a direct source or as protoliths for weathered ore deposits. References Cited Note: All Web links listed were active as of the access date but may no longer be available. Abuodha, J.O.Z., 2002, Environmental impact assessment of the proposed titanium mining project in Kwale district, Kenya: Marine Georesources and Geotechnology, v. 20, no. 3, p. 199–207. [Also available at ://dx.doi.org/ 10.1080/03608860290051895.] Ashwal, L.D., 2010, The temporality of anorthosites: Canadian Mineralogist, v. 48, no. 4, p. 711–728. [Also available at ://dx.doi.org/10.3749/canmin.48.4.711.] Attanasi, E.D., and DeYoung, J.H., Jr., 1992, Grade and tonnage model of shoreline placer Ti—Model 39c, in Cox, D.P., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 270 –273. [Also available at ://pubs.er.usgs.gov/publication/b1693/.] Bedinger, G.M., 2013, Titanium mineral concentrates: U.S. Geological Survey Mineral Commodity Summaries 2013, p. 174–175, accessed March 15, 2013, at ://minerals.usgs.gov/minerals/pubs/commodity/ titanium/mcs-2013-timin.pdf. Brooks, D.B., 1976, Mineral supply as a stock, in Vogely, W.A., ed., Economics of the mineral industries: New York, N.Y., American Institute of Mining, Metal, and Petroleum Engineers, p. 127–207. Bykhovskii, L.Z., and Tigunov, L.P., 2011, Titanium raw materials of Russia: Russian Journal of General Chemistry, v. 81, no. 6, p. 1328–1344. [Also available at ://dx.doi.org/10.1134/S1070363211060387.] Charlier, Bernard, Namur, Olivier, Duchesne, Jean-Clair, Wiszniewska, Janina, Parecki, Antonia, and Vander Auwera, Jacqueline, 2009, Cumulate origin and polybaric crystallization of Fe-Ti oxide ores in the Suwalki anorthosite, northeastern Poland: Economic Geology, v. 104, p. 205–221. [Also available at ://dx.doi.org/ 10.2113/gsecongeo.104.2.205.] Charlier, Bernard, Namur, Olivier, Malpas, Simon, de Marneffe, Cedric, Duchesne, Jean-Clair, Vander Auwera, Jacqueline, and Bolle, Olivier, 2010, Origin of the giant Allard Lake ilmenite ore deposit (Canada) by fractional crystallization, multiple magma pulses and mixing: Lithos, v. 117, June, p. 119–134. [Also available at ://dx.doi.org/10.1016/j.lithos.2010.02.009.] Chernet, T., 1999, Effect of mineralogy and texture in the TiO2 pigment production process of the Tellnes ilmenite concen trate: Mineralogy and Petrology, v. 67, nos. 1–2, p. 21–32. [Also available at ://dx.doi.org/10.1007/BF01165113.]
References Cited T19 China Mining Association, 2006, Metallic mineral resources— Section 3.5 titanium: China Mining Association, accessed November 13, 2012, at ://www.chinamining.org/Facts/ index-64.. Christie, A.B., and Braithwaite, R.L., 1998, Mineral commodity report 16 —Titanium: New Zealand Mining, v. 23, p. 15–25. Christie, Tony, Douch, Colin, Winfield, Barry, and Thompson, Bruce, 2000, Industrial minerals in New Zealand: New Zealand Mining, v. 27, p. 14–25, accessed March 28, 2014, at ://www.nzpam.govt.nz/cms/ pdf-library/minerals/publications/Commodity Reports/ report20a_indmins.pdf/view/. Clark, J.R., and Williams-Jones, A.E., 2004, Rutile as a potential indicator mineral for metamorphosed metallic ore deposits: Montreal, Quebec, Canada, DIVEX, Rapport Final Sous-project SC2, 17 p. [Also available at ://www.divex.ca/ projets/doc/SC2-Williams-Jones-2004.pdf.] Corriveau, Louise, Perreault, Serge, and Davidson, Anthony, 2007, Prospective metallogenic settings of the Grenville Province, in Goodfellow W.D., ed., Mineral deposits of Canada—A synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods: Geological Association of Canada Special Publication no. 5, p. 819–848. Czamanske, G.K., Force, E.R., and Moore, W.J., 1981, Some geologic