Search Documents

By E. D. Gardner

This paper is one of a series on mining methods and costs being published by the United States Bureau of Mines. In April 19.74 the St. Joseph Lead Co., at Atlanta, Elmore County, Idaho, was mining and milling about 225 tons of gold ore daily with a total force of 150 men. The mine, which comprises the old Boise-Rochester and Monarch properties, is at an elevation of about 6,000 feet. Snow lies on the ground about 5 months each year but does net interfere greatly with local operations. However, the road to Mountain Home, the shipping point 80 miles distant, passes over a high range and usually is closed by snow from about November 15 to June 15. Heavy supplies are brought in and concentrates trucked out during the summer. In winter the district is served by a biweekly mail plane and a passenger and express plane making 4 to 6 trips weekly. Mine timber is cut locally. A plentiful supply of water is obtained from a stream brought to the property through 7,500 feet of plume.

Jan 1, 1935

By Nutter R. S.

A methodology has been developed for qualitative safety hazard evaluation and quantitative reliability analysis of mine monitoring and control systems. Detailed application of these techniques were made to two commercial monitor/control systems and to a West Virginia University distributed microprocessor-based system. A controlled environmental test was conducted on a set of one of the commercial system's outstations. A software reliability evaluation methodology was also developed and applied.

Jan 1, 1982

By A. W. Deurbrouck

This Bureau of Mines report describes the preparation characteristics of the significant coalbeds from which samples could be obtained in Upshur County, W. Va. One of the 14 samples collected was of metallurgical quality as received, 6 could be sufficiently upgraded to provide acceptable products, and 7 could not be upgraded to metallurgical quality because of their high sulfur contents.

Jan 1, 1967

By Robert H. Essenhigh

A stirred reactor (SR) combustion system has been developed to gather information on the mechanisms of ignition and flame propagation of coal dust under conditions similar to those found in coal dust explosion flames. The prime scaling variable considered in this study is that of rapid particle heating (between 105 and 106°K/sec) which is accomplished by means of turbulent mixing during combustion. The SR combustors tested in this study have consisted basically of spheres hollowed in the centers of refractory housings. Coal and air mixtures have been injected into the spherical combustion chambers through a single jet, two opposed jets or four opposed jets. The diameters of the jets have ranged from 0.63 to 0.22 cm. The volumes of the combustion chambers have ranged from 1.0 to 0.2 liters. The reactors have been equipped with thermocouples embedded in the combustion chamber wall as well as a thermocouple located in the exhaust gas stream. In the latter versions of the SR, provisions were made for both solid sampling and gas sampling of the reactant stream exiting from the combustion chamber. Experiments have been carried out using pulverized bituminous coal. The coal has been reacted in an SR in mixtures of air and air/nitrogen. These experiments have provided information on the mode of ignition of the coal as well as yielding information on the kinetics of coal pyrolysis through the use of SR theory. Ash tests performed on the reacted samples collected from the SR indicated that the majority of the values of weight loss percentage were between 60 and 70 percent. The percentages of weight loss were relatively unaffected by changes in temperature which varied between 1100 and 1700°K and by changes in residence time which varied between 10 and 20 millisec. Volatile matter tests performed on the samples indicated that the volatile matter left in the char ranged from 3 to 20 percent of the original content. By assuming that all the mass loss was due solely to pyrolysis with no combustion occurring at the particle surface, Q-factors for each test have been calculated. The results of these calculations indicate an average value of Q equal to 1.88. This finding shows that the majority of mass loss can be attributed to pyrolysis. The fact that the extent of reaction varies only slightly over the range of test conditions has been examined in the context of the two component hypothesis of coal constitution. This approach leads to the conclusion that the reaction of the "easily evolved" component VMI is extremely rapid and that the majority of it is removed from the coal in times less than the residence time in the system. This means that the volatile residue remaining in the char can be considered to consist of component II, VMII. If the mass fraction of VMI = 0, then an activation energy of 18.0 kcal is obtained for the pyrolysis reaction. If the mass fraction is assumed to be 0.75, the activation energy increases to 31.2 kcal.

