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By G. M. Martinez

The Bureau of Mines has investigated methods for the recovery of byproduct heavy minerals from sand and gravel operations in Oregon and Washington. These heavy minerals are not currently recovered except for gold in a few areas. The recovery of byproduct heavy minerals would provide a domestic source of minerals presently imported, and a more efficient use of domestic resources would be accomplished. Samples from more than 40 locations were treated by gravity separation to yield heavy mineral concentrates (black sands). Magnetite, ilmenite, zircon, rutile, chromite, platinum-group minerals, radioactive minerals and gold were identified in the concentrates. Individual zircon, ilmenite, chromite; magnetite, and gold products were recovered from selected concentrates by low-and high-intensity magnetic, high-tension, and heavy-medium separation techniques. The recovery for the individual mineral products ranged from 67 to 95 pct.

Jan 1, 1981

PRODUCTION of cesium, cesium salts, and rubidium salts in the United States declined somewhat from 1961 levels; rubidium production was virtually unchanged. Imports of pollucite declined because consumption was supplied partially out of inventory. Domestic Production.-About 50 tons of pollucite was reported mined at the Tin Mountain mine in the Black Hills of South Dakota. The Dow Chemical Co., Midland, Mich., MSA Research Corp., Callery, Pa., and Penn Rare Metals, Inc., Revere, Pa., produced a total of 159 pounds of cesium. Rubidium production remained essentially the same as in 1961. Shipments of the two metals by these companies and by American Potash & Chemical Corp., Trona, Calif., totaled 279 pounds. Production of cesium and rubidium salts by American Potash & Chemical Corp., Penn Rare Metals, Inc., and Rocky Mountain Research, Inc., Denver, Colo., declined substantially during 1962.

Jan 1, 1963

By Joseph Daniels

[Adequate supplies of suitable coal and coke are prime requisites in many industries, particularly those dealing with the utilization of mineral resources, recently interest has been focused on the possibilities of using electricity produced at Bonneville and Grand Coulee, Wash., in many electrochemical and electrometallurgical processes, in which core or some form of carbon is necessary in addition, discussion has been revived on the possibility of making iron and steel by the conventional methods employed in blast and open-hearth furnaces. The subject also is important at this time because of its relationship to industrial preparedness for national defense. A supply of coke from local sources on the Pacific coast is necessary in any program of production for strategic sufficiency of certain materials. An anal trio involving tae establishment of such industries should include detailed data on available supplies of coal, the quality and properties of the coke produced, and the technologic and economic factors involved in manufacture of echo and disposal of byproducts.]

Jan 1, 1941

By Victor Himel

This report documents a systematic approach towards implementing an improved ensemble for the mine rescue team system that will protect against the hazards of mine rescue and recovery and will also afford improved performance through increased comfort and maneuverability, lighter burdens, and improved human engineering designs. In the first part (Task 1) the mine rescue team's protective needs were defined along with the test methods required to evaluate whether a particular piece of gear met these needs. Task 2 assessed existing gear against performance criteria and standards developed in Task 1. Task 3 consisted of the conceptual design and construction phases of the MRPE program. Special consideration was given to advanced concepts, materials, and equipment.

Jan 1, 1982

By Robert K. Guthrie, James W. Amyx, D. B. Taliaferro

"INTRODUCTION Secondary recovery of oil by water-flooding is practiced more extensively in North Texas than in any other section of the State, and the progress and experience of the operations in that area are of continuing interest to all branches of the oil industry. The first Bureau of Mines report on water flooding in North Texas 7/ chronicled the activities from December 7, 193f', when the Railroad Commission of Texas granted The Texas Co. the first permit to inject water into an oil-bearing sand, through 1944. This second report has been prepared as a supplement to Report of Investigations 3906 to show the progress and expansion of water-flooding. The format of this report is almost identical with what of report of Investigations 3906, except for a few miner changes. For the sake of brevity, certain basic information contained on the first report has not been repealed, and the reader is urged to consider the two reports as corporation writings.The North Texas area, as encompassed by the two reports, corresponds Railroad Commission of Texas Districts 7P and 9. Oil-development operations in the two districts, since oil was discovered in 1904, have resulted in the recovery of approximately 1,400,000,000 barrels of oil from a proved area that has been estimated to exceed 413,000 acres. During October barrels of oil was produces by primary and secondary-recovery methods from 1,746 flowing wells and 25,211 pumping wells, a daily average 6.6 barrels per well. Of this total volume of oil recovered in October 1947, 47,965 barrels (0.87 percent) was recovered from leases on which water-flooding operations were in progresses."