and potential resource aspects of rutile in porphyry copper deposits: Economic Geology, v. 76, p. 2240 –2256. [Also available at ://dx.doi.org/10.2113/ gsecongeo.76.8.2240.] Daniels, W.L., Genthner, M.H., and Hodges, R.L., 1992, Soil development in sandy tailings derived from mineral sands mining in Florida, in Achieving land use potential through reclamation—Proceedings of the 9th Annual Meeting of the American Society for Surface Mining and Reclama tion, Duluth, Minn., June 14–18, 1992: Princeton, W. Va., American Society for Surface Mining and Reclamation, p. 37– 47. [Also available at ://www.asmr.us/Portals/0/ Documents/Conference-Proceedings/1992/0037-Daniels.pdf.] Daniels, W.L., Orndorff, Z.W., and Schroeder, P.D., 2003, Chemical and physical properties of mineral sands mine soils in southeastern Virginia, in Barnhisel, R.I., ed., Working together for innovative reclamation—Proceedings of a Joint Conference of [the] 9th Billings Land Reclama tion Symposium and American Society of Mining and Reclamation 20th Annual National Conference, Billings, Mont., June 3–6, 2003: Lexington, Ky., American Society of Mining and Reclamation, p. 209–228. [Also available at ://www.asmr.us/Publications/Conference Proceedings/ 2003/0209-Daniels.pdf.] Duchesne, J.- C., 1999, Fe-Ti deposits in Rogaland anortho sites (south Norway) —Geochemical characteristics and problems of interpretation: Mineralium Deposita, v. 34, p. 182–198. [Also available at ://dx.doi.org/10.1007/ s001260050195.] Elsner, Harald, 2010, Heavy minerals of economic importance—Assessment manual: Hanover, Germany, Bundesanstalt für Geowissenschaften und Rohstoffe, 218 p.. [Also available at ://www.bgr.bund.de/DE/Themen/ Min_rohstoffe/Downloads/heavy-minerals-economicimportance.pdf?__blob=publicationFile&v=5.] Erickson, R.L., and Blade, L.V., 1963, Geochemistry and petrology of the alkalic igneous complex at Magnet Cove, Arkansas: U.S. Geological Survey Professional Paper 425, 95 p. [Also available at ://pubs.usgs.gov/pp/0425/report.pdf.] Ettner, D.C., 1999, Pilot scale constructed wetland for the removal of nickel from tailings drainage, southern Norway, in Mine, Water & Environment, 1999 International Mine Water Association (IMWA) Congress, Sevilla, Spain, Proceedings: Wendelstein, Germany, International Mine Water Association, p. 207–211. [Also available at ://www.mwen.info/docs/imwa_1999/IMWA1999_ Ettner_207.pdf.] Ettner, D.C., 2007, Passive mine water treatment in Norway, in Cidu, R., and Frau, F., eds., Water in mining environ ments—International Mine Water Association (IMWA) Symposium 2007, Cagliari, Italy, May 27–31, 2007: Wendel stein, Germany, International Mine Water Association, 5 p., accessed January 28, 2012, at ://www.imwa.info/docs/ imwa_2007/IMWA2007_Ettner.pdf. Federici, Gillian, Shaw, B.J., and Handy, R.D., 2007, Toxicity of titanium dioxide nanoparticles to rainbow trout (Oncorhynchus mykiss); gill injury, oxidative stress, and other physiological effects: Aquatic Toxicology, v. 84, no. 4, p. 415– 430. [Also available at ://dx.doi.org/10.1016/ j.aquatox.2007.07.009.] Fish, G.E., 1962, Titanium resources of Nelson and Amherst Counties, Virginia (in two parts) —Part 1—Saprolite ores: U.S. Bureau of Mines Report of Investigations 6429, 25 p. Flohr, M.J.K., 1994, Titanium, vanadium, and niobium mineraliza tion and alkali metasomatism from the Magnet Cove Complex, Arkansas: Economic Geology, v. 89, p. 105–130. [Also available at ://dx.doi.org/10.2113/gsecongeo.89.1.105.] Force, E.R., 1991, Geology of titanium-mineral deposits: Geological Society of America Special Paper 259, 112 p. [Also available at ://dx.doi.org/10.1130/SPE259-p1.]
