Search Documents

By Robert B. Worthington

This investigation was undertaken to develop a more efficient copper smelting practice that would help meet the increasingly stringent antipollution standards. Continuous smelting to copper and a 0.8-to 5-percent copper slag using pure oxygen has been demonstrated for several hours at a time in a unique double furnace, which was devised to overcome the heat losses inherent in a laboratory furnace. The use of pure oxygen to effect the smelting and conversion of copper sulfide concentrate in a single unit to produce blister copper and a very high S02 concentration provides a much reduced gas volume for more economical and thorough sulfur recovery. Although the process was successfully demonstrated for several hours at a time, extended test work using longer runs will be required to balance the system and to obtain test data for adequately demonstrating its technical feasibility.

Jan 1, 1973

By Choon Kooi Quan

Water availability is essential for mining and minerals processing. To provide government and industry with recent data for water use planning and management, the Bureau of Mines canvassed a number of U.S. producers of nonfuel minerals to determine their water use in 1984. Data were analyzed and compared with previously published data in order to examine historical trends in water utilization in the nonfuel minerals industry and to estimate water requirements in the year 2000. Total water use in the domestic nonfuel minerals industry during 1984 was estimated at 2,267 billion gal, of which 571 billion gal was new water and 1,696 billion gal recirculated water. The largest users of water were the phosphate rock, iron ore, copper, sand and gravel, and crushed stone industries, together accounting for almost 90% of total used. More than one-half of all water was used in Florida, Michigan, and Minnesota. In the year 2000, total water use will amount to an estimated 2,679 billion gal, of which 810 billion gal will be new water and 1,869 billion gal recirculated water. Most of this water would be used in producing the foregoing suite of minerals,

Jan 1, 1988

By Ronald Branstetter

Gaseous and particulate exhaust emissions from 20 diesel engines in service at five underground mines were measured with high accuracy instrumentation. The engines that were tested were checked for faults or maladjustments. The vehicle and engine maintenance organization was studied at each mine and an idealized maintenance program was devised. Faults were induced in a new diesel engine to determine their effect on the characteristics of the exhaust emissions. The results, conclusions and recommendations from this investigation are presented in this final report.

Jan 1, 1983

By R. L. Zick, J. D. Byars, T. P. Mucho

Recently, a large Pittsburgh seam longwall mine was nearing depletion of a major portion of its current reserves and had begun to develop in a different direction from its original portal area to access additional reserves. This meant that a large area of the mine would be abandoned and sealed. However, continued use of the original mine portal area required that the water accumulating in the abandoned mine would eventually need to be pumped to the surface. This would be in addition to the discharge water associated with the new portion of the mine. Several pumping and sump options were investigated to handle the quantity and quality of the anticipated discharge water. This paper describes some of these options, their advantages and disadvantages, and the final engineering decisions. Some problems and unanticipated outcomes, as well as the eventual solutions are discussed, including: (1) estimates of pump requirements, (2) water pool size, (3) eventual water quality, (4) anticipated inflows, and (5) integration into the overall mine water system.

