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By R. H. Lien

The Bureau of Mines developed a flue gas desulfurization process as part of its goal of minimizing the undesirable environmental impacts associated with energy and mineral-processing plants. The modified citrate process involves absorption of sulfur dioxide (S02) in a buffered citric acid solution. The S02-loaded solution is regenerated by countercurrent contact with steam in a packed tower. The wet S02 product is then dried and can be liquefied or further processed to make sulfuric acid. Test data from process investigation unit studies are presented. Material balances, flowsheets, and cost estimates are given for recovering S02 from copper smelter reverberatory gas, lead smelter sintering machine tail gas, and power-plant stack gas. Operating cost estimates show the process will add $0.04 per pound of copper, $0.01 per pound of lead, and $0.015 per kwhr to the cost of the respective operations. These costs could be substantially reduced if a source of waste heat was avail-able to provide the process steam requirements.

Jan 1, 1982

By Edward L. McHugh, Charles Sabine, Louis J. Denes, Jami M. Girard, Peter Metes

The Spokane Research Laboratory, National Institute for Occupational Safety and Health, is investigating various remote sensing technologies as possible tools to detect, monitor, and mitigate hazardous situations in surface mines that could lead to catastrophic slope failure. Promising technologies include a field-portable spectro-polarimetric imager and a stationary interferometric radar device. Field tests were conducted of a prototype visible and near-infrared spectro-polarimetric imager (SPI) built at the Carnegie Mellon Research Institute. The SPI employs anacousto-optical tunable filter (AOTF) to control wavelength, a phase retarder to measure polarization signatures, and a digital camera and computer to capture data. Images obtained at the Mountain Pass and Castle Mountain mines in southeastern California showed that the instrument is capable of obtaining hyperspectral images of highwalls, outcrops, hand samples and drill core in the field. We have retrieved spectra from Mountain Pass images that closely match those of bastnaesite and have had some success in classifying images. Although radio frequency noise in the data limited spectral classification of imagery, we project that careful alignment of the AOTF should minimize the noise and greatly improve classification.

By Paul Hopkins

The following methods have been selected from a large number tried while assaying several hundred samples of placer concentrates. It is thought that some of these methods may be useful to those who are required to assay similar products containing large quantities of metallic articles, such as jeweler's sweepings. No great difficulties will be encountered in assaying black sand from beaches or river bars. Such samples require care in grinding and sifting so that no oversize particles of sold or platinum are lost. It is also necessary to have sufficient silica in the flux to form a fluid slag with the excess of iron, magnesium, or chromium Which such samples contain.

Jan 1, 1934

By Jr. Harty

Intensive work on the deoxidation of steel with manganese-silicon alloys by the U. S. Bureau of Mines has shown that the use of those alloys, which may be produced from our domestic manganese ores, would decrease the ferromanganese requirements of a very large tonnage of our steel by from 60 to 80 per cent and in some cases by 100 per cent. The open-hearth heats made with these alloys have been of excellent quality. The tonnage of our ferro-grade ores Which has been made available by the bureau's ore-dressing studies, combined with the products resulting from such processes as those developed by the bureau and by Bradley for Cuyuna ores, should easily fill our reduced ferromanganese requirements when manganese-silicon alloys and ordinary Spiegel are used in the way described in this report. There are no technical difficulties in the application of this practice, and any difficulties involved in its wide and immediate application would only be those arising from habituated ideas of the necessity of ferromanganese. General acceptance of this practice and development of the available sources of domestic ferro-grade material by already proven processes should make this country independent of foreign ores. This paper resents the results of work done under a cooperative agreement between the Pittsburgh Experiment Station of the United States Bureau of Mines and the Carnegie Institute of Technology, the Metallurgical Advisory Board, and the University of Pittsburgh, Pittsburgh, Pa.; between the Mississippi Valley Experiment Station of the United States Bureau of Mines and the Missouri School of Mines and Metallurgy, Rolla, Mo.; between the North Central Experiment Station of the United States Bureau of Mines and the University of Minnesota, Minneapolis, Minn.; and between the Rare and Precious Metals Experiment Station of the United States Bureau of Mines and the University of Nevada, Reno, Nev.