Jan 1, 1978

By Tuncel M. Yegulalp

This final report contains the results of all work performed under BOM Grant J0333905. A preliminary systems analysis of coarse-particle coal slurry pipelines as a haulage method for longwall mining systems was performed. Two exhaustive literature surveys on state-of-the-art longwall mining and slurry transport technologies were prepared. Two representative longwall systems were designed, one with conventional haulage and one with slurry haulage. These two systems were then compared on the bases of cost, safety, and reliability. The conclusions were that for the case of a two-face longwall mine, a coarse slurry transport system does not have a clear-cut cost advantage over a conventional (conveyor-hoist) system. However, indications were that a cost advantage could occur under different analytical conditions such as: (1) a larger scale mine, (2) if intangible benefits were quantified, and (3) if new generation technology rather than currently available technology were applied to the study. Budget and time constraints prevented exploration of these conditions.

Jan 1, 1982

By J. W. Paul

This paper deals with the third phase of on extensive research on coal-mine ventilation factors. A comprehensive report of the entire work is in course of preparation, but abstracts of the various chapters are being prepared in order to make the results public as rapidly as possible. Parts I and II of this paper were issued Serial 2621 and Serial 2647 of the Bureau of Mines in July and October, 1924. They dealt with the resistance of unobstructed entry and the resistance caused by mine cars in untimbered entry. Description of the Tests After the resistance of unobstructed entry and of mine cars in untimbered entry had been determined by tests in the Experimental Mine, three different types of timbering were installed in the test section and the increased resistance caused by the timbering was determined.

Jan 1, 1925

By W. E. Miller, W. P. Yant, G. W. Jones, R. E. Kennedy

"The determinations of the limits of inflamability of diethyl ether and ethylene in air described in this report were made primarily for comparison with similar determination of other compounds in the same apparatus and by the same laboratory technic. The experimental procedure and the results obtained differ somewhat from those of other investigations. The work also included determinations of the limits of inflamability of these combustibles in oxygen The investigation,was conducted at the Pittsburgh Experiment Station of the United States Bureau of Mines in cooperation with Merck & Co., Inc. LIMITS OF IMFLAMIABILITY OF DIETHYL ETHER-AIR MIXTURESThe limits of inflamability if diethyl ether in air were determined for upward propagation of flame in an upright, closed 8-liter, cylindrical iron bomb 10.2 cm in inside diameter and 96.5 cm in length. This bomb been described in a previous publication. 6Two brands of diethyl ether were used, one a C. P. sulphuric ether manufactured by Baker & Adamson, and,the other Merck & Co. product manufactured for anaesthesia and containing about 3.5 percent of ether alcohol."

Jul 1, 1935

By Foster Fraas

A separator for minerals of low magnetic susceptibility and fine particle size in a water suspension is described. A ring-shaped matrix of ferromagnetic fragments rotating so as to pass successively through magnetic-field and field-free regions provides for the separation. Application is illustrated in the separation of hematite and ilmenite from quartz.

Jan 1, 1966

By E. R. Cole

The Bureau of Mines developed a procedure that enables substitution of zinc cathodes for the aluminum cathodes normally used in commercial zinc electro-winning. Using zinc cathodes eliminates the necessity for stripping and makes it possible to electrowin zinc from solutions derived from material containing excessive amounts of soluble fluorides; for example, zinc concentrates obtained as a byproduct of fluorspar mining in Kentucky and Illinois. To demonstrate the viability of using zinc cathodes, fluoride-containing zinc concentrate was roasted, leached, and purified according to current commercial practice. Electrolysis was carried out in 0.8-, 1-, 5, and 10-liter cells at 35° to 40° C with a cathode-current density of 8 amp/dm2 in a solution containing 65 g/l Zn++ and 200 g/l H2S04 using PbO2 anodes. Zinc deposits were produced on zinc cathodes with good morphology and excellent current efficiency (90 to 94 pct) in solutions containing enough fluoride (~0.5 g/l, F+) to cause sticking of zinc to aluminum cathodes. The approach described has failed previously because of severe solution-level corrosion of the zinc cathodes. The present investigation found that the use of a simple mechanical barrier to prevent oxygen migration from the anode was sufficient to prevent solution-level corrosion of the zinc cathode starting sheet.

