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By Suresh K. Bhatt

A mathematically simulated modeling technique is used in this U.S. Bureau of Mines report to represent a hypothetical mining operation with existing mining technology and prevalent mining costs. Mining scenarios were prepared and evaluated for potential benefits and costs available through computer-assisted mining. Base criteria, parameters, and methodology are described.

Jan 1, 1991

By Clinton C. Knox

During the latter part of 1943, a magnetometric survey was conducted by the Geophysical Division of the Bureau of Mines at the Mahopac magnetite mine, Putnam County, N. Y., in an endeavor to locate a segment of the ore body that reports state was cut off by a fault. The Mahopac mine was abandoned about 1895 after producing nearly 1,000,000 tons of high-grade magnetite iron ore. The results of the investigation indicate the termination of the ore body by "pinching", or a displacement of such magnitude as to place any extension at a considerable distance from the original are body. This report describes the work done on the project and presents the data obtained.

Jan 1, 1948

The mineral industry of Benin contributed less than 1% of the 1977 gross domestic product (GDP), which was estimated at $500 million.' Other than limestone and salt, no exploitable mineral deposits have yet been discovered in Benin, which has been rated by the United Nations as one of the world's least developed nations. In 1977, the economy was further weakened by petroleum price increases and severe drought. The country continued to depend on foreign assistance, which averaged $20 million per year, to finance development projects. The country's first 3-year plan, which was put into operation in October 1977 after many delays, allocated more than $1 billion to projects in infrastructure, agriculture, and light industry. The most important infrastructure project was the expansion and modernization of the port of Cotonou, valued as an entrepôt port for the transit of goods to the neighboring countries of Niger and Nigeria. Plans called for an increase in handling capacity to 1 million tons of cargo annually, the improvement of port and cargo handling operations, and the upgrading of the efficiency of the Port Autonome de Cotonou (PAC) management system. The $46 million project was to be financed by a consortium led by the International Bank for Reconstruction and Development (IBRD) and including Canada, France, Nigeria, and Abu Dhabi. Construction was scheduled to begin in 1978 and be completed in 1980.

Jan 1, 1981

By F. H. Nehl

Ion elutriation was used to extract silver cyanide complexes and free cyanide from aqueous streams containing up to 10 ppm silver and 5 ppm free cyanide. Screening tests selected nine of 350 different surfactants for further, larger scale experiments. The screening procedure used 0.1 g of each of the surfactants in 300 mL of synthetic wastewater. Air was sparged into the test cell at 50 cc/min. The foam was refluxed during the tests and was not sampled. Samples of the solution were taken at specified intervals and analyzed by wet chemical methods for free cyanide and by atomic absorption for silver content. The most effective surfactants lowered the silver and free cyanide concentrations to less than 0.5 ppm in 1 h or less. These surfactants were quaternary amine salts with one long chain (C12-C18) organic group and three methyl groups. Experiments using 3 L batches of wastewater or an ion elutriation cell continuously fed with solution draining from an inactive heap leach operation confirmed the results from the screening tests.

Jan 1, 2010

By F. S. LOTT

Publication of the Bureau of Mines annual surveys of the capacity of petroleum refineries in the United States was suspended after the entry of the United States into World War II . The last published survey was that of January 1 , 1941 , released in April 1941 as Information Circular 7161 . The purpose of this publication is to provide comparable information with respect to crude - oil and cracking capacity on January 1 , 1947. No attempt is made at this time to bridge the gap in annual statistical series from the date of the last published survey to the present one . However , complete summary tables will be included in the succeeding survey for January 1 , 1948 .

Mar 1, 1948

By Edward F. Divers

Tills U.S. Bureau of Mines report briefly evaluates the advantages and disadvantages of basic dust control techniques presently used by U.S. coal preparation and mineral processing plants. These include ventilation, baghouse-type collectors, wet scrubbers, electrostatic precipitators, source control, sprays, good housekeeping, and personal protection devices. Two specific problems in these types of operations are also considered: dust collector system duct clogging, and control room dust control. Information provided in this report results from dust control research projects conducted by the Bureau at various coal preparation and mineral processing plants over the past decade to reduce workers' dust exposure. These studies indicate that plant ventilation systems normally provide the most cost effective method for dust control. Baghouses and scrubbers were also effective in specific applications, and examples of each are given. In extreme dust conditions, personal protection devices, such as respirators or the dust helmet, can also be highly cost effective.

