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By Earl F. Hastings

The Pilgrim mine, operated by the Pioneer Gold Mining Co., is 9-1/2 miles west of Chloride in the Pilgrim mining district on the eastern slope of the Black Mountains, or River Range, Mohave County, Ariz. In March 1937, 100 tons of gold ore per day were being mined and milled at the property by a total force of 5i men. Climatic conditions allow year-round operations. Due to present activity in the county there is an ample supply of labor for the requirements of the mine. The Pilgrim is the only producing property within s radius of 6 miles; recently, however, the South Pilgrim Mining Co. has launched a development campaign on claims that adjoin the Pioneer Co. property to the south.

Jan 1, 1937

By W. Hermanson

This report, which covers the period from January 16 to October 21, 1974, describes the work performed in compliance with the requirements of contract no. H0242028 and modifications 1 and 2 thereto. The purpose of the contract was to further reline and modify three of the canopies (shuttle car, loader, and roof drill) which were developed under contract no. H0220031, and to conduct further testing and demonstration of the relined designs. Modifications I and 2 involved conducting further in-mine evaluations of the face. drill and cutter canopies, also developed under contract no. H0220031. In addition to the canopy modifications, the contract involved an evaluation of an operator's seat concept for a shuttle car which was developed for the USBM by another contractor.

Jan 1, 1974

Improve mine refrigeration system efficiency while providing free electrical energy to mines. Approach Convert the potential energy of incoming mine water falling down long vertical shafts into electrical energy by means of a turbine-generator system located at the bottom of the mine shaft. How it Works Converting the energy of falling water into useful work is a well-developed engineering concept. Water flowing down long vertical pipelines into deep mines develops high pressure that can be used to operate a turbine-generator system at the bottom of the pipeline. A thermal energy recovery system of this type offers three advantages: 1. In systems without turbines, the potential energy of the water is converted to heat. The water temper-ture will automatically

Jan 1, 1985

By A. W. Deurbrouck

This report describes the preparation characteristics of the significant coalbeds from which samples could be obtained in Webster County, W. Va. In 1964, approximately 825,000 tons of coal was produced in the county, of which 732,000 tons was mechanically cleaned in three preparation plants. The Sewell coal bed accounted for 94 percent of the coal produced. Twelve samples were collected from five coalbeds. Four of the samples would require upgrading to meet metallurgical requirements; two others of just over 8.0 percent ash would require some upgrading. In general the coalbed samples collected in the county were of medium-sulfur and medium-to low-ash content as received or after removal of the sink 1.58-specific-gravity material.

Jan 1, 1966

By Foster Fraas

This report describes the application of pulsed magnetic fields derived from alternating and intermittent magnetizing currents. Application of such pulsed magnetic fields to the matrix-type separator permits (1) the complete discharge of the magnetic fraction with wet feeds and (2) the dry separation at particle sizes down to 325 mesh. At smaller particle s indications are that frequencies above 60 hertz will be required. Applications of intermittent magnetizing current to the cross-belt separator give the cross-belt-separator an advantage over the conventional constant-field cross-belt and induced roll separators; the intermittent current enables the cross-belt separator to separate matted fibrous and magnetically coagulating feeds, a type of feed that occasionally occurs with mineral, industrial, and secondary materials.

Jan 1, 1973

By James P. Bennett

To improve construction materials for emerging chemical and metallurgical technologies, the Bureau of Mines is investigating the acid resistance of ceramic materials. In the study described here, eight commercial ceramic materials comprising two red shale, two fire clay, a silica, a silicon carbide, a carbon, and a high-alumina brick were evaluated. Samples were exposed to 20 wt-pct HC1 at 50° C for 110 days. The test apparatus designed to evaluate the materials is described. Changes in chemical and mineralogical composition, cold crushing strength, volume, and weight, and leach rates of AI, Ca, Fe, K, Mg, Na, Si, and Ti ions were monitored. In general, the statistically significant physical property changes that occurred were small. In many cases, no changes were detected.

Jan 1, 1982

By Ann G. Kim

Gas samples containing 02, N2, H2, He, CO2, CO, CH4, and trace amounts of C 2 to C6 hydrocarbons are analyzed by a gas chromatographic method that utilizes both thermal conductivity and flame ionization detectors. A porous polymer support and molecular sieve columns are used with argon as the carrier gas. A column selector valve makes it possible to perform a complete analysis either on one 1-ml sample in 40 minutes or on two samples in 20 minutes, one sample for each detector. Samples are introduced either by on-column injection or through a gas sampling valve. By varying operational parameters, the speed, sensitivity, and accuracy of analysis may be modified to suit a particular situation.

