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By John D. Rockaway

Failure of the mine floor supporting coal pillars frequently occurs when the subcoal strata include "underclays" or other low strength strata. The failure process has been studied to define the response of these materials to applied coal pillar loads and to determine the applicability of bearing capacity analysis to evaluate unsafe conditions. The study has been accomplished through an investigation of both the intact and insitu geotechnical properties of the subcoal strata and through the installation of floor movement monitoring instrumentation. The results of these studies have indicated that both the shear strength of the underclay and the stratigraphy of the subcoal strata must be considered in the analysis. The shear strength was the major controlling factor determining the ultimate load carrying ability of the materials, but the thickness and stratigraphic position of the weak layers influenced the mechanism of the failure process. The methods of bearing capacity analysis were used to define pillar stability that included provisions for taking into consideration a two-layer system. Conditions assumed for a coal mine where a weak underclay overlies firmer strata. The results of the analysis compared very well with observed mine conditions, indicating marginal conditions in areas of the mine which later experienced pillar support failure. In addition, a "heave factor" was derived to predict potentially unstable floor conditions in the mines studied in detail.

Jan 1, 1979

By G. R. Hopkins

According to reports received by the Bureau of Mines, Department of Commerce, as of January 1, 1929 there were 413 completed refineries in the United States, with a total daily crude-oil capacity of 3,509,540 barrels. In addition, 14 refineries, with a potential capacity of 99,000 barrels, were being constructed. Of the completed refineries, 341, with a capacity of 3,325,890 barrels, or 95 per cent of the total capacity, were in operation; and 72, with a capacity of 183,650 barrels, or 5 per cent of the total, were shut down. The improved condition of the refining industry in 1928 was indicated in several ways; namely, in an increase in the total capacity of the completed plants, in the opening up of a few plants which were shut down during 1927, in a decrease in the number of plants dismantled, and in an increase in the number of plants under construction. The majority of the refiners have followed a steady expansion program commensurate in most cases with the increase in demand for petroleum products. Obsolete equipment has been dismantled and modern equipment has been installed, with the net result that the total capacity of the completed refineries in the United States has shown a steady increase since January 1, 1918, the date of the first Bureau of Mines survey. Between January 1, 1928, and January 1, 1929, the number of completed plants fell from 423 to 413, but their total capacity increase 259,160 barrels, or 8 per cent. This compares with an increase in runs to stills of domestic and foreign crude petroleum of 10 per cent, and of domestic crude alone of 7 per cent.

Jan 1, 1929

By R. E. McIvor, Brian Cornish, J. A. Finch, Yue Tan, Claude Gagnon

Fred C. Bond is recognized throughout the mineral processing world as the father of comminution equipment applied science and engineering. The Bond Work Index became a universal standard, and is the most widely used measurement tool for comminution energy consumption. This biography is the story of his lifetime of study, work experiences, experimentation, analyses and findings. His numerous published writings are reviewed. His legacy is one of comminution process engineering that will be used in perpetuity.

Feb 1, 2024

By G. S. Beaumont

This report presents a programme of work to demonstrate the use of a surface-based centralised computer control system for the remote monitoring and control of underground conveyors in a US coal mine. The system selected for demonstration was the 'Dynalink' Micro MINOS system which is manufactured by Hawker Siddeley Dynamics Engineering Limited. The site selected was Barnes S Tucker Lancashire No. 20 Mine located near Carrolltown, Cambria County, Pennsylvania. The system concept, operating and application software was designed and developed by the. British National Coal Board. The report describes the selection of the site, specification of the system requirements, commissioning, operation and evaluation of the system under typical US mine operating conditions. Experience with the system, based primarily on the system reliability and performance of conveyor control, was favourable. Mine management personnel felt that the system had successfully achieved its objectives and were keen to expand monitoring and control to other activities.

