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By Robert G. Lundquist

This report summarizes all relevant findings and conclusions regarding capabillty of high-energy projectile impact to operate effectively in an open pit mining environment and to successfully handle secondary breakage and bench scaling problems. A silenced, aimable, mobile projectile launcher was designed and fabricated, utilizing a Government-furnished smooth-bore, 90 mm cannon. The silenced launcher was tested at the contractor's test site prior to shipment to ANAMAX Mining Company's Twin Buttes Mine near Tucson, Arizona. Demonstration tests were conducted at an inactive waste dump in the mine on 39 oversize boulders to determine the relationship between boulder size and projectile energy required for secondary breakage. The high energy projectile impact method (known by the acronym REAM -Rapid Excavation and Mining) was tested on an additional 23 boulders in the working mine and on 31 areas of potentially loose rock high on the pit walls. Most of the secondary breakage tests were successful and acceptable for open-pit mining purposes without producing large amounts of fly rock. Five of the 31 scaling tests were successful with one shot, but most of the remainder required two or more shots, and a few could not be dislodged because they were not as loose as they appeared to be, based on visual examination from a distance. Cost comparisons between the REAM method and conventional methods of secondary breakage and bench scaling are discussed. A film documentary, REAM--Mining Applications of High Energy Projectile Impact, has been produced by the contractor depicting the applications of the silenced cannon.

Jan 1, 1976

By L. A. Haas

The U.S. Department of the Interior, Bureau of Mines, is conducting laboratory-scale research to determine the leaching conditions required with sulfuric acid for extracting base metal from a matte with a copper-to-nicke1 ratio of 6 to 1. The matte (61.2 pct Cu, 9.7 pct Ni, 3.3 pct Fe, 21 pct S, and about 5 oz of precious metals per ton) was prepared from Duluth Complex (Minnesota) ore by smelting a bulk sulfide flotation concentrate. The matte was pre leached at atmospheric pressure to selectively extract 20 pct of the nickel, and the undissolved solids were referred to as the matte residue. Autoclave leaching of the matte residue extracted over 95 pct of the nickel, copper, and iron. The remaining leach residue in the autoclave contained over 100 oz of precious metals per ton. The leaching conditions required were matte grind of greater than 98 pct minus 325 mesh, pulp concentration of 50 g/1, total pressure of 100 psig with oxygen at 150° C or 400 psig with air at 180° C, 50 g/1 H2S04, 700 rpm agitator speed, and 6 hours of leaching time. The leaching time was decreased to 2 hours by increasing the agitator speed to 1,300 rpm. Sulfuric acid concentration greater than 50 g/1 did not appreciably enhance the base metal extraction, but with less acid, residues with higher iron concentrations were obtained. Supersaturation of the liquor was prevented at 150° C by using a 1ixiviant that contained 30 g/l Ni and 20 g/1 Cu.

Jan 1, 1979

By H. F. Yancey

Traditionally the Pacific Northwest has relied on hydroelectric power, which has been both abundant and cheap. However, comparatively few hydroelectric sites capable of providing low-cost power remain, therefore the need for supplemental thermal generation, perhaps within the next decade, is generally recognized. Based on the present cost and availability of competing fuels, coal seems to be the logical choice for projected thermal power plants. Power companies and public utilities have become interested in establishing reserves of coal for future use. One deposit explored in 1958-59 lies in southern Thurston and northern Lewis Counties, Wash., near Centralia. Drilling, totaling 22,700 feet, proved the existence of 70 million tons of strippable coal--an ample reserve for the projected power plant. The coal, like most others and particularly those of Washington and Oregon, when mined in full seam section by mechanical methods, would require cleaning to make it suitable for use. The amount and nature of the impurities in this coal dictated a thorough investigation of its cleaning characteristics to establish economic factors and to insure proper preparation-plant design. Therefore, arrangements were made through a cooperative agreement to conduct such work at the Seattle Coal Research Laboratory of the Bureau of Mines. This report describes that investigation. The results are of interest primarily in connection with the utilization of this particular deposit, but some of the information developed is applicable to other deposits of low-rank coals in the West, because the impurities in these coals differ greatly in behavior from those generally associated with the higher rank coals of the Appalachian field.