By Xinquan Zhou, Rudolf E. Greuer

MFIRE, written in Fortran 77, is a computer program for ventilation state simulation in the steady state or transient state condition. It can be applied for the calculation of normal ventilation system planning or the analysis of the dynamic state variation in a ventilation system under thermal or mechanical disturbance. The state simulator MFIRE is a useful tool for mine fire fighting. In the case of a mine fire, mine ventilation engineers want to get some help to obtain more information, such as what is happening in the underground mine and how to control the mine fire, for correct decision making. By use of program MF'IRE, forecasts can be made on the variation of airflow, temperature, and contaminant distribution in a ventilation system during a mine fire. The paths which the contaminant takes at each time interval can be traced. The program MFIRE can be of assistance in the preplanning of escape routes. It can also be helpful during a mine fire emergency and mine recovery operation. Besides of offering the information of state simulation during a mine fire, MFIRE can be applied for state control by pretesting the suitability of the selected state control measures. It is to simulate the effects of the state control measures on the airflow distribution of a dynamic ventilation system. The testing result can be used for fire fighting in a similar real case of a mine fire. By employing empirical methods or a qualitative analysis like Budryk approach, ventilation engineers can choose different combinations of locations and sizes of control devices as samples of state control for an underground mine fire. Program MFIRE can simulate the different combination samples, that consist of a certain mine fue, the corresponding different control measures, and obtain the control effects. After the different control results are compared, the state control measure, which creates the best effect among the different state control measures, will be chosen for that fire case. When a mine fire, which is similar to one of the pretested cases, breaks out, the corresponding choice of the state control measure is applied to the ventilation system. It means that the simulator MFIRE has the function of indirect state control [10]. To achieve the above two functions, state simulation and state control, the mine ventilation system condition, sometimes, should be changed in a wide range to meet the requirement of the fire fighting. These wide system condition changes, such as adding operating fans, stopping or reversing fans, changing fan characteristics, adding regulators and making airflow shortcuts are represented in the time table of the input data set When the data files are changed in a wide range, however, an iteration divergence and some other computing errors in the distribution of airflow, temperature, and contaminant may occur. More serious logical programming and flexible selection on the algorithms are wanted to meet the request of the different data sets, to achieve correct state distribution simulation and improve the iteration convergence. To enhance the reliability and common suitability of program MFIRE, it is necessary to make investigation, analysis, and modification for the formal versions of MFIRE. The version 1.29, permitting dry .calculation, and versions 2.01/v2.0, permitting dry and humidity calculation, are widely applied

By Mark I. Copeland

The Bureau of Mines investigated the effect of up to 1 wt-pct of copper and silicon on the heat treatment response and hardness, tensile, and impact properties of hot-rolled medium-carbon steels. The steels were prepared by induction melting and fabricated into plates by forging and rolling. The tensile strength of 0.2-wt-pct carbon steels containing 0.3 wt-pct silicon was affected significantly by copper in both the hot-rolled and heat-treated (600° C) conditions, whereas the tensile strength of the 0.3-wt-pct carbon steels was less affected. A 600° C treatment was considered optimum as a post-rolling treatment to strengthen the steels by copper precipitation. Strengthening of 0.2-wt-pct carbon steels by silicon was reduced by increasing copper contents.. Optimum impact strengths occurred at about 0.3 wt-pct silicon in 0.2-wt-pct carbon steels containing 0.6 and 0.8 wt-pct copper. The impact strengths were lowest for 0.2-wt-pct carbon steels containing over 0.8 wt-pct copper and greater than 0.3 wt-pct silicon, especially in the heat-treated condition. Copper and silicon solutes and copper precipitates strengthened the steels. This effect was augmented slightly by strengthening through grain refinement by these solutes.

Jan 1, 1973

By David L. Bickel

The following instructions and descriptions are presented in two parts to assist an individual to make the borehole deformation gage transducer, and to assemble and test the three-component borehole deformation gage. This Bureau 8 of Mines three-component borehole deformation gage (4, 8, 11)2 fits in a 1-1/2-in-diameter borehole that is drilled in rock and then overcored to determine rock stress.

Jan 1, 1978

By David L. Veith

This Bureau of Mines bibliography of U.S. and Canadian literature pertaining to revegetating coal-mined lands contains 805 references published from 1977 to 1984. Each reference is evaluated by keywords, providing the reader with a means of rapidly sorting through the references to locate only those dealing with the coal mining region and subject of interest. All references are annotated. Other sources of information are given, including Office of Surface Mining (OSM) and State reclamation agencies and other published bibliographies.

Jan 1, 1985

By John C. Machisak

This publication, for the calendar year 1959, contains statistical data on injuries and employment pertinent to metal mines, ore-dressing plants, and primary nonferrous smelters, refineries, and reduction plants. The Bureau of ,Mines is authorized to request data on injuries and employment in the metal-mining industry, and the information, voluntarily submitted by the operators, contributes immeasurably to the promotion of safety in the metal- mining industry. Every effort has been made to make the annual canvass as complete as possible. The data presented are classified according to the hind of ore mined and includes information on copper, iron, lead-zinc, gold-silver lode, placer, uranium- vanadium, and miscellaneous metals. A breakdown of miscellaneous metals by commodity is shown in tables 17 and 18.

