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By Clarence Hall, CHARLES F. MUNROE

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its impor- tance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes. Both the quantity of explosives used and the number of purposes to which they are applied are increasing. They are now made at about 150 plants, in different parts of the United States, and the product of a single year is estimated at nearly 500,000,000 pounds. Nothing in all this material is a safe or "safety" explosive when in the hands of a careless or ignorant person; and this is true whether considered in connection with the shipment or the use of these explosives. In addition to the large losses of life and property resulting from an improper use of explosives in mining, the recent statistics of the railway bureau for the safe transportation of explo- sives have shown more than 400 persons killed or injured and over $3,000,000 worth of property destroyed by explosives in transit by rail. The fact that three years of cooperative effort under the wise supervision of this bureau has reduced these losses to almost nothing encourages the hope that similar cooperative effort may likewise greatly lessen losses of life and property from the use of explosives in mining. The additions to the large death roll of our mines make a recurring appeal to the public for fair treatment of the coal-mining industry, and to the miner and the manager that they join in every possible effort for greater safety. It may never be possible under conditions such as exist to-day to prevent mine accidents entirely. Little can be accomplished in that direction by either the operators or the miners working alone, but experience in all countries shows that

Jan 1, 1911

By P. M. Ambrose, A. C. Fieldner

This , the 11th annual report of research and technologic work conducted by the Bureau of Mines on coal and coal products , is issued following the closing of the Bureau's war work on fuels and contains references to most of the published articles containing results of war investigations . The few remaining papers will be discussed in next year's report . The trend in coal research in the Bureau of Mines was discussed in Mechaniza- tion . This publication , covering the period from the close of armed con- flict to resumption of normal coal -research activities , includes a section never previously presented . There is included for the first time a discussion of the Bureau's activities in the Liquid Fuels and Lubricants and the Solid Fuels Subcommittees of the Technical Industrial Intelligence Committee . This report does not replace the more comprehensive ones prepared by individual authors and listed as footnote references in this publication . purpose is to bring to the reader a résume of the work for the fiscal year ended June 30 , 1946. The material presented herein is based largely upon publications , but the results of some research and testing, which would not otherwise be published in the near future, are presented in detail .

Jul 1, 1947

By Roswell W. Prouty

As part of a general plan for control and economic utilization of the waters of the Missouri River Basin as well as development of its inherent power resources, the Corps of Engineers of the United States Army has under construction a rolled earth dam near the site of old Fort Randall in South Dakota. The dam is in Charles Mix and Gregory Counties on the Missouri River at a point about 922 miles above its mouth. It is approximately 125 air-line miles southeast of Pierre and 55 miles southwest of Mitchell, S. Dak. The storage reservoir to be formed by the dam will extend upstream for 150 miles and, at maximum operating pool level, will cover an area of some 107,000 acres. It will have a storage capacity of 6.2 million acre feat.

Jun 1, 1949

By Harold J. Barnett

In January 1948 , the Secretary of the Interior directed that a study be made of energy resources and requirements that would provide a basis for continuing appraisal of the adequacy of the Department's programs in the energy field . That this instruction was timely has been demonstrated by the increasing interest being evidenced by Congress , industry , labor , and the public in the future of the energy segment of our national economy . Several studies of individual energy sectors have appeared . Various legislative proposals have been made in Congress for obtaining more information on this subject . Substantial interest in energy projections is not , of course , a recent innovation . Energy availability and consumption are strategic factors in peacetime prosperity and growth and in our national defense as well . The past generation's literature of earnest public discussion and of legislative consideration of matters involving energy projections is very extensive . This is an exploratory study produced in the Program Staff of the Office of the Secretary of the Interior in the first half of 1949 and revised recently to take account of certain of the preliminary energy data from the 1947 Census of Manufactures and critical comments . It is offered at this time solely as a technical contribution in economic research technique . As the Bureau of Mines has recently undertaken to revise this preliminary study , critical and other comments are invited .

Oct 1, 1950

By F. E. Cash

The Holmes Safety Association , organized and named in honor of the late Dr. Joseph A. Holmes , first director of the United States Bureau of Mines , has for its object the prevention cf accidents , the improvement of health conditions at work, in the home , and in public places , and the promotion of the general welfare of its members . As a means of preventing accidents and advancing health and safety , the Holmes Safety Association disseminates information , gives instructions on subjects related to safety , and promotes first -aid and other forms of protective and accident - prevention training . This organization is intended to work and cooperate in the closest possible way with existing mine or plant safety organizations in conducting educational , social , and recreational activities for the promotion of health , safety , and efficiency .

