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By Shirley F. Colby

A continued rise in construction activity in 1941 forecasts further increases in the demand for building materials of mineral origin, Recent studies by the Bureau of Mines, United States Department of the Interior, reveal that sales of mine and quarry products and their derivatives as a class have followed the long-term trend of construction activity in the past and are benefiting now by the upswing in all types of building. At present most building materials of mineral origin are holding their own in the competitive arena. A few are slipping behind, but others have forged fax ahead. Prominent among those that have surpassed general construction activity since 1925 are sand, gravel, and crushed stone (used in concrete and road metal and railroad ballast) and cement. Both building stone and roofing slate have followed the building curve closely, although in the last few years sales of roofing slate have risen above the curve and sales of building stone have dropped below it. Clay products and building lime, on the other hand, have lagged behind the general procession. Gypsum sales likewise dropped behind, but during the last few years, this industry, thanks to the wider acceptance of its newer products, has staged a marked recovery so that it now stands in about the same relation to total construction activity as it did is 1927-25.

Jan 1, 1941

By James V. Kelly

During the spring and summer of 1947, the Bureau of Mines conducted an investigation and core-drilling program in the vicinity of the Rodham mine, approximately 4 miles north of Shullsburg, Wis. This work was undertaken as a part of a general study of the zinc and lead-producing area of southwestern Wisconsin. Work in the Rodham-mine area was done to investigate further a mineralized area frilled in part by the Puritan Exploration Co., a Delaware corporation, with offices in Galena, Ill. Some significant lead-bearing samples were obtained, but no continuous ore body was disclosed as a result of the Bureau of Mines work.

Jan 1, 1949

By Arthur L. Murray

"Oil-shale camps are peculiarly favored, in that before they are established it can be ascertained with a,of certainty, that the life of the project is not limited. Unlike camps at metal mines, where the metal content of a given area is frequently an unknown quantity until after years of development, oil-shale camps should, from the outset, be planned and built as permanent types of camps. Where this procedure is followed camps will be established which better serve the needs of the industry and the cost of their general care and upkeep will be less.Selection of camp or townsite.The site of the camp or town, whether on company property or not, should be selected with care. It should be separate if possible from the location of the plants of the company so as to be free from noise and fumes and so as to provide a change of environment for employees in going from their work to their homes.The principal features governing the site to be selected are as follows:Drainage. The general contour of the surrounding country should be such that drainage is away from the site. The camp or town should, if practical, be situated on higher ground than that in its immediate vicinity.Soil. The nature of the soil on which the camp or town is located may bear a decided relation to health. A porous, well under drained top soil of at least four feet in depth insures dryness and facilities the placing of foundations and the laying of water mains and sewer pipes. Such a soil also is an advantage in growing trees, shrubs and grass plots, which are a decided adjunct to making the community attractive."

Jun 1, 1921

By Gwendolyn D. Hood

The U.S. Bureau of Mines developed a dewatering technique for treating wastewater that was tested on waste slurry from a commercial tile company in Alabama. Raw wastewater samples were pretreated with 10 Ib calcium chloride and 10 lb Wyoming bentonite per 1,000 gal of slurry. After pretreatment, polyethylene oxide (PEO) at dosages varying from 0.05 to 0.20 lb per 1,000 gal was mixed with the waste slurry, forming strong, tough floes that were separated from the clarified water using a trammel. The flocculated slurry was dewatered to a consistency that could be handled for subsequent disposal in a landfill. The clarified water quality was equivalent to that of the company's present treatment system.

Jan 1, 2010

By John B. Umhau

In 1930 , 65,448 long tons of virgin or primary tin were consumed by 1,292 establishments in the United States , representing about 91 per cent of the total consumption as computed from imports , exports , and stocks at the beginning and the end of the year . The reported consumption was equivalent to 38 per cent of the world's tin production in 1930 , estimated at 171,000 tons , and was 12 per cent less than the 74,369 tons consumed by 1,307 establishments in 1928 . Decreased consumption of new tin in 1930 ás compared to 1928 was a reflection of the general industrial depression . All of the tin- consuming industries showed substantial decreases except tin plate and terneplate , white metal , and tinning , which showed small tonnage increases aggregating only 1,200 tons . The largest tonnage decrease was in the use of new tin in babbitt which declined 33 per cent in 1930 as compared to 1928. This was largely attributable to the decreased production of automobiles and trucks , which was 24 per cent lower in 1930 than in 1928. Percentage decreases in other important tin- consuming industries were as follows : Solder 18 per cent , bronze 19 per cent , tin foil 40 per cent , chemicals 23 per cent , tin oxide 44 per cent , and type metal 46 per cent . The distribution of the amount consumed by various uses during 1927 , 1928 , and 1930 is shown in table 1 . Consumption studies indicate the fact that variation in tin consumption from year to year parallels the fluctuations in demand for the already wellestablished tin products . For example , the manufacture of motor cars and trucks3 required only 11,000 tons of tin in 1930 compared to 19,000 tons in 1928 ; the canning industry continues to require the greater portion of the tin plate and much of the solder . Recently developed industries , while affecting total consumption of bearing metals , solders , etc. , to some extent , have made little change in the relative importance of these commodities as consumers of tin .

