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By B. J. Moore

The Bureau of Mines has estimated helium resources of the United States at 727 billion cubic feet as of January 1, 1979. These resources are divided into four categories in decreasing degrees of assurance of their existence: (1) Helium in storage and in measured natural gas reserves, 185 billion cubic feet; (2) helium in indicated natural gas resources, 150 billion cubic feet; (3) helium In hypothetical natural gas resources, 186 billion cubic feet; and (4) helium in speculative natural gas resources that makes up the remaining 206 billion cubic feet. The identified helium reserves, which are made up of that in measured and indicated natural gas categories, are further divided into depleting, non- depleting, and stored classifications. The depleting resources are those that are associated with natural gasfields that are, or will be, produced for the natural gas they contain. All of the helium in undiscovered natural gas resources are included in this classification. These depleting resources comprise 600 billion cubic feet of the total resource base. The nondepleting helium resources are estimted tototal 88 billion cubic feet. There is 39 billion cubic feet of helium in storage in Cliffside gasfield near Amarillo, Tex.

Jan 1, 1980

By Leonard Obert

[Part I of this report3/ proposed a sonic method for determining pressure, in situ, on rock pillars, arches, and other structures. Tin r Loa required (1) a laboratory determination of the variation of the velocity of sound with pressure in samples of rock taken from mine pillars to establish a velocity pressure relationship for the type of rock, and (2) a measurement of the velocity of sound in the mine pillars from which the laboratory samples were taken. The pressure on the pillars could be determined by correlating the velocity in the pillar with the velocity-pressure relationship established in the laboratory. The success of this method depends on the extent to which velocity of sound varies with pressure. Furthermore, Young's modulus of elasticity, E, can be calculated from longitudinal velocity, V, by the relationship, E V2d .....(1) where d = density. Hence, the variation of the elastic modulus with pressure also can be determined. It pointed out that this method might be extended to assist in the prediction of rock bursts, inasmuch as the rock is subjected to extreme pressure in these instances.]

Jan 1, 1940

By Joseph Gersic

In 1989-90, the Bureau of Mines appraised selected high resource potential areas containing gold, rare-earth-element, or pegmatite deposits in or near the Black Hills National Forest. Available mineral resource data were used to construct mine and mill models and to compute discounted cash-flow rate-of-return analyses. Using this information, the economic feasibility of possible operations and probability (in the nonmathematical sense) of exploration and development within the next decade were assessed. High exploration and development probabilities are forecast for gold deposits around existing and permitted mine areas near Lead-Deadwood and west of Galena. The area east of Galena has low to moderate exploration and development probability; the Rochford area has low to high exploration probability and low to moderate development probability; the Keystone area has low to moderate exploration probability and low development probability; the Medicine Mountain area has moderate to high exploration and low to moderate development probabilities. Exploration probability in the Bear Lodge Mountains area is high for rare-earth elements and gold; development probability is low. Exploration probability for gold in the Mineral Hill area is low to moderate; development probability is low. The current level of activity associated with pegmatite mining in the Black Hills would probably not change significantly in the next decade; both exploration and development probabilities are low to moderate.

Jan 1, 1990

By Pete G. Kovalchik, Lynn A. Alcorn, Rudy J. Matetic, Adam K. Smith

Over-exposure to noise remains a widespread, serious health hazard in the U.S. mining industries despite 25 years of regulation. Most other categories of illnesses and injuries associated with mining have improved, with the exception of hearing loss. Mine Safety and Health Administration (MSHA) coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage is comprised of seven different types of machines. The continuous mining machine is first among all the equipment with 35% of the noise overexposures. The ational Institute for Occupational Safety and Health (NIOSH) is conducting research to reduce excessive exposure for operators of continuous mining machines and preventing additional cases of oise Induced Hearing Loss (NIHL) by developing low-cost retrofit noise controls for mining equipment. This paper describes a noise control for reducing the noise overexposures of continuous mining machine operators. Underground results show a 26.4% and 27.4% noise exposure reduction for the continuous mining machine operator. This research is providing the mining community with an additional noise control to be utilized on continuous mining machines, therefore reducing operator noise overexposure. Utilizing this newly developed noise control, along with previously proven controls for the continuous mining machine chain conveyor, will provide operators of these machines an opportunity to be within the MS HA-Permissible Exposure Limit (MSHA-PEL).