Jan 1, 1979

By C. Gary Reiness

A safety glass eyepiece which had been repeatedly exposed to mine environment over a number of years was studied to determine some of its optical properties. In the regions from 385 to 400 mµ and from 625 to 760 mµ, the transmittance was less than the 89 percent required by the American Standard Safety Code for Head, Eye, and Respiratory Protection. From 200 to 320 mµ the relative transmittance of two parts of the eyepiece was found to vary widely, having a maximum of 38 percent difference at 315 mµ. Irradiation of the glass by ultraviolet light caused enhanced absorption in the range from 200 to 1,200 mµ. There was a time-dependent increase of 1016 color centers per cubic centimeter throughout this range after 36.5 hours of irradiation. The rate-of-growth curve for the optical density, at 243.5 mµ and 23° C, was resolved into linear and saturable components, indicating zero order and first order

Jan 1, 1968

By E. Morrice

The Bureau of Mines investigated methods for beneficiating platinum-palladium ores from the Stillwater Complex, Montana. Results of bench-scale and pilot-scale studies employing froth flotation to recover sulfide concentrates containing platinum-palladium values from a serpentinized ore are presented. Best results in the pilot mill were obtained with a sodium isobutyl xanthate-normal dodecyl mercaptan col-lector combination at a natural pH of 8.2. A rougher concentrate con-taining 1.7 oz/ton Pt and 4.7 oz/ton Pd was prepared. Recoveries of platinum and palladium were 96 pet and 86 pet, respectively. Batch cleaner flotation of rougher concentrates yielded concentrates contain-ing 3.7 oz/ton Pt and 9.8 oz/ton Pd.

Jan 1, 1984

By Eugene T. Sheridan

The Bureau of Mines annually canvasses the peat producers in the United States and publishes economic data on the industry, based upon reports from producers. This publication lists all producers that reported commercial production to the Bureau for 1959. The companies named herein represent virtually all commercial producers of peat. A few companies, however, may not have been canvassed or failed to respond, as tine survey is voluntary For producers, arid the industry has many small operations that operate intermittently. No consideration was given to the quantities of peat produced and output of the various companies listed ranged from less than 100 tons to more than 50,000 tons, Peat is included in the Bureau's annual surveys of the mineral industries because, technically, peat is a fuel. Although none is used for fuel in the United States, peat is a potential source of energy and one of our large mineral resources. The domestic peat industry produces peat chiefly for use as a soil amendment. The industry has expanded rapidly during the past decade with active operations increasing from 45 in 1947-49 4/ to 105 in 1959. Output during this period has increased 218 percent, rising from 131,782 net tons to 419,460 net tons.

Jan 1, 1960

By Ludwig Schmidt

The disposal of the brines produced with crude petroleum and natural gas has long been a constant source of trouble to oil and gas operators as well as to farmers and stock-raisers in the vicinity of producing fields. The amount of oilfield brines Produced from wells on new properties may be almost negligible, but some older wells may produce several hundred barrels a day. A survey of almost 200 wells on 31 properties in the eastern part of Osage County, Okla., showed that during the month of November, 1928, the average production of water was 3.26 barrels per barrel of oil produced. The age of the wells included in this survey ranged from two to 28 years; the maximum amount of brine produced was 26 barrels of water to one barrel of oil and the lowest was one barrel of water to 27 barrels of oil. These figures apply to a small area. In other fields the production of water also varies widely; for example, in the Cushing4, Okla., field several yells were reported as having produced 100 barrels of water to every barrel of oil produced. Often the production of oil-field brines is decreased materially and the production of petroleum increased by the use of bottom hole Plugs and by a general repair and cementing of wells. The records5 of 22 wells cemented in the Gushing field showed that prior to the repair work, the average total dally production was 242.5 barrels of oil and 3,977.5 barrels of water. The total Production of

