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By Irving Hartmann

The Experimental Coal Mine of the Bureau of Mines has served principally as a valuable and unique testing laboratory for studies of the explosibility of coal dust and mine gas; studies of the numerous complex and interrelated chemical and physical factors that govern the ignition of coal dust and the propagation of mine explosions; and studies designed to develop measures for preventing explosions or reducing their destructive effects. These researches, coupled with educational efforts by the Bureau of Mines and enlightened safety consciousness in the mining industry, had fruitful results. This is evidenced by the remarkable reduction in the frequency of major coal-mine explosions and the number of fatalities from explosions since the Bureau of Mines was established. Despite this progress, further important unresolved problems arise; these are due in part to changes in mining conditions and methods, which have brought about increased production of fine coal dust in highly mechanized operations. To solve the new problems, research must be continued without interruption. The results of many very recent and current studies in the Experimental Coal Mine are summarized briefly, and pertinent studies by European mine-safety-research organizations are listed.

Jan 1, 1957

By W. W. Adams

"The National Safety Competition of 1930, the seventh annual contest conducted by the United States Bureau of Mines to promote safety in the mines and quarries of the United States, has been concluded, and the five winners of the bronze trophies, The Sentinels of Safety,' which are provided by the Explosives Engineer magazine and awarded annually for the most excellent safety records, have been determined by the committee of award. One trophy was awarded to an anthracite mine in Pennsylvania, one to a bituminous coal mine in the same State, one to an iron-ore mine in Michigan one to a gypsum mine in Ohio, and one to an iron-ore opencut mine in Michigan.These trophies were awarded to the companies for having the smallest loss of time from accidents in proportion to the total number of man-hours worked by all employees at their mine or quarry. Honorable mention was awarded to each mine or quarry that ranked second, third, fourth, or fifth in its own ground and to all plants that were operated without a lost-time accident during the contest year. Eighty-four out of 337 plants that competed for the trophies were operated without an accident that disabled an employee beyond the day on which the accident occurred.Under the contest rules, all mines and quarries were divided into five groups, four of the groups representing different classes of underground mining operations (anthracite, bituminous coal, metallic ore, and nonmetallic mineral), and the fifth group repre-senting the quarrying or opencut mining of minerals whether metallic or nonmetallic. Twenty-seven mines were included in the anthracite group, 68 in the bituminous group, 52 in the metal group, 24 in the nonmetallic-mine group, and 166 in the quarry and opencut-mine group. The total of 337 mines and quarries was 26 more than the number of plants that completed the contest during the previous year.The committee of award which determined the winners of the contest was composed of seven members, all known throughout the mineral industry but not connected with the United States Bureau of Mines. The committee included W. H. Cameron, managing director of the National Safety Council; William Green, president of the American Federation of Labor; James F. Callbreath, Secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of Mining and Metallurgy; C. B. Huntress, executive secretary of the National Coal Association; A. J. Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the bureau of engineering of the National Crushed Stone Association."

Jun 1, 1931

By Alla D. Mah

Compilation of data on materials of metallurgical interest is one of the important activities of the Berkeley Thermodynamics Laboratory of the Bureau of Mines. Recent renewed interest in metallurgy of vanadium renders the present compilation a timely guide for experimentation to improve present methods or to develop better methods of extractive metallurgy. Thermodynamic data for vanadium and its inorganic compounds have been critically surveyed, selected, and compiled into one convenient reference from which information can be readily obtained for evaluating heat balances, determining trends, and establishing limits of metallurgical processes. By indicating the direction of experimentation, this report enables the saving of time, effort, and expense which would otherwise be necessary for trial and error experimentation. Much of the data has been obtained experimentally at the Berkeley laboratory. Other data were collected through an extensive survey of worldwide literature through April 1965. Estimates were made when no data were avail-able. Data on the vanadium halides was sparse, and the results derived from existing data were at times divergent. Some of the selected values for the halides may need modification as more or better experimental data become available.

Jan 1, 1966

By T. A. Lang

The objective was to develop a Program Plan of analytical studies and tests for determining ( 1) the optimum installation tension of a coal mine roof bolt, (2) the most valid bolt support theory or theories, and ( 3) the most valid roof failure theory or theories. On this basis a comprehensive literature search was made and significant material dealing with coal mine roof behavior, roof bolting and roof support was collected, reviewed, classified and analyzed. Emphasis was given to the influence of rock reinforcement on the control of deformation, stress field modification and mine roof stability. An assessment was made of the effect of various parameters including bolt tension, bolt pattern and time of installation, on the effectiveness of rock reinforcement systems, and equations developed for bolt tension as a function of these parameters, and rock properties. From these studies, a major program plan of tests and studies was developed for verifying and validating the most tenable theories of roof behavior and roof support and for determining optimum bolt installation tension.

