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By James Westfield

This report covers the calendar year 1954 and has been prepared and submitted to the Congress of the United States in accordance with the provisions of Sec. 106(a) and Sec. 2l2(c) of the Federal Coal-Mine Safety Act (66 Stat. 692; 30 U.S.C. Sec. 451-483). Background The Federal Coal-Mine Inspection program was established to carry out the provisions of Public Law 49, 77th Congress, H. R. 2082, approved May 7, 1941. This act has since been amended to be known as Title I -Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also includes Title II -Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal-Mine Safety Act.

Jan 1, 1956

By Les A. Beckett

The Bureau of Mines has developed MULSIM/BM, an improved computer program using the boundary-element approach for geomechanical analysis of mine plans in single or multiple coal seams. This Information Circular presents the improved features of the MULSIN/BM program. The four major improvements are the following: (1) Ability to specify up to 26 material property sets. (2) A new material model capability for gob and inserted materials such as packwalls or cribs. (3) Ability to model a large area with a grid of undivided blocks and to subdivide only a specified fine-mesh portion of these blocks into elements. (4) Specification of extraction ratios for the undivided blocks. In addition, an interactive graphics mesh generator program was written to accompany MULSIM/BM. A complete user's guide and program listings are included within the appendixes. The MULSIM/BM and mesh generator programs are available on tape from the National Technical Information Service.3

Jan 1, 1988

By Rodney D. Rosenkranz

The Bureau of Mines evaluated the potential supply of primary copper from domestic mines and deposits and found that increases in copper price will be required in order for many domestic deposits to continue production. As part of the study, a tonnage-price relationship was developed indicating the quantity of copper that could be produced economically from known deposits at various copper prices and at various rates of return on the required capital investment. Costs of production are based on estimated capital and operating costs for mining, concentrating, transporting, smelting, and refining. Direct and indirect operating costs, recovery of investment, and return on investment have been included in the smelting and refining costs. Capital and operating costs are calculated in January 1978 dollars, and byproduct credits are based on January 1978 prices. Known domestic copper mines and deposits contain nearly 92 million metric tons of copper in about 14 billion metric tons of demonstrated mineralized material. These tonnages represent the current domestic copper reserve base. Approximately 74 million metric tons of copper are recoverable from the reserve base using existing technology. Of this quantity, slightly more than 50 million metric tons are economically recoverable assuming a price of 51.00 per pound of copper, credit for the recovery of byproducts, and a 15-percent rate of return on capital investment. Approximately 60 percent of the copper occurs in mines that were producing at the time of the study.

Jan 1, 1979

By L. D. Johnson

On a project which is to develop a system to suppress coal dust explosions, a facility has been built and several devices tested. The facility is a 317-foot, 4.5-foot diameter shock tube and to date 53 tests have been carried out with methane-air and methane/coal dust-air as the explosive mixtures. Suppression of slowly propagating (up to 300 ft/sec) flame fronts has been successfully carried out on two tests using the dry chemical extinguishing agent Purple K. Delivery of the material directly into the flame front Seems to be required if effective suppression is to be accomplished.

Jan 1, 1972

By J. C. Fowler

The field testing of the Seismic Mine Monitor System is described. This system consists of nine geophones buried about 40 feet deep over a ten-square-mile area, the amplifiers and electronics needed to get the signals to the mine office, and a central processor unit to detect and locate explosions and large roof falls. Since the problems associated with the original installation were solved, this system has worked for 2 1/2 months. The system has detected roof falls in the pillar areas and has located blasts as small as 114 pound of dynamite. The location accuracy has, in general, been within 250 feet. The system is now being used to gather long-term data on the seismic activity of the mine.

Jan 1, 1974

By Robert P. Bruno

This report covers the study of the feasibility of using a hand-held infrared viewer as a methane indicator to observe methane gas at the face of an underground coal mine. The objective of this program was the development of a hand-held device to remotely detect the presence of concentrations of methane gas in underground coal mines. Convenient "mapping" of methane from a remote location would allow rapid and safe corrective procedures for working personnel. Modified commercially available equipment was evaluated both in the laboratory and in a working mine. Although readings were obtained and the general principle of operation demonstrated, the power levels necessary, and protective enclosures required, would raise the weight of the instrument beyond practical limits of portability. Based on currently available technology, it is the conclusion of the investigations that a practical, portable, hand-held visual methane indicator is beyond the state-of-the-art. The recommendation was, therefore, made that work be suspended, and the results and data compiled and presented in a final program report.

