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By G. A. Smyres

A GaC12--B2 l-eachtng procedure and meEal-recovery method for treating an arsenical Cu-Co sulfide concentrate was developed by the Bureau of Mines as an alternative to smelting, which is no longer considered an environmentally acceptable method for treating arsenic-containing ores. The procedure involved leaching in a CaC12 solution with CaC03 for 96 h at 26 pct solids (concentrate and CaC03), 1150 C, and a pressure of 50 psig (345 kPa) with oxygen. More than 98 pct of the cobalt and 97 pct of the copper were extracted, and 99.98 pct of the arsenic and 99.9 pct of the iron remained in the leached residue. A filtration rate of 2.9 gal/(ft2.h) [118 L/(m2.h)] and a cake formation rate of 36 Ib/(ft2.h) [172 kg/(m2.h)] were obtained by filtering reacted pulp at 1000 C. More than 99 pct of the copper in the pregnant solution was extracted as CuCl2 by golvent extraction with a new copper extractant. Copper was stripped from the loaded organic with a sulfate-chloride solution, which was used as the anolyte for electrowinning of copper in a membrane cell. Copper plate produced was more than 99.99 pct pure and requi.red 0.81 (kW'h)/lb Cu [1.78 (kW·h)/kg Cu]. Cobalt sulfide was precipitated at pH 3 with Ca(HS)2.

Jan 1, 1986

By C. Daniel Kealy

Finite-element,, mathematical models that solve LaPlace's and Richard's equations numerically were used to locate the phreatic surface within tailings pond embankments and to define the subsurface flow of water from the pond. Both must be known to design structurally and environmentally safe tailings dams. The permeability distribution within and beneath the embankment, the fluid potential values upgradient and downgradient from the embankment, and the geometry and elevation of an approximately impermeable layer at some depth beneath the embankment were used as computer inputs in analyzing over a dozen finite-element models of tailings dams varying structurally from simple to complex. Results predicted with the finite-element model were confirmed with measurements in a laboratory model of a tailings pond and in the field. Of particular importance to the design of safe slopes, all data indicated that the phreatic surface within a tailings dam is concave upward, a configuration opposite that in most earth dams. The close correlation between predicted and experimental values confirmed the practicability of using the finite-element technique to design safe tailings dams.

Jan 1, 1971

By O. C. Blade

The oil fields of Arkansas, all situated in the southern part of the State, have played an important part in the development of petroleum production in the northern coastal plain region of the Mid-Continent area. From the first discovery of oil in southwest Ouachita County in 1920 to December 31, 1930, a total of 480,167,5604/ barrels of crude petroleum has been produced from' this region. Development of the Arkansas fields proceeded rapidly after 1920. The El Dorado field was discovered in Union County in 1921. Drilling in Ouachita County resulted in the discovery of the Smackover field in 1922 and subsequently in the development of the whole southern area. To November 31, 1939,459 / producing wells had been drilled in 25 fields, aggregating 53,7356 acres of proved territory in 6 counties. Peak annual production for the State was reached in 1925, when 80,823,7007/ barrels was produced, resulting largely from flush production from the Smakover field, which rose td an average of 444,9507 barrel daily during that year. During 1924, 1925, and 1926 Arkansas ranked fourth among the oil-producing

Jan 1, 1940

By O. C. Blade

The oil fields of Arkansas, all situated in the southern part of the State, have played an important part in the development of petroleum production in the northern coastal plain region of the Mid-Continent area. From the first discovery of oil in southwest Ouachita County in 1920 to December 31, 1930, a total of 480,167,5604/ barrels of crude petroleum has been produced from' this region. Development of the Arkansas fields proceeded rapidly after 1920. The El Dorado field was discovered in Union County in 1921. Drilling in Ouachita County resulted in the discovery of the Smackover field in 1922 and subsequently in the development of the whole southern area. To November 31, 1938, 6,4595/ producing wells had been drilled in 25 fields, aggregating 53,7356/ acres of proved territory in 6 counties. Peak annual production for the State was reached in 1925, when 80,823,7007/ barrels was produced, resulting largely from flush production from the Smackover field, which rose td an average of 444,9508/ barrel daily during that year. During 1924, 1925, and 1926 Arkansas ranked fourth9/ among the oil-producing