Jan 1, 1986

By Henry G. Granger

A RESIDENCE of 14 years in the Republic of Colombia, spent in almost continuous traveling and prospecting-trips, has given me an intimate knowledge of the resources of that wonderful country. The man who best knows Colombia is unquestionably General Rafael Reyes, President of the Republic for the past three years, and with seven years more to serve in his present term. Such is the strength of his personality and the wisdom of his policies that his term of office will no doubt endure as long as he is willing to serve. The vastly improved economic situation and the brilliant outlook for Colombia are so directly due to the influence of President Reyes that a few lines concerning him. will not be amiss, if they serve towards a better understanding of his personality. Born of a distinguished ancestry in the mountains of Boyaca, he is now 57 years old, just the age of his friend Porfirio Diaz when be began the work which has placed Mexico in the rank of great modern nations. It was Reyes who came to Washington to protest against the action of the government of the United States of America in reference to the establishment of the Republic of Panama, and, without entering into a discussion of this affair, it can be fairly said that there was not an American in Colombia whose feelings of justice were. not outraged at the government action and subsequent refusal to submit the matter to the impartial judgment of the' Hague. President Reyes is an accomplished linguist, speaking English, French, German, Portuguese, Spanish, and Italian. He has a remarkably. powerful voice, which can readily be heard by a large assemblage. His height is about 6 ft., and his weight exceeds 200 lb. He has clear gray eyes. Reyes was the leader of those who favored the approval of

Sep 1, 1908

By Cornelius F. Kelley

DURING the war, events moved with unprecedented rapidity. Situations, industrial, economic and financial, arose over night that stressed to the uttermost the ingenuity and ability of those who dealt with them. It was essentially a time demanding action rapid and concentrated, and not one for discussion, either academic or polemic. As a result, matters of importance were necessarily transacted without the desirable opportunity being afforded of enabling a general understanding to be gained as to the relative merit or demerit involved, and in some instances, legislation essential to enable the consummation of an important matter was passed without attracting the public attention then deeply engrossed in the larger aspects of the situation. The result was that so long as the public mind was occupied, little or no concern was given to questions that ordinarily would have invited immediate attention; and in some instances, only when as an aftermath of war a particular subject has become a matter of discussion, criticism not altogether fair is made without first obtaining accurate knowledge as to the conditions that prevailed, the purpose sought to be accomplished, or the results obtained by the action taken.

Jan 1, 1921

By J. W. Thompson

ORES PROCESS OF ORE CONCENTRATION-PATENTABILITY. The patent issued to Sulman, Pickard, and Ballot, November 6, 1905, and assigned to Minerals Separation and Minerals Separation American Syndicate, for new and useful improvements in ore concen- tration, its object being to separate metalliferous matter from gangue by means of oils and fatty acids that have a preferential affinity for such metalliferous matter, the principal feature of which is "agitat- ing the mixture to cause the oil-coated mineral to form a froth," was clearly anticipated by other patents, and each step in the process described in the Sulman, Pickard, and Ballot patent is fully described in more than one of the prior patents, with the single exception of the reduced quantity of oil used; but the discovery that the small fraction of oil is sufficient to produce flotation of the metalliferous matter can not be made by itself or in combination, the subject of a patent. Hyde v. Minerals Separation, 214 Fed., 100, p. 109, May, 1914. ACTION FOR CONVERSION OF MINERALS. In an action by the grantor of a certain mine and mining property against his grantee to recover damages for the conversion of a quantity of ore that the grantor before the conveyance had mined and extracted from the mine and placed on the dump near the mine, the plaintiff is not entitled to recover where it appears that at the time the ore was placed on the dump the mine was owned and operated by a mining company and that at the time the ore was taken out of the mine the company had no intention of doing anything with it but simply deposited it on the dump as waste and to give an opportunity to develop the mine and get better ore to send to the smelter, and that

Jan 1, 1915

The value of processed materials of mineral origin was estimated to have exceeded $310 billion in 1990. U.S. raw nonfuel minerals mine production in 1990 was estimated at $33 billion, a 3.1 % increase over that of 1989. The value of minerals production increased in all but 3 of the last 30 years. The metals component of production value has fluctuated much more than the industrial minerals component. This reflects the greater volatility of metal prices. In 1990, total employment in metal mining continued the increase that began in 1987. This growth was partially offset by a slight decline in employment in industrial mineral mining, resulting in an overall in-crease of 1.1 % to 179,100 in 1990. Continuing high (by historical standards) metal prices led to expansions at some mines, as well as opening or reopening of additional mines, resulting in increased employment.

