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By Paul M. Hall

In the last several years, the coal mining industry has made significant changes in the design of longwall mining systems to make them more productive. Some changes, such as increasing the length of the coal faces and increasing the capacity of the face conveyors, have resulted in problems with achieving sufficient motor torque to start and operate the longwall face conveyors. Other changes, such as increasing the size and/or decreasing the percent impedance of longwall power center transformers, have resulted in problems with the short-circuit currents on the transformer secondaries exceeding the interrupting ratings of the molded case circuit breakers used to protect the secondary circuits. A survey of 24 longwall mining systems in northern West Virginia was conducted to investigate both problems. The results of the survey are presented and analyzed. Several recommended solutions to the problems are presented to enable the coal mining industry to design safe and productive longwall mining systems.

Jan 1, 1982

By S. H. E. Phillips

This report describes the initial feasibility, the development and the field demonstration of a system for shaft sinking employing a high energy mechanical impact rock breaker and a compatible muck disposal system. The increased shaft sinking rates, decreased costs and improved safety conditions obtainable by the elimination of the less efficient conventional drill-blast-muck cycles are discussed. Four shaft sinking concepts utilizing the impact rock breaker in various shaft configurations are developed and the field demonstration in a rectangular shaft is described. The progress achieved, the problems and their remedies and the proposed modifications to improve the machine are described.

Jan 1, 1978

By A. Brown

This report details work performed and results obtained in a study of the water management aspects of oil shale mining and retorting in the Piceance Creek Basin. Three specific sites were investigated, and optimal water management systems for both conventional and in-situ extraction processes were generated. Water-related legal and environmental constraints on development were identified and the water management schemes were developed in compliance with these regulations. Limitations on shale oil production implied by limited water supplies were evaluated. Potential Basin-wide effects of development were evaluated using a computer model, and mitigation strategies were developed. Recommendations for additional investigation and analyses were presented.

Jan 1, 1977

By David Garry, Michael J. Brnich, Lynn L. Rethi, Henry P. Cole, William J. Wiehagen, Roberta A. Calhoun

This document contains most of the materials needed to use the exercise. The main part of the document is the instructor's copy. It tells how to use the exercise, presents the objectives, the master answer sheet, the scoring key, and discussion notes to be used following the exercise. The next section summarizes results from field tests of the exercise, and reports the miners' evaluation of the activity. The last part of this document is three appendices. Appendix A is the exercise problem booklet. This booklet can be duplicated locally. The booklets are reusable. One is needed for every person in the classroom. Appendix B is the answer sheet and the trainee's questionnaire. Copies of this answer sheet must have the latent image (invisible) ink answers that appear in Appendix C printed on them.1 Answer sheets are consumable. One is needed for each person or each small group of persons who work the exercise. Exercise Summary Read this section first. It determines if the exercise is appropriate for your classes. If you choose to use the exercise, examine the table of contents and review the remainder of this document. Type: Latent image Audience: Supervisors, Safety Personnel and Accident Investigators Length: Eight questions (30 minutes for administration plus 30 for discussion) Skills: Developing a strategy or plan to prevent slips and falls Following correct procedures in conducting an accident investigation Preventing unsafe work practices Recognizing and instituting hazard controls in the section Identifying and implementing safe work procedures Location: Underground coal mine section Problem: You have been the general mine foreman at White Rock Mine for 4 years and have worked at this mine for 12 years. The mine superintendent calls you into his office. He gives you an accident report of an employee in 4-G section who was injured while carrying rock dust bags from the rock dust car to a battery powered scoop. It is several days after the accident and the mine superintendent assigns you and the safety supervisor to thoroughly investigate the accident to determine all the contributing factors. Your job is to make specific recommendations to prevent future slipping/tripping accidents.

Jan 10, 1999

By W. D. Mcmillan

Important reserves of nickel ore occur in the Levies district in Oriente, Cuba. The area is mountainous and mostly covered by heavy vegetation. The ore bodies comprise surface tracts of nickeliferous laterite underlain with decomposed serpentine of ore grade. The Cuban Nickel Co., a wholly owned United States Government corporation, owns a plant for leaching the nickel from its ores at Nicaro, Oriente, Cuba, Between December 1943 and March 31, 1954, 5,902,225 short tons of ore was treated, with a recovery of 116,206,519 pounds of nickel (52,711 metric tons). In 1953, 1,330, 224 short tons of ore was mined and 27;"3,129 pounds of nickel produced. The Cuban Nickel Co. also owns a townsite, with the necessary facilities, mining equipment, and 11 miles of railroad. Ore for the plant has been produced from the Ocujal-San Juan claims on lends owned by the Nicaro Nickel Co., a sub¬sidiary of Freeport Sulphur Co. The Government enterprise is man-aged by the Nickel Processing Corp. The Cuban Nickel Co. has denounced mineral concessions and has purchased other claims from private owners.