T20 Critical Mineral Resources of the United States—Titanium Force, E.R., and Creely, Scott, 2000, Titanium mineral resources of the Western U.S.—An update: U.S. Geological Survey Open-File Report 00 – 442, 37 p. Force, E.R., and Lynd, L.E., 1984, Titanium mineral resources of the United States—Definitions and documentation: U.S. Geological Survey Bulletin 1558–B, p. B1–B11. [Also available at ://pubs.usgs.gov/bul/1558a-b/report.pdf.] Fryklund, V.C., and Holbrook, D.F., 1950, Titanium ore deposits of Hot Spring County, Arkansas: Arkansas Resources and Development Commission Division of Geology Bulletin no. 16, 173 p. Gambogi, Joseph, 2012, Titanium, in Metals and minerals: U.S. Geological Survey Minerals Yearbook 2010, v. I, p. 78.1–78.17. [Also available at ://minerals.usgs.gov/ minerals/pubs/commodity/titanium/myb1-2010-titan.pdf.] Geological Survey of Finland, 2013, Fennoscandian Ore Deposit Database (FODD): Geological Survey of Finland, accessed April 17, 2013, at ://en.gtk.fi/information services/databases/fodd/index.. Gomes, C.B., Ruperti, E., and Morbidelli, Lucio, 1990, Carbonatite complexes from Brazil—A review: Journal of South American Earth Sciences, v. 3, no. 1, p. 51– 63. [Also available at ://dx.doi.org/10.1016/08959811(90)90017-U.] Gross, G.A., 1996, Mafic intrusion-hosted titanium-iron, in Eckstrand, O.R., Sinclair, W.D., and Thorpe, R.I., eds., Geology of Canadian mineral deposit types: Geological Survey of Canada Geology of Canada series, no. 8, p. 573–582. [Also available at ://publications.gc.ca/ collections/collection_2016/rncan-nrcan/M40-49-831-eng.pdf.] Grosz, A.E., and Schruben, P.G., 1994, NURE geochemical and geophysical surveys—Defining prospective terranes for United States placer exploration: U.S. Geological Survey Bulletin 2097, 9 p., available at ://pubs.usgs.gov/ bul/2097/report.pdf. Grosz, A.E., Hathaway, J.C., and Escowitz, E.C., 1986, Placer deposits of heavy minerals in Atlantic Continental Shelf sediments, in Proceedings of the 17th Offshore Technology Conference, Houston, Texas, May 5–8, 1985: Richardson, Texas, Offshore Technology Conference, p. 387–394. [Also available at ://dx.doi.org/10.4043/5198-MS.] Guéguin, Michel, and Cardarelli, François, 2007, Chemistry and mineralogy of titania-rich slags, Part 1—Hemoilmenite, sulphate, and upgraded titania slags: Mineral Processing and Extractive Metallurgy Review, v. 28, no. 1, p. 1–58. [Also available at ://dx.doi.org/10.1080/08827500600564242.] Hamilton, N.T.M., 1995, Controls on the global distribution of coastal titanium-zirconium placers: International Geology Review, v. 37, no. 9, p. 755 –779. [Also available at ://dx.doi.org/10.1080/00206819509465426.] Hauck, S.A., Severson, M.J., Zanko, L.M., Barnes, Sarah-Jane, Morton, Penelope, Alminas, H.V., Foord, E.E., and Dahlberg, E.H., 1997, An overview of the geology and oxide, sulfide, and platinum-group element mineralization along the western and northern contacts of the Duluth Complex, in Ojakangas, R.W., Dickas, A.B., and Green, J.C., eds., Middle Proterozoic to Cambrian rifting, central North America: Geological Society of America Special Paper 312, p. 137–185. [Also available at ://dx.doi.org/10.1130/ 0-8137-2312-4.137.] Herz, Norman, and Force, E.R., 1987, Geology