Jan 1, 1991

By Douglas W. Fuerstenau, Pradip Pradip

The design and development of selective flotation collectors has been the key to the remarkable success of flotation in beneficiating complex, difficult-to-process ores. Sustained research efforts in the field over the past hundred years have led to delineating the scientific basis of selective mineral flotation in terms of the crystal chemistry and the surface and colloid chemistry of minerals including their solubility, and the aqueous solution chemistry of added reagents. It is now well-established that the electrical double layer theory (EDL) is the most powerful means of quantifying the relative strength of mineral-reagent interactions in the case of nonsulfide minerals. We illustrate the utility and the power of the EDL in delineating the science underlying selective mineral flotation with the help of a few examples taken from our own work, in particular on the selective flotation of rare-earth minerals (bastnaesite) from associated semisoluble minerals (barite and calcite) using alkyl hydroxamate collectors and the flotation separation of lithium-containing minerals (spodumene) from associated alumino-silicate minerals with oleate (fatty acids). Both of these mineral separation systems are of contemporary research interest and of immense value to the industry today. Recent advances in utilizing molecular modeling computations, particularly in the context of quantifying the effect of crystal chemistry and the relative distribution of adsorption sites available on mineral cleavage planes, are also reviewed.

INTERNATIONAL conferences on safety in mines originated in 1912 when, in response to an invitation issued by the United States, representatives of Austria-Hungary, Belgium, France, and Germany participated in a conference held in Pittsburgh, Pa The record shows that a permanent organization was proposed to be developed through. diplomatic channels. However, the advent of war 2 years later prevented this proposal from coming to fruition. No further cooperation between the Bureau of Mines and a group having: similar interests in a foreign country took place until 1924, when formal cooperation with the Safety in Mines Research Board of Great Britain was established. Interchange of personnel and results of research under that arrangement have resulted in a number of publications in both countries and more rapid advance in knowledge than could have been obtained through the same efforts exerted independently.

Jan 1, 1950

By Others, C. M. Weld

During the past two years the Bureau of Mines has issued a series of mimeographed reports giving the results of research work and experiments conducted as part of its war minerals investigations. In this bulletin the reports on manganese are presented, which range in scope from the beneficiation of the ore to the utilization of the metal. The bulletin is in eleven chapters, each comprising a separate report, arranged in the order given below. 1. General information regarding manganese, by C. M. Weld. 2. Uses of manganese other than in steel making, by W. C. Phalen. 3. Problems involved in the concentration and utilization of domestic low-grade manganese ores, by Edmund Newton. 4. Preparation of manganese ore, by W. R. Crane. 5. Leaching of manganese ores with sulphur dioxide, by C. E. Van Barneveld. 6. The Jones process for concentrating manganese ores; results of laboratory investigations, by Peter Christianson and W. H. Hunter. 7. Cost of producing ferromanganese ores, by C. M. Weld and W. R. Crane. 8. Production of manganese alloys in the blast furnace, by P. H. Royster. 9. National importance of allocating low-ash coke to the man- ganese-alloy furnaces, by P. H. Royster. 10. Electric smelting of domestic manganese ores, by H. W. Gillett and C. E. Williams. 11. Use of manganese alloys in open-hearth steel practice, by Samuel L. Hoyt. As each chapter was originally prepared as a unit, there is neces- sarily some duplication and overlapping. With certain exceptions, however, each paper is reproduced in practically its original form. In chapter 1, covering certain general phases of the industry, such as uses, specifications, prices, and statistics, the subject matter has been somewhat modified in view of changes in conditions.About 95 per cent of the manganese consumed in the United States goes into the manufacture of steel. The remaining 5 per cent is used in a number of minor industries, the chief of which is the manufacture of dry cells. These minor uses are described in chapter 2. No discussion of the geology of manganese eres is presented, but a short bibliography on the subject is appended. With few excep- tions the manganese deposits of the United States are irregular, pockety, and uncertain. Largely for this reason, mining methods are crude and hardly warrant descriptions. The concentration of manganese ores, however, is an important problem and involves some details not common to other ores. Chapter 3 discusses the concentration and utilization of low-grade ones, notes the relationship of concentration to metallurgical prao- tices, outlines concentrating processes, and treats of commercial problems. In general, as regards concentration methods, manganese ores may be divided into two groups, as follows: (1) Ores permitting mechanical separation of the manganese minerals and the gangue, and (2) ores in which the manganese minerals and the gangues are so intimately associated that separation requires some hydrometal- lurgical or pyrometallurgical process. Heretofore, attention has been confined almost wholly to mechanical separation, chiefly by gravity. In fact, so far as known, all production of concentrates has been by wet gravity methods, although during the war some companies investigated the commercial pessibilities of magnetic separation and reported favorable results, the construction of one magnetic con- centration mill being started. The usual wet gravity methods are described in chapter 4. During the war, the Bureau of Mines undertook investigations of methods applicable to ores of group 2. A hydrometallurgical process involving leaching with sulphur dioxide was studied at the mining experiment station of the bureau at Tucson, Ariz. The results of this work, presented in chapter 5, indicate that the process is metallurgically feasible but the cost makes it unattractive. The results of an investigation of a pyrometallurgical process known as the Jones process are presented in chapter 6. The process, which is still in the experimental stage, was found to be metal- lurgically sound. The manganese product is not a concentrate but an alloy, made directly from a lean unconcentrated ore. The custom- ary method is to manufacture alloys from high-grade ores or from concentrates of leaner ores. A discussion of the costs of ferro-grade manganese ores is pre- sented in chapter 7. This discussion is in general terms only, but should be of use in so far as it relates to competitive conditions.

