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By A. J. Forney

Recent experiments used catalysts of plate assemblies in synthesizing high-Btu gas and gasoline indirectly from coal. A gas with a heating value of 925 to 943 Bt-: per cubic foot has been prod u la the hot-gas-recycle pilot plant from synthesis gas (3H2+100) with lathe turnings used as catalyst in the first reactor, and assemblies of parallel sprayed plats of nickel in the second. Solid plates made of Raney nickel, and steel and aluminum plates sprayed with Raney nickel or nickel oxide were tested. Those catalysts had very low resistance to gas flow; 90 percent lower than nickel granules used in previous experiments. In a single stage of synthesis thee nickel plates were only partially successful. Although the heating values of the product gas ranged from 856 to 941 Btu per cubic foot, the carbon monoxide content of he gas was above 0.1 percent. Both steel and wrought turnings were tested in single-stage synthesis, but the conversion of hydrogen and carbon monoxide was too low to attain the desired heating value of 900 Btu per cubic foot in the product gas. Assemblies of plates thermally sprayed with fusel iron were tried in an experiment to make gasoline. A gasoline yield of 52 percent (of the hydro¬carbons produced) was obtained using a 1H2-10O feed These sprayed assemblies were in service for 1,500 hours, the longest that this type of catalyst has been used. When a second reactor containing Raney nickel catalyst was added in series with the first reactor, complete utilization of the feed gas was obtained because in addition to the liquid product, a high-Btu gas with a heating value of 800 Btu per cubic foot was made.

Jan 1, 1965

By Ronald P. Hollenbeck

Samples of clays, shales, and slates from 29 locations in the Appalachian Region of Alabama and Georgia were tested and evaluated to determine their suitability as raw material for the manufacture of lightweight aggregate by the rotary-kiln method. Samples from 11 locations in Alabama (one each in Etowah, Lawrence, and Morgan Counties and two each in Colbert, Cullman, Tuscaloosa, and Walker Counties) and one location in Walker County; Ga., produced satisfactory lightweight aggregate.

Jan 1, 1969

By Gary E. Sherman

The Bureau of Mines estimated the remaining lode gold endowment of eight mining districts in Alaska using historic production data. A log-arithmic model of cumulative tonnage of ore processed versus cumulative grade was applied to the following districts: Chichagof, Fairbanks, Homer, Hope-Seward, Juneau, Ketchikan, Prince William Sound, and Willow Creek. To assess the remaining endowment, a computerized production data base was compiled from Bureau records. These data were aggregated in 5-yr intervals for each district. Data were sorted in order of declining grade, and log cumulative grade was plotted against log cumulative tonnage. Linear regression was performed on the data for each district. The linear equation for each curve was used to predict remaining endowment at a limiting mining grade. Based on conservative extrapolation of the grade-tonnage curves, a substantial total endowment of 8,415,100 tr oz of gold remains in the eight districts. The districts with the greatest remaining endowment are the Juneau, Chichagof, Fairbanks, and Willow Creek Districts.

Jan 1, 1987

By A. B. Campbell

The Bureau of Mines is developing alloys using ion implantation as an alternative to bulk alloys that consume large quantities of strategic materials such as chromium and nickel. These alloys are formed at the outer layer of relatively common materials. To more fully understand the corrosion characteristics and physical properties of this outer layer, it was necessary to deter-mine the alloy concentration as a function of depth into the substrate material. Also, since many of the ion-implanted alloys would be utilized at elevated temperatures, it was necessary to determine the diffusion behavior of the implanted element. Proton-induced X-ray emission and inert gas ion sputtering have been utilized to generate composition depth profiles for Fe-Cr, Fe-Ni, and Fe-AI ion implanted alloys fabricated by implanting 25-kev Cr+, Ni+, or AI+ into iron substrates. The data were fitted (utilizing a computer program) with symmetrical Gaussian profiles yielding values for the range and range straggle of the ions. These parameters were then compared with those calculated from theory. Changes in the profiles due to annealing were investigated and values for the diffusion coefficient were obtained assuming diffusion according to Fick's Law. For the Cr+ and Ni+ implantation, the profiles as-implanted agree reason-ably well with theory and exhibit ?norrmal" diffusion characteristics at 500° C. For the Al+ implantation, the profile as-implanted is much broader than predicted and exhibits substantial enhanced diffusion at temperatures up to 500° C.