and mineral deposits of the Roseland district of central Virginia: U.S. Geological Survey Professional Paper 1371, 56 p. [Also available at ://pubs.er.usgs.gov/publication/ pp1371/.] Hou, Baohong, Keeling, John, Reid, Anthony, Fairclough, Martin, Warland, Ian, Belousova, Elena, Frakes, Larry, and Hocking, Roger, 2011, Heavy mineral sands in the Eucla basin, southern Australia—Deposition and province-scale prospectivity: Economic Geology, v. 106, p. 687–712. [Also available at ://dx.doi.org/10.2113/econgeo.106.4.687.] Hou, Baohong, Keeling, John, and Van Gosen, B.S., 2017, Geological and exploration models of beach placer deposits, integrated from case-studies of southern Australia: Ore Geology Reviews, v. 80, p. 437– 459. [Also available at ://dx.doi.org/10.1016/j.oregeorev.2016.07.016.] International Programme on Chemical Safety, 1982, Environmental Health Criteria 24 —Titanium: World Health Organization, accessed January 9, 2013, at ://www.inchem.org/documents/ehc/ehc/ehc24.htm. Kabata-Pendias, Alina, and Mukherjee, A.B., 2007, Trace elements from soil to human: Berlin, Germany, SpringerVerlag, 550 p. Kaminsky, H.A.W., Etsell, T.H., Ivey, D.G., and Omotoso, Oladipo, 2008, Characterization of heavy minerals in the Athabasca oil sands: Minerals Engineering, v. 21, no. 4, p. 264 –271. [Also available at ://dx.doi.org/10.1016/ j.mineng.2007.09.011.] Kärkkäinen, N.K., and Bornhorst, T.J., 2003, The Svecofennian gabbro-hosted Koivusaarenneva magmatic ilmenite deposit, Kälviä, Finland: Mineralium Deposita, v. 38, no. 2, p. 169 –184. [Also available at ://link.springer.com/article/ 10.1007%2Fs00126-002-0297-0.)
References Cited T21 Korneliussen, Are, McEnroe, S.A., Nilsson, L.P., Schiellerup, Henrik, Gautneb, Håvard, Meyer, G.B., and Størseth, L.R., 2000a, An overview of titanium deposits in Norway: Norges Geologiske Underskøleske Bulletin 436, p. 27–38. [Also available at ://www.ngu.no/ FileArchive/102/Bulletin436_3.pdf.] Korneliussen, Are, McLimans, Roger, Braathen, Alvar, Erambert, Muriel, Lutro, Ole, and Ragnhildstveit, Jomar, 2000b, Rutile in eclogites as a mineral resource in the Sunnfjord region, western Norway: Norges Geologiske Underskøleske Bulletin 436, p. 39– 47, available at ://www.ngu.no/FileArchive/102/Bulletin436_4.pdf. Krause, H., Gierth, E., and Schott, W., 1985, Fe-Ti deposits in the South Rogaland igneous complex, with special refer ence to the Åna-Sira anorthosite massif: Norges Geologiske Underskøleske Bulletin 402, p. 25–37. Liou, J.G., Zhang, Ruyuan, Ernst, W.G., Liu, Jun, and McLimans, Roger, 1998, Mineral paragenesis in the Piampaludo eclogitic body, Gruppo di Voltri, Western Ligurian Alps: Schweizerische Mineralogische und Petrographische Mitteilungen—Bulletin Suisse de Mineralogie et Petrographie, v. 78, no. 2, p. 317–335. Liu, Qi, Cui, Z., and Etsell, T.H., 2006, Characterization of Athabasca oil sands froth treatment tailings for heavy mineral recovery: Fuel, v. 85, nos. 5– 6, p. 807–814. [Also available at ://dx.doi.org/10.1016/j.fuel.2005.08.032.] Mackey, T.S., 1994, Upgrading ilmenite into a high-grade synthetic rutile: Journal of Metals, v. 46, no. 4, p. 59–64. [Also available at ://dx.doi.org/10.1007/BF03220676.] Marsh, S.P., and Sheridan, D.M., 1976, Rutile in Precambrian