Jan 1, 1929

By H. Tomlinson

"PURPOSE OF REPORTThe purpose of this report, which is the third of a. series on the coal mines of the Western States, is to give the findings of a study of the causes and methods of prevention of accidents from falls of root and coal in the mines of Lincoln County, Wyo. The three mines covered in this report, referred to as A. B. and C, account- for 9 per cent of the coal production in the county and nearly 9 per cent of the State's total production. For comparative purposes some statistical data are presented bearing upon the relation of injuries to their causes, to tonnage produced, to men employed, to days worked, and to days lost as the result of injuries.FATALITIES IN WYOMINGTo show the necessity for this study, Table 1 given the fatalities that occurred during 1928 in the bituminous—coal mines of the United States, of the State of Wyoming of Lincoln County, and in Mines A, B, and C, followed by a brief description of the Kemmerer coal dis-trict, its coal beds and immediate roof, thickness of cover, dip of coal beds, methods of mining timbering for roof support, roof testing, and supervision. All of these factors must be considered in any plan outlined to prevent accidents resulting from falls of roof and coal.ACKNOWLEDGMENTAcknowledgment is made to the officials of the operating companies for their cooperation and assistance during the study and collection of data to complete this report.GENERAL INFORMATIONLocation and Ownership The mines included in this report are within 18 miles north and south of Kemmerer, Lincoln County, Wyo. (fig. 1), and are owned and operated by various coal companies to supply the domestic, smelter and railroad markets. They are severed by branch lines of the Oregon Shorty Line Railroad Coal production and men employed underground in the three mines are indicated in essential detail in Table 2."

Sep 1, 1932

By L. B. Pankratz

High-temperature heat contents were measured for two praseodymium oxides and three terbium oxides. There were: Pr2O3 (298° to 1,600° K), PrO1.833 (298° to 1,050° K), Tb2O3 (298° to 1,600° K), TbO1.719 (298° to 880° K), and TbO1.812 (298° to 850° K). With the exception of PrOl.833, all results were regular. PrO1.833 had a small thermal anomaly at 760° K with an extra absorption of 380 cal/mole. The measured heat content values, tabulated smooth heat contents, and entropy increments are reported. Heat content equations were derived.

Jan 1, 1966

By John C. Ferm

This report contains a summary of Phase I and complete results of Phase II portions of a study of geologic factors associated with roof falls in mines on the Pocahontas #3 coal seam in southern West Virginia and southwestern Virginia. Principal objectives of Phase I was the selection of five mines that best portrayed the spectrum of roof and mining conditions and Phase II consisted of a measurement and documentation program for each of the five mines. The documentation measurement program included reconnaissance mapping, detailed mapping, joint measurements and coring roof rock. 1.2 PHASE I RESULTS The results of Phase I consisted of the selection of the following five mines for detailed study: Virginia Pocahontas #3 (Island Creek Coal Company), Bishop (Consolidation Coal Company), Shannon Branch (Allied Chemical Company), Keystone II (Eastern Associated Coal Company) and Macalpine-East Gulf (Westmorelenad Coal Company). In addition, Phase I results, which were based on questionnaire data, indicated that the kind of rock in the roof --gray sandstone, crystallized sandstone, laminated sandstone and shale, grey shale, slickensided shale, and rider seams could be associated with good and bad top areas. Also presence of vertical separations, bolt length, entry and cross-cut width, length and torque on bolts and depth of overburden seemed to be related factors. These data provided a focus for the Phase II measurement program.