Jan 1, 1979

This Bureau of Mines report on underground mine communications addresses methods and equipment to meet the communication requirements of working sections and places of coal and metal-nonmetal mines. A review of the status of trapped miner detection is also presented.

Jan 1, 1977

By Eugene Frey

"INTRODUCTION The Iron Mountain deposits were examined in the summer of 1943 by engineers of the Bureau of Lanes, and a diamond-drilling project was set up under the Strategic Minerals Program. Actual drilling operations, under the supervision of a Bureau engineer, commenced November 9, 1943, and were completed on November 1, 1944. When the Bureau began detailed exploration of the Iron Mountain deposits, the Federal Geological Survey participated. Dr. I. W. Newhouse, of the Survey, and Dr. A. F. Hagner, of the Wyoming Geological Survey, were assigned to the investigation.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, acknowledgment is made to S. R. Zirrmerley and F. T. Allsman, Bureau of Mines, Salt Lake City, Utah, who supervised the work of this project."

Nov 1, 1946

By Walter E. Lewis

The Cuyuna iron range in Crow Wing County, Minn., is the principal producer of manganiferous iron ore in the United States. The ore is mined from a manganiferous iron formation in the bedrock of the Cuyuna district. This iron formation is divided into two general lithologic types-thin-bedded and thick-bedded. The unoxidized, thin-bedded iron formation is composed of iron silicate with associated fine-grained carbonates of iron and manganese. The thick-bedded iron formation carries iron and manganese oxides with intimately associated silica. Oxidation and leaching of the original iron formation have been the most influential factors in producing manganiferous iron-ore concentrations in quantities large enough to exploit on a commercial basis. The unoxidized and the partly oxidized and enriched iron-formation materials are suitable as a source of ferrograde manganese ore. These materials have been classified according to their amenability to mineral dressing and degree of oxidation and leaching.

Jan 1, 1958

By John J. Sammarco

This report details the testing and evaluation of a modular azimuth and positioning system (MAPS) to provide navigational information for a continuous mining machine. Vehicle navigation is part of the U.S. Bureau of Mines research program in computer-assisted mining serving as a tool to increase mining health, safety, and productivity. The Bureau is investigating other navigation systems, but MAPS seems to have the most promise. MAPS was installed on a continuous mining machine. An operator used the machine to cut coal while researchers collected machine and MAPS data. A comparison of MAPS data for xy position and data obtained with an electronic transit showed an increasing error for MAPS. After 30 min of operation, the easting position error was -0.02 m, and the northing position error was 0.019 m; after 60 min of operation, the easting position error was -0.19 m, and the northing position error was -0.26 m. Modifications to MAPS software and to the operational procedure of the machine significantly reduced this error by a factor of 3.7. Researchers continue to reduce these errors.

Jan 1, 1993

By R. K. Koch

The normal spectral emissivities of liquid Ti, V, Zr, Mo, and Pt were determined at the fusion temperatures in an electron-beam furnace using a water-cooled copper hearth. The normal spectral emissivities were estimated above the melting points by using adjusted two-color temperatures as approximations of the true temperatures for substitution in Wien's equation. Simultaneous brightness temperatures were determined with a micro-optical pyrometer. The true temperature ranges covered were 1,668° to 1,885° C for Ti; 1,919° to 2,013° C for V; 1,855° to 2,367° C for Zr; 2,610° to 2,751° C for Mo, and 1,772° to 1,990° C for Pt. The spectral emissivities for titanium and zirconium decreased with increasing temperature. At an effective wavelength (?) of 658 mµ the emissivity of titanium ranged from 0.51 to 0.45 and zirconium, from 0.47 to 0.41. The emissivities of vanadium (? = 658 mµ) and molybdenum (? = 657 mµ) were constant at 0.41±0.02 and 0.33±0.01, respectively. The spectral emissivity of platinum (? = 658 mµ) was constant at 0.39±0.02 up to 1,900° C; above that temperature anomalous data were obtained. A mass spectrometric study indicated that platinum was reacting with back-streaming silicon vapors from the diffusion pump when the ambient pressure was greater than 2 X 10-5 torr.