Jan 1, 1974

Arsenic.--Inorganic arsenic has been added to the Environmental Protection Agency's list of hazardous air pollutants because of a high probability it can cause cancer. EPA estimates that inorganic arsenic emissions into ambient air total more than 6,000 tons per year, with about 65;L of this coming from the operations of copper, lead, and zinc smelters. Asbestos Detection.--In June 14, the President signed S. 1658 providing $172.5 million to detect and remove asbestos hazards in schools. Asbestos Use Must be Reported.--All firms using asbestos in the manufacture of some 30 categories of products must describe in detail how they use the mineral to the Consumer Product Safety Commission, for all manufactures since January 1, 1977.

Jan 1, 1980

By H. Carroll

An ozone detector was built and evaluated for its applicability in smog-chamber studies. The detection method is based on the reaction of ozone with ethylene and the measurement of resultant chemiluminescence. In the first phase of evaluation, the detector's response to ozone was studied as a function of several instrument parameters, and optimum conditions were defined for the maximum and most stable responses to ozone. In subsequent evaluations, the method was checked for sensitivity, precision, and interferences and was compared with two alternative methods. Results showed the chemiluminescence method to be acceptably sensitive and precise for smog-chamber studies and superior to the Mast ozone meter and KI (colorimetric 1 percent neutral-potassium iodide method) methods in that it is specific for ozone.

Jan 1, 1972

Objective Develop field measurement and computer modeling methods to predict the potential for hang-ups and structural failures in underground mine ore paws. Background Analysis of Mine Safety and Health Administration (MSHA) accident statistics has identified ore pass hazards as a significant safety problem in underground metal mines in the United Stales. Recent ore pass failures have underlined the lack or ore pass design methods ant1 standards available to both MSHA and mine engineers. Injury and fatality data for the 20-ycar period between 1975 and 1095 show that nearly 75% of the injuries were directly or indirectly related to pulling or freeing ore pass chutes, the use of hand tools, falls or broken rock, and structural failures or chutes or gates and ore pass walls.

Feb 1, 1998

By H. Dolezal

An investigation was made on the use of magnesium for the direct reduction of rutile to make low-cost, offgrade titanium which could be upgraded to an acceptable grade of metal by electrorefining. Reductions made with charges containing magnesium chloride under hydrogen yielded products with oxygen con-tests close to the theoretical equilibrium composition. Two reduction products were made from rutile for use in electrorefining amenability tests: (1) a product from reduction in an inert atmosphere which contained 88.9 percent titanium and 4.42 percent oxygen, and (2) a product from reduction in a hydro-gen atmosphere which contained 92.5 percent titanium and 2.40 percent oxygen. Reduction products obtained under both of these conditions were amenable to electrorefining.

Jan 1, 1965

By G. W. Birge, D. E. Wolfson, J. H. Lynch

This report by the Federal Bureau of Mines describes the carbonizing properties of coals from the principal beds in Boone County , W. Va . Results are given for samples of coals from No. 5 Block , Stockton - Lewiston , Coalburg , Winifrede , Chilton , Hernshaw , Cedar Grove , Alma , and No. 2 Gas beds . Boone County coals rank as high -volatile A bituminous . Eighteen of the 21 samples tested contained from 3.3 to 7.9 percent ash and 16 of the samples contained from 0.6 to 0.9 percent sulfur . Two samples from the Alma and No. 2 Gas beds , the lowest stratigraphically of the seams tested in Boone County , contained from 1.4 to 2.7 percent sulfur . Most Boone County coals yield

Jul 1, 1960

The method of using large-diameter augers to recover coal was introduced to the mining industry about the end of World War II, and production of bituminous coal with augers has increased steadily to an estimated 7 million tons, or approximately 1.4 percent of the total mined in 1956. Although auger mining has proved to be a reliable and economical method of mining coal, a number of unfortunate fatal accidents have been experienced; consequently the need for these recommended safety standards is indicated for this comparatively new method of coal mining. As mining methods and equipment change from time to time and new hazards are introduced, these standards will be revised; therefore, questions or suggestions from the coal-mining industry will be welcomed and carefully considered.

