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By H. D. Kline

Manganese ores have been mined in the Batesville district since 1849. Although not continuous over the intervening years, production had totaled approximately 432,000 tons of manganese ore and ferruginous manganese ore to the end of 1953. The ores occur in deposits, essentially low in manganese content, distributed over an east-west belt 24 miles long and 4 to 8 miles wide, the core of which is about 6 miles north of Batesville, Independence County. Although the reserves of high-grade ores in the district are comparatively small, the large deposits of subgrade ores and low-grade manganiferous material comprise potential sources of supply of manganese that may have increasing future importance. The manganese occurs as primary oxide and carbonate minerals in relatively flat-lying limestone and shale formations in which they were originally deposited and as oxides in residual clays resulting from decomposition of the shale and lime-stone. Most of the deposits underlie from a few to over a hundred feet of sedimentary chert, but many occur in the residual clays on exposed slopes of chert-covered hills.

Jan 1, 1956

By E. A. Barrett

The U.S. Bureau of Mines (USBM) conducted experiments to determine if training using a latent-image, three-dimensional (3-D) slide simulation exercise improved miners' ability to recognize roof and rib hazards. The effectiveness of this innovative type of classroom training was investigated by measuring workers' performance on a hazard recognition task. The study was unique in that hazard recognition skills were assessed in the workplace using actual coal mine roof and rib hazards. Results showed that training with a latent-image, 3-D slide simulation exercise significantly improved each subject's performance on the in-mine hazard recognition task. Further, the USBM researchers concluded that transfer of learning from the classroom to the workplace occurred.

Jan 1, 2010

By A. B. Hooker

Many attempts have been made to develop methane detectors that will be safer and more accurate than the flame safety lamps used to detect methane in mines. The development has taken two general forms, namely: (1) Methane detectors, in which the evidence of methane depends entirely upon changes in the appearance of the detecting element, such as a flame or filament; (2) indicating methane detectors or those equipped with scales upon which the approximate percentage is definitely indicated. As an aid in the development of suitable detectors, the United States Bureau of Mines has assembled and published in its Schedule 8B a set of minimum requirements which tests and experience have shown desirable for methane detectors. Any manufacturer may submit his detector for inspection and tests leading to approval under this schedule.

Jan 1, 1930

By W. J. Crawford, P. M. Gruzensky

"Several experiments have been carried out in efforts to evaluate qualitatively a variety of electrolytes for refining bismuth. Most extensive work was done with the basic tartrate, hydrochloric acid, and hydrofluosilicic acid electrolytes. Deposits that are smooth and adherent can be obtained from these three electrolytes if low cathode current densities are employed. All three electrolytes were effective in purifying crude bismuth considerably, with additional purification indicated in each instance by a reelectrolysis step.With the basic tartrate electrolyte best results were obtained when the electrolyte was at 40° C. and contained at least 100 grams of bismuth per liter. An apparent disadvantage was depletion of bismuth from this electrolyte, causing the deposits to become spongy and nonadherent.The hydrochloric acid electrolyte had the greatest tendency to yield rough, dendritic deposits. Best deposits were obtained at cathode-current densities below 2 amperes per square decimeter. A small amount of glycerin helped to produce a smoother deposit, and adding sulfuric acid or methyl sulfuric acid retarded the deposition of impurities. Very good results were obtained in electrowinning bismuth from a bismuth trichloride-hydrochloric acid electrolyte.Smooth and adherent deposits were obtained from a hydrofluosilicic acid electrolyte, with very good refining as regards lead and silver impurities; however, higher reagent costs and slow decomposition of the electrolyte have discouraged its use.INTRODUCTIONMethods of recovering bismuth from ores and byproducts were underdeveloped for many years because of the limited uses for bismuth, the pharmaceutical industry being the chief consumer. In the past decade or so additional uses for bismuth, particularly in the metallurgical field, have brought about increased demand for the metal with the result that bismuth is being recovered from byproducts that were once discarded. In addition to such uses as low-melting alloys, solders, bearings, die setting, etc., some interest has been indicated in bismuth as a possible coolant for nuclear reactors. The advent of ductile bismuth and bismuth-alloy thermocouple wire has contributed greatly to temperature measurement, particularly in the below-zero range."

Jan 1, 1956

By Gerald W. Elger

To determine the feasibility of removing nonferrous metal impurities from automobile scrap by thermal treatment in a rotary kiln, the Bureau of Mines conducted four series of tests with synthetic scrap mixtures heated at various temperatures under oxidizing and reducing conditions. The treated scrap mixtures were melted in an electric-arc furnace and cast into small ingots for impurity evaluation. Analyses showed that the ingots were essentially free of residual metal impurities except for copper. Test data indicated that in an oxidizing atmosphere the percentage of copper removed increased with treatment temperature. Percent of copper removed in a reducing atmosphere was found not to be temperature dependent. A significant finding was that copper was embrittled under some of the operating conditions and was mechanically removed by fragmentation.

