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By K. K. Kershner

Sulfide ore concentrates containing cobalt, nickel, copper, lead, and iron were salt roasted and leached on a laboratory scale. More than 95 percent of the cobalt, nickel, and copper was recovered. Heating patterns for salt roasting different concentrates were established. More cobalt, nickel, and copper were recovered from a bulk concentrate composed of a mixture of copper concentrate and iron concentrate. This mixture corresponded roughly with the mixture of these materials in stockpiles in southeastern Missouri. A temperature range of 375° to 400° C. was best for salt roasting. Metal chlorides were leached at a pH of 1 from chloridized charges of concentrates, Although the amounts of cobalt, nickel, and copper extracted were high, the amount of iron dissolved simultaneously interfered with subsequent separation and recovery of these metals. The amount of dissolved iron was reduced substantially by steam treating chloridized charges of bulk concentrate at 300° C. In this way, the ratios of cobalt, nickel, and copper to iron in leach liquors permitted satisfactory separation and recovery of these metals. INTRODUCTION The Federal Bureau of Mines is experimenting with chloridizing reactions.4 5 6 7/ Salt roasting of sulfide ores and concentrates, or their calcines, to form metal chlorides has certain advantages. Chlorides of

Jan 1, 1961

By W. R. Hardwick

This paper describing the mining methods of the Inspiration Consolidated Copper Co. is one of a series being prepared by the Bureau of Mines on mining methods and costs in various mining districts of the United States. The story of mining at Inspiration is of particular interest because, after 127,812,000 tons of low-grade copper ore were successfully mined, the mining method was changed from block caving to open-pit. As the open pit became deeper, many features of the former block-caving operation that were exposed elucidated concepts of the mechanics of caving that previously had been assumed but not observed. The conversion to open-pit mining was accomplished by unique combinations of equipment and the introduction of ingenious engineering and operating practices that have extended the expected life of the mine for many years.

Jan 1, 1963

By W. R. Hardwick

This paper describing the mining methods of the Inspiration Consolidated Copper Co. is one of a series being prepared by the Bureau of Mines on mining methods and costs in various mining districts of the United States. The story of mining at Inspiration is of particular interest because, after 127,812,000 tons of low-grade copper ore were successfully mined, the mining method was changed from block caving to open-pit. As the open pit became deeper, many features of the former block-caving operation that were exposed elucidated concepts of the mechanics of caving that previously had been assumed but not observed. The conversion to open-pit mining was accomplished by unique combinations of equipment and the introduction of ingenious engineering and operating practices that have extended the expected life of the mine for many years.

Jan 1, 1963

By H. F. Weaver

The 19th National First-Aid and Mine Rescue Contest was held in the Civic Center, Charleston, w. Va., on October 2, 3, and 4, 1961. The meet was sponsored by the Bureau of Mines and the Joseph A. Holmes Safety Association, in cooperation with State mine inspection agencies, management and labor of the mineral extractive industries, and other groups interested in safety. The Arrangements Committee, as authorized by the General Committee, made the necessary arrangements for conducting the 1961 contest. Members of the Arrangements Committee were: George Trevorrow (chairman), Bituminous Coal Operators' Association; James B. Benson, Southern Coal Producers' Association; Charles Ferguson, United Mine Workers of America; Harry Gandy, Jr., National Coal Association; and James Westfield, Bureau of Mines.