Jan 1, 1979

By James D. Noll, Jon A. Hummer, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health conducted a study to determine the effects of selected, state-of-the-art emission control technologies on the ambient concentrations of particulate matter and gases emitted by underground diesel-powered mining equipment. Tests were conducted in an isolated zone of an underground mine to evaluate the effectiveness of alternative fuel formulations, namely, water-fuel emulsions, blended biodiesel fuels, ultralow sulfur diesel fuel, and #1 diesel; and selected exhaust after treatment devices, namely, diesel oxidation catalysts (DOCs), diesel particulate filter (DPF) systems, and filtration systems designed around high-temperature disposable filter elements. The results showed that using a cold-weather and warm-weather water-fuel emulsion formulation reduced mass concentrations of elemental carbon (EC) by about 70% and 85%, respectively. The 20% and 50% soy biodiesel blends reduced EC by 49% and 66%, respectively. The reductions were slightly less pronounced for the 20% and 50% yellow grease biodiesel blends—33% and 56%, respectively. EC concentrations were unaffected by using ultralow sulfur diesel in place of #1 diesel. Use of the reformulated fuels did not substantially alter the concentrations of nitric oxide and carbon monoxide. However, a measurable increase in the nitrogen dioxide (NO2) peak concentration was observed during the biodiesel tests. The ArvinMeritor (AM) fuel-burner DPF system with a palladium-catalyzed DOC reduced EC concentrations by 92%. The diesel filter elements from Donaldson Co., Inc., and Filter Service & Testing Corp. reduced the EC concentration of the mine air by 92% and 70%, respectively. When the palladium-based DOC was used with the AM DPF, it raised the average and peak downstream NO2 concentrations by a factor of three. Tests of the AM DPF system with a platinum-catalyzed DOC and CAP/ETG catalytic particulate oxidizer system had to be terminated because the elevated NO2 concentrations threatened to overexpose the operator. The tests with only a selected DOC also resulted in increased NO2 concentrations in mine air.

Jan 8, 2006

By Joseph M. Singer

Having established that sodium chloride reduces the incendivity of explosives, the Bureau of Mines studied the effect of sodium nitrate in reducing ignition hazards. Gallery experiments showed that sodium nitrate reduced the incendivity of certain explosives to 8 percent natural gas in air but increased their incendivity to coal dust predispersed in air. Laboratory experiments using hot jets from explosions of stoichiometric mixtures of methane-oxygen-nitrogen showed that both sodium chloride and sodium nitrate reduced the incendivity to methane, to mixtures of coal dust and methane) and to coal dust. The difference between the gallery and laboratory results with respect to coal dust is attributed to temperature-time effects.

Jan 1, 1967

By F. W. Benn

The Bureau of Mines investigated flotation methods for recovering fluorite and byproducts from two samples of the Fish Creek deposit in Eureka County, NV. The preferred method for tre.ating a fluorite-beryllium sample included (1) fluorite rougher and cleaner flotation, (2) desliming at 20 um, (3) muscovite flotation, (4) silicate flotation, (5) sodium hypochlorite wash of silicate concentrate, and (6) beryllium rougher and cleaner flotation from the silicate concen-trate. Laboratory results showed that over 94 pct of the fluorite was recovered in a recleaner concentrate containing 98 pct CaF2, Beryllium flotation produced concentrates containing in excess of 5 pct BeO with recoveries over 70 pet. The preferred method used for a fluorite-mica sample consisted of (1) fluorite rougher and cleaner flotation, (2) desliming at 20 um, and (3) mica flotation using an anionic-cationic collector system. Laboratory results showed that 84 pct of the fluorite was recovered in a recleaner concentrate containing 96 pct CaF2, Mica flotation produced a concentrate containing 95 pct mica at 85-pct recovery.

