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By Webster S. Anderson

Bureau of Mines planer mining tests on the phosphate bed of the Douglas mine, near Drummond, Mont., indicated that a competent bed with a Mohs' scale hardness of 3 to 4 cannot be mined economically with the planer. Although planer mining was feasible where the bed was fractured enough for a 4-inch depth of cut to be consistently maintained, the depth of cut in the competent beds at the Douglas mine did not exceed 0.5 inch. Average production rates were 0.15 ton per minute and 9 tons per man-shift.

Jan 1, 1966

By John C. Machisak

THIS CHAPTER of the Minerals Yearbook (Volume III) contains overall employment and injury experience for coal mines-bituminous, lignite, and anthracite; coke, petroleum and natural gas; and peat and slag plants; metal and nonmetal mines; sand and gravel operations; stone quarries; metallurgical plants, including metal mills and smelters; and nonmetal mills for 1959. Volume I of the yearbook contains injury experience and employment data in the metal, non-metal, sand and gravel, slag, and quarrying industries, and the milling operations and related plants. Volume II contains the injury experience and employment data in the fuel industries--coal, coke, petroleum and natural gas, and peat. Surveys conducted by the Bureau of Mines were the source of injury and employment data used to compile the tables and furnish information for the accompanying text. Response to the surveys was voluntary except that for coal mines. The Coal Mine Safety Act requires operators of coal mines to furnish the information requested.

Jan 1, 1960

By E. L. Rawlins

The Bureau of Mines, with the cooperation of the Natural Gas Association of America, has conducted a study of leakage losses from natural-gas transmission lines. This study has shorn that surveys to determine the leakage from transmission lines lead to line repair work that not only aids in the conservation of gas, but can be made to show financial returns of large magnitude.2 In order to conduct the study, it was necessary to develop accurate and reliable methods of determining the actual leakage from pipe lines. METHODS OF TESTING Three methods that were developed and used to determine the leakage losses from high-pressure natural-gas transmission lines are: (1) The "pressure-drop" method, (2) The "metering-in and metering-out" method. (3) The "metering-in" method.

Jan 1, 1926

By G. L. Oldright

The data presented in this paper were collected et the smelter of the Consolidated Mining A Smelting Co. of Canada, Limited, Trail (Tadanac), British Columbia, through the courtesy of S. G. Blaylock, vice president and general manager; James Buchanan, smelter superintendent, George Murray, assistant smelter superintendent; and the staff members listed in Paper XI, Report of Investigations 3243. INTRODUCTION This paper is the twelfth of a series on smelting in the lead blast furnace and the fifth4 dealing with blast-furnace gases.

Jan 1, 1934

By Walter E. Pittman

This Bureau of Mines study surveys the current state of technology and the various research efforts that have been undertaken to dewater the dilute phosphatic clays generated in the production of phosphate rock. The research described includes early dewatering experiments, fundamental studies of clays and of flocculation, and minor dewatering techniques such as freeze-thaw methods, the ANDCO process, moving screens, sand wick, crust development, and overburden pumping. Some methods that are currently being evaluated are described. They include the Estech sand-clay mix process using the Enviro-Clear thickener, sand-clay sandwiching, dredge mix, dredge process, and the sand-spray process. Developing technology for dewatering phosphatic clays also is described, including the Bureau of Mines rotary trommel method and the Gardinier process.

Jan 1, 1984

This report describes a U.S. Bureau of Mines investigation into the removal of gate road chain pillars in conjunction with longwall retreat mining. The research objective was to determine, through evaluations of the loads imposed on the gate road pillars and supplemental support elements in the entries, how the pillars, supplemental support, and entries were affected by the longwall abutment pressure. To achieve this goal, vibrating wire stressmeters and hydraulic flat jack pressure cells were installed in the support elements to monitor stress change caused by abutment pressure as a function of longwall face advance. The findings documented in this report are the result of information collected from instrumentation and observation at the mine. Pillar and support loading measurements and stability observations revealed that the roof and the support elements remained stable during panel retreat, while the face progressed at a normal rate of advance. The ability to safely and efficiently mine chain pillars during panel retreat increases resource recovery and can provide several other benefits described in this report.

