Information Circular 6121: Method and Cost of Mining Zinc and Lead at Mine No. 2, Tri-State District, Picher, Oklahoma

United States Department of Commerce Bureau of Mines · 1929 · Historical

The mode of ore occurrence and the methods and costs of mining at .one of the zinc-lead mines in the Tri-State zinc and lead district, Oklahoma

This 1929 document, Information Circular 6121: Method and Cost of Mining Zinc and Lead at Mine No. 2, Tri-State District, Picher, Oklahoma, is preserved in the Mountain Man Mining Library for research and reference. Original source: archive.org.

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CirRCULAR 6121 May, 1929

Information Circular

Department Of Commerce —- Bureau Of Mines

METHOD AND COST OF MINING ZINC AND LEAD AT MINE NO. 2, TRI-STATE DISTRICT, PICHER, OKLA.

By

Wh. F. NETZEBAND

Circular No.6121. May, 1929.

Information Circular

Department Of Commerce - Bureau Of Mines

METHOD AND COST OF MINING ZINC AND LEAD AT MINE NO. 2 TRI-STATE DISTRICT, PICHER, OKLA, 1

'By Wn. F, Net zeband?

Introduction

The mode of ore occurrence and the methods and costs of mining at .one of the zinc-lead mines in the Tri-State zinc and lead district, Oklahoma, are presented in this paper for the information of mine - eer in other districts.

| History

No. 2 mine property was acquired by lease in 1918 after some 30 holes had béen drilled and a shaft had been sunk to the 305-foot level by the first lessees. After acquisition of the lease, the présent operating company drilled a rich ore body on the' 260-foot level and in 4920 started sinking two shafts. Production Was begun late in 1921, and the mine has been hada more or pone continuously to

the present time.

The mill has a capacity of 400 tons in 10 dae. the usual length of the mill shift in the district,

'Geology

The geology of Mine No. 2 is very similar to that of Mine No. 13 except that the Cherokee shale is thicker, ranging from 80 to 160 feet, and all the formations are correspondingly deeper, the Short Creek oolite horizon here being at a depth of about 300 feet. The oolite has not been found on this property, but the lime comes in at about the level at which the oolite should appear. .

Ore Deposits

The ore deposits of Mine No. 2 occur in the brecciated and bowlder ground above the Short Creek oolite, The main or 260-foot level is about 40 feet above the oolite horizon, and the lower or 300-foot level is immediately above it...

1 The Bureau of Mines will.welcome reprinting of this article, but requests that the following footnote acknowledgment be made: "Printed by permission of the Director, U. S. Bureau of Mines. (Not subject to copyright.)" .

e One of the consulting engineers, U. S. Bureau of Mines.

5 Netzeband, Wm. F., Bureau of Mines Information Circular 6113, 1929, 11 pp.

Inf. Cir.6121.

The ore deposition is controlled by a zone of shearing and fracturing, and the mineable areas are divided into two distinct runs which have a northwest trend with a lean or practically barren area dividing them. This characteristic has controlled the mining tc a large extent, for it enables the mine superintendent to locate the large pillars in lean ore and leave only small pillars in the richer ore, Figure 1 shows the outlines of tne ore body and the pillars, ~

The ore on the. main level occurs dissetiinated throughout the jasperoid breccia as patches or lenses in the jasperoid, or cementing massive bowlders of jasperoid breccia and chert, The ore of the lower level is more of the bowlder type than that on the main level and occurs chiefly cementing the bowlders but also with some disseminated ore in the jasperoid breccia,

The gangue minerals are jasperoid breccia, chert, and dolomite. Calcite is found in minor quantities. Sphalerite is the principal: ore mineral; galena is found only in mimor quantities around the. edges 'of. the ore. body; '. When galena is encountered in this ore body, the limit.of thé ore: can be expécted.