Jan 1, 1931

By T. W. Johnson

The Bureau of Mines, in cooperation with the Natural Gas Department of the American Gas Association, has in progress a study or the flow of natural gas through high-pressure transmission lines. A major problem of this study is to compare the deliveries calculated from the gas pipe-line flow formulas commonly used, with the metered deliveries from pipe lines in operation. In order to obtain such comparisons a series of tests has bean made on 25 operating pipe lines in Kansas, Oklahoma, Louisiana, Arkansas, Texas, and California ACKNOWLEDGEMENTS Study of the flow of natural gas through high-pressure transmission lines was made under the general supervision of H. H. Hill, former chief petroleum engineer of the Bureau of. Mines, H. C. Fowler, acting chief petroleum engineer of the Bureau of Mines, N. A. C. Smith, superintendent of the Bureau of Mines Petroleum Experiment Station at Bartlesville, Okla., and T. Brandenthaler, chief of the oil and gas action of the Bartlesville station.

Jan 1, 1929

By James C. Barker

Gold placer deposits along the upper Yukon River, in the region between the river villages of Circle and Eagle, were investigated by the Bureau of Mines. The investigation was conducted intermittently between 1976 and 1985 as part of an evaluation of mineral resources on lands proposed for inclusion in the National Park System. At least 230,000 troy ounces (tr oz) of gold has been produced in the region, principally from Woodchopper, Goal, and Fourth of July Greeks. The placers are underlain by, or occur downstream of, early Tertiary sediments that have been deposited in the Eagle Trough. Strike-slip displacement along the Tintina Fault is responsible for creation of the trough and may have been a factor in the formation of the present placers. Placers were found to have a close spatial correlation to certain altered fault lineaments of the Tintina Fault trench. Placer concentrates contain several different textural forms of gold, suggesting multiple origins. Geological studies and a survey of 162 panned concentrates throughout the region indicated previously unreported sites of placer gold, and potential exists for the discovery of additional placer and lode gold. Because of nearly continuous soil and vegetation cover, further evaluation of the region will require subsurface sampling.

Jan 1, 1986

By Elaine T. Cullen, Albert H. Fein

Federal law mandates that all miners receive safety and health training when first entering the mining industry and at least 8 hours annually thereafter. Although the mining industry has historically relied on an experiential master-apprentice model for training new employees, the formal safety training provided to miners is generally done in a classroom, with mixed results. In a series of stakeholder meetings held by NIOSH across the West in 1997-2000, trainers identified significant gaps in materials that were available to teach new and experienced miners. They asked whether NIOSH could develop effective materials to fill these perceived gaps, as well as make training more effective for those who were required to attend, but who often refused to be attentive. Adult learning theories, social learning theories, mentoring, and storytelling were all employed in the development of a series of safety training videos that have become very popular in the mining industry. This Report of Investigations describes the theoretical frameworks that were used, the process that was developed to produce the videos, and the results of the evaluations as to whether or not they were effective in training new and experienced miners.

Jan 8, 2005

By Thomas J. Peters

In 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 34,310-acre Diablo Mountain (Additional) study area (OR-001-058), in order to evaluate its identified mineral resources and occurrences. The study area lies along the east shore of saline Summer Lake in Lake County, OR, about 145 miles southeast of Bend and 45 miles northwest of Lakeview. The climate is semiarid and temperate, and the study area is almost treeless. Geologically, the (Additional) study area is in a region of fault block-formed mountains and basins, characterized by interior drainage. The area is mainly underlain by unconsolidated Quaternary and Pleistocene lake and playa sediments, which may include subsurface evaporite mineral deposits and resources. Near the center of the eastern margin of the study area are an occurrence of dolomitic limestone of unknown extent, and an area of basalt outcrop totaling 1.5 square miles. A veneer of windblown sand covers about one-half the study area.