Feb 1, 1948

By Oliver Bowles

This paper is the third of a series of reports on asbestos prepared by the Bureau of Mines. The reports already issued contain general information, including descriptions of deposits throughout the world.3/ The present paper deals chiefly with milling and marketing. Many grades of asbestos are marketed, and an important phase of milling is the grading of fiber; these subjects therefore are related so intimately that contiguity in their treatment is fully justified. Although the Bureau of Mines is interested primarily in the mining and preparation of raw materials, the fabrication of asbestos products has attained such importance in the United States that brief reference to processes of manufacture is included. CLASSIFICATION OF FIBER Canadian asbestos fibers are divided into three main groups - crudes, mill fibers, and shorts. The term "crude" is applied to fiber of spinning grade measuring three eighths inch or longer, that is. hand-cobbed and not passed through a mill. Mill fibers are obtained by crushing and beating the fiber-bearing" rock, until the, asbestos is freed and, then removing the fiber from the rock by screening or air separation. Shorts are the lowest grades of mill products.

Jan 1, 1935

By Robert W. Metcalf

Corundum, natural alumina, or aluminum oxide (A1203) is the hardest mineral known except diamond. Theoretical composition is Al 52.9 percent and 0 17.1 percent, but it always contains small quantities of impurities, chiefly silica, iron, and lime. The melting point of corundum is above 1950° C., and it is insoluble in the strongest acids. Its hardness (9 on the Mohs scale) varies slightly according to purity, and its specific Gravity ranges from 3.95 to 4.10, 4 being a fair average. The index of refraction is 1.760 to 1.768 and its streak is white. Luster is adamantine to Vitreous, come specimens pearly, and color varies widely from white, gray, pink, and blue to black, brown, or bronze. Gem varieties are transparent or translucent, and of more brilliant coloring - red, blue, yellow, purple, or green. Corundum occurs in opaque massive or block structure with parting planes little developed or only roughly delineated and in granular form as minute crystals or small, irregular grains interspersed throughout the contact zones of schists and gneisses.

Jan 1, 1944

By Jack O. Jones

The Furnish mine, Caharrus County, W. C., was operated intermittently until 1905 as a gold mine. Scheelite was discovered by A. L. Mash in the mine dumps of the Furniss and Phoenix mines, and he later informed the Bureau of Mines of his discovery. The Bureau of Mines, in two projects at the deposit in 1948 and in drilled 12 holes totaling 1,706.6 feet, examined and sampled the underground workings, excavated by bulldozer and hand, 3,155 linear feet of trenches and collected numerous samples for assay. The best scheelite shown; was found in the underground exposure of the Furniss mine.

Jan 1, 1950

By R. H. Sprute

This report describes Bureau of Mines laboratory test results in electrokinetic dewatering and consolidation of metal-mine tailings. Tailings were placed in 0.3-cubic-foot Plexiglass models, and dc potential was applied until dewatering ceased. Time-oriented measurements of water removal, changes in resistivity, and power consumption were recorded during the dewatering process. Dewatered material was tested for moisture content and density. Equipment and procedures were developed to optimize the method for unclassified mill tailings from a particular mine in the Coeur d'Alene, Idaho, district. Results indicate the method to be highly effective in dewatering and consolidating this material.

Jan 1, 1974

By G. Ahnell

Throughout portions of four (4) heavily mined Appalachian states subdivided by the Mine Safety and Health Administration (MSHA) as: District 3 -Northern West Virginia and Maryland; District'" -Southern West Virginia; District 5 -Virginia; and District 6 -Eastern Kentucky, active coal mine waste embankments associated with mechanical and/or chemical coal processing facilities of various levels of coal preparation were inventoried. For each site plant specifications, disposal techniques, embankments' characteristics, and coal source data were accumulated. Mapping at 1: 24, 000 and 1: 250,000 scale and Disposal Site Characterization forms were developed to present the findings. Associated abandoned surface and underground openings near each site were also indicated as well as locational data for each site and the areas environmental conditions - temperature, precipitation and vegetation types. A state-of-the-art review of coal preparation, waste disposal, and alternative uses of coal waste is also included.

Jan 1, 1982

By Gordon R. Sima, John L. Bennett, Roger L. King

Electric shocks are a serious problem in the mining environment. Because of extremely wide ranging use of electrically powered equipment in the mining industry, the hazard to personnel due to electrical shock and related injuries are not restricted to any single area but cover the entire spectrum of mining activity. Electrical accidents, resulting in personal injury, due to im- proper or complete lack of grounding of electrically operated mining machines, form a significant percentage of the overall electrical accident picture. The object of this paper is to describe methods of detection of unsafe electrical conditions with respect to the grounding of electrically operated mining equipment. It also includes a discussion of prototype instruments which effectively monitor the condition of the grounding safety devices currently in use on mining equipment and warn of dangerous conditions as soon as they appear. The paper is based on work accomplished under USBM Contract Number 50357115. The contract was initiated under the Pittsburgh Mining and Safety Research Center Program. It was administered under the technical direction of PM and SRC with Mr. Roger L. King as the Technical Project Officer. Mr. Daniel B. Dawkins was the Contract Administrator for the Bureau of Mines.