Jan 1, 2010

By A. T. Iannacchione, D. G. Puglio

The Bureau of Mines established geologic factors affecting the mining of the Lower Kittanning coalbed to aid in coalbed minability studies and examined the occurrence of "wants" (places where coal is missing) and types of unstable roof rock strata. Trends established from mapping, including prediction of areas of high methane emissions, were extrapolated to unmined areas. "Wants" in the coalbed are of two types: Erosional and depositional. Erosional features occur where north-south-trending sand-filled channels cut into the coalbed. Variations in depositional environments have caused the coalbed to "split" into several thinner units. Slickensides, commonly indicative of unstable roof, are adjacent to and on the underside of sandstone channels; they were caused by differential compaction and by soft sediment sliding along the contact between the sandstone and adjacent shale. The frequency of unstable roof also increases where the interval between the Middle and Lower Kittanning coalbed is less than 30 feet. The zones of weakness at the contacts above and below the Middle Kittanning coalbed are the controlling factors for unstable roof in these strata. Methane emissions from the coalbed are controlled primarily by depth, fracture permeability, and rank of coal. Local geologic factors are coalbed thickness, associated rock strata, structure, and proximity to outcrop.

Jan 1, 1979

By J. W. Thompson

The Sullman, Picard & Ballot patent, No. 835120, is a process of concentrating ore which consists in mixing the powdered ore with water, adding a small proportion, a fraction of 1 per cent on the ore, of an oily liquid having a preferential affinity for metal- liferous matter, agitating the mixture until the oil-coated mineral matter forms into a froth and separating the froth from the remain- der by flotation. The process is known as an air-flotation process which consists in the use of a frothing agent in conjunction with such agitation of the ore pulp as will distribute the metallic particles of the ore throughout the mixture and produce bubbles of air and bring them in contact in the mixture with the metallic particles so dis- tributed. The bubbles will become attached to such metallic par- ticles, carrying them separately from the particles of gangue up through the surface of the mixture where they can be readily collected by skimming, by overflow, or by the use of other well-known devices. The air-flotation process was a patentable invention in the discov- ery made in March, 1905, and was not anticipated and is valid. Prior to that time there had been no suggestion in the arts that a propor- tion of 0.1 per cent of oil to ore or of any other fraction of 1 per cent of oil to ore would or might result in successful concentration. While the ascertainment that such a minute proportion of oil would affect a successful concentration of ore through a flotation process was a discovery, it was nevertheless of such a character, viewed with respect to the circumstances under which it was made, as to involve inven- tion and confer patentability. Claims 1 and 12 of the Sullman, Picard & Ballot patent, No. 835120, for a process of concentrating ore, known as the air-flotation process, are valid; but claim 9 is so indefinite as to render the claim void. The object of the Sullman, Greenway & Higgins patent, No. 962678, dated June 28, 1910, for improvements in ore concentration, is to separate metalliferous matter, graphite, and the like from gangue by means of oil, fatty acid, or other substances which have a prefer- ential affinity for metalliferous matter over gangue, and it is valid. The Greenway patent, No. 1099699, dated June 9, 1914, for improve- ments in the concentration of ores is invalid, as in view of the prior art the omission to use acid in the process can not confer patenta- bility.

Jan 1, 1917

By J. M. Kuchta

The Bureau of Mines used laminar hot air jets of l/8- to 3/4-inch diam-eter to determine the hot gas ignition temperatures of various combustible vapor-air mixtures. The combustibles were n-hexane, n-octane, n-decane, a hydrocarbon jet fuel (JP-6), and an adipate ester aircraft engine oil (MIL-L- 7808). Minimum ignition temperatures occurred at a fuel to air weight ratio of about 0.5 and were not greatly sensitive to variations of fuel concentra¬tion. Moderate variations of jet velocity also had little influence on these ignition temperatures. However, these temperatures decreased with increase in heat source dimensions (jet diameter). The hot gas ignition temperatures of the combustibles were not necessarily much greater than corresponding autoignition and wire ignition temperatures when the size (,F the heat source and the ignition criterion were the same.