Jan 1, 1920

By P. L. Russell, M. E. Volin, F. L. C. Price, D. H. Mullen

Tin deposits in Catron County, New Mexico, were explored by the Bureau of Mines under authority of the Strategic Minerals Act of August 1939. The investigation covered both lode and placer deposits and was later extended to deposits in Sierra County. Six of the known deposits were examined by E. D. Gardner, supervising engineer of the Southwest Experiment Station of the Bureau of Mines, and S. G. Lasky, a geologist of the Federal Geological Survey, in June and July 1939. It was recommended that the more promising occurrences be explored by test pitting, trenching, and sampling. Field work, under supervision of M. E. Volin, began in September and continued through December 1939. The area was mapped by Carl Fries, Jr., of the Federal Geological Survey, in 1939 and 1940. The La Cruz Development Co. acquired control of the Squaw Creek placer claims in 1942 and began active sampling and development preliminary to large-scale operations. The result of this work showed a considerably higher tin content than that found by the Bureau of Mines in 1939. Because of this report and reports from other parts of the district that large-scale operations for the production of tin from lode deposits were possible, it was recommended that the Bureau of Mines resample parts of Squaw Creek and conduct a mill test of lode material to determine whether a concentrate could be made that was high enough in tin and low enough in iron to be acceptable in American smelting practice. This work, under the supervision of Paul L. Russell, was begun in November 1942 and completed in January 1943, during which time the Sierra Metals Co. acquired control of a large area in Sawmill Canyon. At the suggestion of the Federal Geological Survey and the War Production Board, which had reason to believe that a great deal of commercial material existed on certain flatlands and gully slopes, the project was extended to include test pitting and sampling of those areas. This work was completed in February 1943.

May 1, 1947

By Christopher Mark

This proceedings volume contains papers presented at W U.S. Bureau of Mines (USBM) technology transfer seminars on New Technology for Longwall Ground Control. These seminars were conducted in Washington, PA, on April 12, 1994, and Denver, CO, on May 10, 1994. The papers herein describe several new, highly practical USBM technologies now available for ground control in longwall mines, including lie Coal Mice Roof Rating (CMRR), cable bolts, the MULSIM/NL model, and the Wood Crib Performance Model. Other significant topics addressed include longwall panel layout, coal pillar design, horizontal stress in longwall mines, roof support selection for gate entries, and ground control monitoring.