Jan 1, 1986

By C. W. JEFFERS

At its annual meeting on March 5, 1928, in Washington, D. C., the Joseph A. Holmes Safety Association gave to the Ford Collieries Co., Curtisville, Pa., a certificate of honor for "having worked 922,628 underground man-shifts from August 14, 1920, to December 31, 1926, producing 5,755,669 short tons of coal without a fatality." This remarkable record certainly deserved recognition. It developed that this company's freedom from fatalities continued until October 2, 1929, hence the full period during which no underground fatalities occurred was from August 14, 1920, to October 2, 1929, or 9 years, 1 month, and 18 days, the total tonnage being over 7,700,000. Table 1, shows the complete safety record of the Ford Collieries Co. since 1920 as given by the officials of the company. The first item in Table 1 shows a remarkable performance. This company since 1920 has mined 15 times more coal per fatal accident than the average pro- duction per fatal accident for the State of Pennsylvania in 1928 (255,257 tons). Excluding the two fatalities (one in 1922 and one in 1929) the severity rate for the same period has been 1.259 per thousand hours worked, a record of which the company may justly be proud. However, including the fatal accidents the rate is 2.407. This compares favorably with an average of 12.4 in 1928 for 66 mines in the National Safety Competition. The Ford Collieries Co. operates three mines located in the vicinity of Curtisville, Allegheny County, Pa. One of these mines, Benjamin No. 1, is idle at the present time. The officials are: A. R. Pollock, general manager, Curtisville, Pa., and C. W. Pollock, assistant general manager in charge of safety and operation.

Sep 1, 1930

By Martin J. Gavin

In an earlier paper (Karrick, Lewis, C. A convenient and reliable retort for assaying oil-shales for oil yield: Bureau of Mines, Reports of Investigations, Loral No. 2229, March, 1921. Reprinted in Eng. and Min. Jour, April 30, 1921, also in Mining & Met., May, 1921) which describes the apparatus and method used in the laboratories of the Bureau of times for assaying oil-shales, no mention is made of the quality of oil obtained when the apparatus is operated under conditions determined to be most suitable for producing highest yields of oils. So many inquiries regarding the nature of the oil have been received, that it seems advisable to present a short report on the subject. Experimental work indicates that it is possible to vary the quantity and quality of the oil obtainable with the assay retort from a given shale by varying the conditions of retorting. As an example, some figures that are averages for several closely agreeing tests are shown below.

Jan 1, 1921

By A. S. Swanson

The Babb fault vein in Crittenden and Livingston Counties, Ky. (fig. 1), is one of an extensive series of such veins in the Western Kentucky and Southern Illinois fluorspar district. First operated in 1904, the production to May 1, 1944, was estimated at 143,000 tons of fluorite ore. There are five mines (fig. 2) on the Babb fault zone - Guill ,Kentucky Babb, Delhi-Babb, Eagle-Babb and Howard-Barnes. The Bureau of Mines developed four of these properties by core drilling from July 9, 1943, to May 1, 1944. During that period a total of 8,177.8 feet of diamond drilling was completed in 28 holes.

Jan 1, 1950

By H. G. Iverson

The purpose of this investigation was to beneficiate the Talladega gray iron ores by flotation. A component of the problem was the determination of the degree of beneficiation possible by flotation as well as the relative selectivity of certain reagents in promoting flotation of either the iron minerals or the siliceous gangue minerals. The scope of the present investigation involved only the use of small-scale laboratory equipment. Treatment by roasting and magnetic separation was not included in this study, inasmuch as a similar comprehensive investigation was completed and the results were published by the Bureau of Mines in 1927. The results of the work on Talladega iron ores are briefly summarized in this report. In the search for efficient and economic methods of beneficiating low-grade iron ores, the flotation process is among those that are receiving considerable attention. The Talladega ores are of particular interest for a flotation study, because they contain two iron minerals (magnetite and specular hematite) that are somewhat dissimilar in their flotative response.

