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By J. B. Littlefield

[A rulp has i~c+:r. ilrsi i,nsd Lo O~JPY:L~ e the mid~ol Llf;pin.5cr rll~!-t-.cxny)lin:: apparatus recently c',ov~-lo.pe;t by tL1e '.liro:ul of !dines- For th-is pilryoac, a po?.-iti~rs-nct.i?~. pvrni? t:,.;~t v:i.l.'l. :.-,,- #?,n c-noot'fl ;L flow nc possiY,].c? is dcni?.oYle. Flota.lS:r vnnc\-t:rre 1jl:~l~l: zrt iln~;xtJsY:or (2s thc:; n1lr.t ke tvrned at h ityh spet.d for rT:oot,c, o;?ey,;ltiori., ~nd at hi:,h s~ee(' the c8n:xcity oi' the s-n:r.llest piqt ott:~ir?:zk?e Is too la~-~:c. nir crrn'rle bler! in nt the intn?~, but t,he mm;nt o nor.;: l.o'q7r ir.:,l soon t ire:. the oyernt or]

Jan 1, 1938

By J. B. Littlefield

[A rulp has i~c+:r. ilrsi i,nsd Lo O~JPY:L~ e the mid~ol Llf;pin.5cr rll~!-t-.cxny)lin:: apparatus recently c',ov~-lo.pe;t by tL1e '.liro:ul of !dines- For th-is pilryoac, a po?.-iti~rs-nct.i?~. pvrni? t:,.;~t v:i.l.'l. :.-,,- #?,n c-noot'fl ;L flow nc possiY,].c? is dcni?.oYle. Flota.lS:r vnnc\-t:rre 1jl:~l~l: zrt iln~;xtJsY:or (2s thc:; n1lr.t ke tvrned at h ityh spet.d for rT:oot,c, o;?ey,;ltiori., ~nd at hi:,h s~ee(' the c8n:xcity oi' the s-n:r.llest piqt ott:~ir?:zk?e Is too la~-~:c. nir crrn'rle bler! in nt the intn?~, but t,he mm;nt o nor.;: l.o'q7r ir.:,l soon t ire:. the oyernt or, ]

Jan 1, 1938

By Arne Landsberg

Accessory metals, although valuable resources, present possible environmental concern in the smelting of base metals. The Bureau of Mines, U.S. Department of the Interior, has undertaken research to define the chemistry involving these metals. Arsenic in copper smelting is the first to be investigated. Roasting, the first step in many copper smelters, was chosen for initial investigation because of the potential for arsenic removal in this primary process. Simple, static-bed, vaporization experiments were devised to obtain the data in this study. Ancillary transpiration and mass spectrometry were also used to delineate conditions necessary for arsenic volatilization from a roaster feed. For nearly complete arsenic removal, a temperature of 650°-700° C, a reducing atmosphere including carbon monoxide, and a source of sulfur were found to be essential.

Jan 1, 1980

By E. G. King

Existing thermodynamic data for compounds of the rare-earth metals are few in number and often inaccurate because, in the past, it was difficult to obtain samples that were pure enough and reasonable in cost--a situation that is rapidly improving. This paper reports the results of low-temperature heat-capacity and high-temperature heat-content measurements for cerous fluoride (CeF3) and supplies the first such published data for a rare-earth fluoride. The low-temperature heat-capacity data cover the temperature range 51°-298° K. and serve to evaluate the entropy at 298.15° K. The high-temperature heat-content data cover the temperature range 298°-1,799° K., including the temperature and heat of fusion. The results are assembled for ready use in thermodynamic calculations. Cerous fluoride is one of the important intermediate compounds in the production of cerium metal.