Jan 1, 1955

By F. V. Meriwether

The Bureau of Mines, in cooperation with the Federal, State, and local health services, and the mining companies, and miners? organizations, has for several years been carrying on sanitary surveys of mining districts in various states, with the purpose of collecting information on good and poor practices in mine sanitation, construction of approved wash-houses and change houses, the measures being taken to combat preventable diseases, the essential features of good houses for mining towns, and other conditions affecting the health and efficiency of miners and their families. The knowledge thus gained is disseminated for the common benefit of the mining industry. The sanitary conditions in the coal-mining districts of Alabama, as found by a recent survey made by the writer, are presented in this report. In addition to the towns on which this report is chiefly based, at least twice as many were visited where no details :were taken, but their general conditions are taken into consideration in summing conditions in the coal districts.

Jan 1, 1926

By David Bendersky

This report covers a technical and economic investigation of old electrical power systems, equipment and practices being used in the metal/non-metal raining industry. The principal sources of information were the MSHA District offices, visits to representa¬tive mines and mills, equipment manufacturers and the literature. A list of 85 mines and mills, submitted by the MSHA Districts as candidates for this study, is given and their characteristics are analysed. The electrical power systems and practices at the 10 mines and 9 mills which were visited are described. The principal areas which do not conform to standard electrical practices are discussed with emphasis on the safety aspects of these practices. The costs to update electrical power systems and practices in metal/non-metal mines and mills are given. The principal findings of the study are summarized and recommendations are submitted.

Jan 1, 1980

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date and is being published as a similar series of seven miners' circulars (Nos. 51-57, revised) on accident prevention in metal and nonmetallic mines. These circulars are: Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the use of investigations and reports of all accidents.

Jan 1, 1957

By A. S. Swanson

In view of the necessity or increasing production of metallurgical fluorspar to satisfy wartime demands, 0, M. Bishop, former district engineer of the Bureau of Mines, L. W. Carrier and. J. S. Williams, senior geologist of the Federal Geological Survey, and E. H. Dawson, mining engineer of the War Production Board made a joint survey of the Illinois-Kentucky fluorite district in July 1942 to determine what steps should be taken to increase production. As part of their recommendations, a program for exploring the idle Klondike mine in Livingston County, Ky., was outlined. All the ore produced at the Klondike mine was mined above the 325-foot level, where some tonnage remains. Factors that influenced selection of the Klondike mine for exploration were favorable geological conditions, the state of mine development and the availability of pumping equipment and some usable mine and mill equipment. In December 1942, the Metals Reserve Co. leased the Klondike mine from the Salem Fluorspar Co.

Jan 1, 1949

Greater mining productivity requires a more efficient cutting process. The cutting force available from today?s mining machines has been optimized with respect to machine size and weight. Researchers have shown that when employing water-jet-assisted cutting, bit forces and drum torques can be reduced significantly, which may allow mining machines to become lighter and more efficient. The Bureau of Mines has initiated a program to develop a water- jet-assisted rotary cutting system using the conventional bit assisted by a directed water jet operating at moderate pressures (3,000 to 10,000 psi). This water-jet-assisted cutting system has the potential to improve cutting efficiency without increasing machine horsepower or water usage (beyond what is presently used for dust control) or requiring fundamental changes in mining practice. IR addition to improvements in productivity, other anticipated benefits of water-jet cutting include reduced generation of respirable dust, elimination of frictional ignitions, increased bit life, reduced fines, and fewer machine vibrations. The papers presented at this open industry meeting discuss the development of water-jet-assisted cutting technology and future application of this technology to a variety of mining techniques including roof drilling and longwall mining.