Jan 1, 1932

By Edward D. Thimons

Because of the high number of accidental methane gas ignitions in metal and nonmetal mines, the Bureau of Mines searched for a simple guideline that would allow mine personnel to evaluate the methane hazard in a given mine. Air samples were collected by the Bureau in 53 metal and nonmetal mines and analyzed for trace evidence of methane gas. Samples were collected in the returns and at the working faces. Those mines classified as gassy by the Mine Safety and Health Administration had a significantly higher average methane concentration than those classified as nongassy. Of the 9 gassy mines sampled, 7 had methane concentrations above 100 ppm, whereas only 1 of the 44 nongassy mines had a concentration above 100 ppm. The 100-ppm concentration may be used as a simple and convenient guideline for forecasting the methane hazard in a mine, whether or not the mine is classified as gassy. There was no consistent correlation between commodity mined and methane concentration, nor was there a correlation between mine depth and methane concentration. Neither of these factors can be considered a guideline for predicting methane hazards.

Jan 1, 1979

By C. J. Chindgren

A refractory-lined, garage-type automobile incinerator with a natural gas afterburner for air pollution control was cooperatively constructed and tested by the Bureau of Mines and the Wasatch Metal & Salvage Co. in Salt Lake City, Utah. The incinerator is capable of relatively smokeless burning of 32 to 60 cars per day, dependent on the degree to which the cars are stripped prior to incineration. Preliminary burning campaigns indicate the cost of incineration to be approximately $2.75 per car.

Jan 1, 1970

By A. C. Johnson

This report is one of a series being prepared by the Bureau of Mines on exploration, development, mining methods, and costs at various mines in the United States. It describes operations at the Black Rock mine, Wah Chang Mining Corp., Mono County, Calif. The purpose of these reports is to promote development and conservation of our mineral resources by disseminating technologic information on mining methods, practices, and costs. The Black Rock tungsten mine of the Wah Chang Mining Corp. is 33 miles north of Bishop, Calif., in the Benton Range, Mono County, Calif. The property was acquired in August 1950 and a well-planned program of exploration, development, and exploitation resulted in a good production record with low costs. Operations were halted in July 1957, about 6 months after suspension of the tungsten purchase program by the Federal Government.

Jan 1, 1960

By J. E. Tress

The Bureau of Mines has developed a process to utilize waste heat from electric arc steelmaking furnace gases to preheat the ferrous material charged to the furnace. Four heat exchangers were designed, tested, and operated successfully on 1-ton electric arc furnaces. Briquets and pellets were charged continuously, both countercurrent to the hot furnace offgasses and at ambient temperatures. A comparison of the electrical energy consumed in each situation showed that preheating can lower energy requirements as much as 15.6 percent.

Jan 1, 1975

By M. S. Seehra, V. S. Babu

"INTRODUCTION The accurate determination of the free silica index in coal mine dusts is an important requirement because severe health hazards are believed to be associated with the inhalation of respirable-sized silica particles.1-6 Free silica refers to the three polymorphs of silica (Si02)viz., quartz, cristobalite, and tridymite-although quartz is usually the dominant form in most mine dusts.6 The free silica index is the concentration in micrograms of free silica in air per m3 of air sampled corrected to standard conditions of 25°C and 760 mm/Hg, the present MSHA (Mine Safety and Health Administration) limit on time-averaged basis being 100 µ.g/m 3 for coal mines. A recent review7 has concluded that quartz, cristobalite, and tridymite particles impart nearly equal long-term hemolytic damage when compared on a per unit surface area basis.At present, two experimental methods-viz., transmission infrared spectroscopy (TIRS) and x-ray diffraction (XRD)-are commonly used for the determination of silica concentrations in mine dusts. In TIRS, which has been adopted by MSHA and is commonly called the P7 method, the silica absorption band near 800 cm - 1 is used for quantification. However the mineral kaolinite, which is commonly present in mine dusts, also has absorption band, albeit weaker, at 800 cm- 1• To correct for this interference, one uses the stronger 915-cm -1 band of kaolinite to determine the concentration of kaolinite, and the kaolinite contribution to the absorbance at 800 cm-1 is then determined from a calibration curve, leading to the determination of silica by subtraction. In the XRD technique, usually an internal standard such as CaF 2 is used to determine the concentration of silica from line intensity measurements. XRD has the added advantage that concentrations of quartz, cristobalite, and tridymite can be determined.8•9 In an exhaustive study on the precision of the techniques ofTIRS and XRD for monitoring worker exposure,9 the conclusion has been reached that both methods measure silica within 253 of the ""true"" value 953 of the time in a single laboratory."