By K. J. Liles

Research was undertaken by the Bureau of Mines to determine the technical feasibility of producing lightweight aggregate from the waste glass fraction of municipal incinerator residues. Tests were conducted to determine the amount and optimum size of glass, the amount of sodium silicate, and the method used to form the material to be expanded. The most suitable mixture, 78 percent glass, 20 percent clay, and 2 percent sodium silicate, was pelletized and then expanded by exposure to a temperature of 1,550° F for 15 minutes The resulting lightweight material had a bulk density of 38 lb/cu ft and exhibited excellent pore structure. Concrete test cylinders made from the light weight aggregate had a unit weight of 104 lb/cu ft and a compressive strength of 2,550 lb/sq in after a 28-day steam cure.

Jan 1, 1976

By Richard J. Mainiero

The Bureau of Mines conducted research to evaluate the optimum design for a rock-breaking explosive charge that could be fired unconfined in a gassy or dusty coal mine without the danger of igniting the flammable atmosphere. Charges of various shapes, with and without cavities, were tested in a gallery using 3-by 3-by l-ft concrete blocks as simulated boulders. For these tests the optimum charge, in terms of cost, weight, and convenience in handling, consisted of a flat l-1/2-lb charge of permissible explosive seven-eighths of an inch thick and 7 in in diameter encased in a l/2-in thick layer of fine salt (NaCI). This work demonstrated that it should be possible to produce an inexpensive explosive rock-breaker charge that would be safe to use in underground coal mines.

Jan 1, 1982

By V. B. Dale

San Manuel has been a modern prodigy from its inception to its present status as a block-caving operation producing 33,000 tons per day. The deposit was discovered, prospected, and developed with modern techniques, and nearly all planning was done from results of an extensive drilling program through an average overburden of 670 feet. The Federal Government had a prominent part in the discovery and primary development of San Manuel. The first 17 holes were drilled by the Bureau of Mines, and discovery of the large, low-grade, disseminated copper deposit is credited to the Bureau. A loan fund of 94 million was granted through the Reconstruction Finance Corporation to the San Manuel Copper Corp. for development of the deposit and erection of concentrating and smelting facilities. Then, while the mine was still being developed, the Defense Materials Procurement Agency contracted to buy a large amount of copper at a pegged price.

Jan 1, 1962

These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar in September 1981 for the purpose of disseminating recent advances in mining technology in the area of premining research. The introduction and descriptive papers discuss techniques and instrumentation used in premining research for metal and nonmetal mining and shaft design and borehole control for premine planning.

Jan 1, 1982

By D. Randolph Berry

The United States Bureau of Mines (USBM) awarded a contract to Foster-Miller, Inc. to develop guidelines for the storage and use of Self-Contained Self-Rescuers (SCSRs) in underground non-coal mines. An SCSR is a device capable of supplying, in an emergency, one hour of self-contained oxygen (no breathing of mine air). The information and recommendations in this report were developed primarily from three sources: discussions with mine representatives (including management, labor, and government), site visits in underground mines I and a detailed analysis of every reported non-coal accident which produced d hazardous atmosphere during the 5-year period 1976-1980 -plus ten other major incidents from prior years. Volume IV has three major sections: Recommendations and Discussion (Section 2), Analysis of Mine Accidents (Appendix A), and a Summary of Discussions with Mine Representatives (Appendix B).

Jan 1, 1983

By Donald W. Baggs

This report describes economic mining feasibility studies conducted by the Bureau of Mines to estimate mining costs in the Porcupine mining area of the Juneau Mining District, southeastern Alaska. Investigations were conducted on the economics of three mineral deposit types: 1) massive sulfide deposits containing zinc, copper, and silver, 2) vein gold, and 3)disseminated gold. Cost estimates were developed using the Bureau of mines Cost Estimating S,-stem. Discounted cash flow rates of return were calculated using the Bureau of Mines MINSIM (mining simulation) computer program. Three sets of metal prices were used in the study based on recent historical price information. Underground longhole stope mining of a massive sulfide deposit containing 25 pct zinc. 1 pct copper, and 63.6 g/mt silver was found to be economic at high metal prices at a quantity of 13,200,000 mt ore. Cut-and-fill mining of a 26,400,000 mt massive sulfide deposit was found to be economic at medium metal prices. Open pit mining of a similar deposit was found to he economic at medium metal prices and 26,400,000 mt ore, or at high metal prices and 6,600,000 mt ore. Underground mining of a vein gold deposit was found to be economic at a grade of 17.1 g/mt medium metal prices and 1,320,000 mt ore. Open pit mining of a disseminated gold deposit was found to be economic at a grade of 1.71 g/mt medium metal prices and a quantity of 39,600,000 mt ore.