Jan 1, 1989

By W. W. Odell

"It is common knowledge that extensive lignite deposits occur in the States of Montana, North and South Dakota and Texas. The total area of these deposits and the total amount of lignite in them is so great that the true economic value of lignite is seldom realized. These deposits underlie areas of thousands of square miles. The area of the lignite lands in North Dakota alone is estimated to be approximately 32,000 square miles. Nearly one-third of the total solid-fuel resources of the United States is lignite and approximately 90 per cent of this lies in the Northwest.To the people of the Northwest the more extended utilization of lignite is of fundamental importance, hence any methods for commercially producing salable products from lignite that promise further development of these great fields deserve careful study.The development of our lignite resources has been slow, partly because the districts wherein lignite is found is not thickly settled or highly developed in manufacturing industries, but also because of the physical and chemical characteristics of the lignite. Lignite is classed as a low-grade fuel and may be con¬sidered as imperfectly developed coal -which has a more or less woody structure; it may be of the brown-coal type or darker, denser and more homogeneous, approaching subbituminous coal in character. As mined it contains more than 30 per cent of moisture exclusive of the -rater of decomposition formed .then it is carbonized or burned. The heating value as determined by the calorimeter is approximately half that of good quality bituminous coal. Upon exposure to the air lignite loses part of its moisture, whereupon the lumps chock and split until after considerable exposure, a large percentage of slack is formed. It cannot be stored in large piles so successfully as come other fuels, and it some instances it is more apt to ignite spontaneously in storage or in transit then the higher grade fuels."

Feb 1, 1924

By R. M. Santmayers

[This paper presents one of a series of digests of foreign mining legislation that is being prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the mining legislation of Bulgaria was prepared from a copy (in French) of the Mining Laws of Bulgaria, promulgated by Royal Decree No. 33 of I. arch. 31, 1910, and published in the "Journal Official," No. 83, April 14, 1910, and checked against a digest prepared by Maynard B. Barnes, First Secretary, American Legation, Sofia, Bulgaria, dated June 10, 1932, which was transmitted through the courtesy of the Department of State. CLASSIFICATION OF MINERAL SUBSTANCES Mineral deposits are classed either as mines or quarries. (Art. l.) Tunes are deposits, the products from which must be processed. Under this class specific mention is made of the metals (gold, silver, copper, lead, zinc, iron, chrome, titanium manganese, tungsten, tin, mercury, platinum, cobalt, nickel, cadmium, aluminum, molybdenum, bismith, uranium, antimony, arsenic), sulphur and other "analogous" mineral substances, phosphate rock, iron pyrites, sulphates, saltpeter, alum, boracic acid and its compounds, talc, asbestos, amber, graphite, merschaum and precious stories of all kinds, reek salt and other salt, peat, coal, petroleum, ozocerite, asphalt and all other bituminous substances. (Art. 2.)]

Jan 1, 1933

By Mayo D. Hercey, Edward W. Butzler

"Purpose and Origin of Investigation.For many investigations of mineral products such as metallic and ceramic materials, especially refractories, a knowledge of thermal conductivity and specific heat at high temperature is required. Such data have been needed by the Bureau of Mines for checking heat balances in kilns, and computing heat loss through furnace walls.Design of apparatus for thermal conductivity tests was undertaken by the Bureau early in 1922, an industry at that time indicated that no equipment intended for extreme high-temperature observations was elsewhere available or likely to be in the immediate future.The Bureau's investigation was begun by C. R. Greenslade, assisted by F. A. Hartgen, and temporarily discontinued owing to their resignations in the summer of 1922. The work was later turned over to the writers of this report, and has been carried forward at intervals, along with other problems."

Jan 1, 1924

By Lloyd A. Morley

Two methods are presented to determine the mechanical shaft torque as a function of time for an induction motor. The methods are based on the motor equivalent circuit and use as input variables of the motor terminal voltage, line current, input power, and power factor. One method uses all four variables and the other uses only voltage and current. The test data deals specifically with continuous miners, but the theory could be applied to other mining machines driven by multiple induction motors. Results are given for the tramming, maneuvering, cutting, and cutting with loading operations and are in the form of a minimum, a maximum, and an average of the shaft-torque time function. The theoretical development and computer implementation are discussed for both methods.