Exploration And Estimation Of Ore Reserves

_ The exploration and estimation of ore reserves. at Mine - No. hes are satan in many respects to the methods used .at Mine No. 1.4 : PS

'After the mine was opened up and the general: en of 'the ore deposit had been determined, drilling. operations. were concentrated along the trend of the shear zone, Later drilling has proved what appears to be a parallel shear zone or an offset of the zone now being mined,

'The shear zone was very difficult to drill before the water was drained off, and in consequence the cost of drilling was high. The early drilling cost $1. 50 per foot, and many of the holes: had to be finished on company time at the rate of $25 per diem, The present price of drilling is #1 per foot. On this property 6l, 080 Teet of en has been. done. |

HARLY MINING METHODS | ." The methods of mining have not 'babiewd at this mine; the. ore is still loaded by hand into cans; the cans are trammed by mules to the shaft and then hoisted to the surface, dumped into: the mill hopper without being detached from the rope, and returned immediately to the ai bottom.

'The mining method, the open 'gtope 'cain with pillar support, has remained the same, but the character of the: ground requires the use of larger ——— than at most mines of the GLADE ACR s

_& 'Net zeband, Th. oer Secaece of lines Infomation n Circular 6 6113, 1929, Te pp.

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Inf. Cir, 6121. DEVELOPMENT SYSTEM

The first shaft was 'gunk by the viet company he a depth of 505 feet. Considerable water was encountered, necéssitating the installation of large pumps, When the present company took over the property, they drilled out a shallower and more extensive ore body upon which they sank two shafts. The original and deeper shaft has been rétained for use as a pump shaft to drain the mine workings.

Main Shafts.— The main ghaft was sunk 'as the mill shaft by the present Company. The shaft is 5 by 11.feet.in cross section. It was originally planned

to install skips, but this: ese never. been done, The shaft was sunk on contract, but no costs are available: Be 8 hy ees

Auxiliary Shafts.+ A field int a was sunk. " 'the time the mill shaft was put down, and the two shafts were connected by a drift on the 260-foot level. This field shaft is of the standard size, 5 by 7 feet in cross section, and is used for handling both men and materials; no* men | are handled at the mill shaft.

Two "field shafte" were 'sunk-in. 1926 . on isolated ore bodies and were connected with the mill by surface trams. The sinking of these shafts was contracted for at the raté of $9 per foot in shale and $13 per foot in rock, The contractor furnished.all. labor and explosives and the company built the sinking

derrick, installed the dump track, and furhi shed: all die aig material, and power, | a a ee ee og

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The. wages oad by the etehtae we re: - $5 3 per shift for the hoistman who also sharpened steel, $6 for the lead shaftman, and $5 for his helper. The contractor's costs were: Labor, 2 hoistmen $600:. 4 shaftmen $7, 5205 labor sawing cribbing $40; explosives $410; liability insurance $104; a total of $2,474. 'The contractor was paid $2, 980 for 'the a. 'shatt » asics 2a was 260 feet deep; sins feet of the shaft, was in| Shale. : . —— |

The shaft was on an operating pene; so that. air could be furnished by piping from the mine c¢émpressor,. The sinking derrick was built to the dimensions of the standard hotstiig derrick so that it could readily be converted into a

standard derrick, Tac shaft was sunk — : The lcs were the costs of the shaft to the company:

Inf, Gir, 6121. ~

— :16-foot sinking derrick ................ $ 160.00 le by 14 foot "dogt! house . eee eee eee 45.00 Rent. on 30-hp, boiler .... ee re 60.00 Rent. on steal hoist .2.......e08- 'eesrése, . O¢O0 Compréesse 1. air Pestinatont ase mans cece. 285.00 Fosl Tre ce ee eee eee ere ee ae ae ee ee ree 90.00 Water for boiler ....... ccc ccc aee. veees 60.00 ** | Cribbing and nails .......eee0.-e2000000 443.00 gi Drill a Sen MitiAieeetiwdekaes, DoogO0: ~ ie . Hoisting .........55 ceees ee fe ee re : 110.00 ' Shaft: and blacksmith tools. ae ere eae 47.00 (OME: ion eiirand 03 bent Hegeicesesimeetes c0c00 - Sail and blower ......ceceeaeee eecesecee | 144,00 4,608 feet of 2-inch pipe eer ee ee oseee 846,00 seated i aiekele saat od ere ree 80.00 ap UM ESSE TS $5342 00 | ue a Shaft: contract price ese c gee EE Ae! 2980.00 Total. cost gk heraes heetae ee aoe ee poe 00 "Total cost per foot ceeee ere BeBe eee wee $ 20.08

Spann ee

The. shaft: in 5 by 7 feet in cross- 'geétzon and Seon o-- foot holes constitutes a shaft round: a four-hole diamond cutis employed. The round is shown in Figure 2. The cut holes are drilled 5- 1/2. feet in-depth and all other holés are 5 feet deep. The side holes are drilled with a slight pitch towards each other. An average' of 4 feet of shaft is broken per round, for which slightly © more than a box of -30 = pent gelatin powde 1" is 3 used.