Jan 1, 1962

By R. Hogg, T. F. Dumm

"Abstract - With increasing interest in the physical cleaning of fine coal, there is a need for extension of the sink float analysis procedure to finer sizes. Problems arise, however, in ensuring complete dispersion of the particles in the heavy liquids. A procedure has been developed in which surfactants are used as dispersing agents, and solids concentration is minimized (using a simple formula to estimate the minimum weight needed for statistical reliability). Using centrifuges to increase separation rates and subsieve particle size analysis of the specific gravity fractions, a complete size specific gravity distribution can be obtained. Analyses have been performed on coal samples as fine as -10 µm.IntroductionTraditional gravity separation techniques such as jigging, heavy media and water-only cyclones, shaking tables, etc., have been used to remove impurities from coal ranging in size from about 15.cm (6 ln.) to about 150 µm (100 mesh). The coal washabilty or float-and sink technique ls a well-established procedure for determining the optimum extent to which a coal can be cleaned by such physical separation methods. Because of the desire to recover even finer coal fractions by gravity separation techniques, there is a need to extend the coal washabillty analysis into the ultrafine range. The purpose of this paper ls to describe some of the significant factors that influence fine particle specific gravity separation. Washability analyses have been performed on three ultrafine ( <10 µm) coal samples representing three general mining districts in Pennsylvania. Results of these analyses indicate that the washabillty technique can be successfully applied to ultrafine particles when proper care ls taken."

Jan 1, 1988

The National Institute for Occupational Safety and Health (NIOSH) recommends that occupational exposures to respirable coal mine dust and respirable crystalline silica* be controlled by complying with the provisions presented in this document. These recommendations are designed to protect the health and provide for the safety of workers exposed to respirable coal mine dust and respirable crystalline silica for up to 10 hr/day during a 40-hr workweek over a working lifetime. The information presented in this document demonstrates that underground and surface coal miners are at risk of developing simple coal workers&apos; pneumoconiosis (CWP), progressive massive fibrosis (PMF), silicosis, and chronic obstructive pulmonary disease (COPD). Adherence to the recommendations in this document should prevent or greatly reduce the risk of adverse health effects in workers exposed to respirable coal mine dust and respirable crystalline silica. NIOSH recommends that preventive efforts be focused primarily on reducing worker exposures. Effective health and hazard surveillance and medical screening are also useful components of a comprehensive prevention effort.

Jan 1, 1997

By Oliver Bowles

Since 1922 when the Bureau of Mines issued a report2 covering the slate industry in detail, changes in technology have taken place which have an important bearing on the industry. The present paper comprises a record of these changes. Though the value of slate, for roofing, structural, blackboard, sanitary, and electrical uses is generally recognized, it has many competitors. To meet this constantly increasing competition producers are promoting economies in manufacture, and improving processes, thereby lessening costs of production, and are placing on the market products of the highest possible quality, thus creating satisfaction and confidence on the part of the user. This endeavor to place the industry on a better basis, both as regards processes and products, is shown in the recent developments in technology which are presented herein. Valuable assistance in obtaining data for this paper was given by W. S. Hays, secretary of the National Slate Association, N. M. Male, president of the National Slate Association, and Robert Notvest, consulting engineer, Cleveland, O.

Jan 1, 1926

By C. E. Augustine, B. A. Landry, P. Nicholls

"Wien bituminous coal is burned in a hand-fired up-draft boiler used for heating purposes it has a decided tendency to produce smoke. A design of furnace and a method of firing and attendance that are satisfactory for fuels low in volatile matter, as anthracite or coke, are not necessarily Satisfactory for bituminous coals. It is therefore becoming common practice to use a special design of furnace for bituminous coals, in order to facilitate the combustion of the volatile matter and soot. This is done by (1) providing a larger combustion space to give more time for the combustion, (2) construction that will produce a better mixing of the gases and secondary air supplied over the fuel bed, or (3) keeping the gases at a higher temperature by preheating the secondary air, as may be done by surrounding them with refractory surfaces, or causing them to pass through a fuel bed of hot coke. A furnace may be built to use any or all of these methods of smoke prevention.In Bureau of Mines Technical Paper 303, Blizard5 and others give tests on a large heating boiler when burning coke, anthracite, and bituminous coal. Certair alternative furnace arrangements were used, but there was no material change in the furnace design for the various fuels. Since that time the manufacturer has made modifications in design to adapt it for use of bituminous coal, and additional tests have been made to determine how this change affected the production of smoke and the efficiency of the boiler."

Jun 1, 1929

By Paul C. Turner

The U.S. Bureau of Mines, through an Interagency Agreement with the U.S. Army Tank-Automotive Command (TACOM), has successfully developed a steel expendable pattern casting process (EPC) for the manufacture of armorplate. The new armor is lighter and more ballistically effective than conventional rolled homogeneous armor (RHA), and costs less. An applique armor spinoff from the program was field-tested during the Gulf War. The applique armor withstood direct impacts from enemy munitions without failure.