Jan 1, 1940

By K. K. Kelley, W. W. Weller

Heat capacity measurements of akermanite ( Ca,MgSiO ) , cordierite (Mg2A14 Sig018 ) , gehlenite ( Ca₂Al₂ SiO ) , and merwinite ( Ca ,MgSiO ) were conducted over the temperature range from 50 ° to 298.15 ° K. The entropies at 298.15 K ( expressed in cal / deg mole ) were evaluated as follows : Akermanite , 50.0 ± 0.5 ; cordierite , 97.3 ± 0.9 ; gehlenite , 47.4 ± 0.4 ; and merwinite , 60.5 ± 0.5 . All four compounds have positive entropies of formation from their constituent oxides at 298.15 ° K ; the values range from 4.6 cal /deg mole for akermanite to 10.1 cal / deg mole for cordierite .

Jan 1, 1963

By T. E. Gray

This report describes the preparation characteristics of the more significant coalbeds in Monongalia County, W. Va. It is one of a Bureau of Mines series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. Over 9.5 million tons of coal was produced in Monongalia County in 1957, of which more than 7 million tons was cleaned mechanically in 8 cleaning plants. On January I, 1954 the Bureau of Mines estimated that 1,576 million tons of recoverable coal remained in the county in beds 28 inches or more thick.

Jan 1, 1960

By J. H. Soulé

"The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County Wyo., and is favorably nituated with respect to rail and truck transportation and high-tension power facilities.Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small treed and shrubs common in the most rugged areas.The deposits lie upon land owned by Wyoming, now leased by a group of Wyoming and Colorado businessman constituting the Copper King Mining Co.Primary copper-gold mineralization seems largely confined to an equigranular, relatively fine grained gneiss that is part of a pre-Cambrian complex of metamorphic rocks ranging from schists to pegmatites. The copper minerals are oxidized to a depth of from 100 to 150 feet, with the occasional occurrence of secondary minerals at greater depths. The copper minerals chalcopyrite, malachite, chalcocite, bornite, cuprite(?), and some native copper were observed in Le deposit.In addition to the 4,030 feet of diamond-core drilling in 11 holes done on the deposit by private companies, the Bureau of Mines drilled 3 holes for a total of 2,630 feet. The sample results of this drilling plus available data from previous drilling and sampling are appended to this report."

Jun 1, 1955

[RESULTS OF THE PRIMARY CONVENTIONAL PERFORMANCE AND COST MODEL OF THE UNIT OPERATIONS OF UNDERGROUND PERCUSSIVE DRILLING AND BLASTING]

Jan 1, 1977

By Carl Belser

This paper, covering Chaffee, Fremont, Gunnison, Lake, Larimer, Park, and Summit Counties, Colo., is the second of a series reporting on the tungsten potential of the Colorado region. The assembled information was obtained by examination of some properties, personal contacts with owners, and access to unpublished reports by other engineers. The tungsten-bearing areas of the 7 counties cover approximately 400 square miles and are in 10 distinct areas, which vary in size (fig. 1) from 1 square mile up to 290 square miles. The tungsten mineral wolframite was discovered by a man named Hackay near Dale on the Florence & Cripple Creek Railroad in the early 1900's, and wolframite and hubnerite were noted at Climax and the adjacent areas in Lake and Summit Counties at an early date, but no records of shipment from any of the areas are available before World War II. It is not known when scheelite was first discovered, but it was recognized in the Stockton mine during World War I. In the counties listed 64 properties are known to contain tungsten; of these, 18 have had some commercial output, although only 3 of them produced in 1953. The total production through 1953 is estimated at 115,000 short-ton units of tungsten trioxide. In 1953 by far the major portion came from the Climax mine.