Jan 1, 1929

Howard N. Eavenson, Gary, W. Va. (communication to the Secretary*):—For some time before the publication of Mr. Scholz's paper, I had been collecting data bearing upon its subject, and I now take pleasure in presenting to the Institute my results in the form of a discussion. It has long been a matter of common opinion among mining-men that mine-explosions are more frequent during the colder, or winter months, than during the warmer ones, and it is a matter of common knowledge among them that the air-ways and road-ways in most mines are much drier and are more inclined to be dusty during the winter than during the summer. In many mines, places which are wet and sloppy in the summer are dry and sometimes dusty during the winter. These changes, of course, can only be due to atmospheric conditions, and are caused by differences in temperature and humidity. Until recently, however, very little attention has been paid to the part that atmospheric conditions may play in mine-explosions, or, rather, to the effect they may have in rendering mine-conditions peculiarly dangerous, and in spreading and rendering more disastrous the effects of what otherwise probably would have been small explosions. To show the difference in mine-conditions during summer and winter months, I have tabulated in Table I. the results of 24 observations of hygrometric conditions in several different mines at different times of the year. Mines Nos. 1, 2, and 6 are located in the Pocahontas coal-region, in McDowell county,w.Va., the first one being a shaft-mine and the others drift. Mines 1A and 2A are drift-mines located in Logan county, W. Va. All of these are mines of fair size, but none of them has been in operation more than six years,

Jan 1, 1910

Lead-zinc production in Canada accounted for 19% of the total value of metals and minerals produced in 1976, says Keith C. Hendrick, president of Noranda Sides Corp. Mine production of recoverable zinc w as 1. 158 million toils of 27.4% of free world production in 1976. Slab zinc pro¬duction was placed at 472,000 tons that year. Canadian mine production of recoverable lead was 247,000 tons or 10.6% of the free world production. Refined lead that year was at 177,000 tons.

Jan 11, 1977

By Reichman J. P

Extensive use is made of a small scale computer (IBM 1130), in the calculations of ore reserves for Western Mining Corporation's nickel mine at Kambalda, W.A. All surface drilling data such as assays, density and location information, are stored on disk files at the Company's Technical Computing Centre at Perth, W.A. The computer is used to search through the data, select significant ore intersections, calculate the area of influence of each intersection and perform the necessary calculations to arrive at an estimate of the ore reserve. Comparing the computer-assisted ore reserve calculation with an entirely manual operation, it is estimated that a saving of 40 percent in time is achieved together with

Jan 1, 1973

By Frank C. Canney

The word "other" in paragraph 4, line 11, column 1, page 205, should read "over;" the correct version of reason 2, this paragraph, is: 'L. . . 2) to evaluate the usefulness of certain geo-chemical techniques, V. C. Kennedy and S. W. Hobbs of the USGS had already studied the distribution of copper, lead, and zinc in the soils (both in background areas and over veins) and in the water and plants, providing a criterion for measuring the magnitude and effect of soil contamination; ...9 On page 206, in the top left hand corner of Fig. 1 (in the area bounded by 47°35' and 116°10), the reference to Fig. 3 is incorrect. The area of Pine Creek, South Fork Coeur d'Alene River, and portion of Big Creek (the area which includes, from left to right, Kingston, Pinehurst, Smelterville, and Kellogg) should be identified as that of Fig. 2A. The headings for columns 1, 3, and 4, Tables I and 11, page 209, column 2, were reversed when the paper was printed. The corrected tables are:

Jan 1, 1961

MR. Woo's succinct description of the mining and smelting of silver-lead in Mongolia, with the roasting-and-reduction process and cupellation, has much interest as a picture of methods that not only may have been in use, as he suggests, a thousand years ago, long before the existence of mining schools or chemical laboratories, but probably vary little, if at all, from the practice of prehistoric times, when King Priam's handsome silver vases, cups and bowls were formed. For it is highly improbable that such large objects were made from comparatively rare native silver, and the metal must have been smelted from ore, and most likely in great part from galena,, with cupellation of the lead. Dr. W. A. P. Martin, in his excellent book on the Lore of Cathay, points out that Chinese alchemy is over 2000 years old, antedating the European by at least six centuries; and he infers that the Chinese skill in metallurgy and many branches of practical chemistry owes its origin to " those early devotees of the experimental philosophy who passed their lives among the fumes of the alembic." Those alchemists, however, may have more likely derived some of their leading ideas from the mys terious, and at that time wholly unexplainable results observed in already very ancient metallurgical processes; in which, for example, certain stones were transmuted, as it were, into metals widely divergent in character from their ores, and even silver and gold were obtained from the most unlikely-looking mate rials. It is therefore, in any case, not improbable that the Chinese may have preceded western nations in the discovery of metallurgical methods. At all events, it is now evident that the Japanese acquired these arts from China, the former source of all their higher civilization. My own observation of old-fashioned silver-smelt ing at Hosokura, on the main island of Japan, and about 220

Jan 1, 1903

By John D. Hanks

INTRODUCTION Chevron's Uranium Mill is located near Panna Maria, Texas; 70 miles southeast of San Antonio. Designed by Kaiser Engineering, the Mill will process a nominal 2500 dry T.P.D. of uranium bearing ore containing 15% uncombined moisture. Earl Torgerson, San Mateo, California, is the consulting metallurgist on process design. Feed to the plant consists of a mixture of high, medium and low grade sandy day ore; the average grade of the ore will be 0.7% throughout the life of the project. The ore is delivered to the mill via truck and stored by type in individual piles on a flat storage area. The ore is fed by conveyor to a semi-autogenous grinding mill. The SAG mill discharge slurry is pumped either to a storage tank or to the first of five mechanically agitated leach tanks where both H2SO and NaC103 are added. Following leaching, the slurry is mixed with thickener No. 2 overflow before being pumped to a six-thickener, countercurrent decantation circuit where the solution containing uranium is separated from the leach residue. The residue is washed essentially free of solubilized U308 values at the sixth thickener and discharged to an adjacent tailings pond. The first thickener overflow, containing approximately 0.4 grams U308 per liter, is filtered for clarification and sent to the liquid ion exchange (solvent extraction) section. The pregnant aqueous solution is mixed with organic solvent containing amine on which the complex uranyl sulfate ions are absorbed. The immiscible aqueous and organic solutions are mixed and separated in each of the four stages of solvent extraction. The final pregnant organic is directed to a stripping section. A strip solution containing (NH4)2S04 (ammonium sulfate) and NH4C1 (ammonium chloride) is contacted and separated from the organic in each of the four mixer-settler units. The strip solution is mixed with NH3 and the uranium precipitates along with trace amounts of sulfate, chloride, and ammonia. After washing in a thickener, the uranium precipitate or yellowcake is centrifuged and dried in a multiple hearth roaster. Overflow from the yellowcake thickener is recycled back to the stripping section of the solvent extraction circuit. The dried yellowcake concentrate contains more than 98% U308; diluents include H20, ammonia, chloride, etc.. Impurity concentratons in the product are sufficiently low, after drying, to permit direct shipment to refinement installations. ORE RECEIVING Ore from one or more mines will be stored on a pad adjacent to the uranium processing mill. Ore stored in the area may total 200,000 tons or more, which is equivalent to over a two month treatment reserve for the mill. In addition to providing surge capacity, the proposed storage facility permits natural oxidation of the ore and affords an area which, in turn, improve plant U308 recovery and reduces consumption of oxidizing reagents. The uranium bearing ore is segregated at the storage area into several distinct types. One group can be identified by its sandy, clay-like matrix and will be distinguished by its U308 concentration of high, medium, or low. Other ores contain substantial quantities of carbonaceous shale, typical of ore in the area. Feed is recovered from any one or combination of piles, in accordance with operating requirements and recovery factors. The run-of-mine ore, at 15% moisture, is transferred to a stationary, 24-inch by 24-inch grizzly. Undersize material falls into a 280-ton surge hopper located below grade, while oversize material is removed for preliminary size reduction. A sump-pump is located at the reclaim hopper to recover excess mositure and ore spillage for processing. Plant feed is continuously drawn from beneath the hopper at an average rate of 120 tons per hour by means of an apron feeder. The hopper is equipped with a low level safety system to protect the apron feeder assemble. The ore is transferred to a belt conveyor, elevated and discharged into a semi-autogeneous grinding (SAG) mill. Water addition at the discharge point is automatically controlled by a feed rate, moisture analyzer system located on the belt conveyor. GRINDING Minus 24-inch ore, at a rate of 120 mosit tons per hour and cyclone underflow at a rate of 137 moist tons per hour are combined with a controlled 186 gallons per minute fresh, warm plant process water. The mixture, at an average 68% solids, is fed to the SAG mill. The viscous mass is subjected to grinding at a temperature moderately above ambient resulting from use of the 140ºF well water. The 16.5'x5.0' Marcy Mill is driven by a 500 H.P. A.C. Motor. The mill will rotate at 73.4% of critical speed or 14.06 R.P.M. Eight percent of the mill's volume will be occupied by steel grinding balls; 22% by pulp. The mill is designed to rotate in either direction, in order to obtain maximum lifter and liner life. The SAG mill is equipped with a trommel having ½ -inch slots for removal of oversize material at its discharge and the large or oversize material is collected and either recirculated periodically or discarded. The undersize slurry is diluted to 64% solids with the addition of hot well water or mine water to the mill discharge sump. The flow is automatically controlled utilizing data from a gamma density meter. The slurry from the mill discharge sump is pumped to hydrocyclones to classify the particles. Underflow from the cyclones, at 80% + 28 mesh, is recycled to