Jan 1, 1973

By William Seymour, L. D. Schmidt

"FOREWORDAmong many problems created by World War II, the question of supplies and distribution of raw materials is of outstanding importance. One of the most critical of these raw materials is fuel, and of the fuels coal is of primary importance. The normal consumption of coal has increased greatly owing to the increased tempo of industry in general. It has been necessary to divert much of the fuel oil, gasoline, etc., ordinarily used for industrial and domestic purposes, to supply the enormous demands of mechanized warfare. Coal must be provided to replace this fuel. Furthermore, the enormous increase in the production of steel has increased the demand for coking coals to a critical point.The Solid Fuels Administration for War is encouraging the use of anthracite fines in the production of byproduct coke for blast furnaces for three reasons. First, the production of anthracite for domestic use; is hampered by the inability to find a market for the fines incidental to the production of domestic sizes. Second, the shortage of low-volatile coking coal is acute, and any action that will decrease the quantity of low-volatile coal required will relieve the situation. As will be seen in this report, there is some promise that use of anthracite fines in coke-oven mixes will lower the amounts of low-volatile coal required. Third, utilization of those anthracite fines will tend also to alleviate the general fuel shortage. It has been the privilege of the Bureau of Mines to cooperate with the Solid Fuels Administration in the technical problems involved."

Apr 1, 1945

By C. C. Popoff

This report reviews the phosphate deposits, mines, and industry, and prospects in 10 districts covering most of the Montana phosphate field. These districts are discussed individually, and an evaluation of the resources and potential of each is presented. Phosphate rock produced from underground mines in the Garrison district is shipped to Canada for processing to fertilizers, utilized locally for production of animal feed supplement, and pulverized and sold for direct application to the soil. Production from the Melrose district is shipped to Silver Bow and processed to elemental phosphorus. The Maxville-Philipsburg district is destined to become a major producer with the development of the Douglas Creek mine and beneficiation plant by Montana Phosphate Products Co. Montana ranks fourth after Florida, Tennessee, and Idaho in total annual production in the United States. Production him increased from about 60,000 long tons of acid-grade phosphate rock in 1940 to more than 660,000 tons of acid-, beneficiation-, and furnace-grade ore in 1961. Montana has the second largest potential resources in the Western field; in the area south of Butte there are approximately 1.2 billion tons of phosphate rock (+18 to +31 pct P2O5) available above and within 100 feet below entry level; and in the northern part of the field there are about 67.6 million tons available above entry level. In contrast to Idaho, most of the phosphate deposits in Montana are best suited to underground mining.

Jan 1, 1965

By Marvin W. Wilson

The Federal Bureau of Mines has conducted laboratory experiments simulating underground gasification of coal to study the feasibility and mechanism of the process and determine the chemical and physical characteristics of a coal-bed during gasification. Laboratory and small-scale field experiments also were made to investigate the properties of coal and other factors affecting the electrolinking-carbonization method of preparing a path through a coalbed before gasification. Laboratory experiments simulating underground gasification of coal: Experiments with a laboratory retort indicated that bituminous-coal deposits could be gasified in place to produce a combustible gas.

Jan 1, 1960

By Robert W. Smith

[In a certain application it was necessary to compute the incomplete beta function, ß(1/2, p, q), for a certain set of values of p and q. Since the set of p and q values was much more finely spaced than those in any published tables, the authors have decided to make their results available in this report. In connection with this application, the function ß(1/2, p, q) was needed at various points in the p, q plane at intervals of 0.05, 0.05 p = 2q < 10.00. Fletcher, Miller, and Rosenhead3/ state that the only tables available in the desired range are those of Pearson.4/ However, the interval used by Pearson was not small enough for the present application. For this reason, it was decided to calculate the function ß(1/2, p, q) for p = q = 0.05 (0.05) 10.00. This table is published because of the fundamental importance in mathematical analysis of the incomplete beta function.]

Jan 1, 1953

By Robert Lee Stahl

Comprehensive field tests were made by the Bureau of Mines at the Schwartzwalder mine near Golden, Colo., to determine whether surface geophysical techniques could be used to detect and delineate faults in uranium deposits. The tests included seismic refraction, magnetometer, electrical resistivity, airborne infrared thermal scanning, and airborne photography. Of the several geophysical techniques tested in the field, horizontal resistivity profiling with electrode spacings in the range of 10 to 15 feet was most diagnostic of faults. The method is quick, inexpensive, and accurate and can be easily used by mining company personnel to detect and delineate faults.