Nov 1, 1995

By James P. McGee

Preliminary calculations show an economic advantage in using nuclear energy to supply the endothermic heat required for gasifying coal. It should be noted that the various assumptions used in preparing these calculations must undergo further evaluation through additional engineering design and research. The proposed system for gasification is the indirect process cycle with helium heated in a nuclear reactor and passed through an exchanger-type gasifier for the reaction of coal and steam to form CO (carbon monoxide) and H2 (hydrogen gas).

Jan 1, 1960

By Arne Landsberg

The Bureau of Mines has undertaken research to elucidate the chemistry involved in the efficient recovery and control of minor elements in base metal smelting operations. These elements should be effectively recovered not only because they have commercial value, but also because of their potential hazard to workers' health and the environment, if they are not controlled during processing. Cadmium, a minor metal in zinc ores, is the subject of this report. The roasting step of the complex zinc-smelting process was chosen for investigation because of the high potential for removing cadmium by volatilization during this primary stage. Commercial roaster feed materials were used to determine the sequence of reactions and the effect of these reactions on the volatilization of cadmium. Electron microprobe examination of both the commercial roaster product and oxidized sulfide solid solutions prepared in the laboratory showed that oxidized iron was of prime importance in preventing cadmium volatilization. The mechanism by which iron prevents cadmium volatilization is proposed, and a preheating technique is recommended for more effectively recovering cadmium prior to roasting.

Jan 1, 1981

By B. J. Dalton

The Helium Research Center, Helium Activity, Bureau of Mines, is presently engaged in a critical examination of all of the PVT data on helium that appear in the literature. The long-range objective is the development of a single equation of state for helium that will allow all of the thermodynamic properties to be calculated and will reproduce all of the data within the accuracy with which the data are known. A preliminary objective is to obtain the best values of the second virial coefficients and to develop an equation that will reproduce the best values as a function of temperature. The method of treatment consists in expressing the PV product of a gas, for a given isotherm, in terms of a power series in either the pressure or the density and evaluating the constants by least squares solution. Associated with these functions whose coefficients have been evaluated by least squares, the following errors, or deviations, are of interest; the standard error of a single measurement; the standard error in each coefficient; and the standard error of the resulting function.

Jan 1, 1964

By William H. Schiffbauer, Ph. D. Mowrey

Proximity warning devices can improve workplace safety by alerting workers when they are in a hazardous area near moving equipment. Industrial work sites often present extreme challenges to safety-based proximity warning devices. Many commercially available types of proximity warning sensors and systems can be rendered useless when covered with mud, ice, snow, ore, rock, and other material. The list includes radar, ultrasonic, capacitive, and visual types of sensors and systems. Addressing these shortcomings, NIOSH personnel have developed a patented active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) which employs lowfrequency, low-power magnetic fields which are quite impervious to severe environmental conditions. A shapeable wire loop antenna which provides the marker of dangerous work areas, has been mounted on a continuous mining machine and was mounted inside 1.3-cm thick angle iron. This loop antenna was exposed to more than six months of active underground coal production, which included being covered by and scraped over with tons of rock, sprayed by a continuous stream of water, and immersed in thick mud. After six months the loop antenna showed signs of wear, but was still capable of performing its intended function. The HASARD system is now being applied to other industrial applications and is showing much promise, especially in harsh environments. This paper details the system, describes the tests that have been done, and mentions other areas where it can benefit the safety of industrial workers.

By R. R. Wells

This report summarizes the results of laboratory testing of copper-bearing magnetite ore from the Poorman, Bush & Brown, and Copper Center deposits, Kasaan Peninsula, Prince of Wales Island, southeastern Alaska. The ores contain minor amounts of chalcopyrite and pyrite. Intimate association of these sulfides with magnetite necessitates fine grinding for adequate liberation and rejection of copper and sulfur and for the production of high-grade iron concentrate low in objectionable impurities. Laboratory tests indicated that the optimum results can be obtained by flotation of ore ground to minus-100-mesh, with subsequent wet magnetic separation treatment of the flotation tailing. A summary of results obtained by this treatment of the three samples tested is shown in table 1.