Jan 1, 1979

By Harvey Patashnick

Current state-of-the-art microweighing technology represented by the Tapered Element Oscillating Microbalance (TEOM) is utilized as the basis for a new generation of Personal Dust Exposure Monitors (PDEM's). Two design configurations are presented. The first is an end-of-shift analysis system which uses small TEOM-PDEM cannisters that replace the filter cartridges in the current PDEM system. All other components carried by the miner (cyclone preseparator and pump) are the same. After the shift the TEOM cannister is plugged into an interface box which enables a minicomputer to automatically identify the unit, determine the dust mass increase during the shift, compute the shift average dust mass concentration, and print out and/or store the data. The second design is a real-time TEOM-PDEM system which is capable of operation over a 10-hour shift and on demand display real-time dust concentration level, time weighted average, and shift average concentration. As a result of the design study, a prototype end-of-shift analysis system was fabricated and delivered to the Bureau of Mines. A description of this system which consists of six TEOM cannisters, interface electronics and minicomputer is given. The system represents a significant advance in the dust monitoring program in terms or accuracy and automation.

Jan 1, 1983

By E. G. Davis

This report summarizes an investigation to determine the occurrence and recoverability of heavy minerals in sand and gravel operations in the Southeastern United States. A total of 61 samples from 34 sand and gravel operations in Alabama, Georgia, South Carolina, and North Carolina were studied. Heavy minerals, in amounts ranging from 3 to 400 pounds per ton, were found in all of the samples. Eighty percent of the samples contained 20 to 40 pounds per ton of heavy min¬eral. Valuable heavy minerals, in order of decreasing amounts, were ilmenite, kyanite, zircon, rutile, and monazite. Large-scale concentration tests were made on five samples from four major producers. Gravity concentration by Humphreys spirals and tables resulted in bulk heavy mineral concentrates that graded from 82 to 98 percent total heavy minerals. Mineral recoveries ranged, in percent, as follows: Ilmenite 60 to 95; zircon 96 to 100; kyanite 37 to 77; rutile 89 to 100; and monazite 96 to 100. Separation studies on the gravity concentrates showed they would respond to high-tension and high-intensity magnetic separation techniques to produce individual mineral concentrates. The recovery of each individual mineral from fractionation of the heavy mineral gravity concentrates, in percent, was: Ilmenite 77 to 94; rutile 41 to 68; kyanite 62 to 79; zircon 49 to 83; and rare-earth products, monazite and xenotime, 42 to 96. The grade of each mineral concentrate was: Ilmenite 51.1 to 68.7 percent Ti02; rutile 93.7 to 94.3 percent Ti02; kyanite 55 percent A1203; zircon 58 to 61 percent Zr02; and rare-earth products containing 73.8 to 90.8 percent monazite and 4.8 to 12.7 percent xenotime.

Jan 1, 1971

By John M. Popovich

Disposing of coal mine waste at the surface has been and continues to be a problem which has yet to be resolved within the coal mining industry. A possible solution to this problem is to return the refuse back into the operating underground mine generating the waste material. It is believed that the approach described will provide an inexpensive and pratical solution to the problem. The designed system is installed and operable at the Millers Cove Energy Company, Inc. property in Lee County, Virginia. This system limits surfact facilities to a minimum size. It incorporates state-of-the-art hydraulic transport and backfilling technology and equipment to systematically backfill areas within the active mine. It maximized the benefits of reducing treatment of coal wasts while it minimizes environmental impacts on groundwater. The system approaches the problem in a manner to maximize benefits and minimize risks. The cost of returning coal waste back underground at the Millers Cove site is estimated at $0.67 per ton of marketable coal (1982 dollars), which is slightly higher than their surface disposal cost of $0.61 per ton of marketable mat (1982 dollars). The underground disposal costs do not include cost savings that should be realized within the preparation plant and treatment facilities at the surface. Preliminary tests of the system were conducted at the surface; funding restrictions prevented an in-mine trial. Efforts should continue to demonstrate the feasibility of solving the problem of refuse disposal. The installed system and plant at Millers Cove should provide the opportunity to test an underground disposal operation. This report contains guidelines to pursue this opportunity.

Jan 1, 1986

By Gordon T. Austin

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1986. Shipments of processed tripoli increased slightly in quantity and 20% in value. Production of garnet, a common iron- aluminum-silicate mineral, decreased 12% in quantity and value. There was a 4% increase in the quantity and an 11% increase in the value of refined garnet shipped when compared with 1985 shipments, a new record high. Production of crude special silica stone decreased 7% in quantity and slightly in value, and shipments of finished special silica stone products decreased slightly in quantity and increased 229% in value. Production of emery, an impure aluminum oxide, increased 77% in quantity and increased 269% in value of product mined and shipped. [ ]

Jan 1, 1988

By Mark P. Zaitsoff

The project involved design, construction, and testing of hydraulic models of culverts, decant and open channel spillways which are typical drainage structures used for protecting mine waste embankments. MSHA (The Mine Safety and Health Administration, U. S. Department of Labor) made a motion picture of the tests. Tests results and products in the forms of graphs, tables and films, demonstrate the principles and factors which govern the function and performance of the three types of drainage structures.