Jan 1, 1974

By J. C. Gerdeen

A new analytical model for the shear stiffness at a joint of the fully-grouted resin roofbolt is developed using the Theory of Elasticity and an analogy to a beam on an elastic foundation, Gerdeen [2]. The model developed in this study treats the elastic foundation modulus of the resin as being composed of both an elastic rock and an elastic resin. All previous attempts have neglected the elasticity of the rock and treated only the resin. A three dimensional finite element model of the bolt-resin-rock system is developed also and comparisons are made between the predictions made by it and the analytical solution. It is found that the agreement between the two representations ranges between 1.2% and 10.5%, with the greater differences being observed for systems of very large or very small bolt diameters and resin annulus thicknesses. Since such configurations are not the rule in practice parameter studies are performed using the analytical solution with the finite element solution being used as a check. For a 0.75 in. bolt, a resin annulus thickness of 0.1375 in., a resin with E = 7 x 105 psi and -1) = 0.210, and a rock of modulus E = 6.8 x 106 psi and V = 0.159 the shear stiffness is found to be 1.220 x 106 lb,/in, from the analytical solution and 1.245 x 106 lb,/in, from the finite element model. Applying the finite element model to the problem of the axial stiffness of the fully-grouted resin roofbolt a value of 6.002 x 106 lb./in. is obtained which proves to be at least 50% higher than any of the now existing analytical predictions.

Jan 1, 1976

By C. C. Merrill

The Bureau of Mines beneficiated the wastes generated by commercial titanium chlorination operations to reclaim metal values and reduce the problem of disposing of solid wastes. A water leach solubilized about 40 percent of the dry weight and over 75 percent of the metallic impurities. The residue from the water leach was rich in titanium dioxide and carbon; it was combined with rutile and recycled to a laboratory chlorinator. The contained carbon was used in lieu of part of the coke requirement.

Jan 1, 1969

By Wilbert J. Huff

The Explosives Division of the United States Bureau of Mines makes certain laboratory and field investigations that deal with explosions, explosives, ignition, and combustion, together with many related problems, such as the cause and prevention of fires, and certain fundamental scientific questions bearing upon the determination of the chemical and physical mechanisms underlying some of the important phenomena encountered. Its work on explosives has been particularly directed toward determination of the chemical and physical characteristics of explosives designed for use in coal mines and in a more limited way to those used in metal mines, tunnels, quarries, and other engineering operations. This testing is handled by two units of the Explosives Division, as follows:

Jan 1, 1937

By Jack E. Fraley

In this Bureau of Mines study, sealants containing mineral wool, cement, etc, were sprayed through dry-process equipment that propels dry material pneumatically to the water-adding nozzle. Advantages over slurry applications include no mixing, no extensive cleanup, and freedom from hardened cement in equipment should power be lost. Sealants with large mineral wool nodules (>l-inch) were sprayable at rates to 900 square feet per hour for 1/2-inch thickness with little dust and smooth material flow through equipment, but they were weak for mine use, Materials containing small wool nodules (1/4-inch) were stronger but tended to plug lines because the nodules were inadequately separated in the shredder. Increasing the dedusting oil also increased line plugging by holding the nodules together in larger lumps. Best results were obtained using a 3/4-inch-nodule wool with cement binder, which provided both smooth flow through the machine and adequate strength.

Jan 1, 1977

By R. W. Michelson

The Bureau of Mines developed computerized mathematical models to estimate the economic availability of Mesabi Range taconite concentrates; these are a quality model, a cost model, and an economic availability model. The quality model evaluates metallurgical test data; the cost model determines iron unit cost from mining and processing cost data; and the economic availability model determines quantity from geologic and ore quality data. By correlating all of the physical resource quality factors and dimensional characteristics with the economic cost factors associated with producing iron ore pellets, these three models combine to establish a final relation between iron ore reserve quantities and iron unit cost.

Jan 1, 1970

By H. W. Kilau

The Bureau of Mines evaluated synthetic fluorspars as substitutes for natural fluorspar in basic oxygen steelmaking using a high-temperature rotational viscometer and a quarter-ton basic oxygen furnace (BOF). Consider-able variation in stability and BOF slag fluidizing properties were found when using the initial synthetic products, but improved synthesis methods produced synthetic fluorspars that were generally comparable to natural fluorspar in laboratory testing. Trials in the furnace showed the synthetic products to be operationally the equivalent of natural fluorspar. Higher sulfur and phosphorus contents in some of the synthetic materials did not adversely affect the steel chemistry. Analyses of wet scrubber samples showed evidence that the pelletized synthetic fluorspars experienced greater physical and chemical disintegration than did natural fluorspar. It was also found that operation of a BOF without fluorspar is possible when making low-carbon steels because iron oxide is intrinsically generated as the slag fluidizer.

Jan 1, 1981