Jan 1, 1959

By Richard A. Winters

In 1985 at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 9,400 acres of the 10,005-acre Duncan Creek Wilderness Study Area (ID-111-78) in order to evaluate the mineral resources. The study area is located in Owyhee County, 10, about 36 miles southwest from Bruneau, ID. No mining districts are in the study area, nor were any mines or claims recorded or found. The southern half of the area was covered by oil and gas lease applications, all of which were cancelled prior to June, 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Duncan Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By Michael P. Moore, Christopher J. Rise

"Over the past twenty years, there have been numerous studies which have attempted to correlate the prevalence of Coal Workers' Pneumoconiosis (CWP) with different characteristics of the coal seam. Some investigators have tried to find a relationship, or the lack of a relationship, between the rank of coal seams and the incidence of CWP. Others have attempted to show that there is a positive correlation between the mean mass of respirable dust in the mine atmosphere and the prevalence of CWP. Still others have tried to determine the influence of the quartz content of respirable dust on the incidence of CWP. Unfortunately, many of these different investigations have conflicting conclusions.One area of research with conflicting conclusions deals with the relationship between the rank of the coal and the incidence of CWP. For example, an inves¬tigation conducted in Pennsylvania and West Virginia coal mines concluded that the prevalence of CWP increases with an increase in coal rank (1). A study in Great Britain also observed a close relationship between the rank of coal and the prevalence of CWP (2). However, another study involving 312 Appalachian coal miners concluded that the association between coal rank and CWP might be fortuitous and that other factors may be more important (3). In addition, an investigation involving 2,600 miners during a period of twenty years in Great Britain established that there is only a weak correlation between the prevalence of CWP and the rank of the coal (4). Consequently, it appears that there is still uncertainty as to whether or not the rank of the coal seam has an influence on the development of CWP.Another area of investigation concerns the relationship between the mean mass of respirable dust present in the mine atmosphere and the prevalence of CWP. A study involving 4,122 miners over a period of ten years in Great Britain noted a high correlation between the mean mass of respirable dust and the incidence of CWP (5). Another investigation involving 3,154 British face workers con¬cluded that the overall mass of respirable dust is the factor most closely related to the ten-year attack rate of CWP (6). However, a study conducted in thirty-one mines in the United States concluded that it is doubtful that the quantity of respirable dust alone is responsible for the difference in the prevalence of CWP (7). Even though there are conflicting conclusions, there are many more investigators who confirm, rather than deny, the relationship between the mean mass of respirable dust and the development of CWP.The third subject of investigation is the role of quartz in the incidence of CWP. For example, two studies in Great Britain concluded that the quartz content in coal mine dust has no relationship to the prevalence of CWP (8,9). But a study involving 312 Appalachian coal miners revealed that the level of exposure to free silica plays an important role in the development of CWP (10). Once again, the conclusions reached by different researchers are conflicting.Probably the most important factor in the discrepancy among the studies is the variability among different coal mines. A mine operating in an inherently ""dusty"" seam may have a low concentration of respirable dust while a mine operating in a less dusty seam may have a high concentration of respirable dust. This discrepancy is a result of variables such as the effectiveness of ventilation or the efficiency of the water sprays. Consequently, it is very difficult to compare the dustiness of different coal seams by in-mine measurements of the respirable dust concentration. A laboratory test would more accurately characterize a coal seam according to its respirable dust production."

Jan 1, 1988

By J. J. Jakowsky

[The legislation in many States against the present method of producing carbon-black by the incomplete combustion of natural gas, and the continually increasing demand for gas for otter purposes, indicates that the supply of carbon-black may Gradually be decreased and that new methods for its production, utilizing a greater parentage of the carbon in the has should be developed. In the course of investigations of the effects on hydrocarbons of high voltage discharges, it was noted that under certain conditions natural gas could be decomposed and that carbon-black could be produced. The effects of several tyres of electrical discharges on natural gas have, accordingly, been studied' in order to find out the fundamental factors underlying the reactions and their possible influence in the recovery of a greater part of the carbon content of natural gas than is now possible. Present commercial plants using natural gas for the manufacture of carbon-black recover from 0.9 to 1.5 pounds of carbon-black per thousand cubic feet of gala consumed, or less than 5 per cent of the total Gabon in the gas: It should be noted, however, that the, present methods involve heating the gas to incandescense by burning it as a luminous flame, and a considerable part of the gas is thus consumed as a source of hest. If this heat can be supplied from some other source, or if a more efficient method of applying the energy con. tamed in part of the gas, to the decomposition of the rest of it, can be worked out, then a greater yield of carbon-black per thousand cubic feet of gas care be expected. The present abort paper contains a brief summary of tie investigations so far conducted upon natural gas.]