Jan 1, 1981

The contract for the Water Jet Chock Mounted Miner Feasibility Study was awarded to FMC Corporation's Advanced Products Division on 18 November, 1974. The program was divided into four phases as follows: ? Phase I - Planning ? Phase II - Conceptual Design ? Phase III - Budgetary Cost Estimate and Economic Feasibility Study ? Phase IV - Final Report During Phase I, which lasted 1 month, most of the necessary information and data for the conduct of Phase II was obtained. To accomplish this, arrangements were made for personal visits to the University of Missouri at Rolla, Illinois Institute of Technology Research Institute, USBM TCMRC, Alpine Equipment Co., Mining Progress, Inc. and Eastern Associated Coal Corporation's Harris No. 1 Mine. Also, a list of manufacturers of high pressure equipment was compiled to be contacted during Phase II. Finally, the objectives to be accomplished during Phase II were outlined. The Phase I Report was submitted on 23 December, 1974. At the beginning of Phase II, personal visits were made to the research centers and firms mentioned above. Later an additional visit was made to the Harris Mine, and to the Pittsburgh Mining Research Center at Brucetun to observe a test of a water jet mounted on an Alpine Mining Machine. Equipment manufacturers of high pressure components such as hoses, tubing, valves, pumps, and intensifiers were contacted to obtain item performance data, availability, and cost.

Jan 1, 1975

This report, the third in an annual series, outlines recent trends and developments in the minerals industry. Discussed are new methods, equipment, techniques, and systems used to more, effectively extract and process minerals and fuels. Environmental considerations, reduced ore grades, and the related increased quantities of material handled were the dominent concerns of the minerals industry in 1972. Productivity increased in most mineral commodities as equipment became more mobile, versatile, and sophisticated. Increasingly, equipment designs incorporated health and safety features. There was considerable interest in the field of energy and in pollution-free metallurgy processes.

Jan 1, 1973

By Terry J. Close

From 1981-84, Bureau of Mines personnel examined and evaluated mines and prospects in the highly mineralized 62,400 acre Inyo Mountains U. S. Bureau of Land Management (BLM) Wilderness Study Area (WSA), located east of Lone Pine, CA. The 62,400 acres studied is the part of the 87,145 acre WSA designated as suitable prior to February 28, 1983. The WSA is underlain principally by quartz monzonite and quartz diorite that have intruded sedimentary and volcanic rocks. Three types of mineral deposits are present: 1) gold in fissure veins, 2) silver in fissure and replacement veins, and 3) talc in metasomatic lenses. Of the 84 nines, mills, and prospects examined, 54 are significant: 1) 5 in the intrusive rocks total about 4.4 million tons of inferred marginal gold reserves averaging 0.24 oz gold and 0.74 oz silver/ton; 2) three associated with intrusive-sedimentary rock contact zones total about 280,000 tons of inferred subeconomic silver resources averaging 7 oz silver/ton; 3) 27 gold and silver occurrences in the intrusive and sedimentary rocks total about 1.2 million tons of material in poorly defined bodies too small or low grade to be resources; 4) 15 gold and silver occurrences in the intrusive and sedimentary rocks are too poorly exposed to estimate tonnage and grade; and 5) four talc deposits along intrusive-sedimentary contact zones have inferred marginal reserves totaling about 640,000 tons. The marginal gold reserves at $450/oz might be profitably mined (reserve) at a gold price of about $600/oz and the subeconomic silver resources at a silver price in excess of about $27/oz. The marginal talc reserves might become minable at prices of about $50/ton and $80/ton for unprocessed and processed talc, respectively, after present supply sources are depleted. At most of the 54 significant mines and prospects, additional reserves or resources would likely be disclosed by trenching or drilling. Present in the WSA are 13 gold mills, numerous small pits and cuts, 270 underground workings totaling about 36,000 ft, and 80 mining benches totaling about 11,000 ft. Gold, silver, or talc were produced from most of the workings. A total of 1,561 lode and 18 placer samples were taken.

Jan 1, 1985

By N. Seidle

Numerous studies conducted in the 1960's and 1970's concluded or implied (1) that a high accident rate in terms of severity and frequency exists among new (first year) operators of mine machinery equipment, and (2) that lack of experience and training is a major cause of this high accident rate. Further studies refined this premise to show that the major causes of accidents among first year operators are: (1) lack of manipulative skills; (2) failure to follow/adhere to routine procedures; and (3) failure to recognize and respond properly to hazards. This report describes the design, development, and manufacture of a shuttle car operator training system, including a program of instruction which: ? Is economically feasible. ? Addresses accident data and specific causes of accidents. ? Includes an aerospace quality simulator of sufficient fidelity to teach and develop manipulative skills, recognition of and response to hazards, and routine and emergency procedures. ? Is designed to significantly reduce the severity and frequency of accidents especially during the operator's first year. ? Is designed to significantly improve the performance of the trainee as compared to the standard learning curve. Development of the simulator produced several valuable by-products including a major state-of-the-art technological advance in visual systems for simulators, and a first-time application of (certain) advanced filming techniques to underground filming.