Jan 1, 1978

By Charles B. Kenahan

Application of ultrasonics in the electrolytic deposition of metallic manganese and manganese dioxide from sulfate electrolytes had several effects. Ultrasonics produced finer-grained deposits of electrolytic manganese at all current densities than obtained in normal cell operation, but at high current densities it resulted in less adherent deposits. Ultrasonic radiation did not affect cell voltage or cathode current efficiency. In the electrodeposition of manganese dioxide at 70° C., ultrasonic-; increased the current efficiency and decreased the cell voltage at a current density of 9 amperes per square foot, but it had little effect at current densities above this. The decrease in cell voltage was caused by the depolarizing action of ultrasonics at both anode and cathode. Ultrasonic radiation produced a smooth, glossy, adherent, and pit-free deposit at all current densities and at each temperature. Radiation had no effect on current efficiency or cell voltage at 90° C. Ultrasonics was more effective than conventional agitation in producing all of these effects.

Jan 1, 1962

By Leonard Obert

[Tng occasional. rock noises in a nice caured by brc,*ing and ripping of the back, settling, and other cailscr, are well-known tc~ a11 mining en- gineers. These noises oftcn prececte certnin tpes of rock failure as such are used to e certain event a; w:,rnlngs. Senides t5ese audible rock noisee t'nere are, l?o\;evpr, even Iprger nw.iber of' s;Lba.J^;li5le rock mis~s, which must; be piclcell UT with sole type of vi-urr,tion rnicroyhoce and qli- fied in order tnnt :hey n;ny e heard. It v:zs s~v;,yestec" Ir, an evlier ? ,I a.ldible noises Ifureau of I.lines s~zb:ic;et.iod that n stud:r of t!ler;c! *- t mig!!t be useful ir. de temining roc^ movemrnt 3 preceding failure.]

Jan 1, 1941

By Leonard Obert

[Tng occasional. rock noises in a nice caured by brc,*ing and ripping of the back, settling, and other cailscr, are well-known tc~ a11 mining en- gineers. These noises oftcn prececte certnin tpes of rock failure as such are used to e certain ev';ent a; w:,rnlngs. Senides t5ese audible rock noisee t'nere are, l?o\;evpr, even Iprger nw.iber of' s;Lba.J^;li5le rock mis~s, which must; be piclcell UT with sole type of vi-urr,tion rnicroyhoce and qli- fied in order tnnt :hey n;ny e heard. It v:zs s~v;,yestec" Ir, an evlier ? ,I a.ldible noises Ifureau of I.lines s~zb:ic;et.iod that n stud:r of t!ler;c! *- t mig!!t be useful ir. de temining roc^ movemrnt 3 preceding failure.]

Jan 1, 1941

By Annie G. Smelley

The Bureau of Mines, U.S. Department of the Interior, as part of its mission to effect pollution abatement, conducted research to devise means for disposing of phosphatic clay wastes and reclaiming mined land. Part of the investigation was performed in a cooperative research project with 10 phosphate companies in Florida. The colloidal properties of the phosphatic clay suspensions, called slimes, make them difficult to dewater and dispose of without impoundment storage aboveground. Various reagents to flocculate and dewater these plant wastes were evaluated, and a polyethylene oxide polymer was found to function in a specialized flocculation dewatering technique. The flocculation dewatering method was investigated in bench-scale batch tests and applied in continuous dewatering tests using standard mineral-processing equipment. In continuous tests at feed rates of up to 58 liters per minute, wastes at 4 percent solids were dewatered to about 20 percent solids. About 0.8 kilogram of polymer was used for each metric ton of dry waste clay solids; processing time was about 4 minutes. Requirements for the treatment system are (1) proper mixing of the clay-waste feed and flocculant, (2) rapid removal of water as it is released, and (3) physical manipulation to promote cohesion of solids.