Jan 1, 2010

By John B. Gayle

The Bureau of Mines has designed and constructed an experimental coke oven, using a commercial oven as a model where practicable. Because the rate of carbonization is important in determining the quality of the coke produced and may affect the "mount of pressure developed during carbonization, particular attention was given to those elements of the design that govern the heat transfer to the charge. The new oven deviates in design from most existing test ovens in that the charge is full width (17 inches), the heating walls ore constructed of 4-1/2-inch silica brick, and zoned, heat-input arrangements compensate for heat losses at the ends, top, and bottom of the charge. This report describes the oven, which was designed by H. S. Auvil and installed under his direction, at the Southern Experiment Station, Tuscaloosa, Ala., while he was supervising, engineer, Coke Section. It gives the results of a limited number of carbonizing tests. These results indicate that the main objective in designing and building this oven, that off duplicating commerical, slot-oven carbonizing conditions, has been accomplished; if coke-discharge conditions simulate commercial-oven conditions, the cokes from the experimental oven arc very similar to oven coke, in soma tests being fully as close is duplicate tests from a Angle batch of coke.

Jan 1, 1952

By Charles L. Kusik

As part of an effort to establish the extent of the domestic chromium supply that could be exploited in case of adverse changes in international chromium production and trading patterns, a two-part study was conducted for the Bureau of Mines, to assess the domestic availability of critical metals in scrap containing significant amounts of chromium. This report describes the part of the study that deals with wrought stainless steels and heat-resisting alloys. Data were collected on types of scrap, sources, quantities, and ultimate disposition, leading to the conclusion that In 1917 about 62,000 tons of contained chromium was unrecycled. Unrecovered obsolete stainless steel scrap accounts for most of these uncollected chromium values. Error margins in the amount of uncollected scrap are estimated to be 10 to 20 percent.

Jan 1, 1980

By W. J. Kroll

This report on the bibliography of zirconium has been confined to those publications and patents that appear to be useful in the commercial development of the metal, both the malleable and the nonmalleable. The methods of production have been stressed and special attention has been given to the alloys. Compounds of importance, like the oxide and chloride, for the manufacture of the metal or of the alloys have been considered. The use of the oxide in refractories anal in the glass and porcelain industries has been omitted. The present survey is critical; that is to say, an attempt has been made to evaluate the effectiveness of suggestions made in the literature. The exhaustive work of Marden and Richy, Bureau of Mines Bulletin 186, published in 1921, has been taken as a base to start from with the intention of bringing the subject up to date with material published in the last 24 years. During this time there was considerable &apos;advance in the preparation of the metal and Its alloys, and in the development of new uses. On the other hand, there was little progress in the methods of decomposing the ores, so that the chapter on this latter phase is necessarily short.

Jan 1, 1946

By G. M. Potter, J. B. Rosenbaum, Masami Hayashi

Most Japanese copper smelters are located in areas of concentrated industrial activity and high levels of atmospheric pollution. A review of unofficial sulfur dioxide emission control data from major Japanese smelters shows capture of 91 to 99.7 percent of the sulfur in the smelter feed. The bulk of Japanese smel ting capacity was constructed in the last 10 years. Six of the major sme lters use flash furnaces, and two use reverberatory furnaces. A prototype three-furnace continuous system is in use as a parallel train with reverberatory furnaces at one smelter. Most of the sulfur dioxide is manufactured into sulfuric acid. The remainder is captured by gas scrubbers that yield gypsum and sodium salts. Ready markets exist in Japan for the acid and other su lfur byproduc ts.