Jan 1, 1963

By William L. Rice

This Bureau of Mines Open File Report on nickel is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign nickel properties and deposits has been abstracted for use in this report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 1984

By Russell Levens

A strategy for prioritizing mining health and safety research by evaluating the potential for risk reduction through interventions is proposed. Mining has one of the highest incidence rates of injury and disease found in major industries. The main premise of this paper is that often the best opportunities to reduce these rates are not revealed by retrospective analysis of injury and illness data. Instead, a proactive approach is needed that accounts for risks to specific hazards that can be abated by engineering or behavioral interventions. The process proposed here begins with development of prospective interventions. The degree of reduction in risk to be expected from an intervention then is determined from statistics on the mining worker population, the expected degree of success of the intervention, and the expected change in the severity of injuries resulting from the intervention. Three disparate mining health and safety concerns are presented to demonstrate common problems in assessing risks of injury and illness and describe additional data needs. Information on events preceding injuries and illnesses and more detailed demographic data on the mining work force are needed to analyze injury and illness data more precisely. Detailed information on exposure to specific hazards is necessary to evaluate the potential for an intervention to reduce risk of injury or illness.

By Robert F. Stewart

The oxidation of structural materials at high temperatures in gas-cooled systems can be greatly retarded by the addition of small amounts of hydrogen to the inert coolant. In experimental equipment for gasifying coal with heat transferred by helium, the oxidation of graphite and metals (molybdenum, tungsten, and certain stainless steels) by trace impurities in the coolant helium was virtually eliminated by adding 0.1 to 1.0 percent hydrogen. The reaction of hydrogen with praphite does not preclude its use to retard oxidation; at 2,400° F. only 0.2 pound of graphite per square foot per year is lost for each percent of hydrogen in the helium. The addition of hydrogen appeared to prevent the mass transfer of carbon often associated with oxidation of graphite, without causing noticeable embrittlement of stainless steels and molybdenum or other damaging effects. This method has been tested in precision gas-recycle systems and applied successfully for more than a year in a pilot-scale unit operating at 250 pounds per square inch gage and 2,400° F. It is now used routinely and can be applied to many gas-cooled systems operating at high temperatures.

Jan 1, 1962

By McHenry Mosier

The Bureau of Mines, United States Department of the Interior, has established a testing adit on the Government reservation at Mount Weather, Virginia, to facility to research on the fundamental tats of mining under actual metal-mining conditions. A number of sites in several Eastern States were investigated, out Mount Weather was selected because the rock seemed best suited for rock drilling and other mining tests and because the ground was already owned by the Federal Government, the site having been acquired in 1902 for use of the Weather Bureau. The testing edit has an advantage over en active metal mine for certain investigations because variable conditions affecting any particular research problem can be controlled and maintained in a fixed status, whereas in an operating mine this seldom is feasible. Operations were begin September 1935, with a crew of four laborers under a resident engineer. The laborers were recruited from, nearby farms, and. although they had no previous mining experience, they have developed into satisfactory miners.

Jan 1, 1939

By Shail J. Butani

In 1986 the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 years; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. stone mining workforce from March through September 1986. Similar reports have been published for the metallic, sand and gravel, and nonmetallic mining industries, as well as for the entire metal and nonmetal mining (includes metallic, stone, sand and gravel, and nonmetallic industries) sector and the coal mining sector.