sillimanite-quartz gneiss and related rocks, east-central Front Range, Colorado: U.S. Geological Survey Professional Paper 959–G, 17 p. [Also available at ://pubs.er.usgs.gov/publication/pp959G.] McEnroe, S.A., Robinson, P., and Panish, P.T., 2000, Chemical and petrographic characterization of ilmenite and magnetite in oxide-rich cumulates of the Sokndal region, Rogaland, Norway: Norges Geologiske Undersøkelse Bulletin 436, p. 49–56. [Also available at ://www.ngu.no/FileArchive/ 102/Bulletin436_5.pdf.] McEnroe, S.A., Robinson, Peter, and Panish, P.T., 2001, Aeromagnetic anomalies, magnetic petrology, and rock magnetism of hemo-ilmenite- and magnetite-rich cumulate rocks from the Sokndal region, South Rogaland, Norway: American Mineralogist, v. 86, p. 1447–1468. [Also available at ://ammin.geoscienceworld.org/ content/86/11-12/1447.full.] Meinhold, Guido, 2010, Rutile and its applications in earth sciences: Earth-Science Reviews, v. 102, p. 1–28. [Correction to incorrect formula published as Meinhold, Guido, 2013, Erratum to “Rutile and its applications in earth sciences” (Earth-Science Reviews 102 (2010) 1–28): Earth-Science Reviews, v. 116, p. 211.] Miller, J.A., 1957, Titanium—A materials survey: U.S. Bureau of Mines Information Circular 7791, 202 p. Morisset, Caroline-Emmanuelle, Scoates, J.S., Weis, Dominique, Suavé, Martin, and Stanaway, K.J., 2010, Rutile-bearing ilmenite deposits associated with the Proterozoic SaintUrbain and Lac Allard anorthosite massifs, Grenville Province, Quebec: Canadian Mineralogist, v. 48, no. 4, p. 821– 849. [Also available at ://dx.doi.org/10.3749/ canmin.48.4.821.] Murphy, Philip, and Frick, Louise, 2006, Titanium, in Kogel, J.E., Trivedi, N.C., Barker, J.M., and Krukowski, S.T., eds., Industrial minerals and rocks (7th ed.): Littleton, Colo., Society for Mining, Metallurgy, and Exploration, Inc., p. 987–1003. Murty, Ch.V.G.K., Gurung, R., Upadhyay, R., and Asokan, S., 2007, Tata Steel’s Titania project—Challenges in slimes disposal, in Heavy minerals conference—Back to basics, 6th, Zulu Nyala, Hluhluwe, South Africa, September 10 –14, 2007: Johannesburg, South Africa, Southern African Institute of Mining and Metallurgy, Symposium Series, v. 48, p. 111–118. [Also avail able at ://www.saimm.co.za/Conferences/ HMC2007/111-118_Murty.pdf.] Natural Earth, 2014, Small scale data—Natural Earth map dataset, scale 1:110,000,000, accessed June 23, 2014, at ://www.naturalearthdata.com. Newton, M.C., III, and Romeo, A.J., 2006, Geology of the Old Hickory mineral sand deposit, Dinwiddie and Sussex Counties, Virginia, in Reid, J.C., ed., Proceedings of the 42nd Forum on the Geology of Industrial Minerals, Asheville, North Carolina, May 7–13, 2006: North Carolina Geological Survey Information Circular 34, p. 464 – 480. Norges Geologiske Undersøkelse, 2012, Deposit area—Tellnes, in The ore database: Norges Geologiske Undersøkelse database, accessed January 8, 2013, at ://aps.ngu.no/pls/oradb/ minres_deposit_fakta.Main?p_objid=4998&p_spraak=E. Olsgard, Frode, and Hasle, J.R., 1993, Impact of waste from titanium mining on benthic fauna: Journal of Experimental Marine Biology and Ecology, v. 172, nos. 1–2, p. 185–213. [Also available at ://dx.doi.org/10.1016/00220981(93)90097-8.]