Jan 1, 1961

By J. K. Whyatt

U.S. Bureau of Mines researchers reviewed an in situ stress estimate developed from measurements of overcore strain taken at test sites on the 7300 and 7500 levels of the Star Mine near Mullan, ID. Although the field measurements of over coring strain were found to be useful, significant deficiencies were found in the stress estimation procedure. A new stress estimate was developed incorporating statistical methods and an improved understanding of stress concentration factors for interpreting overcore strains recorded by doorstopper' cells. Spatial variability of overcore strains and the implications for stress field variability were explored.

Jan 1, 2010

By R. W. Watson

In January 1980, the Bureau of Mines initiated an experimental program to examine the fire and explosion hazards of one-hour self-contained self rescuers (SSRs). This action was prompted by a growing concern on the part of government and industrial safety officials over the potential hazards of these devices when deployed on a large scale in underground coal mines. Prior evaluation of the safety of these devices had been at best sporadic and usually limited to experimental models. The recent availability of preproduction models of a l-hour SSR fabricated by the Mine Safety Appliance Company* and a production model manufactured by Dragerwerk Ag Lubeck of the Federal Republic of Germany allowed for a more comprehensive and meaningful evaluation of their safety in underground coal mines. This report summarizes the results of a 5-month study of the potential hazards of these two items. During the course of the work, periodic progress reports were presented to officials of the Mine Safety and Health Administration and various mining organizations including the American Mining Congress, Bituminous Coal Operators of America. National Independent Coal Operators Association, and the United Mine Workers of America. The free exchange of ideas that occurred during these meetings had a significant impact on the direction of this study and a serious attempt was made to address all of the issues that were raised at these meetings. The authors are extremely grateful to the individuals that participated in defining the specific problems that could arise as a result of deploying the self-contained self rescuers in an underground coal mine environment.

Jan 1, 1980

By L. T. Grose

The Bureau of Mines conducted a comprehensive study of the Kanab, Kolob, Kaiparowits, and Harmony coalfields of southwestern Utah to obtain additional information and to determine the potentials of these coalfields as sources of energy for steam-electric power-generating plants. Field examinations were made to ascertain the geologic structure and the stratigraphy of the coalfields, the accessibility of the coal-bearing strata, and the general nature of the coal-bearing strata and the terrain. Many mines, both active and abandoned, were examined, and key personnel in the coal industry in the area were consulted. Available analyses of southwestern Utah coals were compiled, and tentative conclusions regarding the rank and quality of the coals were drawn. Coals have been classified by rank according to the standards established by the American Society for Testing and Materials in 1964. The Parr formula for moist, mineral-matter-free British thermal units has been used to calculate the rank of each sample, except as otherwise noted. Water resources related to the areas of the coal reserves also were investigated. Existing literature and maps pertaining to the geology of the areas were reviewed. Production potentials of the coalfields and economic conditions affecting the possible utilization of the coal reserves as sources of energy for steam-powered electricity-generating plants were investigated and analyzed. The data obtained and the conclusions reached as a result of this study are included in this document. The total reserves of subbituminous A and high-volatile bituminous C coals in the fields of southwestern Utah are estimated to be at least 8 billion short tons at depths generally less than 2,000 feet. It appears likely that this estimate will be increased as additional data are made available through exploration and other investigations. Sufficient coal is available in four southwestern Utah counties to supply three or four large steam-electric plants. If the States involved grant water rights to companies planning to build steam-electric plants, the cost of producing power with coal might be attractive and might justify the construction of one or more of these plants.

Jan 1, 1967

By G. M. Kintz

The data in this circular were taken from publications of the United States Bureau of Mines and published annual reports of the Wyoming State Inspector of Coal Mines. The tables included are complete only' with regard to major disasters; the Bureau of Mines considers a major disaster one in which 5 or more men are killed. However, minor disasters and gas ignitions recorded in these publications are included. It is known that a number of gas ignitions have occurred of which no record is available. This is one of a series of papers by the Bureau of Mines giving by States available data regarding coal-mine explosions. This information is published in condensed form in the belief that it may be of vale to mine operators in preventing future coal-mine explosions.