Jan 1, 1922

By James P. Bennett

In this Bureau of Mines study, portions of four acidproof bricks (two red shale and two fireclay) were exposed to 20 wt pct RCI at 900 C for periods of 30 days. Three different techniques were selected to deter-mine volume expansion of these materials after exposure. Linear expansions ranging from about 0.02 to 0.12 pct were noted from Ta pin and dilatometer measurements. The use of strain gages to measure expansions was not successful. The red shale and fireclay brick with the lowest apparent porosities had the lowest expansions. Expansion data obtained by direct measurement of samples exposed for 30-day periods or by dilatometric measurement of autoclaved samples ex-posed for 2 h were comparable. This suggests the use of an accelerated autoclave exposure procedure for determining volume expansion effects of ceramic materials in acid environments.

Jan 1, 1985

By M. R. Peterson

The U.S. Bureau of Mines investigated column flotation for recovery of a high-grade fluorite (CaF2) concentrate and byproduct concentrates from the Fish Creek fluorite deposit in Eureka County, NY. The recovery scheme consisted of (1) grinding the ore to minus 48 mesh, (2) fluorite rougher and cleaner flotation, (3) desliming the rougher fluorite flotation tailings at 20 Jjm, (4) mica flotation, and (5) silicate rougher flotation. Acid-grade fluorspar, mica, free silica (Si02) sand, and low-grade beryl (Be3Al2S~018) concentrate were produced in a 100 lb/h continuous column flotation unit (CCFU). The highest results achieved were %.6-pct CaF2 recovery in a fIrst cleaner concentrate containing 99.7 pct CaF2. Beryl recovery was as high as 92 pct at a grade of 5.3 pct BeO. The silica sand, which assayed 98 pct Si02, was recovered as the rougher beryl flotation tailings. Collector reagent consumption was reduced 45 pct for fluorite and 58 pet for silicate flotation in comparison with bench-scale conventional flotation. All products were signillcantly improved in both grade and recovery over conventional flotation results, and the recovery scheme was simplifIed by removal of several stages of flotation in the fluorite and silicate flotation steps.

Jan 1, 1990

By Oliver Bowles

This paper is the fourth of the current series issued by the Bureau of Mines on lime- plant problems . It is hoped that the information presented in these reports will develop sufficient interest among lime- plant operators to prompt them to discuss with the Bureau their own experiences , for it is believed by such an interchange of ideas conclusions will be reached that will be of practical benefit to the entire industry . Much valuable information has been obtained from replies to the papers already issued , but a more general response is greatly desired . It is hoped that many operators will contribute additions to the information on transportation systems now at hand by answering the questions on the final page .

Mar 1, 1923

By Arthur L. Murray

The first thought in the case of an accident or contagious disease is naturally that aroused by our humane instinct , how serious is the case and will the person recover ? The economic effects of such cases , owing to their many ramifications , are seldom realized either by those directing mining operations or those engaged in the labor of producing . This paper is based on the accident experience of the State of Utah and the number of cases of two well known preventable diseases , typhoid fever and smallpox , in that State for the fiscal years 1917-1918 , 1918-1919 , 1919-1920 , and 1920-1921 . The data and figures presented are from coal -mining camps only . W. W. Adams , mine- accident statistician of the bureau, contributed valuable corrections and suggestions . The economic results of accidents are considered first , and those of the two preventable diseases later .