Jan 1, 1949

By Rov G. Stott

In recent years there has been no loss of life from fires in the underground mines of the Lake Superior district, but numerous minor fires and several serious ones involving loss of property and production have occurred. The iron-ore-producing companies recognize that well-equipped mine rescue stations are a valuable asset against the ever-present ranger of mine fires or the possibility of hazardous atmospheric conditions underground. Prompt action by trained and properly equipped rescue teams is recognized as the prime essential in saving lives, property, and production when fires occur. To achieve this purpose, the mining companies have provided themselves with mine rescue equipment and maintain trained mine rescue crews. This circular describes how one progressive company has provided, maintained, and improved upon such protection for its underground iron-ore mines on the Marquette and Menominee iron ranges of Michigan's upper peninsula. SUMMARY The central mine rescue station of The Cleveland-Cliffs Iron Co. at Negaunee, Mich., has provided the company's mines with competent and well-equipped mine rescue teams. The new central mine rescue station at the Mather mine "B" shaft has the distinction of having underground training facilities provided as a part of the station. The company maintains the largest trained force in mine rescue in the Lake Superior district, and mine rescue training is employed as a part of the accident-and fire-prevention program. One of the most important results has been the promotion of closer cooperation and understanding between the management and the workmen. In addition to the service rendered to company mines, the station and its personnel have given assistance to others. The station and its equipment have also been used for training several nearby community volunteer fire departments. This mine rescue station and its personnel have been a dependable and valuable asset to the community in which it is located.

Jan 1, 1954

By H. W. Kilau

The Bureau of Mines used a high-temperature rotational viscometer to test basic oxygen furnace slags to determine fluorspar requirements and to evaluate colemanite and fused boric acid as substitute fluidizers. A continuous technique of viscosity measurement was adapted to better determine the viscosity-temperature profiles of volatile fluorspar slags. Criteria used for estimating slag fluidizer effectiveness were (1) the apparent solidification temperature, and (2) the temperature range of slag crystallization. Colemanite and fused boric acid in high-basicity slag were superior fluidizers to fluorspar when compared on the basis of boron versus fluorine concentration. Fused boric acid was nearly equivalent to ceramic-grade fluorspar when compared on a simple weight basis, while colemanite was inferior to fluorspar. Fluorspar slags volatilized fluorine during viscosity testing. Colemanite and fused boric acid slags were stable, no boron losses being detected. A fluidizing limit was found for fluorspar at 2.9 percent fluorine concentration; higher concentrations impaired viscosity and caused foaming and crusting of slag. Concentrations of boron up to 4.4 percent resulted in very fluid slags with no fluidizing limit.

Jan 1, 1978

By Robert T. Langland

The Bureau of Mines, at its Denver, Colo., research center, has developed a computer program to solve nonlinear regression problems. The program is written in a general form so that, regardless of the functional relationship assumed, the unknown parameters may be evaluated by the Newton-Raphson method of iteration. Variances and covariances of the parameters are derived, based on the propagation of errors. A creep function is established from shale test data as an example of program utility. Program accuracy is compared to the accuracies of other programs in present day use.

Jan 1, 1974

By Thomas J. Peters

The King Mountain study area is centered about 120 air km northwest of Blackfoot, and 30 air km north of Arco, Idaho. The study area makes up the southern one-third of the northwest-trending Lost River Range--the highest mountain range in Idaho. The area is predominantly underlain by Paleozoic-age marine limestone and lesser dolostone, with a relatively small inlier of silica-rich, Ordovician-age quartzite. There are vast, unquantified resources of these industrial minerals present; however, special markets need to be developed for these resources which are near enough for transportation costs to be competitive. Five prospects were found in the study area; however, only one, the Elbow quartz silica prospect, contains resources and current claims. There has been no mineral production in the study area.