Jan 1, 1956

By James S. Grichar

Interest in mergers in the nonfuel mineral industry developed when 5 were listed among the 50 highest valued mergers in the United States in 1981. This report presents a Bureau of Mines study of trends in merger activity from 1960 to 1979 and explores motives for mergers in the nonfuel mining and mineral industry. The objective was to determine precedent for or a trend toward the 1981 acceleration in merger activity and to examine certain financial motives for non fuel mineral mergers. Data indicate that the relative value of non fuel mineral mergers has grown since 1972 although the number of mergers has remained proportionate to historical trends for all mergers. Since 1974, the assets acquired in "large," nonfuel mineral firm mergers, those of $10 million or more, have comprised at least 93 pct of assets acquired. More nonfuel mineral firm mergers involved mineral companies as the acquiring firm than vice versa but mining and minerals firms acquired were of higher value than nonmining firms. A major motivation for mergers involving large mineral firms was the acquisition of assets at less than replacement costs. Univariate statistical testing, a methodology chosen for its applicability to the data, confirms this hypothesis while rejecting other financial motives. The remainder of the work is devoted to a discussion of suggested areas for future study.

Jan 1, 1984

By J. D. Davis

The Bureau of Mines Coal Carbonization Laboratory has been interested for the past 20 years in the quality of coke in connection with the selection of coals for the manufacture of coke. The principal experimental. method of carbonization, whereby 100- to 200-pound charges are carbonized in sheet-steel cylindrical retorts with recovery and determination of the properties of coke, gas, and products, was developed in cooperation with the American Gas Association,4 5 and it is known as the BM-AGA method. Results of the investigations of 90 coals included in the BM-AGA Survey of the Carbonizing Prop¬erties of American Coals have been published; 6 and, in addition to these, about 200 coals have been carbonized over limited temperature ranges. Because coke from cylindrical retorts differs in shape from that made in rectangular ovens, the BM-AGA method has been criticized, although those who developed it have always believed that it served well as a means of measuring the relative strengths of cokes from different coals. It is recognized that no laboratory-method carbonization, even on a large twit, can yield results that exactly duplicate those obtained in commercial ovens and retorts. However, with the completion and satisfactory performance of an experimental vertical slot oven of 500-pound capacity at the University of Illinois Geological Survey Laboratory,' the opportunity to directly compare BM-AGA coke with coke made by two-sided heating became available and the necessary test apparatus was installed. The Bureau of Mines slot oven, which is similar to that designed by the University of Illinois Geological Survey, has been used to carbonize 11 coals (or blends) tested by the BM-AGA method. This report compares the results obtained by the two methods.

Jan 1, 1950

By T. M. Barczak

This U.S. Bureau of Mines report investigates shield mechanics and component stress development in a two-legged longwall shield for unsymmetric canopy and base contact configurations. Previous studies analyzed shield behavior for symmetric contact configurations. The goals of these efforts are to improve longwall support selection and design. This study provides vital information that will help develop improved procedures for performance testing of longwall supports and will benefit future research to improve support design through stress optimization and evaluation of failure mechanisms. Combinations of six canopy (three symmetric and three unsymmetric) and six base (four symmetric and two unsymmetric) contacts provided a total of 36 configurations for evaluation. Of these 36 configurations, 10 were eliminated because of fixture limitations or shield instability. Controlled vertical and horizontal displacements were applied by the Bureau's mine roof simulator to the remaining 26 configurations. Component responses were determined from pressure transducer and strain gage instrumentation in order to identify contact configurations and boundary displacements that produced maximum loading in each of the support components. This report describes these test results and provides conclusions relevant to critical contact configurations for performance testing of longwall supports.