Jan 1, 1975

By H. Stanley Benson

This report is an account of research conducted to improve the performance of and then further field test Draft Power Sensor (DPS) equipment, the use of which enables a bulldozer operator to optimize his machine's work rate. Significant improvements were made in DPS hardware, and extended field testing was conducted at two working strip mines: the Glenharold Mine of Consolidation Coal Company, near Stanton, North Dakota, and the Beulah Mine of Knife River Coal Company, near Beulah, North Dakota. This report documents the increase of bulldozer work production by greater than twenty percent while using the Draft Power Sensor when compared to baseline work production without benefit of the Draft Power Sensor. Research was done by Southwest Research Institute under contract with the Bureau of Mines.

Jan 1, 1980

This report presents depth and producing rate statistics pertaining to oil reservoirs (or fields) in each of the 14 States that produced more than 20 million bbl of oil during 1965. The combined oil production was about 2.6 billion bbl, or 96 pct of the U.S. total. Data are presented for each of the 14 States, each Texas Railroad Commission district, and four geographical areas of Louisiana. About 8 pct of the total oil produced in the 14 States was from depths of lees than 2,000 ft, 24 pct from 2,000 to 4,000 ft, 22 pct from 4,000 to 6,000 ft, 16 pct from 6,000 to 8,000 ft, and 30 pct from 8,000 ft and deeper. The average production per well in the 14 States ranged from 4.4 bopd for wells less than 2,000 ft deep to 57.6 bopd for wells 8,000 it and deeper. Data indicate that 9.5 pct of the 460,968 wells produced more than 1.2 billion bbl or 46.6 pct of the total oil. Oil production from reservoirs (or fields) not undergoing stimulative recovery operations, such as steam, air, gas, or water injection, wee about 1.1 billion bbl or 42.1 pct of the total.

Jan 1, 1967

By R. Blickensderfer

Test equipment that simulated frictional impacts between coal-cutter bits and mineral inclusions at a coal face during operation of a continuous coal mining machine was used by the Bureau of Mines in the laboratory to study the incendivity of impacts between various rocks, metals, and hard-metal alloys in an explosive mixture of air-7 pct natural gas. Quartzitic sandstone was found to be the most incendive of several rocks tested. Limestone concretions from a coal seam, known locally as "sulfur balls," sparked furiously but were not incendive. Among the metals tested, the type of steel used in commercial coal-cutter tools was the most incendive material tested. A l7-4PH stainless steel was less incendive and appears to be the most promising high-strength steel alloy, reasonably economical, for use in coal-cutter bits. Some hard-metal alloys, primarily titanium and zirconium diboride composites, were also evaluated as possible replacements for the conventional cobalt-bonded tungsten carbide used in the tip of coal-cutter bits. The metal-bonded diborides were generally less inc endive but more brittle than the conventional tungsten carbide. Carbonitride coatings on tool bits were also tested but found to have no advantage. The source of ignition during frictional impact between metal and rock was studied. Immediately after impact, a yellow flash was observed and a smear of metal near its melting point occurred on the rock. This hotspot on the rock, rather than the yellow flash or sparks or metal fragments, was observed to be the cause of the ignition.

Jan 1, 1974

By L. H. Banning

Recent dry-top electric smelting tests at the Northwest Electrodevelopment Experiment Station, Albany, Oreg., indicate that a high-titanium slag and a good grade of pig iron can be produced from alluvial Idaho ilmenite. A total of 120 tons of concentrates were smelted during this investigation, to yield an average of 0.5 ton of slag and 0.3 ton of pig iron per ton of ilmenite. Power consumption averaged 1,400 kv.-hr. per ton of ilmenite, at a feed rate of 400 to 500 pounds per hour, when operating at an electrical energy input of 290 to 370 kilowatts. The optimum operating voltage appeared to be 110 volts, phase-to-phase. Graphite electrode consumption averaged 15.6 pounds per ton of ilmenite smelted. Magnesite furnace refractory withstood the corrosive action of the hot metal and slag better than carbon refractory.

Jan 1, 1955