By John J. McClelland, Gerald T. Homce, John R. Thalimer

The U.S. Bureau of Mines has investigated the early detection of insulation failure in squirrel cage induction motors for the past 4 years. Research was done using a sophisticated empirical data-modeling technique based on values calculated from a motor's voltage and current phasors. This technique produces two polynomial equations that calculate the insulation leakage current and power. These models were implemented in a prototype system that monitors six motors on a continuous miner for insulation leakage. These insulation leakage values are used to anticipate insulation failure. The system consists of a motor-data-system for each motor on the machine and a control computer located away from the miner. Each motor-data-system consists of an analog interface to the motor's voltages and currents, a single-board computer that reads digitized data and calculates voltage and current phasors, and a bus node that interfaces the single-board computer with the rest of the system by way of a serial bus system. Using this bus system, the control computer requests and receives phasor data from the motor-data-systems. From these data the control computer calculates and displays two deterioration values for each motor, for leakage current and power, using Bureau-developed models. These values are stored in a data base from which the user can display graphs of each motor's deterioration values over time.

Jan 1, 1992

By M. M. Fine

"INTRODUCTION One of the principal activities of the Bureau of Mines during the recent war was to help to increase the supply of strategic and critical minerals. Fluorite was one of the most critical of the nonmetallic minerals because of the increased demand for it as a flux in basic open-hearth and electric steel furnaces and as a raw material for the production of artificial cryolite used in the aluminum industry. Wartime developments in the technology of hydro-fluoric acid, such as the use of the anhydrous acid as a catalyst in high-octane-gasoline production and the use of organic fluorides as carriers for insecticides, also increased the demand for acid-grade fluorspar. 2/ In 1943 the consumption of acid-grade fluorspar was advancing at a more rapid rate than production and was only slightly less than production during the latter half of the year.The outlook for the postwar market for fluorspar is encouraging. Steel production is expected to remain high until the domestic demand for commodities not manufactured during the war is satisfied. The uses for hydrofluoric acid also are expected to increase under the impetus of war-initiated research. In consideration of these and other factors some authorities predict a new peacetime demand for fluorspar equal to 60 to 75 percent of the war production, 5/ 6/ and others believe that the fluorspar industry will be permanently expanded. 7/"

Dec 1, 1947

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960

By T. F. Mitchell, Walter J. Long

"SUMMARYThis report is one of a series giving results of laboratory and pilot-plant investigations of the concentration of western manganese ores begun in December 1940. Data given summarize results of laboratory investigation of three samples of complex oxide manganese ores from the Madeline property, Lake View, and Victory claims, Clallam County (Olympic Peninsula), Wash. The samples represented an extremely intimate and complex association of manga¬nese oxide minerals with silica and iron.Owing to the complex nature of the ores, no effective concentration by ore-dressing methods was possible. No high-grade manganese concentrates were produced and the highest recovery at minimum accountable grade was only 55 percent on one of the ores tested.Since the Clallem County ores did not respond to ore-dressing methods, leaching processes were investigated, results of which are to be published in a separate report.INTRODUCTIONOre-beneficiation tests were conducted on three samples of manganese oxide ere from the Madeline, Lakeview, and Victory claims, Clallam County, Wash. The ores are extremely complex because of the unusually small size of manganese mineral particles, their mode of occurrence, and relationship to the gangue. None of the three ores was amenable to the production of high-grade manganese products by ore-dressing methods."

Dec 1, 1945

By J. D. Lane

The U.S. Bureau of Mines is conducting research on guidance systems for computerized haulage in underground mines. This report describes the process of component selection, installation and testing, perception algorithm development, and steering control algorithm development, to produce a real-time steering control system for an articulated haul truck for underground mining. Ultrasonic transducers were mounted on the truck to provide perception data by measuring the distance to the ribs. Linear potentiometers mounted inside the steering cylinders measured the steering angles. Algorithms, implemented on an inexpensive, robust onboard computer system, analyzed the data and controlled the steering via an electro-hydraulic proportional valve. The steering algorithm presented follows a zone defined by the relative position between the truck and a rib. Experimental verification of the ability to follow the zone in a test corridor on the Colorado School of Mines campus is presented. The automatic steering system successfully negotiated straight sections, curves, and the transition zones between straight and curves with the truck in first and second gears. The resulting real-time automatic-steering system can be applied to many underground articulated machines.