Jan 1, 1990

By R. B. Porter

Bench-scale tests were performed by the Federal Bureau of Mines on lignite and subbituminous coal at pressures to 1,000 p.s.i.g. (pounds per square inch gage) in atmospheres of hydrogen or nitrogen to obtain information concerning the influence of pressure on carbonization of normally noncaking coals. The distribution of gaseous, liquid, and solid products as a function of processing pressure was determined. Except for special experiments, the carbonization was at 940° F. In a hydrogen atmosphere above 400 p.s.i.g., agglomeration of the solid residue (especially with lignite) became noticeable and increased directly with the processing pressure. Although in some instances the solid particles fused together, the mechanical strength of the agglomerate was always low. On the basis of visual inspection, the coals agglomerated in the following order of decreasing intensity: (1) Steam-dried lignite; (2) lignite; and (3) subbituminous coal. Addition of lignite tar in quantities to 25 percent by weight of charge did not increase agglomeration or change the carbonization characteristics of the coal.

Jan 1, 1961

By J. Douglas Causey

No mines are active in the Hunter Mountain Wilderness Study Area (WSA), and no mineral resources have been identified in the WSA. However, the Monarch Mine has low potential for silver, copper, tungsten, and gold resources in quartz veins; the Shirley Ann Group and Sal Group have moderate and low potential, respectively, for silver, lead, and copper resources in skarn; claims overlying the Eureka Quartzite have low potential for silica resources; and the Tourmaline N1-4 Prospect has low potential for tourmaline resources in quartz monzonite. Copper, lead, silver, tungsten, molybdenum, wollastonite and garnet occur in skarn zones between monzonitic and carbonate units. Silver, tungsten, and copper also occur in quartz veins within monzonite. Known metallic mineral deposits are small, erratic and discontinuous. The J. 0. Mine, adjacent to the northeast corner of the WSA, may contain as much as 26 million tons of subeconomic wollastonite resources. The crest of an open pit to produce that resource would extend into the WSA. No information exists on geothermal potential because no exploration has been done in the area. No occurrences of energy minerals are known within the WSA.

Jan 1, 1983

By Wils L. Cooley

Two major grounding topics are covered: mine ground systems and ground-check monitors. Performance characteristics of ground-check monitors for high-voltage surface mine distribution cables and low-voltage underground mine trailing cables are evaluated. Over 20 commercially available monitors are studied to determine their utility. Several monitoring concepts are incorporated into an unusual monitor design, the prototype of which is described in detail. A comparative study of the effectiveness of several alternate methods of grounding surface mine equipment supports the system currently proposed by MSHA. An instrument design to measure earth voltage gradients is described, as well as an instrument design for measuring the effectiveness of dc haulage current return systems. An extreme analysis is made of techniques for measuring earth resistivity and resistance of safety ground beds. Electrolytic corrosion studies of earth electrodes are reported extensively also.

Jan 1, 1979

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By David E. Nicholson

In a Bureau of Mines investigation of the dynamic compaction of mine hydraulic backfills, two basic forms of mechanical vibration inducers were used and compared for effectiveness of compaction. Internal compaction, using concrete probe vibrators of various sizes, and external compaction, using plate vibrators} were studied and evaluated for use in underground stopes. An aluminum plate, which was light and displaced sufficient volume to remain afloat in fluid fill, and a steel plate were both used in the external compaction tests. Efficiency of compaction was better in studies conducted with internal probe vibrators. Tests were conducted in an underground backfilled stope with three different-sized probe vibrators (2-, 4-, and 6-inch-diameter) to determine an approximate area of influence. Results showed the areas of influence to be approximately 3, 4, and 5 feet in diameter, respectively, for the three different probes. Physical properties of hydraulic slurries were determined; preferred grain-size distributions, water exudation properties, and water contents of hydraulic slurries are reported. The best compaction results were obtained with moderately well-graded, fully saturated backfills, with slow rates of water exudation, which were capable of remaining in a semifluid state during the compaction process.