Jan 1, 1988

By W. W. Adams

The first full year of the second World War for the United States presented a picture of the metal-and nonmetal-mining 4 industry which, without proper analysis and explanation, would convey a distorted view of achievements during 1942, especially because employment at gold and silver (lode and placer) mines-the largest group-declined to such an extent that the over-all totals for the country were reduced even though increases were made at mines producing copper, lead-zinc, iron, miscellaneous metals, and non-metals. A complete panorama of the metal-and nonmetal-mining industry, exclusive of coal mining, reveals a decrease in the number of men employed, the man-hours of employment, and the accident-frequency rates. Were the gold and silver (lode and placer) mines to be considered as a separate category; it would be seen that the number of men employed at all the other groups of mines increased appreciably over 1941. These other increases must be considered important, since these mines produced the vital war minerals that made valuable contributions to the military successes of the United States and its Allies during the year. A separate analysis of each of the various groups of mines may be found elsewhere in this bulletin. For the purpose of maintaining continuity in this series of bulletins, however, the discussion in this introduction will be confined to the entire metal-and nonmetal-mining industry (excluding coal mining, for which a separate bulletin, No. 462, has been published).

Jan 1, 1945

By Sterling J. Anderson

To define the technical competence and capabilities of a nonexplosive excavation concept, the Bureau of Mines conducted reduced-scale laboratory tests of a mechanical excavation tool called a rock splitter. Hydraulically actuated splitters, capable of generating both radial and axial loads on a predrilled hole, were designed and fabricated. Through paired variable testing and drifting simulation, reduced-scale splitter performance was evaluated in concrete. Testing proved that the rock splitter is capable of excavating within the highly confined drift set-ting and that it offers a distinct advantage over splitters that can generate radial loads only.

Jan 1, 1982

By Joseph B. Cummings

"INTRODUCTION The property was first examined by an engineer 3/ of the Bureau of lanes in December 1942 and was later investigated by the sane engineer in January and February 1943. Prominent outcrops and underground exposures of high-grade iron ore, together with mention of sizable intersections of hematite in logs of four widely scattered churn—drill holes, indicated the possible occurrence of a substantial tonnage of iron ore at this old copper producer.From March to May 1943, detailed topographic and geologic mapping of the property was done by the Federal Bureau of Mines, the Federal Geological Survey, and the Arizona Bureau of Mines.Funds were allotted for exploration of the property by churn and diamond drilling. This work was started in December 1943 and completed in June 1944.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Nines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to 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 Drench, Lowell B. Moon, Chief, conducts preliminary exmination, performs the actual exploratory work, and prepares the final report, The Metallurgical Branch, P. G. Knickerbocker, Chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision Dr. R. S. Dean, Assistant Director."

Dec 1, 1946

By William H. Pomroy

The Bureau of Mines, through a 4-year program of combined in-house and contract research, has developed the necessary hardware and software technology to provide rugged, reliable automatic fire protection for surface mining mobile equipment. One element of this program was a continuing effort to help foster rapid mining industry acceptance of the technology by keeping end user costs reasonable. This report is an analysis of the economic impact of surface mining mobile equipment fires and the cost benefit of utilizing automatic fire protection systems to abate these losses.

Jan 1, 1982

By Wils L. Cooley

The report covers tests and criteria for the establishment of safe grounding systems for coal mines. The work deals primarily with under-ground coal mines, but much is applicable to surface mines as well. Included is an extensive guide to grounding and bonding procedures for mine surface substations. Xit-Rods are evaluated and shown to deviate from manufacturer's claims. An analysis shows that very long cables are difficult to monitor using audio frequency ground-check techniques. A method is developed to detect failing cable splices without removing the cable from service. Simulation and measurement are compared for a technique to detect bad rail bonds, and an assessment is made of grounding techniques for dc face equipment.

Jan 1, 1979

By J. R. Thoenen

[Before 1914 Germany held a virtual monopoly on the world supply of potash for fertilizer purposes. During the World War, potash shipments to the United States ceased, and recourse was had to domestic supplies. High war-tine prisms stimulated interest in various sources, and domestic production increased rapidly. At the close of the war, resumption of shipments from Germany mad other sources reduced prices to below pre-war levels, and, as a result, most of the domestic procedures ceased operations. This experience demonstrated that a domestic source of potash was necessary but that it must be of such a nature that it could compete in price with foreign sources. As a direct result the potash content of thick]

Jan 1, 1941