Jan 1, 1994

By D. B. Taliaferro

Information regarding the pores or voids in reservoir rocks is vitally important in the scientific extraction of petroleum from natural underground reservoirs, and petroleum technologists concerned, with subsurface, conditions have devised various methods that give reasonably accurate information as to the porosities of oil and gas-bearing sands.5/ In this, work, several investigators have made use of the experience of the ceramic and other industries. The method of determining the effective porosity of oil sands described in this report falls within the general classification of gas-expansion methods. It was devised and developed at the United States Bureau of Mines Petroleum Experiment Station, Bartlesville, Okla., as a part of the research dealing with fluid and energy relations in reservoirs and improved oil-recovery methods. The apparatus and procedure are well adapted to the requirements of the Bureau, and the following detailed description has been prepared so that others may make use of the information. A tabulation at the end of the report gives the results of several hundred porosity determinations for oil sands in fields of 11 States.

Jan 1, 1937

By T. Christos

The explosive oils, nitroglycerin (NG) and ethylene glycol dinitrate (EGDN), were extracted from dynamites by a halocarbon solvent and were then determined by high-pressure liquid chromatography. Separation was achieved by liquid-liquid chromatography on a column packed with Durapak-Carbowax 400/Corasil II and the eluted NG and EGDN were detected with a double-beam ultraviolet detector.

Jan 1, 1973

By Robert W. Ageton

Optimal planning for mining the deep, lead-zinc-silver deposits of the Coeur d'Alene mining district, Shoshone County, Idaho, could be facilitated by a knowledge of the magnitude and direction of the pressure acting in the virgin rock. The distribution of primary stresses should be considered in order to prevent possibly destructive mining-induced stress concentrations. This particular investigation was concerned with determining stress in a zone 4,000 feet below the surface and known to be ender stress concentrations due to mining operations. Disking of the stress-relief cores obtained in a vertical down hole permitted qualitative evaluation from visual observations; the results indicate that a high lateral stress existed at the time the measurements were made. Stress-ellipsoid determinations gave a compressive principal stress of -13,000 psi oriented about N 45° W and nearly horizontal, a compressive principal stress of -11,000 psi oriented about S 45° W and abut 60° off the vertical pointing away from the vein, and a compressive principal stress -5 -7,000 psi oriented N 45° E and about 60° off the vertical, pointing toward the vein. Subsequent to the overcoring stress-relief drilling, a rock burst occurred about 100 feet northwest of the test site.

Jan 1, 1967

By F. P. Haver

The Bureau of Mines is developing a leach-electrolysis procedure to produce Special High Grade (SHG) zinc from sulfide concentrate without the generation of sulfur oxide gases. Chlorine-oxygen leaching of the concentrate yields zinc chloride (ZnCI2) which, after purification, is electrolyzed in a fused-salt cell to obtain molten zinc metal and chlorine gas for recycle. This paper describes a laboratory-scale investigation made to develop a procedure for electrowinning zinc metal from ZnC12. Zinc chloride by itself is not a suitable electrolyte because it fumes badly above its melting point and is a poor conductor of electricity. Other salts therefore must be added to prevent fuming and improve the conductivity. Optimum results were obtained with a KC1-LiCl-ZnCl2 bath at 500° C, using a current density of 5 amp/in2 and an electrode spacing of 0.5 inch. Under these conditions, SHG zinc was produced at a current efficiency of 94.3 pct and an energy requirement of 1.16 kwhr/lb. Fused-salt electrowinning eliminates the need to handle and melt cathodes and increases the production of metal per unit cell volume through the use of higher current densities than are possible with aqueous electrolysis.