Apr 1, 1922

By A. L. Engel

A representative sample of gold-silver ore from the Keystone Mine, Manhattan, Nye County, Nev., was submitted for these tests. The ore was an altered diorite rock with very small amounts of sulfide minerals of copper, lead, zinc, antimony, and arsenic disseminated in fine grains throughout. As indicated by test results, much of the silver content of the ore apparently was associated with these sulfide minerals. The gold probably occurred with iron oxides in the ore. Assays showed 0.16 ounce of gold and 2.8 ounces of silver per ton of ore. This investigation was made to study application of activated carbon in the cyanidation treatment of the ore. The treatment proposed for u.se at the mill is as follows: The ore is crushed to minus-10-mesh size and separated into plus -and minus-65-mesh portions. The minus-10, plus 65-mesh sands are cyanided by leaching and the minus -65-mesh slimes by agitating. After 48 hours of agitation the slime pulp is thickened to about 1:1 water:solid ratio, and part of the pregnant solution is recovered. The pulp is then diluted to a 2:1 ratio, and the remaining dissolved values are extracted with the activated carbon. The barren pulp then can be discarded. This procedure eliminates the necessity for further washing the slime pulp and also recovers most of the excess sodium cyanide required for extracting the optimum amount of silver from this portion of the ore.

Jan 1, 1951

By James S. Browning

The Bureau of Mines conducted laboratory batch and pilot plant flotation tests to determine the technical feasibility of recovering commercial-grade mica from a California micaceous schist. Best results in the laboratory batch tests were obtained using sodium carbonate and sodium silicate for pH control and quartz depression, and a combination of fatty acid and cationic reagents as the mica collector. In continuous pilot plant flotation tests, an alkaline fatty acid-cationic method recovered about 70 percent of the mica in a concentrate analyzing 95.6 percent mica.

Jan 1, 1965

By W. L. Schmidt

The effect of a water-repellent film in sandstone cores on the effective permeability-saturation relationship was investigated as part of a cooperative research program between the Bureau of Mines and the American Gas Association. The repellent film was formed by the reaction of methyltrichlorosilane3 with the connate water in the core. Other researchers have reported on the use of silicone chemicals to alter the flow characteristics of porous media (1-3, 5-7, 9, 10).4 The previous studies, however, dealt almost entirely with oil-water or oil-gas systems and not with water-gas systems. The primary purpose of this study was to determine the feasibility of using silane to retard the influx of water into natural-gas storage wells and to determine the necessary requirements for achieving this result. The success or failure of silane treatment as a remedial measure depends on its effect on gas-production rate and attendant water production.

Jan 1, 1961

By J. B. Gayle

Although heated circuits frequently have been employed in the conditioning stases of certain flotation processes, particularly the flotation of fluorite, the control of temperature is not generally considered economically feasible for the flotation of coal. This viewpoint, although widely held, can neither be substantiated nor refuted by reference to published data. Some evidence is available, however, that temperature is an important variable in the floatability of coal as well as other minerals. For example, Gayle and Swelley4 found that contact angles for coal and related substances were definitely dependent on temperature. Bailey and Whalan5 showed that changes in pulp temperature may exert a pronounced influence on recoveries of coal in batch flotation tests. The present laboratory-scale investigation was undertaken to obtain information about the effects of changes in pulp temperature on coal flotation recovery and also on the selectivity of separation possible using different reagents. The results indicated that flotation recoveries were markedly affected by temperature variations when certain reagents, particularly simple aliphatic alcohols, were used. For other reagents, particularly kerosine, flotation recoveries were substantially independent of variations in pulp temperature. Release-analysis results indicated that temperature variations did not greatly affect the selectivity of separation possible with the reagents tested.

Jan 1, 1961

By K. J. Maggs

The U.S. Bureau of Mines has investigated the chemical vapor deposition of diamond films on tungsten substrates. The effects of deposition parameters on the adhesion of the films was determined. The films were produced using a hot filament chemical vapor deposition system. Parameters investigated were substrate temperature and methane concentration in the feed gas. Film quality, morphology, and composition were characterized by scanning electron microscopy and Raman spectroscopy. Adhesion testing was performed using an indentation technique, and the results were quantified by relating adhesion to interface fracture toughness. Diamond films with well-faceted crystalline morphology with grain size greater than 1 µm had poor adhesion properties regardless of substrate temperature or methane concentration. Diamond films with smooth morphologies consisting of rounded clusters of small (<0.2 µm) diamond crystallites and amorphous carbon phases displayed much higher adhesion, although the conditions that led to the growth of these films are not understood.