Jan 1, 1934

By Louis C. Brichta

The rapid; depletion of' known high-grade ore deposits in the Tri -State lead-zinc district and the recognized need for the development of additional reserves led the Bureau of Mines to make preliminary examination of sites possibly adaptable to low-cost open-pit mining methods. Abandoned mines whose ore deposits were known to have occurred at shallow depths naturally presented favorable test points for the development of possible open-pit orebodies. The Lone Elm mine was in this category.

Jan 1, 1949

By James C. Duchon

The use of extended workdays (regular shift lengths of 10 or 12 h (hour), while still maintaining a 4O-h workweek) in mining operations is attracting growing interest in the United States. There is very little doubt that extended workdays is a very popular alternative among the work force because of the significant increase in days off, including weekends, especially when compared with traditional rotation schedules of working seven straight shifts or having only one weekend off every 4 to 6 weeks. However, there are some serious concerns by management, workers, unions, and various governmental policymakers that working 10-or 12-h days may create an added risk of accidents and health problems. The U.S. Bureau of Mines reviewed the literature studies related to the safety and performance issues of extended workdays. This report presents a summary of those findings. The studies examined in this review are divided into three sections: (1) laboratory, (2) field, and (3) accident and injury analysis. In general, results are inconclusive. Studies have shown both positive and negative effects. It is concluded, therefore, that in industries such as mining where accidents are a serious concern, special measures and evaluation in the use of extended workdays be considered.

Jan 1, 1994

By The Staff, Explosives Research Center

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1962, to June 30, 1963, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1963; in general, the research reported in these publications antedates the report period.

Jun 24, 1964

By Frank C. Andreuzzi

The Division of Environmental Activities, U.S. Bureau of Mines, conducted a solid waste demonstration project on a burning coal refuse bank. The primary objective of this project was to develop and evaluate an efficient method of extinguishing burning coal refuse and moving it. A series of tests were performed using water monitors and related apparatus to quench the burning material and, at the same time, using earth-moving equipment to transport, spread, and compact the extinguished material. The method found to be most effective consisted of water-quenching the surface material to a workable depth, ripping, and removing the quenched material with a bulldozer and tractor-scraper. The total cost was estimated to be $0.44 per cubic yard.

Jan 1, 1970

By Larry A. Haas

The chemistry of current or potential SO2 removal processes can be placed into four categories: (1) reduction, (2) Liquefaction, (3) direct dissolution, and (4) oxidation. Methods that involve reducing SO2 to elemental sulfur appear promising since this product can be easily handled, shipped, and stock- piled. Unfortunately, SO2 cannot always be reduced directly when other oxidizing agents are present. Thermodynamic data indicate that some oxidizing reagents will also consume reductant at the reduction temperature. A two- stage process can be applied to waste gases that contain excessive quantities of oxygen, nitrogen oxides, and water vapor. The best sorbent for the first stage appears to be a nonalkali or nonalkaline earth medium since this medium more readily releases the SO2 for reduction in the second stage.

Jan 1, 1973

By R. D. Leitch

"INTRODUCTION The general program of the investigation of coal mine drainage which the Bureau of Mines is making includes, among its many phases and objectives, a study of the fate of the acid, content of drainage after it enters natural streams, and the effect of seasonal variations on the degree of contamination of streams. Opportunity for studying these under comparatively normal conditions and variations can readily be found, but there is only a chance opportunity for studying than under extreme conditions. The unusual drought that prevailed during the summer of 1930, however, created a condition of low water favorable to a study of one of the extremes.This report gives the results of an investigation of Bennett Branch of Sinnemahoning Creek, Pa., made under this condition.ACKNOWLEDGMENTSThis work was conducted under the direction, and with the advice, of Dr. R. R. Sayers, chief, Health and. Safety Branch, and of W. p. Yant, supervising engineer, Pittsburgh Experiment Station.DESCRIPTION OF BENNETT BRANCHBennett Branch, as shown in Figure 1, is a tributary to Sinnemahoning Creek. Its source is in Huston Township, northwestern Clearfield. County, from which it flows in a general northeasterly direction through Elk County, thenceeasterly in Cameron County to Sinnoning Creek at Driftwood. The total length is about 37 miles. There are nine towns along the stream that have an average population of about 350. There is no industrial pollution other that from coal mines and very little. domestic, pollution."