Jan 1, 1967

By M. J. Ankeny, J. J. Forbes

"One of the main functions of the U. S. Bureau of Mines, as authorized by Congress, is to investigate safety and health conditions, to disseminate information regarding safe and unsafe practices in mining, and to aid in improving safety and health conditions of mining communities and in promoting the welfare of the miner. Among several methods of reaching the miner and interesting him in safety work, perhaps the most effective is through the 11 mine safety stations and 11 railroad cars known as mine rescue, or more correctly, mine safety cars.Frequently, the Bureau of Mines receives requests for information regarding the purpose, equipment, personnel, and construction of its safety cars used in the field service. It is the intention of this circular to present to the mining public in particular, and to the public in general, some definite information regarding these safety cars and their functions.The cars are operated throughout the mining fields of the United States and are headquartered as follows (see fig. 1): Car 1, Reno, Nev.; Car 2, Raton, N. M.; Car 3, Pittsburgh, Pa.; Car 4, Terre Haute, Ind.; Car 5, Pineville, Ky.; Car 6, Pittsburg, Kans.; Car 7, Huntington, W. Va.; Car 8, Duluth, Minn.; Car 9, Butte, Mont.; Car 10, Des Moines, Iowa; Car 11, Anchorage, Alaska.One of the most important purposes of the U. S. Bureau of Mines safety cars is to render service at mine fires and explosions where human life is endangered. State mine inspectors and other interested persons are supplied with itineraries of the car operating in their districts from time to time, so that they may know at all times where the car can be found in case of emergency. When these disasters occur the car may be reached direct or through its field headquarters, and upon receiving word of a mine disaster, or request for assistance, it immediately proceeds to the scene of trouble. Frequently a special locomotive is supplied by the railroads and in many instances the movement of the car is given the right of way over all other railway traffic. Upon reaching the destination, the facilities and personnel of the car are immediately available for rescue and recovery operations.Following most mine disasters a thorough investigation is made by engineers of the Bureau of Mines, and a confidential report is submitted to the operator. The information gained in this manner from a large number of mine fires and explosions, together with the knowledge gained from the experimental work carried on at the Experimental mine of the bureau at Bruceton, Pa., serves as a basis upon which the bureau is able to recommend preventive measures whereby similar occurrences may be averted. The bureau car is often used as headquarters for the investigating engineer when such an examination is being made."

Mar 1, 1931

By Walter R. Storms

The Iron Mountain tungsten deposits first were visited by a field party of the Federal Geological Survey in May 1942 while beryllium deposits in that district' were being examined . Later they were examined by F. A. Rutledge , an engineer of the Bureau of Mines , and an exploration project was recommended , work upon which began in March 1943 and was terminated in April 1943 after intensive trenching and sampling had been completed .

Mar 1, 1947

By James V. Kelly

"INTRODUCTION In the course of Bureau of Mines investigations of iron ores near Scappoose, Columbia County, Oreg. during 1942, occurrences of laterite were noted in road cuts and outcrops at many localities in the county. In 1944, the State of Oregon Department of Geology and Mineral Industries completed a preliminary examination of alumina-iron-bearing laterite occurrences in Washington County north of Hillsboro, Oreg.3/ Their report suggested that the lateritic material might be amenable to treatment by the Pederson process for the commercial production of iron and alumina. In order to determine the extent and character of some of the reported lateritic occurrences, the Bureau conducted preliminary explorations in Columbia County near St. Helens, Oreg., from January through June 1945. Almost simultaneously the Alcoa Mining Co. began to explore nearby areas. Their work was continued and expanded after the Bureau's work had been discontinued. This report presents the data obtained from the exploratory work of the Bureau of Mines.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral re¬sources 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 Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, O. C. Ralston, chief, analyzes samples and performs beneficiation tests.Samples were assayed at the Reno, Nev., laboratories of the Bureau of Mines under the supervision of A. C. Rice, acting supervising engineer, and at the Albany, Oreg., laboratories under the supervision of Dr. B. A. Rogers, chief, Albany Division, Metallurgical Branch."

May 1, 1947