Jan 1, 2010

By JOEL H. SWARTZ

During a series of resistivity measurements carried out in 1929 and 1930 a number of questions arose concerning the effect of topography on the character of the curves and the depths attained , the ratio of true depth to certain radii interpreted as representing depth , etc. To answer these questions it was decided to undertake a series of experimental investigations on artificial strata . It is the purpose of the present paper to present the results of the studies thus undertaken .

Feb 1, 1931

By William W. Elmer

This paper, describing the mining method at the Black Butte quicksilver mine, is one of a series of papers being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various districts of the United States. It is presented to show the mining practice and costs in the successful treatment of low-grade quicksilver deposits. The operation discussed is an excellent example of w1-pat can be done in working a limited tonnage of low-grade ore under sound management. The Black Butte mine is situated at Black Butte, Lane County, in the southern part of the State of Oregon, 17-1/2 miles from Cottage Grove -- a station on the Siskiyou branch of the Southern Pacific Co. The Black Butte mining district lies in the foothills of the Calapooia Mountain Range, which connects with the Cascade Range on the east and with the Coast Range on the west. The elevation at &apos;.lie reduction plant is 1,000 feet above sea level. The apex of Black Butte Mountain, or which the mine is situated, has an elevation of 2,700 feet. The district possesses exceptional natural facilities infrequently met with elsewhere for the mining and reduction of cinnabar ores. Several factors which contribute to the unusually low mining costs are:

Jan 1, 1930

By W. A. Jacob, E. W. Dean

The Pittsburgh petroleum laboratory of the Bureau of lines has recently developed an improved method for the determination of water in pctroleum emulsions. It has been described in detail in an article entitled "A convenient method for the determination of water in petroloum and other organic emulsions" by E. W. Dean and D. D. Stark (Jour. Ind., and Enc. Chem. Vol. 12, ſay, 1920, page 436). It is essentially a modification of the familiar procedure of "distillation with an iniscible solvent", the improvement consisting in the use of apparatus that is rºck more convenient than any previously employed. The method has been used with marked success in the Bureau's laboratories for a period of about a year and has also been tried with equal satisfaction by a number of other laboratories. It has been most extensively employed for determining the water content of heavy fuel oils but has been applied also to several other types of emulsions, including shale oils, tars derived from coal, greases, and mixtures of powdered coal, oil and water. The Bureau has received a number of requests for information regarding commercial sources for the apparatus used, and having been assured of the value of the method, has taken steps to render it available for general use. - The equipment is, with the exception of two items, made of parts that are obtainable from the ordinary stock of chemical supply houses. The two exceptions are (1) the so-called "distilling tube receiver" and (2) the electric heater. The former is an essential part of the equipment; the latter is a convenient ac cessory but it can if necessary be roplaced by a gas burner. Efforts on the part of the Bureau staff to ronder these two items of apparatus available for purchase from supply houses, or for production by the user are hero described.

Sep 1, 1920

By D. E. Shanks

As part of its program to lessen dependence on foreign bauxite as the Nation&apos;s primary source of cell-grade alumina, the Bureau of Mines is investigating sulfuric acid (H2S04) leaching procedures for the recovery of alumina from domestic aluminous materials. The successful application of a H2S04 leaching process depends on the recovery of the aluminum values in an easily washed and filtered form, containing a minimum of water to be driven off in the subsequent calcination step. This goal was met by the high-temperature hydrolysis of simulated aluminum sulfate [A12(S04)3] leach liquor. Crystalline, insoluble aluminum hydroxy sulfate [A1(OH)S04], which had a water-to-alumina mole ratio of 1:1, was produced. Eighty-six percent of a solution containing 127 g of A12(S04)3 per liter and 76 pct of a solution containing 336 g of A12(S04)3 per liter were hydrolyzed to insoluble aluminum hydroxy sulfate by autoclaving for 1 hr at 320° C and rapidly quenching to room temperature. Higher operating temperatures were precluded by corrosion of the autoclave. The yield of aluminum in the hydrolysis product increased with increasing hydrolysis temperature and decreasing A12(S04)3 concentration.

Jan 1, 1981