Jan 1, 1968

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Galis Mfg. Co. roof drill. The instructions are based upon two actual installations: one made in a mine on roof drill, model 300, and one in the factory. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other roof drills with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other roof drills and can determine any necessary modifications if they are not.

Jan 1, 1973

By B. H. Eccleston

Experimental data were obtained from two medium-duty diesel engines derated to qualify for use in underground mines. Gaseous and particulate emissions from these engines were measured and results provide information on the effect of exhaust treatment devices on the emissions. The devices in the study were a catalyst, a particulate trap, and an exhaust gas cooler of the water scrubber type. Emission levels of carbon monoxide and hydrocarbons were observed to be very low in comparison with emission levels of comparable engines in full-rated operation. Oxides of nitrogen and benzo(a)pyrene content of the exhaust also were found to be somewhat low in comparison with previous findings. For particulate reduction, the combination of a particulate trap and a scrubber was observed to be the most effective combination tried; in some cases, over 60 pct particulate reduction was effected by the trap-scrubber combination.

Jan 1, 1981

By C. L. Karr

U.S. Bureau of Mines (USBM) research has shown that fuzzy logic and genetic algorithms (GA's) have great potential for industrial process control. A technique has been developed by the USBM in which GA's are used to substantially reduce the time needed to design fuzzy logic controllers (FLC's).This technique shows promise as an efficient, robust approach to developing control systems. The research described in this report is twofold. First, the basic approach to developing an FLC using GA's is presented. The GA-designed FLC is developed for a specific physical system, a pH titration system. Second, empirical results are presented in which variations in the FLC implementation are compared. Specifically, the effects of altering five aspects of the pH FLC are considered: (1) membership function form, (2) number of fuzzy classes, (3) the center-of-area method, (4) implication operator, and (5) fuzzy rule form. Results indicate that (1) the technique in which GA's are used to design FLC's is effective, and (2) when this technique is used, variations in FLC implementation have little effect on FLC performance in a chosen control problem.

Jan 1, 2010

By Carl Rampacek

The conversion of dilute sulfur dioxide gas into sulfuric acid by autoxidation in mechanical cells of the flotation or gas absorber types was investigated. Bench-scale tests were made with sulfur dioxide-air mixtures to determine the influence of several factors on autoxidation of sulfur dioxide, using iron and manganese salts as catalysts. The laboratory investigation subsequently was extended to pilot plant acid-making tests, using a modified turbomixer gas absorber having a 12-inch-diameter impeller. Sulfur dioxide gas was produced for the tests by roasting pyrite in a fluidized-bed reactor. In the better tests, made with manganese sulfate as the catalyst, the equivalent of 1,000 pounds of anhydrous H2SO4 was produced per 24 hours as a 10-percent solution; power consumption was 0.2 kwhr per pound of equivalent anhydrous acid synthesized. The batch and continuous tests demonstrated the technical feasibility of producing dilute sulfuric acid by autoxidation of sulfur dioxide gas in mechanical cells when converting pyrite roaster or waste smelter gases.

Jan 1, 1963

By P. G. Clites

A laboratory furnace was developed by the Federal Bureau of Mines for use in studying the interrelationships among variables associated with skull melting and casting high-temperature metals. Although additional work is necessary to determine the extent to which the information obtained by using this furnace can be extrapolated to larger furnaces of the same type, many casting characteristics of metals and alloys can be determined on equipment of this size. This furnace is a laboratory-size, consumable-electrode, skull-casting furnace equipped with a water-cooled copper ladle. The ladle, which is a tilt-pour or over-the-lip type, has a volume of approximately 30 cubic inches and provides up to 20 cubic inches of molten metal for castings. Castings of various reactive and refractory metals, including zirconium, titanium, hafnium, columbium, molybdenum, tantalum, and tungsten, have been produced. In addition, castings of iron, chromium, and copper have been made. The simplicity and versatility of the apparatus would make it useful to metallurgical laboratories preparing cast specimens.