T22 Critical Mineral Resources of the United States—Titanium Orndorff, Z.W., Daniels, W.L., Meredith, K.R., Alley, M.M., and Wick, A.F., 2011, Effects of prime farmland soil reconstruction methods on post-mining productivity of mineral sands mine soils in Virginia, in Barnhisel, R.I., ed., Reclamation—Sciences leading to success, Proceedings of the 28th Annual National Conference of the American Society of Mining and Reclamation, Bismarck, North Dakota, June 11–16, 2011: Lexington, Ky., American Society of Mining and Reclamation, p. 504–518. [Also available at ://landrehab.org/UserFiles/DataItems/7A5A56505 64671794835553D/Orndorff%20et%20al.,%202011%20 ASMR%20Effects%20of%20prime%20farmland.pdf.] Owens, B.E., and Pasek, M.A., 2007, Kyanite quartzites in the Piedmont province of Virginia—Evidence for a possible high-sulfidation system: Economic Geology, v. 102, p. 495–509. [Also available at ://dx.doi.org/10.2113/ gsecongeo.102.3.495.] Pepin, Geneviève, Bussière, Bruno, Aubertin, Michel, Benzaazoua, Mostafa, Plante, Benoît, Laflamme, Donald, and Zagury, G.J., 2008, Field experimental cells to evaluate the generation of contaminated neutral drainage by waste rock at the Tio Mine, Quebec, Canada, in Rapantova, N., and Hrkal, Z., eds., Proceedings of the 10th International Mine Water Association (IMWA) Congress on Mine Water and the Environment, Karlsbad, Czech Republic. June 2–5, 2008: International Mine Water Association, p. 309–312, accessed January 14, 2013, at ://www.imwa.info/docs/imwa_2008/ IMWA2008_136_Pepin.pdf. Pirkle, F.L., Pirkle, W.A., and Pirkle, E.C., 2007, Heavymineral sands of the Atlantic and Gulf coastal plains, USA, chap. 45 of Mange, M.A., and Wright, D.T., eds., Heavy minerals in use: Boston, Mass., Elsevier Developments in Sedimentology Series, v. 58, p. 1145 –1232. [Also available at ://dx.doi.org/10.1016/S0070-4571(07)58045-3.] Plante, B., Benzaazoua, M., and Bussière, B., 2011, Predicting geochemical behavior of waste rock with low acid gener ating potential using laboratory kinetic tests: Mine Water and the Environment, v. 30, no. 1, p. 2–21. [Also available at ://dx.doi.org/10.1007/s10230-010-0127-z.] Plante, B., Benzaazoua, M., Bussière, B., Biesinger, M.C., and Pratt, A.R., 2010, Study of Ni sorption onto Tio Mine waste rock surfaces: Applied Geochemistry, v. 25, no. 12, p. 1830 –1844. [Also available at ://dx.doi.org/10.1016/j.apgeochem.2010.09.010.] Premaratne, W.A.P.J., and Rowson, N.A., 2003, The processing of beach sand from Sri Lanka for the recovery of titanium using magnetic separation: Physical Separation in Science and Engineering, v. 12, no. 1, p. 13–22. [Also available at ://dx.doi.org/10.1080/1478647031000101232.] Puffer, J.H., and Cousminer, H.L., 1982, Factors controlling the accumulation of titanium-iron oxide-rich sands in the Cohansey Formation, Lakehurst area, New Jersey: Economic Geology, v. 77, p. 379–391. [Also available at ://dx.doi.org/10.2113/gsecongeo.77.2.379.] Rabbia, O.M., Hernández, L.B., French, D.H., King, R.W., and Ayers, J.C., 2009, The El Teniente porphyry Cu-Mo deposit from a hydrothermal rutile perspective: Mineralium Deposita, v. 44, no. 8, p. 849–866. [Also available at ://dx.doi.org/10.1007/s00126-009-0252-4.] Reimann, Clemens, and de Caritat, Patrice, 1998, Chemical elements in the environment: Berlin, Germany, SpringerVerlag, 398 p. Rio Tinto, 2009, Health, safety and environment, chap. 3 of Adaptation sustanaible [sic] development report: SorelTracy, Quebec, Canada, Rio Tinto Fer et Titane, p. 