Most of the holes. An 'the shaie cai. 'be' "drilled with augers, but in the. rock all holes have to be drilled with jackhamme rs. Four cut holes and four. Corner holes, using 40 sticks of 30 per cent gelatin powder, will advance..the shaft 4-1/2 feet per round in shale. It is''customary to break three rounds dn the shale before 'cribbing, Where the flow of surface water is not strong, Staggered cribbing igs 'used, otherwise it is necéssary to use solid cribbing. Care mist be taken to put..in enough. 'lagging behind the cribbing, because the shale tends to slack upbn.exposure and tus to put an undue strain upon the cribbing, Figure 3 shows the method of susporting shafts in heavy ground. The foregoing information has been taken from a paper by S. S. Clarke', which was read before the Jcplin-Miami Section of the American Institute of Mining and Metallurgical Engineers.

When water is encountered in sinking, pump seats are cut in the shaft at convenient intervals, and often as many as five or six of these seats are neces- Sary. Sinking pumps suspended from chains or cable are seldom used in the district,

Sena rece ses cackling te i germ ini ecient mens aeaatamimaiia o Clarke, S. S., "Shaft-sinking in the Tri-State district": Min. and Met., vol. 9, Angust, 1928, pp. 358-359,

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_ An underground shaft or winze has been sunk from the main to the lower level through loose bowlder ground. It had to be cribbed and lagged very carefully. This. shaft is the only connection between the main and the lower levels, and all ore, supplies, and men are handled throven., it. :

"Pull" Drifts.— Prospect of "oul" drifts are driven 7 by 7 feet in. Gross ' section. Several drifts were contracted for at the rate. of $9 per foot; the contractor furnished all labor, including the hoistman. and the powder, and the _ Company furnished the power 7 all : eens No total costs are availabde for these besser ;

A drift was. driven on coimany 'tine' at a.cost of $6.50 per foot for labor and powder, The machineran was paid a bonus of 25 cents per shift, and the mucking was contracted for at the rate of $7 per round, The costs were as follows:

Drill labor ......ceceeeee $ 1,46 . Mocking labor .....6....-. 1.17, HOLStINS Geklewkceweeesees «19 Miscellaneous labor ...... (A? Explosives er ee eeheoe ..Verel Cost per foot. eh eee $ 6.50

| A 10-hole round with. two cut holes, -two side holes, three roof holes, and three stope or bottom holes was used. About 24 sticks of 30 per cent gelatin powder were used in each hole, or about 2-1/4 boxes to the round. re 6 feet _ were broken per. round. :

For soft. spongy sheik a, 12-hole round is used, as shown in Figure 4, The four-hole diamond cut, two side holes, three roof holes, and three stope or bottom holes constitute the round. The holes are drilled 8 feet deep; 7 feet are broken per round, using 2 boxes of 30 per cent gelatin powder, This ground is a soft, spongy, leached lime and flint and is known locally as "cottonrock." The drift is advanced whenever a machine is available from the regular mining operations, and the mucking is done on company time; no costs are available,

| Raises,— eee have been driven in this mine, for no mineable ore bodies have been found above the main level.

Present Mining Method

- The plan and sections of Mine No. 2 are shown in Figures 1, 5, and 5a, The headings are kept well in advance of the main stope except where the face is low, when no stope is carried; the entire face is advanced by the same method as the i

The ore breaks into large bowlders making it necessary to. do a considerable amount of. "bowlder popping" before loading into, cans. All bowlders are drilled with jackhammers before blasting. .. : |

Inf, Cir. 6121.