Jan 1, 1979

Jan 1, 1977

By J. A. Murray

Maintaining satisfactory air quality in electro-winning tankhouses has been problematic and costly, particularly as plant operating current densities have increased. Conventional approaches, including the use of beads, hollow spheres, surfactants and coalescer devices, have not proved completely effective, requiring that powerful ventilation systems be installed. As workplace and environmental regulations become more stringent, containment of the acid mist at its source is more attractive. An electrode cap system based on this approach has been developed and tested in two commercial copper electrowinning tankhouses. The design, development, installation and cost of the new electrode cap system are described.

Jan 1, 1996

By Brian V. Roulston

Potash is Canada's leading industrial mineral in terms of value of production, with 11.1 M tonnes of muriate of potash produced in 1992 for a value in excess of $1 billion U.S. Each tonne of potash produced generates about 2 tonnes of waste salt, together with slimes and brine. The disposal of these waste products, particularly the salt and slimes which are discharged on the surface, has recently become an environmental concern. This concern is forcing companies and regulatory authorities to review disposal practices. In New Brunswick, on Canada's east coast, Potash Company of America operates a mine at which 2 M tonnes of potash ore and 0.5 M tonnes of rock salt are mined each year. The mine is situated in an environmentally sensitive area, noted for its dairy farming and salmon angling. In such an area it was recognized that the storage of waste on surface would be unacceptable, and the mine was designed around this principle. Three main waste streams - salt, slimes, and brine - must be managed as an integral part of the mining system. Around 1.5 M tonnes of fine salt tailings from the milling process and the rock salt screening operation, are sent directly to the active cut-and-fill potash stopes to be used as backfill. Slimes and excess brine from the mill are piped underground as a slurry to be discharged into one of the basin shaped stopes created by mining of the rock salt. While the slimes settle out, the clarified brine is withdrawn from part of the stope to be pumped to surface as a feedstock for the evaporator - a process which recovers the contained potash values in the brine. By designing a system which integrates the mining, processing and disposal of all product streams, and by careful production planning, it has been shown that zero effluent potash mining is possible and points the way for the industry in the future.

Jan 1, 1995

By Tom L. Enos

Increased production through the plant was limited due to thickener circuit constraints. To overcome these constraints and maximize plant throughput to match grinding circuit capability, two options were considered: A. Adding 2000 TPD CIL circuit to operate in parallel with the existing CCD circuit. B. Adding a CIL circuit to treat the entire 4600 TPD while retaining some thickeners for tailings thickening. Option B was selected based on simplified plant operations, reduced operating costs, minimal capital requirements, reduced solution losses, and bullion grade improvement.