Jul 1, 1931

By Lindsay D. Norman

Eleven major pyrometallurgical processes and operations suggested for recovering manganese from domestic resources are described. These include seven pyrometallurgical processes that usually yield a ferroalloy or a product from which ferromanganese can be produced in one operation. The remaining four involve pyrometallurgical operations whose products require either an additional two-stage process to produce ferromanganese or chemical processing to recover a high-quality manganese oxide product.

Jan 1, 1962

By R. R. Lowery

The Bureau of Mines developed hypereutectic aluminum-silicon alloys which 11.7.d better mechanical properties than the unmodified hypereutectic alloy. A commercial aluminum-20 weight-percent silicon LIr alloy was selected as a ary base for improvement. The primary silicon. grains were reduced from ASTM 4-5 to ASTM 8.5 by the use of phosphorus and phosphorus compounds. The remaining eutectic matrix was refined by sodium metal additions of 0.2 weight-percent. Solid solution strengthening of the alpha aluminum was obtained by adding 2 percent copper and 0.5 percent magnesium. Also, 1 percent nickel was added to harden the alloy. Optimum thermal treatment consisted of a solution treatment for 10 hour:, at 480° C with hot water quench, followed by aging for 6 hours at 175° C. The final alloy exhibited a Rockwell B hardness of 75 ±2 in the heat-treated condition. The ultimate tensile strength was 39,5O0 psi with no recordable elongation. The coefficient of linear thermal expansion was 20.4 x 10-6 per °C in the temperature range 20° to 300° C. No wear resistance data were collected.

Jan 1, 1966

By Franklin H. Persse

Domestic bismuth supply was projected from production figures for the ores in which it occurs--copper, lead, zinc, and tungsten. Published and unpublished data concerning host ores were examined to determine bismuth reserves and resources, and mine production. Potential recoverable bismuth occurring with reserves and resources of copper, lead, and zinc was estimated to be 36.3 million pounds. A bismuth availability diagram was developed from quantity estimates and ratios of production cost to value for these host ores. Additional recoverable bismuth occurring with domestic tungsten reserves was estimated to be 1.5 million pounds. Domestic byproduct production of bismuth will approximate 1.3 million pounds annually by 1980. This quantity will provide about 37 percent of the 3.5-million-pound estimated requirement for that year. Known world supply of bismuth appears to be sufficient for world demand to the end of this century. The study indicates that bismuth reserves and potential resources in the rest of the world have not been adequately reported.