13–25, accessed January 8, 2013, at ://www.riotinto.com/ documents/ReportsPublications/RTFT_SD09_eng.pdf. Rose, E.R., 1969, Geology of titanium and titaniferous deposits of Canada: Geological Survey of Canada, Economic Geology Report no. 25, 177 p. Roy, P.S., 1999, Heavy mineral beach placers in southeastern Australia—Their nature and genesis: Economic Geology, v. 94, p. 567–588. [Also available at ://dx.doi.org/ 10.2113/gsecongeo.94.4.567.] Roy, P.S., and Whitehouse, John, 2003, Changing Pliocene sea levels and the formation of heavy minerals beach placers in the Murray basin, southeastern Australia: Economic Geology, v. 98, p. 975–983. [Also available at ://dx.doi.org/10.2113/gsecongeo.98.5.975.] Rudnick, R.L., and Fountain, D.M., 1995, Nature and compo sition of the continental crust—A lower crustal perspective: Reviews of Geophysics, v. 33, no. 3, p. 267–309. [Also available at ://dx.doi.org/10.1029/95RG01302.] Schiellerup, Henrik, Korneliussen, Are, Heldal, Tom, Marker, Mogens, Bjerkgård, Terje, and Nilsson, Lars-Petter, 2003, Mineral resources in the Rogaland Anorthosite Province, south Norway: Origins, history and recent developments, in Duchesne, Jean-Clair, and Korneliussen, Are, eds., Ilmenite deposits and their geological environment: Norges Geologiske Undersøkelse Special Publication 9, p. 117–135. Shacklette, H.T., and Boerngen, J.G., 1984, Element concen trations in soils and other surficial materials of the conter minous United States: U.S. Geological Survey Professional Paper 1270, 105 p. [Also available at ://pubs.usgs.gov/ pp/1270/.]
References Cited T23 Sharma, V.K., 2009, Aggregation and toxicity of titanium dioxide nanoparticles in aquatic environment—A review: Journal of Environmental Science and Health Part A, v. 44, no. 14, p. 1485–1495. [Also available at ://dx.doi.org/ 10.1080/10934520903263231.] Shi, Guanghai, Li, Xianhua, Li, Qiuli, Chen, Zhenyu, Deng, Jun, Liu, Yingxin, Kang, Zhujuan, Pang, Ercheng, Xu, Yongjin, and Jia, Xiuming, 2012, Ion microprobe U-Pb age and Zr-in-rutile thermometry of rutiles from the Daixian rutile deposit in the Hengshan Mountains, Shanxi Province, China: Economic Geology, v. 107, p. 525–535. [Also avail able at ://dx.doi.org/10.2113/econgeo.107.3.525.] Stamper, J.W., 1970, Titanium, in Mineral facts and problems 1970: U.S. Bureau of Mines Bulletin 650, p. 773–794. Stanaway, Kerry, 1996, The Eastern North America titanium province—A review: Lithology and Mineral Resources, v. 32, p. 509–517. Temple, A.K., and Grogan, R.M., 1965, Carbonatite and related alkalic rocks at Powderhorn, Colorado: Economic Geology, v. 60, p. 672– 692. [Also available at ://dx.doi.org/10.2113/gsecongeo.60.4.672.] Towner, R.R., Gray, J.M., and Porter, L.M., 1988, International Strategic Minerals Inventory summary report—Titanium: U.S. Geological Survey Circular 930– G, 59 p. [Also avail able at ://pubs.er.usgs.gov/publication/cir930G.] U.S. Bureau of Mines and U.S. Geological Survey, 1980, Principles of a resource/reserve classification for minerals: U.S. Geological Survey Circular 831, 5 p. [Also available at ://pubs.er.usgs.gov/publication/cir831. U.S. Environmental Protection Agency, 2010, Provisional peer-reviewed toxicity values for titanium: U.S. Environ mental Protection Agency Chemical Assessment Summary, CASRN 7440 –32– 6, accessed January 9, 2013, at ://.ornl.gov/issue_papers/Titanium.pdf. U.S. Geological Survey, 1996, Global 30 arc-second elevation (GTOPO30): Reston, Va., U.S Geological Survey dataset (digital elevation