Jan 1, 1966

By R. V. Lundquist

The specific conductance of solutions of sodium hydroxide and of sodium aluminate was directly proportional to the temperature. The specific conductance of sodium aluminate solutions with identical sodium ion concentration and at constant temperature decreased with increase in aluminum concentration. The aluminate ion population in solution was shown to consist of a mixture of monovalent and polyvalent ions. Aluminate ions did not influence the temperature dependence of pH in caustic solutions containing sodium aluminate. The density and viscosity of a solution was inversely proportional to the temperature and directly proportional to the concentrations of sodium and aluminate ions.

Jan 1, 1965

By R. H. Storch

The work described in this report was part of a Bureau of Mines program to appraise the titanium-mineral resources of Idaho. Part of the program included churn drilling of alluvial deposits that previous preliminary testing, primarily for rare minerals, had indicated to be potential sources of titanium minerals. The first spot churn drilling began in the Deadwood placer area, Valley County, Idaho, in July 1956 to determine both the amount and grade of the ilmenite, FeTi03. Ten holes, ranging in depth from 6 to 40 feet and aggregating 251 feet, were drilled; 54 samples were taken. The samples were sent to the Spokane field laboratory for concentration and visual estimation of the amounts of the more common minerals in the heavy sand concentrates. For specific determinations samples from each drill hole were composited and shipped to the Bureau of Mines laboratory in Albany, Oreg., where petrographic, quantitative X-ray spectrographic, and chemical analyses were made.

Jan 1, 1958

By T. O. Llewellyn

The Bureau of Mines investigated the use of a heavy liquid in combination with fluid cyclones to separate brucite from a Nevada ore on a continuous basis, using a mixture of dibromomethane and trichloroethylene having a density of 2.44 grams per cubic centimeter. Single-stage cyclone separation produced a concentrate that contained 84 percent of the total magnesia at a grade, on a calcined basis, of 95.6 percent MgO.

Jan 1, 1974

The Bureau of Mines has conducted considerable research to improve life support technology for underground mining applications. This proceedings volume presents several new developments that may help increase the chances of mine workers in surviving underground disasters. Several papers address the performance of present self-contained self-rescuers (SCSR's) and provide proposed guidelines for the design and testing of a second-generation SCSR. Improvements In the safety and effectiveness of mine rescue and recovery operations are described, including the design of a low-profile rescue breathing apparatus and a rescue team helmet.

Jan 1, 1987

By L. C. IlsLey

In the normal operation of mines, the aggregate effect of many seemingly minor op rations may be very important as respects economy and safety. Anion: these operations is the method employed in coupling and uncoupling mine cars. For economic reasons the equipment in mines has not been protected as well as railroad equipment. It is pertinent that haulage accidents rank second in severity among mine accidents, and that manual coupling of cars has been one of the most frequent causes of such accidents. One study4/ revealed that coupling was responsible for about 20 percent of haulage accidents underground. A review of early conditions on steam railroads, which were responsible for the introduction of safer methods of coupling cars, indicates how conditions in might be improved. THE STORY OF RAILROAD COUPLING As any considerable improvement in mine-car coupling probably will follow lines somewhat similar to those that brought order out of chaos for the railroads, it seems appropriate to review briefly the steps taken to improve railroad coupling from the days of link and pin couplings of various types to the adoption of the standard ?M.C.E? automatic coupler.