For all drilling except the "bowlder popping" the heavy Leyner drill is - used, The headings are drilled from a post, but the stopes are drilled from a tripod, For ordinary work 33 per cent ammonia powder is used, but for primers and "bowlder pops," 30 per cent gelatin powder is used. The cost of ammonia powder —— $0.1315 per pound, and the gelatin powder: $0.1 1500. — pound for | the year 1928, . The ratio of ammonia to gelatin is 5 to l. :

Underground Support.~ The mine is supported almost entirely by pillars of ore from 15 to 70 feet in diameter, with an average of 30 feet. 'The larger pillars are left in the lean ore zone which runs through the center of the ore body, and the smaller pillars are left in the richer portions of the two ore runs. The pillars are spaced 40 to 60 feet, center to center, with an average of 50 feet

One section of the mine has a shale roof that batons ial, sanukeias that the drift be cut down to a "pull" drift size and necessitating the use of several sets of caps and posts with lagging. This method of support is of minor importance. No mud sills are required, for the floor is hard,

The roof stands well if it has been properly arched and carefully trimmed as the faces are advanced. All. mines in the district employ a "roof trimmer" — whose sole duty is to examine all working faces every day and keep the walls and roof free from loose rock. Most of the trimming can be done from the top of the broken ore or from the heading floor, but for work too high to be reached in this manner the "trimmer" employs a ladder. Ladders are in 20-foot sections, and in very high headings three sections of ladder are often needed. The "roof trimmer's' tools comprise a short bar of 7/8-inch hexagon steel which has been pointed at one end and shaped like a nail. bar at the other end; This bar is 6 to 10 feet long. For places that can not be reached with this, a longer bar, made usually of l-inch pipe, is employed. The "roof trimmer" wears the ordinary carbide cap lamp, but usually a larger reflector replaces the one which comes with the lamp. The reflector from a Model T Ford car with the nickle plating removed makes an ideal lamp reflector, although it. is a little heavy for continuous wear,

Drilling And Blasting Practice

Compressors.- Air is furnished by two belt-driven, two-stage compressors. The main compressor has a capacity of 1,050 cubic feet per minute, and the booster has a capacity of 950 cubic feet per minute. The pressure is maintained at 110 pounds at the compressor, which gives an effective pressure - 95 _o at the machines.

Drills.~ Several makes of drills are used but they are all of the heavy _ Leyner type. Some of the lighter drills can be run as one-man machines, but they afe all used as two-man machines at this property, The drills are mounted on posts for heading and."pull" drift work.and on tripods for drilling the stopes. All Leyner drills use 1 1/4-inch hollow round steel and the jackhammers use 1-inch hexagon hollow steel. . |

Inf, Cir, 6121.

The pedal cross bit with an 180 taper is used.: The gauges are tien 1/4 inch for steel length changes up to 1l feet and then the gauges are dropped 1/8 inch for steel changes up: to 20 feet, The starter bits are three feet long with a gauge of 2-3/4 inches. The steel lengths increase 2 feet for each change _ except the last one, which'is 3 feet. The 20-foot steels have a gauge of 1-1/2 ° 'inches, The steel consumption is 0.008 pounds per ton of ore mined,

The blacksmith shop is located on the surface near the collar of the | material shaft, fhe drili steels are bitted and shanke d here on a power sharpener,

Blasting.- The blasting practice at Mine No.. 2 is essentially the same as that used at Mine No. 1, but the character of the ground is different enqugh to Warrant a dif ferent type of heading round and different loading of the squib shots," |

The heading rounds are drilled from a 7 1/ e-foot post using 10-Toot steels, A round consists of seven to nine holes, The nine-hole round is shown in Figures ~ 6, which also shows the manner of drilling the stopes or benches, Two boxes of powder are used for, each round, and about a feet are broken per round,

The ae are not so high in Mine No. 2 as at Mine No. 1. 'The high faces . average only about 25 feet, so that most stope and splitter holes are drilled only 12 to 15 feet deep, The slope of the stope from the crest to the floor is main- © tained at about 459, For a 25-foot face the collars of the splitter holes are about 10 feet behind the crest of the stope, and the collars of the stope holes are the same distance behind the collars of the splitter BaAehs