Jan 1, 1990

By Henry Kreisinger, John Blizard

This preliminary statement presents some of the results of tests carried out at the Lakeside Station of the Milwaukee Electric Railway and Light Co. , by the fuel section of the U. S. Bureau of Mines , in cooperation with the research department of the Combustion Engineering Corporation of New York . The object of these tests was to determine the thermal efficiency , ease of operation , and other particulars of a boiler equipped with specially designed furnace and burners for burning powdered coal . The boiler tested haş 13380 square feet of heating surface , and is one of eight boilers equipped with the Lopulco powdered coal system supplying steam to two 20,000 -Kw . steam turbines in the largest power house burning powdered coal . Twenty- six tests were run at rates of heat transference varying from 4000 to 8000 B.t.u. per square foot of boiler heating surface , and the mean thermal efficiency attained was about 84 per cent , based on the gross calorific value of the fuel as fired . The efficiency varied little with the rate of steaming , and its high value is accounted for by the small loss from incomplete combustion and the small amount of excess air which varied from 5 to 36 per cent . The coal burned had a gross calorific value of about 11500 to 12800 B.t.u. per pound , contained 2 to 5 per cent moisture , 33 to 36 per cent volatile matter and 9 to 13 per cent ash, and was so ground thaf 89 to 95 per cent would pass through a 100- mesh sieve . The ash had a softening point of 2150 to 2450 degrees F. , but did not fuse together at the bottom of the furnace because it was partly protected from the flame radiation by means of a series of water tubes connected to the boiler which were placed between the fumace bottom and the flame, ..

Jan 1, 1923

Rapidly identify unstable mine waste embankments and similar dam structures. Approach Aerial photography, geotechnical instrumentation, and telephone or satellite data transmission are used to supplement walk-around inspect ions. How It Works Embankment stability and other indicators of structural integrity are evaluated using aerial photography, and on-site unattended instruments and data transmitting systems. Evidence of external movement and water seepage is obtained from aerial photography and photogrammetric evaluation techniques. Surface points marked by stake- mounted targets are monitored photographically at time intervals of several weeks or months. Photographic measurements of x, y, and z coordinates of these points are obtained from flying a series of photo-runs over the dam.

Jan 1, 1979

By J. J. Forbes

The Act of Congress authorizing the establishment of the United States Bureau of Mines became effective July 1, 1910. One of the most important duties Congress delegated to the Bureau in this Act was the study of health and safety conditions in the mineral industries. Early investigations of these conditions revealed the need of prompt Care of injured employees, as, under the difficulties inherent in their occupation, seemingly unimportant wounds if not treated promptly might become infected and cause permanent disability or even death. Many seriously injured persons brought out of mines and plants by fellow workers ignorant of approved methods of giving first aid or of safe means of transportation have been caused suffering and have had injuries accentuated to such a degree as to bring about permanent disability or death. The need of general instruction in first aid thus became apparent. BRIEF HISTORY OF FIRST-AID WORK The education of miners in the United States in first aid probably was conducted systematically first by the anthracite industry in Pennsylvania. Subsequently, first-aid training was carried on actively in Alabama and Indiana. Meanwhile, a general training campaign was carried on among industrial workers by the American Red Cross Society; when the Bureau of Mines began its nation-wide campaign of instructing employees of the mineral industries, the Red Cross turned over that part of its industrial training work to the Bureau but continued to cooperate by furnishing surgeons as judges in important first-aid contests and demonstr tions and assisted for a number of years in determining training methods.

Jan 1, 1937

In 2004, data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 891 underground (6.2%) and 13,587 surface (93.8%) mining operations.

Sep 1, 2007

Mainland China To Pay Japanese Company On Contract Claim. - Mitsubishi will receive $39 million from Red China, half of what was asked, for China's having, curtailed work on a 5369 million steel rolling mill at Baoshan near Shanghai. Copper Found in Chile. - Utah International Inc., in conjunction with Getty Oil Co., has discovered a cooper deposit in northern Chile. Early drilling reveals an enriched zone grading 1.2% to 2 3% copper. Chile already has tie world's largest Cu reserve base. Soviets To Aid Laotian Tin Industry. - The U.S.S.R. has agreed to help strengthen the tin industry in Laos, a client state. In the past, Laos has only produced small amounts of tin concentrate, 500 tons to 1,000 tons per year presumably shipped to smelters in Singapore or Penang, Malaysia. Under the agreement made in June, the Soviets are to supply equipment to increase the out put of tin from the Phontieu, Neng, and Nongsen mines and help Laos with the construction of a tin smelter. The U.S.S.R. itself is a net importer of tin, although a substantial producer of the metal.