Jan 1, 1943

By C. E. Jordan

Domestic cobalt resources are relatively large, but low grade. The full potential for cobalt production from domestic sources is at least 19.4 million lb of cobalt per year exclusive of offshore resources. A summary of the cobalt processing technologies for the major domestic resources is presented in this Bureau of Mines report. The processing technologies for the Blackbird, Madison Nine, Duluth Gabbro, iron ore pyrite, laterites, and manganese sea nodules are nearly complete, but the economics are not favorable. Research on these resources should be limited to approaches that promise to cut the total processing costs by at least 50 pct. The most promising sources of cobalt are the spent copper leach solutions and siegenite from the Missouri lead ores. Research on cobalt processing from these two sources needs to be completed.

Jan 1, 1988

Lower noise exposure levels for operators and cleanup personnel working in portable nonmetallic mineral crushing and screening plants.

Jan 1, 1983

By Frank J. Susko

The U.S. Bureau of Mines is developing a process for removing metals from mining and mineral processing waste streams by precipitation. The precipitation process is accelerated by flocculation when a high molecular weight polymer is added. Infrared (IR) studies were performed on zinc hydroxide [Zn(OH);J, copper hydroxide [Cu(OH);J, and zinc sulfide (ZnS) flocculated with both non ionic and anionic polyacrylamide (PAM) and polyethylene oxide (PEO). The IR data were compared with general trends in the performance of the polymers observed during flocculation. These studies will help to understand the bonding between the precipitate and polymer and indicate the effectiveness of a flocculant for dewatering. Two types of bands showed up on the IR spectra; one type described the interlayer water of the flocs, the other described the organic bonds of the polymers. A general decrease in the areas of the three water bands, hydroxyl (O-H) stretching (3,200-3,500 cm-1), water bending (1,610-1,630 cm-1), and torsional oscillations (600-700 cm-1), indicate interlayer water being driven off, which is a favorable condition in flocculation. Shifts in the O-H stretching band indicate water bridging between the precipitate and polymer. Shifts in the amine (N-H) deformation, carbon-nitrogen (C-N) stretch band (1,600-1,610 cm-1) indicate the amine group of the PAM is involved in the bonding. Evidence suggests that ether oxygen of PEO is also involved in the bonding process.

Jan 1, 1990

By Blair Burwell

This paper describing the method of mining a deposit of vanadium ore near Rifle, Colo., is one of a series of similar papers on metal-mining methods and costs being issued by the United States Bureau of Mines. This vanadium deposit probably is the largest yet found in North America. It is situated 12 miles northeast of Rifle, Colo. (see fig. 1), on the southern flank of tae White River plateau, and is at an altitude of 6,500 feet. Between 150 and 200 tons of ore are mined daily and trucked to the mill at Rifle. The product of the mill is fined vanadium oxide, which is shipped to the company's plaits at Columbiana, Ohio, and Niagara Falls, N. Y., for the electric manufacture of ferrovanadium. HISTORY The deposit was discovered about 1909 by men prospecting for carnotite. Its outcrop on the bola cliff of Rifle Canon had been known to stockmen for many years.

Jan 1, 1932

By Robert S. Sanford

In April 1948, the Bureau of Mines was requested to evaluate the graphite deposit' known as the Benjamin Franklin and Just mines in Chester County, Pa. After preliminary investigation, it was recommended that the Bureau core-drill, trench, and sample the deposit and make beneficiation tests on the ore. During the first and second World Wars, flake graphite was in short supply, and a number of deposits in the United States were exploited. In 1942, the Defense Plant Corporation, through its lessee, the Benjamin Franklin Graphite Co., purchased 70.263 acres of graphite-bearing land and built a complete mining and milling plant with a capacity of 300 tons of crude ore per 24-hour day at a cost of $426,250 (Plancor No. 1254).

Jan 1, 1949

By Fred N. Kissell

Methane concentration peaks were measured by the Bureau of Mines at coal mine working faces during entry development. The statistical distribution of peaks was found to be normal or log normal depending on how well the methane was being mixed into the ventilation airstream. A normal distribution indicated good mixing, whereas a log-normal distribution indicated that mixing was poor. In addition, the "highest" peaks over selected intervals were found to fit a type I extreme-value distribution, a result similar to that obtained while mining longwall faces.

Jan 1, 1974