model), accessed June 23, 2014, at ://lta.cr.usgs.gov/GTOPO30. Van Gosen, B.S., 2009, The Iron Hill (Powderhorn) carbonatite complex, Gunnison County, Colorado—A potential source of several uncommon mineral resources: U.S. Geological Survey Open-File Report 2009 –1005, 28 p. [Also available at ://pubs.usgs.gov/of/2009/1005/.] Viers, Jérôme, Dupré, Bernard, and Gaillardet, Jérôme, 2009, Chemical composition of suspended sediments in the world rivers—New insights from a new database: Science of the Total Environment, v. 407, no. 2, p. 853–868. [Also avail able at ://dx.doi.org/10.1016/j.scitotenv.2008.09.053.] Wang, Jiangxue, Liu, Ying, Jiao, Fang, Lao, Fang, Li, Wei, Gu, Yiqun, Li, Yufeng, Ge, Cuicui, Zhou, Guoqiang, Li, Bai, Zhao, Yuliang, Chai, Zhifang, and Chen, Chunying, 2008, Time-dependent translocation and potential impairment on central nervous system by intranasally instilled TiO2 nanoparticles: Toxicology, v. 254, nos. 1–2, p. 82–90. [Also available at ://dx.doi.org/10.1016/ j.tox.2008.09.014.] Wilmart, E., Demaiffe, D., and Duchesne, J.- C., 1989, Geochemical constraints on the genesis of the Tellnes ilmenite deposit, southwest Norway: Economic Geology, v. 84, p. 1047–1056. [Also available at ://dx.doi.org/10.2113/gsecongeo.84.5.1047.] Woodruff, L.G., Nicholson, S.W., and Fey, D.L., 2013, A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: U.S. Geological Survey Scientific Investigations Report 2010–5070–K, 47 p. [This USGS publication supersedes Scientific Investigations Report 2013–5091; also available at ://pubs.usgs.gov/sir/2010/5070/k/] Wynn, J.C., 1988, Titanium geophysics—The application of induced polarization to sea-floor mineral exploration: Geophysics, v. 53, no. 3, p. 386–401. [Also available at ://dx.doi.org/10.1190/1.1442472.] Zhang, Weinsheng, Zhu, Zhaowu, and Cheng, C.Y., 2011, A literature review of titanium metallurgical processes: Hydrometallurgy, v. 108, nos. 3– 4, p. 177–188. [Also avail able at ://dx.doi.org/10.1016/j.hydromet.2011.04.005.] Zhou, M.F., Robinson, P.T., Lesher, C.M., Keays, R.R., Zhang, C.-J., and Malpas, John, 2005, Geochemistry, petrogenesis and metallogenesis of the Panzhihua gabbroic layered intrusion and associated Fe-Ti-V oxide deposits, Sichuan Province, SW China: Journal of Petrology, v. 46, no. 11, p. 2253–2280. [Also available at ://dx.doi.org/ 10.1093/petrology/egi054.] Zimmerman, Clint, Stilson, Chuck, and Daniels, W.L., 2008, Reclamation of mineral sands mine and topsoil replacement study, in Proceedings of the 25th Annual Meeting of the American Society of Mining and Reclamation and 10th meeting of the IALR, Richmond, VA, June 14 –19, 2008: Lexington, Ky., American Society of Mining and Reclama tion, p. 1429 –1444. [Also available at ://landrehab.org/ UserFiles/DataItems/61326B4E366357773754493D/ Zimmerman%20et%20al.,%202008%20ASMR%20 Reclamation%20of%20Mineral-VA.pdf.]
For more information concerning this report, please contact: Mineral Resources Program Coordinator U.S. Geological Survey 913 National Center Reston, VA 20192 Telephone: 703– 648– 6100 Fax: 703– 648– 6057 Email: minerals@usgs.gov Home page: ://minerals.usgs.gov Prepared by the USGS Science Publishing Network Reston Publishing Service Center Edited by J.C. Ishee Illustrations by Caryl J. Wipperfurth Layout by Caryl J. Wipperfurth and Cathy Y. Knutson Posting by Angela E. Hall
Woodruff and others—Critical Mineral Resources of the United States—Titanium—Professional Paper 1802–T ISSN 2330-7102 (online) ://doi.org/10.3133/pp1802T