Jan 1, 1981

By CDC CDC

In 2004, a total of 251 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Metal mines were the smallest mining commodity sector, comprising 1.7% of all mining operations. • Gold mines

Sep 1, 2007

By C. E. Julihn

In the past few years the advance of the Sunshine mine to national prominence as the chief silver-producing mine of the United States has revived interest in the area in which it is situated. Although this area lies between the great lead-Zinc-silver mines at Kellogg and those in the vicinity of Burke and Mullan it was generally presumed to be almost barren, as little ore had been found there until substantial ore bodies were developed on deep levels of the Sunshine mine. In early days it was called the "dry belt" because its ores were siliceous and contained little lead; but the classification of ores in smelting as wet or dry, although once customary, has long been obsolete The area will therefore be referred to in this paper as the silver belt of the Coeur d'Alene district because the value of its ore is due chiefly to silver, the current production of which is large, providing over 60 percent of the silver output of Idaho. Silver Belt - Its Limits and Character With a daily production of half a ten of silver or more from the Sunshine mine, the silver belt has become the scene of extensive exploration at many properties, and the outlook for its future seems promising enough to warrant the lively interest now being displayed in the area by the public.

Jan 1, 1936

By J. Roger Loebenstein

This report presents a U.S. Bureau of Mines study of the flow of arsenic-containing materials in the United States, based on the best data available in 1991, includes a consideration of arsenic as a byproduct of the processing of nonferrous metals, the fate of arsenic in manufacturing wastes, the quantity of arsenic used in products, tile fate of arsenic in dissipative uses, and the useful life of discarded products. Where possible, estimates are given of the amounts of arsenic lost from the materials flow. Arsenic byproduct of mining nonferrous metals. Historically, most U.S. production has been from the states of Montana, Washington, and Utah. The smelters in these states are believed to be the areas of the country where arsenic is most concentrated in the soil, tailings ponds, and waste dumps. Since the closure of the last domestic producer of arsenic in 1985, all arsenic has been derived from imported sources. Historically, arsenic was important in agricultural applications as an insecticide, herbicide, and cotton desiccant. As the environmental movement gained momentum and the toxicity of arsenic became better understood, most of the agricultural uses for arsenic were banned. Beginning about 1975, the use of arsenic as a wood preservative began to grow. After 1980, wood preservative uses became more important than agricultural applications. By 1990, 70% of the arsenic consumed in the United States was used by the wood preservative industry and 20% by the agricultural industry. The major source of domestic arsenic emissions in 1989 was from the U.S. copper processing indus¬try. About 7,800 mt/yr of arsenic was discarded in leach dumps, tailings, and slag. Another 800 mt/yr was liberated to the atmosphere and 1/100 mt/yr was exported in copper concentrates. On the consumption side, 9,200 mt/yr was lost, mostly from dissipative agricultural uses and the disposal of obsolete arsenical products.

Jan 1, 1994

The Appalachian Mountains divide Pennsylvania into two distinct coal regions, bituminous and anthracite. The western region of the the state, where the majority of bituminous mines are located, is characterized by mountains and gently rolling hills. Bituminous coal seams underlie about 12,000 square miles in 28 counties. The anthracite coal region, located in the northeast, covers approximately 3,300 square miles. This area contains more than 20 different coal beds that vary in thickness from a few inches to 50 or 60 feet. The anthracite region is characterized by steeply pitching seams that require highly specialized mining techniques and present unique challenges for solving problems such as the mine subsidence associated with abandoned underground anthracite mines. For more than a century, coal has played a major role in the economic and industrial development of Pennsylvania, particularly the steel industry. Estimated bituminous reserves total 23 billion tons, or 5.3 percent of U.S. reserves, and anthracite reserves total 7.1 billion tons, or 97 percent of U.S. anthracite reserves. Pennsylvania received conditional approval of its regulatory program July 31, 1982. Pennsylvania's Abandoned Mine Land Program was approved on the same date.