Jan 1, 1986

By E. D. Calvert

Molybdenum has been successfully cast into static and rotating molds in conventional equipment used for casting titanium and zirconium. Melting was accomplished by using an arc potential of 36 to 40 volts with a current of 10,000 amperes. Pouring efficiency, after a skull had been formed in the crucible, averaged 70 percent. Techniques are described by which four successful castings were made. Tensile properties on specimens cut from one centrifugally cast tube averaged: Tensile strength, 39,800 p.s.i.; yield strength (0.1 pct. offset), 35,300 p.s.i.; elongation, nil; reduction in area, nil; impact strength, 2 ft.-lb.; hardness DPH (diamond pyramid hardness) 180. Mold reaction was not evident in shapes cast in machined graphite. This was not true, however, for rammed graphitic-base molds.

Jan 1, 1960

This publication summarizes the in-house and contract research and development projects programed for fiscal year 1981 by the Bureau of Mines under its Minerals Environmental Technology activity. The document provides a mechanism for interested parties, including potential contractors, to gain insight into ongoing and projected work of the Bureau?s environmental research efforts. Research to identify and correct environmental problems associated with mining and metallurgical operations has long been an integral part of the Bureau's mission. The environmental research and demonstration activities of the Bureau were consolidate in 1979 with the formation of the Minerals Environmental Technology program, which is directed toward the elimination or reduction of environmental problems associated with the extraction and processing of minerals. Among the efforts underway are development of data and technology for assessing the potential environmental impact of minerals development, for monitoring minerals extraction operations, and for establishing viable reclamation requirements on abandoned mine lands; development and demonstration of technology 'or control of environmental disturbances during minerals extraction operations; development and demonstration of land reclamation and mine closure techniques to restore or enhance the productive use of mined lands; development of engineering techniques that incorporate state-of-the-art mining environmental technology in the design and planning of minerals extraction operations; development and demonstration of new mining systems that greatly reduce or eliminate the adverse environmental impacts of minerals extraction; and providing the technologic base for Federal, State, and local establishment of environmental standards for mining operations. Included in the minerals-processing-related work are projects to clean mineral-processing waters: demonstrate a Bureau process for scrubbing SO from powerplant stack :;as; recover dissolved minerals from process streams; stabilize discarded dusts, slags, and tailings: remove hazardous contaminates from byproduct wastes; reduce generation of waste solids; and improve metallurgical process engineering to eliminate pollution. Approximately $21 million was appropriated for this work in fiscal year 1981.

Jan 1, 1981

By R. Karl Zipf, Suresh Bhatt

Highwall mining is an important coal mining method. It appears that upwards of 60 highwall miners are presently in operation, and they may account for approximately 4% of total U.S. coal production. A review of the Mines Safety and Health Administration (MSHA) data over the 20 year period from 1983 to 2002 identified 9 fatalities attributable to auger and highwall mining of which inadequate ground control accounted for 1/3. In the past 5 years, 1 fatality occurred in highwall mining. Estimates of the manpower requirements in highwall mining suggest that its fatality rate is essentially the same as for surface coal mining, thus highwall mining appears to be a very safe modern mining method. Highwall stability is the major ground control related safety concern, and operators are required to develop and follow an appropriate highwall mining ground control plan. The plans usually specify the following geotechnical parameters: hole width, maximum hole depth, maximum overburden depth, seam thickness, web pillar width, barrier pillar width and number of holes between barriers. Calculated web pillar stability factor exceeded 1.3 for most designs evaluated. This study examined records from 5,289 highwall miner holes with a total completed footage of about 2,560,000 feet to understand the reasons for early pull out. Average lost footage is typically about 20% of planned footage. Only 35% of the holes reached planned depth, and 20% were short due to rockfalls. Water and adverse geology accounted for 15% of the losses. Mechanical/electrical problems, guidance, and slope stability problems accounted for the remaining 30%. Web pillar stability factor for these holes also exceeded 1.3 in 95% of cases. Best practices to avoid trapped miners include: avoid mining in stream valleys, avoid mining near outside corners, careful alignment of each hole and the use of an onboard guidance system. Several issues in highwall mining ground control require further investigation including highwall mining through old auger workings, highwall mining near old underground mines, multiple-seam and multiple lift highwall mining and finally the size and frequency of barrier pillars.