Jan 1, 1984

By William G. Pariseau

A brief description of a two-dimensional elastic-plastic finite element program intended for mine stability analysis is presented that includes detailed instruction for input data preparation and how to obtain output.

Jan 1, 1978

This study estimates costs of producing bituminous coal and lignite by strip-mining methods in 12 hypothetical mines. Basic costs are developed by geographic area, rank of coal, and output capacity. Seam thickness and depth and type of overburden are considered typical for the area in which the hypothetical mine would be located. The cost analyses are based on the use of new equipment, the prevailing union wage scales, and the payment of all miscellaneous costs including royalties, contributions to the miners' welfare fund, and license and permit fees. All model mines are considered to have a life span of 20 years. Capital costs of bituminous strip mines with a capacity of 1 million tons per year range from $12.7 million in the Appalachian region to $16.0 million in the Interior province. The corresponding selling price, assuming a discounted cash flow return of 12 percent on investment, is $5.40 and $6.95 per ton, respectively. For bituminous coal strip mines producing 3 million tons annually, a capital investment of $24.9 million will render a selling price of, $3.46 per ton in the Interior province, whereas a similar mine in the Appalachian region requires a capital investment of $28.0 million to produce coal selling for $4.01 per ton. Subbituminous strip mines of 5 million tons of output per year range in capital costs from $28.7 million in the Southwest to $13.9 million in Wyoming and Montana. Coal produced in the Southwest would sell for $3.03 per ton, while coal from Wyoming and Montana would sell for $1.83 and $1.64 per ton, respectively. The capital costs for the strip mining of lignite range from $6.4 million for an output capacity of 1 million tons annually to $20.7 million for an annual capacity of 5 million tons. The corresponding selling prices of $3.01 and $2.12 per ton, respectively, Indicate the advantages of a large-capacity strip mine.

Jan 1, 1972

By Gabriel S. Esterhuizen, Anthony T. Iannacchione

The roof rock in underground limestone mines in Northern Appalachia can be subject to high horizontal stresses in spite of the shallow depth of the workings. The high stresses can cause roof stability problems. The National Institute for Occupational Safety and Health staff have observed a distinctive asymmetrical mode of failure at the pillar-roof contact in two underground stone mines, which is different from the typical failure mode observed in response to excessive levels of horizontal stress. A dip of greater than 5° was identified as a possible cause of this mode of failure. Numerical model experiments showed that an increase in the dip of the workings can cause an increase in the stress at the up-dip corner of the roof beam. A case study is presented in which failure at the pillar-roof contact was observed where the dip of the workings was 7° in a high horizontal stress field. Numerical modeling showed that the relatively small dip of the workings could have induced stresses changes in the immediate roof that would explain the failures. The model results also showed that this mode of failure is less likely to occur if the limestone pillars contain weak bedding planes that provide stress relief. In addition, the results showed that for the conditions at the case study site, the stress in the roof beam was not sensitive to the thickness of the roof beam or to the excavation span. The high horizontal stresses at this site are an important contributing factor to the observed failures.

By W. W. Adams

[The s1xteeilth an.nual National Safety C mpeti t1on, concluc ted "by the Bureau of t4ine g, Un+ ~ed st tag' DepartIilent 0:1' the Interior, has jast been closed, and the results reveal t:'W.t. t_!e co~)eting comps.nies had fewer a.ccidents in proportion to the number. of !\1a..."1-h(J1J.l'~ :orkcd than in a:ny other yeex in the record of the contest. These annUk~l contestn are thus achieving the r purpose of promoting safety in tho minin induC'tr:r. ]

Jan 1, 1941

By Thomas Gales

Longwall mining has a high potential for producing bulk production from a single face. Production is interrupted for a considerable time when it is necessary to move the equipment to a new block of coal. The frequency of such moves can be reduced by increasing the dimension of the block to be moved. Merely doubling the tonnage in a block to be mined may increase production by more than 21,000 tons per year. The time taken to move the equipment can be reduced by careful preplanning, industrial engineering analysis, and specially designed equipment. Reducing its move time from 30 days to five days can increase production by more than 25,000 tons per year. Increasing the panel dimensions and reducing the move time can give an increase in pretax profits of more than $600,000. A comprehensive bibliography is included.

Jan 1, 1977