Jan 1, 1967

By H. W. Sohns

A retort was constructed in which fine particles of shale, entrained in steam or other gaseous media, could be retorted at controlled temperatures and residence times and the effects of retorting variables upon quality and quantity of products could be determined. Studies of the effects of temperature upon products obtained from Green River (Piceance Creek Basin, Colo.) and Chattanooga (Tenn.) oil shales were completed. The feasibility of using the retort to process a shale of extremely high moisture content from Brazil also was investigated. Air was used as the entraining medium in a series of studies in which combustion of some of the products of retorting within the retort tube supplied a major portion of the process heat. In another series, shale oil from a conventional retort was cracked thermally to obtain data for comparison with results of retorting en-trained shale. In still another series the effects of rates of steam flow and solids feed upon rates of heat transfer from the furnace to the process stream were studied. Crushed quartz rather than oil shale was charged to the retort in this series. A study was begun in which raw shale was partly retorted, the products separated, and the partially retorted shale recharged to the retort. The shale was to have been recycled until it was completely retorted in an effort to improve oil yield by recycle retorting; however, the project was terminated before the investigation was completed.

Jan 1, 1959

By M. M. Barr

Rapid expansion of the titanium-metal industry focused attention upon ilmenite as a possible substitute for the more expensive and less abundant rutile in producing titanium tetrachloride. Most of the rutile available for this use is imported. Preliminary studies were undertaken to determine the chlorination characteristics of high-titanium slags produced by electric-arc furnace smelting of alluvial Idaho ilmenite at the Federal Bureau of Mines Northwest Electrodevelopment Experiment Station, Albany, Oreg. Low silicon, calcium, and aluminum contents of the slags enhanced their potential value for chlorination.

Jan 1, 1958

By Jan C. Still

The Haines-Klukwan-Porcupine subarea of the Juneau Mining District (JMD) is located in the northern portion of the JMD and consists of the land between the Alaska-British Columbia boundary, the Chilkoot Valley, Glacier Bay National Park boundary, and extending south to the Davidson Glacier and the Chilkat Peninsula and Islands (fig A-I). This area was studied as part of the larger JMD study in a cooperative effort between the Alaska Division of Geological and Geophysical Surveys (ADGGS) and the Bureau during 1985 to 1988. Prior to this, during 1984, the ADGGS and the Bureau cooperated in a study of the Porcupine mining area and during 1981 to 1983 conducted separate studies in the area. Field work was conducted by foot, boat, truck, and helicopter. Figure A-I shows the Haines-Klukwan-Porcupine sub-area and shows the areas covered by previous Bureau and ADGGS studies. PHYSIOGRAPHY AND CLIMATE The physiography of the subarea ranges from gentle to rugged. Glaciers formed the major features in the sub-area and left "U" shaped steep walled valleys and rugged mountains. The Chilkat, Chilkoot, Klehini, Tsirku, and Takhin are the major rivers in the subarea. The higher mountains are glacier clad and some valleys still harbor glaciers that reach the valley floors. Lush forests and dense brush predominate up to timberline at about the 2,000-foot elevation. Low point in the subarea is at sea level in the area around Haines while the high point is 7,434 feet at: Mount Henry Clay in the Porcupine mining area.

Jan 1, 2012

By E. H. Rose

This paper, describing the concentrator practice of the Moctezuma Copper Co., is one of a series being prepared by the Bureau of Mines. The Nacozari concentrator of the Moctezuma Copper Co. (the Mexican subsidiary of the Phelps Dodge Corporation) is located about 75 miles south of Douglas, Ariz., in the Moctezuma District of the State of Sonora. Nacozari is the southern terminus of the Nacozari Railroad, ever which all concentrate is transported to Douglas for smelting.