Jan 1, 1961

By Arthur V. Petty

The Bureau of Mines has investigated the effect of refractory oxide additions, introduced in soluble form, on the refractory properties of 42-, 58-, and 70-pct-A1203 brick. Brick having porosities ranging from 12 to 16 pct were impregnated with solutions containing chrome, chrome-iron, zirconium, calcium, magnesium, cobalt, nickel, tin, and manganese ions. Additions of some of these ions provided dramatic improvements to such properties as hot modulus of rupture, hot load, and particularly slag resistance. These improvements can be related to reduction of porosity, amorphous grain boundary phases, formation of more refractory bond phases, and reduction of the wettability of Al203-containing refractories by metallurgical slags. Fifty-eight-percent-AI203 brick, impregnated with chrome, showed hot modulus of rupture, hot load, and slag resistance two to five times better than those of untreated 70-pct-AI203 brick. This could result in reducing the Nation's dependence on imported refractory-grade bauxite generally required for high-A1203 brick, as domestic alumina resouces could be used to produce the improved refractories.

Jan 1, 1984

By Farrel W. Lytle

An X-ray emission spectrographic method of analysis is presented for determining rare-earth elements in fractions obtained from bastnaesite ore. The method includes determination of yttrium, thorium, lanthanum, and the rare-earth elements in various complex mixtures. The analysis technique is based upon comparing the samples with synthetic standards approximating the composition of the samples. Working curves are plotted on an absolute-intensity basis, with no correction for back-ground. Examples of working curves and the analyses of typical rare-earth concentrates are included. The selection of spectral lines for the various sample matrices is discussed. A special technique is used for samples in which rapid hydration and carbonation occurred. By analyzing synthetic samples of known composition, the accuracy of the method was determined. The average error of analysis was about 3 percent of the amount present in the range from 5 to 100 percent and about 7 percent in the 0.2-to 5-percent range. A maximum of about 40 samples per day may be analyzed for 7 elements each.

Jan 1, 1957

By T. T. Campbell

Studies were conducted by the Bureau of Mines to develop a process for preparing thorium-magnesium master alloys or pure thorium metal by magnesium reduction of thorium tetrachloride in a semicontinuous reactor. Thorium tetrachloride was prepared in a fluidized-bed reactor by chlorination of thorium oxide or thorium oxalate. Conditions were established for producing a suitable thorium oxide feed for a fluidized-bed reactor. Thorium tetra-chloride was purified by vacuum sublimation and subsequently reduced by magnesium in a semicontinuous reactor to form thorium-magnesium alloys. Relatively pure thorium was produced by removing magnesium from the alloys by vacuum sublimation. Close to 100 percent of the thorium fed into the reactor was recovered either as metal (~93 percent) or as thorium oxide (~7 percent). The oxide can be recycled directly into the process.

Jan 1, 1971

By John R. Shattuck

The Shasta and California Iron-ore deposits are 14 miles northeast of Redding, Shasta County, Calif.; and since 1907 have produced more than 300,000 short tons of exceptionally pure iron ore. Although some ore was mined and smelted from 1907 through the First. World War, most of it has been produced from 1942 through 1945 for use in making heavy ship ballast and concrete anchorages for mines. Irregular masses of magnetite, ranging from lumps of a few tons to pods containing about 25,000 tons, occur associated with skarn near the contact between the McCloud limestone and a younger granitic intrusive. Some of the deposits are low-grade, whereas others are nearly pure magnetite. Selective mining and hand sorting are necessary to produce a high-grade product. Investigation of these deposits by the Bureau of Mines included 2,910 feet of diamond drilling, some surface sampling of the principal mineralized zone and beneficiation tests. Resulting factual data are given in the body of this report.

Jan 1, 1948

By J. E. Tiffany, N. A. Tolch

The Pittsburgh Experiment Station has made a survey of the properties and characteristics of the brands of fuse manufactured in the United States ; 25 samples were procured from 4 manufacturers representing the different brands offered on the market when the investigation was begun . It is believed that the field was completely covered except for special fuse made to order for a particular job .

Jun 1, 1934

By J. W. Miller

Wyoming County had for many years supplied large quantities of coking coals to coke plants throughout the eastern United States and Canada. Up to the present most of the coal has been produced from relatively few beds, but in the future the coal will be produced from beds not previously mined in quantity. This trend is shown in the entire Winding Gulf field, of which Wyoming County is a part. This publication is one of a series of Bureau of mines reports appraising the Nation's coking coal, which y be used to determine the practicability of upgrading marginal deposits to metallurgical standards. This investigation of the preparation characteristics of Wyoming County coals is the third of the series undertaken in West Virginia.