Jan 1, 1994

By Ernest A. Hersam

"INTRODUCTION.Luring the year 1923 a complete survey was made of the condition of research in the reduction (milling) and concentration of ores and nonmetallic minerals - that is, up to the stage where the ores or concentrates were ready for hydro- or pyro-metallurgical treatment. This survey was carried on under the general supervision of L. A. Lyon, assistant director and chief metallurgist of the Bureau of mines, in cooperation with the milling committee of the American Institute of mining and metallurgical Engineers, the Massachusetts Institute of Technology, and the University of California. Other institutions, including the National Research council, were of assistance and outlined recommendations during the study.While this report is on ""ore dressing"", it contains short sections on coal and clay. The mechanical handling that these minerals undergo is ""dressing"", so that ore dressing is inclusive of metallic and nonmetallic minerals. ""milling"", in its broadest sense, includes with ore dressing certain other metallurgical treatment which the report is not designed to cover.The survey revealed that considerable experimentation is being carried on great cost to the mining industry, but that the research is in general poorly coordinated while companies and firms are adequately taking care of routine tests and the mechanical features involved in their own operations, no comprehensive study of the fundamental principles of ore reduction is now in progress or contemplated. Many industries, besides mining, are interested in the preparation of materials for final treatment, rendering this investigation of value also to them. This class of fundamental research is neglected by industry unless there is some agency which can bring together at least a majority of this interested in a cooperative effort. It can not be effectively handled by a single company; and, moreover, no company can be expected to bear the whole burden of an investigation to benefit the entire industry or a number of industries hence there is need for concerted study within reasonable limits. Furthermore, co-operation eliminates duplication, which is largely a waste of effort and capital."

Mar 1, 1925

By C. H. Larsen

A 9-month study of the uses of wire rope associated with U. S. underground coal mining is reported. Rope applications are broken down into hoisting and nonhoisting applications where "hoisting" refers to transport in vertical and inclined shafts. The former receives the greatest emphasis since it represents the most critical rope application from the stand-point of production and safety. The discussion of hoisting practice includes aspects related to the mine operators as well as those related to the equipment builders and wire rope manufacturers. U. S. state and Federal laws regulating hoisting and wire rope use are also presented and discussed. Canadian and other foreign hoisting practice and laws are included. The state of the art in electromagnetic nondestructive inspection of hoist ropes is presented. Capabilities and use of one Canadian electromagnetic device are discussed in great detail. Conclusions are drawn regarding the present state of wire rope and hoisting technology in U. S. coal mines. Recommendations are made for improving rope practice, in general, and hoisting, in particular, consistent with greater safety.

Jan 1, 1971

By Robert S. Hill

"In November 1942, a preliminary report on the Swartz Mining District by John H. Soule, an engineer of the Bureau of Mines, recommended an exploratory program of diamond drilling. The existence of zinc and lead deposits in this region had been known for many years. In 1943 and 1944, the Federal Geological Survey made a detailed study of the same area. Later work done by the Bureau of Mines in this district followed the suggestions made by these geologists.3/In the latter part of 1944, Felix A. Vogel, Jr., another Bureau engineer, made a study of the Grey Eagle mine in the Kingston Mining District, a few miles northeast of the Swartz district, and his recommendations for diamond drilling were followed in so far as funds permitted. Drilling was started in October 1943 and was completed in June 1945.4/In its program of exploration of Mineral deposits, the .Bureau of Mines 'Ms as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution t national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples of ore and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, special acknowledgment for assistance is due to C. H. Johnson, chief of the Rolla Division, Mining Branch, and to various members of the Geological Survey."

Sep 1, 1946

By E. C. Yeager, E. O. Wagner, A. W. Koth, V. F. Parry, J. B. Goodman, D. G. Gernes, W. L. Patty