Jan 1, 1993

By L. S. Sundae

The Bureau of Mines conducted a series of tests to compare the cutting forces required by radial and point-attack bits when making similar cuts. Three radial and four point-attack bits were tested in two coal mines using the Bureau's in-seam tester to measure coal-cutting forces in situ. Tests were also conducted to investigate the effects of weathering and cleating. The test results show that in each case, at a specific clearance angle, the radial bits required less tangential and much less normal force than the point-attack bits. The resultant of the cutting forces for some types of cut was 50 pct less at mine 1 for radial cuts compared to cuts with the best point-attack bit, and 40 pct less at mine 2. There was some difference between three types of radial bits, but it was not as significant as the difference between each type of point-attack bit. Cutting coal perpendicular to the cleat planes required less cutting and normal force than the same type of cuts parallel to the cleat planes. Test results showed no effect due to weathering on cutting force data. Cutting parallel increased forces only because cuts were made in the rock band.

Jan 1, 1987

By Oliver Bowles

Chalk is defined as a noncrystalline, soft, friable, fine-grained, light-colored type of limestone. It consists essentially of calcareous shells of minute organisms known as "foraminifera," although skeletal remains of molluscs, corals, and sponges are also present. Flint balls which are found so commonly in the chalk cliffs of Europe are regarded as segregations of the remains of certain organisms, such as radiolarians and sponges, that secrete siliceous shells or spicules. The famous chalk beds of northwestern Europe are of Upper Cretaceous age, a geological period that was particularly favorable for the develop- ment and multiplication of foraminifera. The distinguishing physical characteristics of true chalk never have been fully defined; probably its noncrystalline and colloidal properties are most important. The properties of chalk, whiting, and whiting substitutes are not well understood, and much re- search is necessary before definite reasons may be ascribed for the behavior of these materials under various conditions of use. The Bureau of Mines has undertaken a detailed study of chalk and similar materials to determine their exact properties and to establish a basis for classifying formations loosely designated as chalk occurring in various parts of the United States, but the results of this study will not be available for some months. Whiting is a pulverized, purified, and carefully sized chalk. Whiting substitutes consist of finely ground limestone or dolomite, ground marble (marble flour), white marl, and chemically precipitated calcium carbonate.

Jul 1, 1931

By Wesley A. Grosh

The Toncrae-Howard copper deposits in Floyd County, Va., were first mined about 1800. The property has been operated or under development at various times since then for iron, copper or sulfur, although the total production has been small. The deposit consists of a vein or zone of sulfide mineralization in schist composed mainly of pyrrhotite with minor copper values in the primary zone and some rich areas of copper mineralization in the altered zone. The Bureau of Mines, in an attempt to develop minable copper ore during the war, opened part of the mine for examination and sampling, deepened the shaft and other underground work, and drilled 29 holes totaling 2,187 feet.

Jan 1, 1948

By Benjamin C. Pollard

The location and production potential of a large block of strippable reserves in North Dakota were determined by using published data as a base and adding new drill hole data or other data contributed by companies that presently own or lease coal lands. Only beds exceeding 5 feet in thickness, under less than 120 feet of overburden, and in large blocks of 5 million tons or more were included in the estimates. All such reserves are in the Fort Union Formation of western North Dakota and are lignite in rank. Sixteen large blocks of reserves evaluated in this study are estimated to contain a total of 4.1 billion tons of strippable lignite.

Jan 1, 1972

By Wallace E. Anable

This investigation by the Bureau of Mines was conducted chiefly on Cuban serpentine nickeliferous ores to determine whether these materials would be amenable to direct carbothermic reduction in an electric furnace to produce a low-carbon ferro-nickel. The project was carried out as one of several under a Memorandum of Agreement between the Bureau of Mines and the General Services Administration (Contract GS-OO-B (D)-152l). Two ore samples were received for this investigation. One was a mixture of nickeliferous serpentine from the North Ocujal, South Ocujal, and San Juan claims of the Nicaro Nickel Co. The other sample was a mixture of material from the Ramona and the Lorna Mulo claims of the Cuban Nickel Co. Most of the ore from the Ocujal-San Juan deposits and about 40 percent of the sample from the Ramona-Lorna Mulo deposits were calcined before smelting. The remainder of the sample from the Ramona-Loma Mulo deposits was smelted after drying to about 8 percent moisture. An arc-resistance, selective-reduction smelting technique was employed in these tests. Either bagasse alone or a mixture of bagasse and coke was used for reductants. No flux was used in the furnace charges.

Jan 1, 1957