Jan 1, 1979

By F. W. Smith

This paper is based largely on a study of experimental data obtained by the Bureau of Mines in its comprehensive 25-year survey of the carbonizing properties of American coals. Although the Bureau was interested in and conducted carbonization research-from time to time ever since it was organized in 1910 (1),4/ no systematic studies of the coke-, gas-, and byproduct-making properties of American coals were undertaken until 1927, when the American Gas Association appointed an advisory committee (2) to cooperate with the Bureau in developing equipment and techniques to obtain-data for the accurate assessment of the behavior of coals on carbonization. It was found, in general, that small-scale laboratory tests were unsuitable for the complete evaluation of the coking properties of coal; hence, larger pilot-plant-scale equipment was designed and used (3). It was decided that the scale of the test should be large enough to determine both the yield and quality of the products and yet small enough to maintain adequate control of the process variables (4). These considerations led to development of a carbonizing retort and furnace-of 80 to 200 pounds of coal capacity, suitable for operation at various temperatures up to 1,100° C. (2,0120 F.) and equipment for recovery and measurement of gas and byproducts. This apparatus and the standardized procedure for its operation became known as the Bureau of Mines-American Gas Association (EM-AGA) method or retort (5).

Jan 1, 1955

By L. B. Berger

In this investigation, the ampoule type of carbon-monoxide (CO) detector which is manufactured under license of U. S. Patent 1,644,014 (October 4, 1927) was tested for sensitivity and reliability. This detector was devised primarily for examining the air of manholes and sewers for possible dangerous contamination with CO before workman enter those places, but dine to the simplicity of the device it may have a more general usage for examination of atmospheres which are known or suspected to be contaminated with CO. Some of the suggested uses are the examination of the air in garages, tunnels, mines, around blast furnaces, gas plants, and in the home.

Jan 1, 1930

By Paul Hopkins

The following methods have been selected from a large number tried while assaying several hundred samples of placer concentrates. It is thought that some of these methods may be useful to those who are required to assay similar products containing large quantities of metallic articles, such as jeweler's sweepings. No great difficulties will be encountered in assaying black sand from beaches or river bars. Such samples require care in grinding and sifting so that no oversize particles of gold or platinum are lost. It is also necessary to have sufficient silica in the flux to form a fluid slag with the excess of iron, magnesium, or chromium which such samples contain. It is much more difficult to assay black sands, or concentrates, produced in large-scale placer-mining operations. These products are usually much harder and more abrasive than the beach black sands. They also contain numerous metallic particles resulting mainly from wear on the mining machinery. These particles consist chiefly of iron or steel but also contain lead, copper, and alloys such as babbitt, solder, brass, ferrosilicon, etc. Fairly large particles of gold are often found. Some samples will contain as much as 10 percent of such metallic particles. It is not feasible to remove the particles of iron with a magnet and discard them, as they invariably contain gold, sometimes a considerable amount. This gold is attached to the iron particles by rust or wedged into cavities. Scraps of sheet iron are often found which have become tightly folded or rolled and contain gold or amalgam within the folds.

Jan 1, 1934

By D. B. Dow

The presence of sulphur compounds in petroleum and its products is, generally speaking, undesirable, and the problems involved in removing such compounds are of great importance to the petroleum refiner and to the manufacturer of gasoline. There are several types of these compounds which are dissimilar in physical and chemical characteristics, as evidenced by different objectionable features which they exhibit, and special treatments have been developed to meet conditions existing in various products. This paper deals with the treatment of natural-gas gasoline for the removal of certain sulphur compounds which, if not removed, impart on objectionable odor and in addition badly discolor the product. The presence of this particular type of sulphur compounds is detected by the "doctor" test.* In some instances natural-gas gasoline is purchased on "doctor" test specifications, and the ordinary purchaser, while not buying on "doctor" specifications, is insistent in his demand for a water white product. Gasoline which fails to meet the "doctor" test, if not received by the buyer within a few weeks after time Of manufacture, may be "off color" enough to warrant a deduction from the market price.

Jan 1, 1923