"In July 1943, the Bureau of Nines received an appropriation to investigate the beneficiation of Minnesota iron ores through the use of lignite. The broad objective was to find a way to link the large deposits of lignite in North Dakota with the low-grade iron ores of Minnesota. It was proposed that sponge iron might be made through new methods of processing, and one of the objectives was to determine the possibilities of gaseous reduction of fine ore. The problem of obtaining high-hydrogen reducing gases from lignite was assigned to the Subbituminous Coal and Lignite Section of the Bureau of Mines in August 1943.Through the advice of technical consultants and men familiar with the mineral resources of Minnesota and North Dakota, a tentative program of development was outlined. The first proposal was to study the gasification of lignite briquets in a standard water-gas machine. Previous experience with gasification of lignite indicated that the raw fuel would not be suitable for use in the conventional water-gas process on account of degradation, but gasification of lignite briquets appeared possible. Through the cooperation of the Northern State Power Co„ a series of tests was made at the company's plant in Grand Forks, N. Dak., on lignite-char briquets made by the Lehigh Briquetting Co. at Dickinson, Dak. These briquets are made by the Lurgi process, and they have been used satisfactorily as a domestic fuel. The object of the tests was to compare gasification properties of lignite-char briquets with those of gas. coke made from Kentucky coal, normally used in the Grand Forks plant. The tests revealed that the lignite-char briquets were not suitable for gasification, in the standard water-gas process because of disinte-gration and low efficiency caused by loss of fine carbon.While these investigations were underway, a joint Minnesota-North Dakota Development Commission was formed to aid in planning investigations on development of mineral resources of the two States. Some members of this commission were technical men, who with consulting engineers on the Bureau's staff made up an unofficial technical committee, and assisted in solving certain problems connected with gasification of lignite and beneficiation of iron ores. This committee has been of 'real assistance in guiding the investigation.A technical meeting was held in Minneapolis on November 10 and 11, 1943, for further discussion of objectives and certain technical problems. Results of tests on lignite briquets were presented, and several reports analyzing other methods of gasification were discussed. The Reyerson-Gernes process for the continuous gasification of lignite in an externally heated retort was considered from several angles. This process differs from others in that the natural moisture in the coal is utilized to help gasify the coal, and the volatile matter is largely decomposed. Although this process had been carried out successfully in a small steel retort, no definite design for a commercial-scale retort had .been developed. It was first proposed that the process might be carried out in a Glover-West retort. However, it was brought out that a Glover-West retort would require modification to simulate the process correctly, and that good results might not be obtained even then owing to the leakage of gas through the refractory walls and to an anticipated low rate of heat transfer at the gasification temperature suitable for lignite. Further, the probable leakage of inert furnace gas into the water-gas would be adverse to the Objective to obtain a gas that could be purified to 96 percent hydrogen."

Jun 1, 1946

By Charles H. Foreman

This paper describing the mining practice of the Hecla and Star mines, both located at Burke, Idaho, is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. It is partly a revision of articles by the author appearing in volume 72 of the Transactions of the American Institute of Mining Engineers, published in 1925, and in the June 1928, issue of the American Mining Congress Journal. About 26,000 tons per month of lead ore is produced at the Hecla mine. Costs at the mine are given for the year 1928. Stoping operations in the Star mine have covered such a short period, during which time the abnormal expenses of starting were incurred, that they are not given in this paper.

Jan 1, 1930

Workers at Anaconda Aluminum Company's primary aluminum smelter at Sebree, Ky., were back on the job December 1, after agreeing to a new 3-year contract. The old contract had expired November 15. On December 20, the Aluminum Company of America reportedly shut down a 42,000-ton-per-year potline at its Wenatchee, Wash., primary aluminum smelter and half of a 23,000-ton-per-year potline at its Vancouver, Wash., smelter as a result of a power cutback by the Bonneville Power Administration. A1 so in December, Kaiser Aluminum & Chemical Corp. reduced overall power at its Mead and Tacoma, Mash,, smelters and shut down one of eight 27,500-ton-per-year potlines at Mead. Reported shutdowns for the firms since September have amounted to 76,000 tons for Alcoa and 50,000 tons for Kaiser. Alcan Aluminum Ltd. announced plans to double the generating capacity at its Kemano hydroelectric power plant in British Columbia to 1,916 megawatts. The additional power would be equal to that required of a primary aluminum smelter with an annual capacity of 567,000 tons.

Jan 1, 1980

By W. L. Cooley

Electrical accidents occurring in coal mines from 1975 through 1979 were categorized and analyzed. The data was searched for common electrical hazards, common activities on the part of those injured, and common negligent or careless behavior. The most common electrical hazard was abnormal arcs or sparks, the most common injured activity was handling energized trailing cables, and the most common careless behavior was failure to de-energize circuits before working on them. The accident data was combined with mine production statistics to form a normalized electrical accident rate. It was found that some mines have consistently more lost workdays per man-hour worked than do other mines. Bureau of Mines electrical safety research contract expenditures were reviewed to judge whether the research effort was directed to those areas which are related to the most accidents. In some cases it was not. A method was devised and utilized to estimate the relative cost to the mining industry to implement certain safety measures developed through Bureau research, and also to estimate the potential safety benefits. Some safety changes are recommended, others are not. MSHA regulations were reviewed for effectiveness in preventing electrical accidents, and suggestions were made for discontinuing, clarifying, or otherwise modifying the regulations.

Jan 1, 1981