The splitter holes are three in number unless the iksbanke between pillars has to be cut down because of unsafe ground, when the number is two. These are drilled in the same horizontal plane and have a rise of 1 inch to the foot.so that they can be readily washed free of cuttings after squibbing,

The stope holes are always the same in number as the splitters and are

_ placed practically vertically under the splitters. These holes are drilled downward with. the same fall as the rise of the splitters. In order to prevent high bottom they are so located that the bottom of the hole will be below the grade of the drift, a

Each splitter and stope hole is squibbed or chambered twice before the breaking charge is loaded, Five sticks of powder are used the first time, The hole is then. thoroughly washed, and 24 hours later it is shot with 15 sticks of powder, The hole is now ready for the breaking charge. The breaking charge takes from one and a half to two boxes of 33 per cent ammonia powder for the stope holes and one to one and a half boxes for the splitter holes. The pockets are always loaded to capacity, and two primers are used to insure against a misfire,

Inf, Cir, 6121.

All primers are made un with SO per cent gelatin powder, using a No. 6 Cap. For the rest of the blasting, except in the "pull" drifts, 53 per cent ammonia powder is used, The cap is placed in the center of the sticle of tala adalll and the entire primer is placed in a safety tube provided for the purpose. Waterproofed fuse with a speed of 2 feet per minute is employed. All charges are stemmed, using clay cartridges made from clay found on one of the company's" a properties. The clay on cost about $0.01 each. :

The | eeestnbentant endeavors to maintain his tonnage at 100 cans or — 60 tons per machine shift, This includes machines on heading and stope work, atid of the faces are low, the average height of face in this-mine being 14 feet.

Loading And Tramaing

All loading is by hand shovelling into cans set on low trucks. 'The cans are 32 inches in diameter by 50 inches deep, and have a capacity of 0.6 tons of ore, The track gauge 38 18 inches,

All tramming from the "lay—bys" near the working faces to the ee shaft is done by miles, There are four rales in the mine, three in daily use and one in reserve for wene ridentiit, On an even grace a mule can pull 12 loaded cans, Figure 1 shows the haulage plan and sc iia ie of hauls,

The northwest part of the mine is 10 feet lower than the | main. level, and hoists are necessary to Haul the loaded cans up the inclines, On the main haulageway a geared, belt-driven hoist is used (fig. 5). Al10—hp. motor furnishes the power, This hoist is capable of handling six loaded cans per trip. Two short inclines from the working faces aré operated by small air hoists or PUREE Be i

The se. hoists can handle only one poaeee can at a time.

| The ore from the lower level is aneinik to the main level by a 52—hp. geared electric hoist,

Pow ING

Ordinarily no pumping is now neces3zary, since adjoining mines working at lower levels keep the water lével below the present workings. In the spring of the year when the rains cause a heavy flow of surface water, the pum at the deep pump shaft is used.

During the summer months' the pumps are run to supply mill water for several of the Company's minés, which are connected with the pump saiagtehd by a 10-inch pipe line, :

| The pumps are electrically driven and have a capacity of 450 gallons per minute, | ; = ,

Inf, Cir, 6121. LABOR EFFICIENCY, 1928

Record of labor performed at Mine: No. 2 for nine months of 1928:

| eS ag Total Shifts "Tons per Shift TrAMMOTs' <cactvucsecdasceaseess "1)080% 40 9 ©» 84508. "x Drill runners and helpers .... 2,924 — 29.94 Muckers ....ccescesccccnsceces§ © 0,784. .-..... 25.14 - Miscellaneous Labor .....esees 2,064. 0 4B 42 Total underground operations . 9,804 | 8.93

Ore hoisted a 1928 rr in, 37 ,063 tons. PERCENTAGE OF EXTRACTION -

At present 2D per. cent of the area minad. is. Left in pillars. Tt is expected that some of these' pillars' can be récoveréd, "so that the "total extraction 'will be about 80 per 'cent. Many or the: pillars willbe left because they are too lean to pay the recovery ; cost, but the greater. number must ake Left to protect 3 the surface because. of. the character of the. grounds: *