Jan 1, 1970

By PALMER LARSEN

INDEX TO GEOPHYSICAL ABSTRACTS

May 1, 1931

By Thoms L. Chapman

The San Manuel is a deposit of low-grade disseminated copper ore. It was brought to the attention of the government in October 1942 through an application to the Reconstruction Finance Corporation for a development loan, supported by a report by Henry W. Nichols. Nichols’ sampling of two outcrops containing copper silicate and his geologic map indicated that a minable body of copper ore might be developed. The Federal Geological Survey was requested to examine the property. The Survey mapped the geology in March 1943 and cut a few check samples, which substantially confirmed Nichols’ sampling of the outcrops and a few shallow workings. The geologists of the Survey recommended some test drilling by the Bureau of Mines. The property was examined by the author and W. D. Hughes, associate engineer of the Bureau of Mines on March 22 and 26, 1943, and a preliminary drilling campaign was recommended. Five shallow churn-drill holes totaling 1,480 feet were put down under the supervision of Chas. A. Kumke, one of the Bureau’s engineers, from November 23, 1943 to January 15, 1944. This work indicated that the deposit extended deeper than the 350-foot depth attained in the deepest hole and might have very considerable areal extent. Additional funds were allotted, and the drilling contract was extended twice to a final maximum of 17,000 feet with 2,000 foot maximum depth of hole. Drilling was continued by the Bureau of Mines until February 2, 1945, when 15,844 feet of hole had been drilled. The Magma Copper Co. took options on this and adjoining property in September 1944 and commenced drilling with two machines. It also engaged the two contract drills used by the Bureau after it stopped drilling. It exercised its options in August 1945 and organized the San Manuel Copper Corp. to operate the property. That company is continuing to explore the ore body with six churn drills. Thomas Lyon took options early in 1945 on holdings adjoining the San Manuel property on the east and is operating two churn drills. Exploration up to the completion of the last holes started by the Bureau of Mines indicated a block of ore 5,100 feet long, 400 to 800 feet wide, and 500 to 900 feet thick, and averaging about 0.8 percent copper. Subsequent drilling showed that the ore body extends considerably beyond this block. The axis of the ore body strikes about N. 61º E. Copper minerals are disseminated in hydrothermally altered quartz monzonite and monzonite porphyry. Ore outcrops in two small areas over the northeast part of the block. Elsewhere the copper-bearing rocks are capped by Gila conglomerate, which thickens toward the west and south. Drilling showed that the ore is in a thick, tabular body with a steep dip to the south. The ore body lies near the surface in the northeastern part of the block. The south side of the block is much farther below the surface than the north side. There the upper part of the copper-bearing rocks is lightly mineralized, so that the hanging wall of minable ore lies deeper than the base of the conglomerate cap, which thickens southward.

Aug 1, 1947

By William I. Nissen, Richard Havens

Continuous flotation studies were made at a 50 - lb - per - hr feed rate to confirm the effectiveness of a batch - scale procedure for concentrating phenacite and bertrandite minerals from Mount Wheeler ores that contained , in percent , 0.47 , 0.78 , and 4.7 BeO . The procedure for selective froth flotation of the beryllium minerals from a gangue composed chiefly of calcite , fluorite , and mica comprised closely controlled preconditioning with sodium fluoride and sodium hexametaphosphate in a series of small mechanically agitated tanks and use of a mixture of oleic acid with kerosine , fuel oil , or turpentine as a collector . It was difficult to adapt the laboratory flotation procedure to continuous operation . The principal problem of achieving adequate conditioning to depress calcite and fluorite ultimately was resolved by conditioning in series . Thereafter , three ore samples of different grades treated on a continuous basis yielded concentrates containing from 12 to 25 percent Beo from these relatively complex and difficult ores . Recoveries , on a BeO basis , ranged from 75 to 88 percent . Losses , which primarily were due to incomplete liberation , probably could be lowered in a commercial operation .

Jan 1, 1964

By R. H. Lien

The Bureau of Mines investigated a roast-leach process for recovering a marketable lithium product from a montmorillonite-type clay deposit located on the Nevada-Oregon border. The clay sample treated in the investigation contained 0.6 wt pct Li. The lithium recovery process consisted of several unit operations. The lithium silicate compounds in the clay were converted to Li2SO4 by roasting a pelletized mixture of clay, limestone, and gypsum at 900° C in a direct-gas-fired rotary roaster. Water--leaching the calcine at 40 pct solids extracted the Li2SO4. Lithium recovery from the leach solution involved concentrating the solution by evaporation, adding Na2CO3 to the concentrated solution to precipitate Li2CO3 , and filtering the slurry to obtain the product. The product filtrate was recycled to the evaporator following a crystallization step. About 80 pct of the lithium in the clay was recovered as 99-pct-pure Li2CO3. Process operating costs were estimated at $2.12/lb Li2CO3 produced; the current Li2CO3 selling price is $1.48/lb. Raw materials. accounted for 30 pct of the total operating cost.

Jan 1, 1985