Jan 1, 1985

By Perry G. Cotter

The objective of this investigation was to synthesize and investigate the properties of a high-temperature refractory material based on a combination of boron, silica, and magnesium. A magnesium-thermic reaction was used for the synthesis. X-ray examination of the product indicates that the crystalline portion of the composition is a combination of magnesium borides, magnesium silicate, and magnesium orthoborate. Chemical analysis of a representative sample shows, in weight-percent, boron 17.6, silicon 23.9, magnesium 17.8, and chromium 0.5. The balance is largely oxygen. The composition is resistant to high temperatures under oxidizing conditions and is stable in water, hydrochloric acid, and hydrogen. It has a low density (less than 3 grams per cubic centimeter) and a hardness value in the range of quartz. It has a melting point above 1,700° C. and can be hot-pressed to shape in the temperature range between 1,200° and 1,350° C. The properties described in this paper indicate that the material may have some uses as a high-temperature refractory, and because of its boron content it may have some value as a thermal-neutron-absorption material.

Jan 1, 1961

The Bureau of Mines conducted a field study to assess the performance of various chain pillar configurations in terms of gate road entry sta-bility. Vibrating wire stressmeters (VWS's) were installed in four consecutive gate road chain pillars. Field data collected during panel retreat were analyzed to gain a better understanding of the mechanics of vertical load redistribution in gate road chain pillars as it relates to ground control problems. Several different pillar configurations were investigated including abutment-yield and yield-abutment-yield designs. VWS data indicate that average pillar loads were lower and appeared abutment-yield pillar arrangement was utilized. port the occurrence of severe roof and pillar to stabilize when an Data analyses also supdeterioration that was visually observed in the tailgate entries during panel extraction.

Jan 1, 1988

By CLARENCE G. SMITH

Prior to the actual development of an oil property it is difficult to determine the quantity of oil under the property and the rate at which this oil can be brought to the surface-factors that determine the ultimate value of the property. Consequently, there has been much confusion in devising accounting systems that, during the entire life of a property, will show costs and profits from which the producer can determine whether his property is being worked at a profit or otherwise. The Bureau of Mines publishes this report in recognition of a distinct need for a simple treatise on accounting methods adapted to the peculiarities of the petroleum industry. Probably many companies operating oil wells are not fully acquainted with details important to the welfare of their business, because their account books fail to furnish them with exact and adequate data. With the accountant rests the responsibility of providing the management with reports setting forth the details of the business expressed in fitting terms as well as in dollars and cents. These reports are a means whereby efficiency may be maintained, waste prevented, oil obtained and sold, and money suitably reinvested. They also enable a concern to study the progress of its business in order to conserve to the utmost the possible benefits from an exhaustible deposit of mineral wealth. When managements realize the extent of the waste at their properties more attention will be given to the character of the accountancy records. Herein are presented descriptions and discussions of balance sheets, profit-and-loss statements, and bookkeeping methods peculiarly adapted to the oil business. As far as possible, technical phrases have been omitted in order that those not familiar with accounting terms may be able to follow the subject matter. The systems of keeping books outlined in Chapter X have all been found practical. For brevity as well as clearness the major part of the work refers to the company operating only one property.

Jan 1, 1917

By G. L. Oldright

The Metallurgical Branch of the Bureau of Mines, as a part of its duties under the Organic Act, works to prevent wastes in industry and to disuse inmate information on the fundamentals of metallurgical processes. During the war, the necessity of large production was increasingly emphasized. Such duties necessitate from time to time the study of units of full commercial size, the operation of which is beyond the facilities of the Branch. When developments have reached this stage; work has been continued in cooperative agreements with operating companies that have been willing to contribute the use of their plants and staffs and to allow the publication of the results obtained for the common good of the industry.

Jan 1, 1948

By G. J. Perrott, H. W. Clark

During the course of the cooperative smoke abatement investigation carried on by the Bureau of Mines , the city of Salt Lake and the University of Utah during 1919-1920 , a study was made as to the suitability of Utah coals for by-product coking with particular reference to low temperature coking . was done because it was realized that a smokeless fuel for domestic consumers was the best remedy for this class of smoke producer . A report of the technical side of the work was included in the final report of the cooperative investiga- Since this report was written (June 1 , 1920) further work has been done by other investigators .

Apr 1, 1922

In 2007, a total of 7,199 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 ? Sand and gravel mines were the largest mining sector, comprising 48.4% of all mining operations. ? Sand and gravel mines were found throughout all 50 states and Puerto Rico.