Jan 1, 1957

By A. J. Kraemer

[During the past several years a great deal of discussion has centered around the question of the permissible limit of sulphur content in fuels for automotive and aviation motors. Under certain conditions of operation, sulphur in motor fuels causes the formation of corrosive substances which attach bearings, wrist pins, and other parts of engines. On the other hand, in making gas¬oline from certain stocks, the gasoline fraction normally contains a relatively large proportion of sulphur compounds. By the generally used processes of reducing the sulphur content, a significant part of the gasoline fraction is lost as motor fuel, and added expenses are entailed for chemicals, labor, and other process costs. This condition has been an economic burden to some refiners of high-sulphur crudes. In some instances the treating losses have been rather severe and the treating costs relatively high, but the data presented in this paper indicate that the reduction of sulphur content of motor fuel is a problem to a relatively small number of refiners and of little or no concern to the remainder; in fact, more then 90 per cent of the 153 samples analyzed passed the Federal specification requirement, which limits the sulphur content to 0.10 -nor cent. 3 This report is based upon the results of an examination for sulphur content, Doctor test, copper strip corrosion, and color of the samples collected during January, 1930, for the twenty-first semiannual gasoline survey of the Bureau of Mines. The results of the gravity and distillation tests of the survey were published as Report of Investigations 2995. The numbering of the samples given in this report is the same' as in Report of Investigations 2995; for example, No. 25 of this report is the same sample as No. 25 of Report of Investigations 2995.]

Jan 1, 1930

By L. E. Geyer, W. W. Adams, M. G. Parry

"More than 73 million pounds of rock dust were used by the bituminous-coal-mining companies in the United States during 1930 to present or limit loss of life and destruction of property from explosions of gas and coal dust in underground mining operations, according to statistics compiled by the United States Bureau of Mines from reports furnished by mine operators. The mines using rock dust produced 65. 691, 753 tons of coal during the year, more than 30 percent of the total production of bituminous coal from underground mines in the United States that year. Although only 382 out of a total of 5,629 active underground bituminous mines applied rock dust to underground working as a precaution against explosions, they were chiefly the larger producing mines, employing 25.4 percent of all of the underground bitumious mine workers in the United States and accounting for 27.4 percent of the total number of man-hours worked underground at bituminous mines.a summary of the reports for the 382 mines using rock dust showed a total production of 96,691,755 tons of bituminous coal, 89,503 men employed underground, and 129,718,965 man-hours worked by the underground employees. (See tables 1 and 2.) These mines averaged 8.76 pounds of rock dust per ton of coal shown by reports from 385 mines using rock dust in 1932 (See table 3.)"

Nov 1, 1935

By Jon C. Volkwein

The U.S. Bureau of Mines has developed a method to measure methane and other gases during the auger mining of coal. An intrinsically safe commercial gas detector with a built-in data logger was mounted in the center of the hollow conveying auger. A sampling head through the wall of the auger conducted a gas sample to the detector. Results showed that gas levels can be monitored on a continuous basis during the auger mining of coal and the data retrieved upon completion of the hole.

Jan 1, 1994

By H. J. Heinen

The Bureau of Mines, investigated a cyanidation-carbon adsorption technique for extracting gold from arsenopyrite concentrates. Agitation leach experiments were conducted on 85-pct-minus-35-mesh gravity concentrates containing 21.8 oz gold and 6.4 oz silver per ton. Results obtained in leaching the concentrates showed that 96.9 pct gold and 90.7 pct silver extraction could be achieved in 96 hours of agitation. Gold and silver were recovered from the resulting pregnant solution by exposure to granular activated carbon in a countercurrent system. Carbon loadings of 2,556 oz of gold and 502 oz of silver per ton were achieved. These loadings are significantly higher than heretofore thought practical.

Jan 1, 1980

By Harry W. Campbell

In 1986 at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 2 acre North Sisters Rocks Wilderness Study Area (OR-12-8) in order to evaluate its identified mineral resources. The Wilderness Study Area is located in Curry County, Oregon, about 15 miles north from Gold Beach. No mines, prospects, or mining claims were located inside the study area, and no mineral resources were identified. Stone from the study area could be quarried and used for construction purposes; however, two nearby quarries have sufficient stone to satisfy local construction needs. 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 mineral resource potential of the North Sisters Rocks WSA (Wilderness Study Area) 1/ 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 investigations will be used to help determine the suitability of the North Sisters Rocks WSA 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, 1987