Jan 1, 1930

By E. W. Dean, W. A. Jacobs

"The petroleum division of the Bureau of Mines in its laboratory investigations, has had occasions to develop a number of types of electrical heating equipment. It was found that electric heaters could be used to particular advantage in the standard distillation test for gasoline. (Dean, E.W., Motor Gasoline, Properties, Laboratory Methods of Testing and Practical Specifications, Bureau of Mines Technical raper 214, 1919, 33 pages.) In order to assist in rendering this type of heater available for general use, a description of the apparatus developed by the Bureau was published. (Dean, E.W., A convenient electric heater for use in the analytical distillation of gasoline,. Jour. Ind, and Eng. Chem., Vol.10, 1918, page 823.) Shortly after the article was printed a chemical supply house undertook the manufacture of an electric heater suitable for gasoline distillation. A preliminary model was examined and tested by the Bureau and modifications were suggested that were incorporated in the type of heater that was finally marketed.Description of the Bureau of Mines-heater: The electric heater developed by the Bureau has an inverted conical resistance Plament surrounded by a layer of heat-insulating material and mounted in a metal case having a top of hard asbestos (Transite) board. The resistance element is a helix of nickel-chromium alloy wire held by a molded core of alundum. The Bureau heaters are generally of about 330 watts capacity and are used with stock types of regulating rheostats capable of reducing the effective wattage to about 43 the full-load maximum."

Jun 1, 1920

By E. W. COCHRANE, R. HOPKINS, G

The number of completed petroleum refineries in the United States continued to decline in 1938, but the total capacity to process crude oil increased materially. This information was obtained in connection with the Bureau's annual canvass of refinery capacity as of January 1, 1939. In spite of the addition of a half dozen plants in Illinois and the inclusion in this year's list of several more "pot-stills" in Montana, the total number of plants, and inactive, declined from 551 on January 1, 1938, to 538 on January 1, 1939. was entirely in shut-down plants, as the number of operating plants rose from both active The decline 431 to 435. Yost of the plants dismantled were situated in Wyoming and Texas, parts or several from the latter being transported to Illinois. About 10 more East Texas refineries were dismantled in 1938, leaving about 15 plants in the field, only 8 of which were operating on January 1, 1939. Although the total completed capacity increased from 4,351,151 barrels on January l, 1938, to 4,508,555 barrels on January l, 1939, the operating capacity declined, and the inactive capacity increased about 50 percent, or from 380,955 to 574,770 barrels. These shifts in capacities reflect the comparative slump in the refining industry in 1938 after the prosperous year 1937. Daily average crude runs in 1938 were 3,192,000 barrels, from which it may be figured that the operating ratio for the active units was about 81 percent of crude and for all completed equipment 74 percent. The highest daily throughput in 1938 was about 3,400,000 barrels, at which time the reserve capacity represented in the active equipment was at least 500,000 barrels, in addition to about that much capacity shutdown. In an emergency, much more reliance could be placed on the reserve capacity of the active equipment, as much of the shut-down capacity is obsolete at present specifications and prices. Regarding obsolescence, the refiners reported 418,165 barrels of their idle capacity in good condition on January l, 1939 and 156,605 barrels in poor condition. However, it is probable that the former reflects an optimistic viewpoint. Refinery activity, as represented by new construction and dismantling, declined materially in 1938. The new capacity added in 1938 was 378,350 barrels compared with 394,680 barrels in 1937. Probably 1939 will see a much larger decline, as the new capacity under construction on January 1, 1939, totaled only 142,250 barrels compared with 283,020 barrels the preceding year. The capacity represented by the new plants was negligible throughout

Oct 1, 1939

By W. F. Watts

This report describes a statistical analysis of 41,502 respirable quartz dust samples collected from 1974 through 1981 in metal and nonmetal mines and mills. The goal of this Bureau of Mines study was to identify commodities and occupations associated with high quartz dust exposure so that future enforcement and research activity can be focused on the high-exposure areas. For this analysis, the Bureau used its computerized Mine Inspection Data Analysis System (MIDAS), which contains data on nearly 350,000 air samples, including data for 61 contaminants in 45 commodities. The samples analyzed were collected by inspectors of the Mine Safety and Health Administration (MS HA). The data were entered into the MIDAS computer and coded according to commodity, occupation, location, and other categorical information. Occupations an. commodities with high quartz dust exposure were identified by grouping the data by code categories. Workers at sandstone, clay and shale, and miscellaneous nonmetallic mineral mills had the highest quartz dust exposures. Within these mills, occupations with high exposures were baggers, general laborers, and persons involved in crushing, grinding, and sizing operations. Dust concentrations in these mills were not necessarily the highest, but because the dust contained a high percentage of quartz, the health risk from dust exposure was the greatest.

Jan 1, 1984