Aug 1, 2009

In 2007, a total of 725 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Nonmetal mines com-prised 4.9% of all m ining operations. ? Mines producing common clay comprised 25.4% (n=184) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the U.S. Virgin Islands.

Aug 1, 2009

By Albert L. Toenges, Theodore R. Jolley

"The development of Alaska depends on the existence of an adequate fuel supply in the Territory. The need to investigate coal deposits was recognized as early as 1911, when the first investigations were conducted in Alaska by engineers of the Bureau of Mines.Conditions existing in the Bering River and Matanuska coal fields, as found by Dr. Robert A. Holmes, former Director of the Bureau of Mines, are described by the Honorable W. L. Fisher, former Secretary of the Interior.4/Following Dr. Holmes' investigation, a party of Bureau of Mines engineers headed by R. Y. Williams visited the Bering River field in 1912 in cooperation with the Navy Department. A detailed examination was made of the Bering River field, and 855 tons of coal were mined from three prospects on Trout Creek. This bulk sample was delivered to the Navy for steaming and other tests. A description of the work of the field party and results of tests of the coal by the Navy Department and the Bureau of Mines has been published.During 1920 to 1922, the comparative steaming properties of Alaska bituminous coal, lignite, and wood were determined by the Bureau of Mines.6/In the early 1920's, the Bureau of Mines established a coal laboratory at Anchorage, where Alaska coals were analyzed. Subsequently, this laboratory was transferred to the Alaska Railroad and was used by the railroad for coal and other tests.Since 1910, the Bureau of Mines has made analyses of coal from Alaska, and the results of these analyses have been published.7/ The coal analyzed was obtained from mines, tipples, delivered lots, and face samples of coal deposits, and these samples were obtained in the field by engineers of the Bureau of Mines and geologists of the U. S. Geological Survey.Because of the shortage of petroleum and petroleum products in Alaska during the war, low-temperature carbonization assays of coals from the Broad Pass, Forty-Mile, Matanuska, and Nenana fields were made by the Bureau of Mines, and the results were published.Coal beds in the Matanuska field contain interbedded impurities in the form of shale, clay, and bone. The coal should be cleaned mechanically to obtain a satisfactory fuel. A coal-preparation study of bituminous coal from the Eska and Evan Jones mines was made by engineers of the Bureau of Mines, and the results were published.9/Coal production in Alaska is less than the requirements, and coal is imported to make up the deficiency. The cost of this imported coal is high. Greater production is necessary to supply coal for Army installations, industry, and homes. At present, there is only one bituminous coal mine (Evan Jones) in Alaska. The output of this mine is used at Fort Richardson, Anchorage, and by the Alaska Railroad. The economic life of this mine is limited (reported to be 3 years), and its closing, because of accidents or exhaustion, will cause great hardship to the inhabitants of Alaska. There is need to develop new, modern mines for the production of bituminous coal in the Matanuska field."

May 1, 1949

By William J. Kemnitzer

This study was made to show the growth of petroleum coking and to determine trends and characteristics of marketing and utilization of coke on the West Coast, comparing these data with those of the United States as a whole. An earlier Bureau of Mines economic survey of petroleum coke was made in 1930 before the widespread use of coking processes. Data, derived from published and unpublished literature as well as from interviews with industry representatives, show a marked increase in the production of petroleum coke since the end of World War II. This increase resulted from the need of refiners to upgrade heavy residuums for which the demand was diminishing. Increasing coke production as well as significant market shifts away from California-produced coke have created excessive stocks of petroleum coke on the West Coast. The causes of these market shifts were based mainly on (1) economic factors and (2) certain undesirable qualities of some of the petroleum coke produced in California.

Jan 1, 1965

By William J. Kemnitzer

This study was made to show the growth of petroleum coking and to deter- mine trends and characteristics of marketing and utilization of coke on the West Coast, comparing these data with those of the United States as a whole. An earlier Bureau of Mines economic survey of petroleum coke was made in 1930 before the widespread use of coking processes. Data, derived from published and unpublished literature as well as from interviews with industry representatives, show a marked increase in the production of petroleum coke since the end of World War II. This increase resulted from the need of refiners to upgrade heavy residuums for which the demand was diminishing. Increasing coke production as well as significant market shifts away from California-produced coke have created excessive stocks of petroleum coke on the West Coast. The causes of these market shifts were based mainly on (1) economic factors and (2) certain undesirable qualities of some of the petroleum coke produced in California.

Jan 1, 1965