Jan 1, 1989

By Josef Martinsen

This paper describes two-lane dual motorway tunnels under construction in Bergen. The tunnels are part of a by-pass motorway system throuth the most congested area of the city of Bergen. The tunnels are unique due to their length, heavy traffic, longitudinal ventilation system and the use of a tunnel boring machine, or "TBM", to excavate through hard rock. The tunnels are being built by The Norwegian Public Road Administration and the TBM was delivered by the Robbins Company. The diameter of the TBM is 7.8 m and the tunnel profile is cut by conventional drill and blasting methods in the tunnel's lower half to attain a two lane motorway tunnel. This paper also describes proposed fjord crossings along the Norwegian west coast where the TBM may be used due to its great advantages in comparison to conventional drill and blasting methods.

Jan 1, 1987

Jan 1, 2009

By R. H. Brooks

Blasthole stoping methods were introduced at Birchtree Mine as an alternative to the original cut-and-fill and shrinkage stoping methods. The object was to take advantage of the ore structure and conditions, and achieve increased productivity. This paper outlines the design, operation and economics of three areas which utilized blasthole stoping. The 108areafrom 2300 level to 1500level was converted from cut-and-fill to sublevel blasthole stoping based on a block mining-and-filling sequence. The second area, the crown pillar of 110 mechanized cut-and-fill stope below 500 level, was recovered using horizontal rings drilled from raises within the ore zone. The third area, the 83 orebody from 1300 level to 1100 level, used the vertical crater retreat (VCR) method with large-diameter blastholes. Blasthole stoping has increased productivity and improved operating conditions.

Jan 1, 1979

[Separates of all the Pamphlets published within the last three years (starting with No. 1469) are available, with few exceptions, at Institute headquarters. Separates of all the Technical Publications are also available. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found either in the TRANSACTIONS or in the special volumes issued by the Institute.] METAL MINING TRANS. PAMPHLET VOLUME NUMBER TITLE AUTHOR MEETING AND PAGE* -1033 Relation of Air Pressure to Drilling H. W. Seamon New York 66,743, 766 Speeds of Hammer Drills Feb., 1921 1034 Time Factor in Depletion of Mines J. W. Roberts New York - 66,711 Feb., 1921 1 1035 Calculation of Ore Tonnage and Grade J. E. Harding New York 66, 117, 122 from Drill-hole Samples- Feb., 1921 1038 Discussion of Papers Presented in 1920 1041 Run-off and Mine Drainage - H. N. Eavenson New York 66, 624, 630 Feb., 1921 1043 The Health of the Underground Worker A. J. Lanza New York Feb., 1921 1045 Dust-ventilation Studies in Metal D. Harrington New York 66, 272, 282 Mines Feb., 1921 1046 Discussion of Papers Presented at New York Meeting, 1921 1072 Breakage and Heat Treatment of Rock- B. F. Tillson New York 66,758 drill Steel Feb., 1921 1073 Discussion of Papers Presented at New York Meeting, 1921 1076-M Analysis of Some Drill-steel Tests F. B. Foley New York - 66,789 Feb., 1921 1077-M Application of Magnetic Analysis to C_ W. Burrows New York 66,796 Root Drills Feb., 1921 1078-M Heat Treatment of Rock-drill Steel G. H. Gilman New York 66,779 Feb., 1921 1080 What is the Ideal Drill Steel? F. H. Kingdon New York 66,807 Feb., 1921 1081 Rock Drill Steels, etc. W. T. Ober New York 66,814 Feb., 1921 1082-C Underground Mine Development, Its J. B. Dilworth Wilkes-Barre 66, 715, 721 Definition and Valuation Sept., 1921 1084 Drill Steel from Hollow Ingots P. A. E. Armstrong New York 66,809 Feb., 1921 1088 Authors' Replies to Recent Discussion 1092 Heat Treatment of Rock Drill Steel A. E. Perkins New York 66,811 Feb., 1921 1096-M Octagonal Ventilation Shaft of Davis- J. L. Bruce Wilkes-Barre 66, 252, 268 Daly Copper Co. Sept., 1921 1100-C Determination of Electrical Equip- G. Bright Wilkes-Barre 66, 580, 605 ment for a Mine Hoist Sept., 1921

Jan 1, 1926

By Seib W

In cut-and-break rock excavation use is made of the fact that breaking rock in tension towards a free face requires a specific energy of excavation which is small in comparison with that required for rock excavation using conventional tools operating by a process of indentation of the rock.The process of cut-and-break excavation comprises firstly a cutting step in which a groove is cut into the rock surface, followed by a breaking phase in which a tool is inserted into the cut in order to break the rock adjacent to the cut.

Jan 1, 1992