Jan 1, 1958

By Wing G. Agnew

The first six Reports of Investigations in this series , pertaining to the investigation of stemming at the Mount Weather Testing Adit, dealt with ( 1 ) the dust produced by blasting , ( 2) the effect of stemming upon gases generated by blasting , ( 3 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 60 - percent ammonia gelatin dynamite , (4) the length of stemming material through which a primer will fire and detonate a charge of dynamite , ( 5) comparison of dust and gases produced when blasting charges of dynamite in drill holes , bombs, and mud - cap shots , and ( 6 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 40 - percent ammonia gelatin dynamite .

Oct 1, 1943

By B. W. Gandrud

The upper part of the Alabama deposits of crystalline graphite consists of an oxidized ore derived from the underlying unoxidized ore through prolonged Weathering. The degree of oxidation in different sections and at different depths within the bed is not uniform. The original ore is hard and blue-gray; the weathered product is soft and brown and is the only part that has been mined to any extent. Samples of both oxidized and unoxidized ores were obtained from two of the large graphite deposits of Clay County. Three additional samples of oxidized ore were obtained from different portions of a third property in the same region. In this report, ores 1 to 5 are of oxidized material and ores 6 and 7 of unoxidized.

Jan 1, 1934

Improve the dust control effectiveness of dry collection systems on surface coal mine drills. Approach Use a dust pelletizer to convert the respirable dust particles discharged by the dry collector into dust pellets that present no health hazard. Background Blasthole drills are well-known sources of respirable dust that can contain significant amounts of quartz. The drills frequently use a dry cyclone-filter type collector that can obtain dust reductions theoretically greater than 95 pct. However, surface mine drills using dry collectors typically have three major dust sources that significantly reduce the overall effectiveness of the collection system: (1) the dust collector dump cycle, (2) drill shroud leakage, and (3) leakage around the drill stem seal in the drill table.

Jan 1, 1989

By R. S. Olsen

The Bureau of Mines is engaged in research to recover aluminum from kaolinitic clay and other nonbauxitic domestic resources. As part of this work, calcined Georgia kaolin was prepared by a process that prevents slime formation and makes the leached residues fast settling and easy to filter. The leaching reaction for calcined kaolinitic clay in a 5 pct stoichiometric excess of boiling 23-to 26-pct HCI was found to be zero order. Rate constants based on the weight-fraction of aluminum in the clay were found to be between 0.095 and 0.15 min-1 depending on feed preparation and leaching parameters. The mathematical relationships between aluminum extraction and time for both batch and continuous, stirred-tank operations were derived and verified experimentally.

Jan 1, 1983

By Oliver Bowles

"Rhodesian asbestos is of high quality and is much in demand by American consumers. Production in Rhodesia was first reported in 1909. The production for this and each succeeding year is shown in the following table:The serious curtailment in production for the years 1912 and 1913 was occasioned by transportation difficulties. In 1914 a railway was projected to Victoria and thereafter production increased greatly. Up to 1916 asbestos was obtained,from the Victoria district only, but thereafter the Bulwayo district became an important,producer with minor quantities from Gwelo.In the Bulawayo district the productive area is about 2 1/2 miles long, with Shebanie mine at the north-west end, the Nil Desperandum at the south end, and the Birthday claims between them."

Oct 1, 1920

By Oliver W. Keener

The operation described herein differs from the usual practice in the Tri-State district in two important respects: (1) the ore is loaded into cars which are tramped to the shaft and hoisted on self-dumping cages, and (2) about 30 per cent of the ore is loaded by power shovels. The four-month period covered by the cost data appended at the end of the paper immediately followed a period of about one year during which the mine was shut down, and the expense incident to the resumption of operations is reflected in the costs. The author acknowledges the assistance of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the preparation of this paper and the compilation of the data.

Jan 1, 1929

By B. J. Scheiner

The Federal Bureau of Mines has successfully demonstrated an electrooxidation-solvent extraction-carbon adsorption process for recovering molybdenum and rhenium from offgrade concentrates. The flow sequence consists of dissolution of metal values by electrooxidation, liquid-solid separation by thickening, acidification and chlorate ion removal by sulfur dioxide treatment, solvent extraction to concentrate the molybdenum and rhenium, separation of molybdenum and rhenium by carbon adsorption, and metal recovery by crystallization. Molybdenum and rhenium were recovered as ammonium paramolybdate and ammonium perrhenate. Electrolysis of brine-concentrate pulps to generate a hypochlorite oxidizing agent in situ resulted in the dissolution of 98.9 and 99.1 pct of the molybdenum and rhenium, respectively, at an energy consumption of 13.7 kwhr/lb of molybdenum extracted.

Jan 1, 1976