Jan 1, 1955

By J. B. Vander Sande, L. C. Rainey, P. Bolsaitis, B. Dirsa

"The structure and composition of silica-rich particles recovered by lavage from the lungs of three active miners with different medical histories were studied using high-resolution electron microscopy and chemical microanalysis. The results arc compared to the similarly determined structure and composition of respirable-size mineral particles obtained from roof-bolter dust-box samples from two coal mines of widely different bulk quartz concentrations. The results show that the lungs of the miners contain silica-based particles with structures not found in the mine samples. Also, the particle structures and compositions found in the macrophages were different in each of the miners. The rau.lu suggest the possibility that intracellular processes may affect the susceptibility of individuals to silica-induced pneumoconiosis. The cytotoxic and fibrogenic potentials of mine dusts result from the activity of their individual components. Whether this effect is additive or even mass (i.e., dose) related is questionable and has been the subject of many investigations. Particle size and size distribution of various constituent minerals, the surface structure and properties of individual particles, and the self-cleaning capability of the lung (i.e., the capacity of the macrophage system) may, among other variables, affect the pathogenic changes induced by dusts lodged inside lungs. Extensive epidemiological investigations conducted on miners from different coalmining districts, where equivalent dust exposures have been shown to result in vastly different frequencies of lung disease incidence, also confirm this hypothesis (1) In a recent study, Ferrer et al. (2) used energy-dispersive X-ray analysis (EDXA) to investigate the inorganic element content in pleura and lung in reference, silica exposed non-pneumoconiosis, and silicotic populations. Constant depositions of silicon and calcium were detected in visceral pleura, parietal pleura, and lung of the refence group and in visceral pleura and lung of the exposed non-pneumoconiosis and silicotic groups. Comparison of the silicon content in pleura between silicotic and exposed non-pneumoconiosis subjects showed a nonsignificant probability of difference, whereas there were no differences with respect to the silicon content in lungs."

Dec 1, 1995

By H. Kenworthy

The objective of this investigation was to evaluate the technical feasibility of smelting certain low-grade domestic iron ores in an electric furnace. Laboratory-scale experiments showed that a high recovery of iron in the form of pig iron can be obtained from east Texas ores containing less than 25 percent iron. The pig iron was amenable to standard-or electric-furnace-refining methods for producing steel. Car-bon, silicon, and phosphorus were the primary impurities removed in refining. Overall recoveries of iron as pig iron exceeded 95 percent, in contrast with commercial mineral-dressing recoveries on these particular ores of 50 percent of the iron as a 45-to 50-percent iron concentrate.

Jan 1, 1958

By Thomas H. Dubaniewicz

Fiber optic systems are being deployed in locations where explosive gas atmospheres are normally present or are present under fault conditions. The National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory (NIOSH, PRL) conducted a study of laser safety in potentially flammable environments. Researchers conducted experiments to estimate the mean and standard deviation of laser powers needed to ignite 6% methane-air atmospheres using single mode optical fiber tips covered by two types of iron oxide (Fe304 and (FeMn)203) mixed with a ceramic adhesive. The iron oxides, heated by a 1064 nm continuous wave laser, ignited the methane-air mixtures ,at similar powers. The minimum igniting power and maximum non-igniting power (10 tests) were 407 and 350 mW, respectively, using a 62.5 pm fiber. Laser beams guided by 125 and 80 pm diameter cladding single mode fibers produced similar methane-air igniting powers. Ignition was not observed using coal particles at powers that produced ignition with the iron oxides. Threshold ignition delays using the single mode fiber were approxinlately proportional to the inverse square of the igniting power. Ignition delays were significantly longer than the reported activation time for a comnlercial fiber optic power limiter. Comparisons are made with the results of other researchers. Published by Elsevier Ltd.

By S. L. Windes

For a number of years, the Bureau of Mines conducted tests on various types of structures to determine the effect of seismic vibrations emanating from quarry blasting in an effort to determine an index of damage . Associated with these tests , occasional records were made of the characteristics of. the air blast or concussion from the explosions . Although the importance of the air - blast problem was recognized , the equipment was not designed for air -blast measurements , nor was the early research program concerned with the problem . After the ground - vibration tests had been completed , attention was turned to study of the air blast and its effect . The air - blast problem in reference to quarry and mine blasting may be divided conveniently into three phases : (1 ) Determination of the fundamental characteristics of the air blast , such as the pressure - time relationship , speed of propagation, attenuation , and the like ; ( 2) effect of blasting conditions on these air -blast characteristics ; and ( 3) determination of the conditions necessary for damage to structures . The initial step was the development of microphones suitable for recording the anticipated blast pressures. Such microphones were designed and built during 1940 , and described in technical detail for publication ( 2)3/. Briefly, the microphone adopted was a small, plate - diaphragm condenser type . The recording was through special transducer amplifiers with low -frequency response to zero cycles per second and a Duddell - type oscillograph of special design .

Feb 1, 1942