: WAGE AND CONTRACT SYSTEM All labor, except ee is Based. on an eight-hour day. . Muckers are paid on contract, 11 cents per can of 0,6 tors on the main jevel and 14 cents per 'can on the lower level. "The bonus is paid.to men employed on the lower level because the ventilation is poorer and they can not compete on an even basis with the men on the main level. The following wage scale was in effect during 1928 when zinc ore prices stayed at ici or under for. prima. opens. ore. oo — Machiné ranners .......0e,000. $. 4, 25 _ Machine bo ee 3,75 Trammers and drivers ........ 3.50 BOLStmen: ots 5%0s ont ewe wads ss "elo POWCG IME!) 6445 4-s6 beas.coaoe os ° 4,50 Roof trimmers ....eeesess-cee 4.00 SCYVECMICH crecsaecsereacwsawe. "S200

This wage scale is based on $40 zinc ore, If the price goes to $45 and stays there for one week, all wages are automatically raised eo cents per shift, and muckers are raised 1/2 cent per can. In the same manner, for every $5 raise in the price of zinc ore above $45 the wages are raised at the same rate, but for every drop of $5 the wages are reduced. Wages are not reduced when the ore price drops below $40, for this is the base price for the wage scale. A week is always allowed between the wage changes to make sure that the market will not fluctuate above or below the critical price,

An average experieneed mucker will load 40 or more cans in an eight-hour shift. There are several men at the mine who will average 100 cans per shift, but they are exceptional men and are usually given the best working places.

Inf. Cir. 6121. VENTILATION

The peak tiuk ton is natural, except in one pines whe re an ore 2 body is being opened. up at the end of a long "pull" drift. A blower has been installed on the surface and air is forced down to this area through a churn-drill hole.

A 'large blower has been installed at the man shaft to. change the draft in the winter * time in order to a the formation of ice. | | |

MINING costs

Below is the tuba me of delivering a tox of oré into 'the mill hopper

- "General" x he ge ee Ander reroun .| Total. | Labor 0.084. 1 0,.53l °° || Supervision os 0.045 Compressed air, etc... 0.114. ® Power cost 0.076 ' Explosives | | | 0,157 ee suppliog 0.070. - Total: Osea 0.993

a "The ae oes expense, which is "airectly epplicubié ¢6 andaiground' open tions, includes the hoist and-screen room, and the surface tram from, the. field.' shafts to the mill hopper; the incline tram into the mill hopper is also included. Ore was mined from field shafts during only a small part of the year; the major part of the ore was hoisted at the mill shaft 7 rn into the mill hopper. | , | |

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Name or number of mine: No. 2, Tri-State district Years

Inf, Cir, 6121,

Summary Of Costs In Units Of Labor, Power, And Supplies

Tons of ore mined and hoisted .....sceeees 87 563

Mining method: Open stove with pillar support.

Breaking (drilling and blasting) ......cceeccccece 0.297 Mucking ...... sd iearatistsdne/oe ase Dee Dae are ee Gabe ee Eee ee. OsOoO Haulage and hoisting ......cceccccccvcsessces iwesea Osco DUDE LV 1 BINS "ecnewigaw ce wale seo see ee wee ea awieueew. OeOOL ENC YAM 5:5. 64ndsihwow aware ee are SE aE enimes a ees - 0.078 Oval UndeTreround: Lap0? civciuweswisceesewneewewaae: Os 070

Average tons per man-shift underground ......... 8.93 Labor, percentage of total Cost ....ccccccsccvces 58, OO

Explosives, 33 per cent ammonis

Total power (kw. hrs, per ton) w.seccsessecescccee Dold (1) Air en i cwaves eee aresienueu~e. CoOL (2) HOUSING ccicousaccesciimetasieian Gate

ko) PUIpINS aaicessetuessnesece neces: Osce Other supplies in percentage of total supplies and power ....e00++eL6e78

Supplies and power, percentage of total cost .....42.00

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underground shaft | Loose, bowlder ground

Cribbing

Lower level

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Figure 5A—Section A-A showing incline-hoist layout

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For arrangement of holes see sketch below

Profile of stope along line_4——4

1 Stope hole

Base of stope

Figure 6——Plan of stope and heading, showing errangement of holes