Jan 1, 1992

By T. R. Taubert, D. H. Carlson, J. H. Johnson

"ObjectiveDevelop a portable emissions measurement apparatus to sample and measure tailpipe concentrations of diesel particulate matter (DPM), carbon monoxide (CO), carbon dioxide (COJ, nitric oxide (NO), and nitrogen dioxide (NOJ under steady-state engine load and speed conditions during a 1-minute test.BackgroundThe U.S. Bureau of Mines (USBM) has a comprehensive research program to develop ways to reduce exposure of miners to diesel exhaust pollutants. Engine maintenance has been shown to have important effects on such exposure.Accurate measurements of tailpipe emissions are becoming an essential part of a good maintenance program for underground mines that use diesel-powered vehicles. Past studies of particulates in U.S. underground coal mines have shown that DPM alone may be present at concentrations greater than 1 milligram per cubic meter (mg/m3), half the 2-mg/m3 limit for respirable coal mine dust. A poorly tuned (smoking) diesel engine may be the sole cause for respirable dust concentrations exceeding the limit. Although there is currently no standard specifically for DPM in U.S. mines, regulatory steps are underway, and significant reductions of DPM levels in both coal and metal mines will most likely be required.Tailpipe emission measurements can provide diagnostic information to identify engine malfunctions such as clogged air cleaners, faulty injectors, or incorrect injection timing. In some cases, mine vehicle tailpipe DPM concentrations have been reduced up to 50 percent by engine maintenance and adjustments.An accurate measuring instrument would also be useful for determining the effects of exhaust control devices on tailpipe emissions. Little information is currently available about the overall effectiveness of exhaust controls after long-term use. Raw exhaust concentrations with and without the control device can be measured in underground mines, and from these data a control efficiency can be calculated. Knowledge of the effectiveness of exhaust control devices over time is needed to make intelligent decisions on bow to use and maintain these devices, and when to replace them."

Dec 1, 1995

By Christopher Mark, Robert J. Tuchman

This proceedings volume contains papers presented at technology transfer seminars sponsored by the National Institute for Occupational Safety and Health (NIOSH) on New Technology for Ground Control in Retreat Mining. The seminars were conducted at five locations: Uniontown, PA (March 26, 1997), Norton, VA (April 8, 1997), Pikeville, KY (April 10, 1997), Charleston, WV (April 17, 1997), and Evansville, IN (April 22, 1997). The papers presented here describe several new, highly practical technologies developed by the NIOSH Pittsburgh and Spokane Research Centers3 to improve safety during pillar retreat operations. Two central issues are addressed: pillar design and mobile roof supports (MRS's). Proper pillar sizing is essential for safe pillar extraction. The Analysis of Retreat Mining Pillar Stability (ARMPS) program and its large data base of actual mining case histories are presented. LAMODEL, a second computer program, can be used for analysis of multiple-seam and other complex mining situations. Other papers address pillar design to avoid massive pillar collapses and the proper role of coal strength testing. MRS's have greatly improved safety where they are used for pillar line support. We studied the application of MRS's at 20 mines throughout the Eastern United States. Conclusions regarding the most effective section layouts, cut sequences, and support placements are reported. Field and laboratory tests of MRS's are also described.

Jan 1, 1997

To improve mining safety and efficiency by providing a practical way of detecting faults and channel sands that disturb coal seams. Approach A seismic system using a shallow blasthole has been developed and tested. How It Works A small shock is caused in a shallow hole, sending seismic waves through the ground. These waves are reflected from the top of the coal seam, acid are detected by a line of geophones on the earth's surface. Dampening of the seismic signals by channel sands and other discontinuities in the seam is detected and recorded. See Figure 1. The seismic shock wave can be produced by exploding small charges, dropping a weight, firing a gas gun, or actuating a vibrator. Depending on the soil cover, the shock is usually generated in shallow vertical holes about 10 feet deep. Hole depth depends on the soil mantle thickness because it is preferable that the seismic shock originate below that layer.

Jan 1, 1976

By Edward F. Divers

A new nonclogging water spray system for continuous-mining machines has been developed under contract with the Bureau of Mines. This paper presents installation and operating guidelines for the system, which consists of improved and easily maintained machine-mounted hardware, including an inline Y-strainer, a hydrocyclone, a backup filter, and two quick-opening valves for flushing particulates from the strainer and hydrocyclone. Underground tests with continuous-mining machines have shown that when properly installed and maintained, the new sys tern virtually eliminates nozzle clogging and thus greatly reduces spray maintenance. The sys tern is relatively inexpensive and has been installed on typical continuous-mining machines for a total cost under $1,000.

Jan 1, 1976

By Matthew J. DeMarco, Anthony T. Iannacchione

Coal bumps have presented serious mining problems in the U.S. throughout the 20th Century. Fatalities and injuries have resulted when these destructive events occur at the working face. Persistent bump problems can result in abandonment of large reserves or lead to premature mine closure. Through the years, alternative techniques such as artificial supports, extraction sequencing, destressing, pillar design changes and specific pillar retreat practices have been successfully implemented to mitigate coal mine bumps. Several techniques have evolved for room-and-pillar operations that control the way the roof rock breaks, regulating the manner in which stresses are redistributed in the mined section. Special mine layouts employed in longwall mines have also proved to be successful in safely redistributing or containing excessive loadings. However, with ever increasing production rates, greater overburdens and new mining systems, the need to evolve even more effective bump control designs will continue to challenge the U. S. coal mine industry.