Jan 1, 1976

By Frank G. Miller

Controlling natural-water drives to effect efficient and economic production of petroleum, through wells, from reservoir sands and rocks is a problem of major importance in the oil-producing industry. Water-drive fields are characterized by large quantities of mobile water under high pressure immediately below the oil in the flanks or extraneous parts of reservoir formations, Hence, the water, which is in fluid connection with the oil and a source of a large proportion of the energy available for moving it, advances up-structure to replace it. This phenomenon of water moving crestward into the oil-bearing parts of the reservoir and replacing oil is termed edgewater encroachment. The mechanism by which oil is flushed out and continually replaced by water as the hydocarbon content of the field is depleted must be understood if natural-water drives arc to be used successfully to, induce efficient recovery of oil from its reservoir rocks. Until recently, the function of water in the production of oil has been somewhat obscure and was not given the consideration it deserved in early petroleum production-research programs because of the greater importance associated with and the effort devoted to investigations concerning the relations of natural gas to production of oil. Thus, with virtually no fundamental information at hand, it is not surprising that at first edgewater was considered a necessary evil, and the manner in which it was dealt with depended largely on the experience of the operators. During the intervening years, however, practical information on encroachment of edgewater in oil sands has been widely disseminated as a result of studies of oil-field depletion, and many theories pertaining to petroleum-reservoir energy and performance have been advanced; these theories necessarily included consideration of edgewater as an integral -art of the reservoir fluids and a source of energy for propelling hydrocarbon fluids through the reservoir and to the surface of the ground.

Jan 1, 1941

By W. R. Reed, J. A. Organiscak

Surface mining operations use large off-road haul trucks extensively to move material at mining properties. Past research, using the United States Environmental Protection Agency’s (EPA) emissions factors for unpaved haul roads, has shown that haul trucks generate the majority of dust emissions from surface mining sites, accounting for approximately 78%-97% of total dust emissions. Observations of dust emissions from haul trucks show that if the dust emissions are uncontrolled, they can be a safety hazard by impairing the operator’s visibility. This increases the probability for haul truck accidents (See photos above). However, the greatest long-term health hazard of dust generated from hauling operations is due to inhalation of the respirable dust [median diameter <4 micrometers (µm)] and tho­racic dust, which is equivalent to the EPA’s definition of PM10 [particulate matter with a median diameter <10 µm]. Exposure to respirable dust has long been considered a health hazard at surface mining operations, especially if silica dust is present. There are two legislative acts that regulate the air quality for mining operations: the Federal Coal Mine Health and Safety Act of 1969 and the Clean Air Act of 1970. The Federal Coal Mine Health and Safety Act of 1969 established the limits for dust in the work place for health and safety pur­poses. The Clean Air Act of 1970 regulates air emissions from facilities from an envi­ronmental perspective.

By R. R. Wells, G. M. Potter, R. Havens, W. W. Agey

"INTRODUCTION As part of the program of investigating possible domestic sources of manganese, ore-dressing studies were conducted at Salt Lake City, Utah, on five samples of manganese oxide ore obtained by mining engineers of the Bureau of Mines from the Havasu Lake District, California and Arizona.Two lots of radically different ores were procured from the Arizona Manganese claims 30 miles above Parker Dam, Mohave County, Ariz. One of the original 11 claims has been flooded by Havasu Lake, formed by Parker Dam. The claims are owned by R. H. Thompson, Parker Lumber Co., Parker, Ariz. The 2-ton lot of high-grade ""TA"" ore represented ore occurring as pyrolusite and psilomelane accompanied by a black calcite gangue in lenses along a series of fault planes in granite. A half-ton lot of low-grade ""TB"" ore was taken from a large lense of reddish iron-bearing material outcropping on another section of the property.A 2-ton lot of ore was taken from the Jones property, 8-1/2 miles southwest of Powell, Mohave County, Ariz. At the time of the investigation, the property was leased by J. H. Jones, of Oatman, Arix., from the owners, the Atchison, Topeka, & Santa Fe Railroad Co. The ore body was described as a re¬placement in a sandstone formation in a region that has been faulted extensively."

Dec 1, 1947

By F. E. Spencer

Calculated equilibrium data are presented for three phases in the flue gas stream from a hypothetical open cycle MHD generator. A typical coal is "burned" with 1.0 gram-mole K2O seed per kilogram coal and with 101 percent of stoichiometric air. Tables of composition and the overt thermodynamic properties, enthalpy and entropy, are given for the temperatures 2200 (-100) 1100 kelvins, pressures 1.0 and 1.5 atmospheres, and slag rejection figures of 90 and 75 percent.

Jan 1, 1973

To provide operators of large-opening mines with a ventilation planning tool that will help them develop a healthier, safer, and more efficient ventilation system in the underground workplace.

Jan 3, 2006

By A. D. Hahn

This report describes reconnaissance by the Federal Bureau of Mines of titanium-bearing sandstone in Kemper County, Miss. The purpose was to determine the ilmenite, rutile, and associated heavy-mineral content of black-sand-bearing Eocene deltaic formations" The investigation was part of a survey of titanium resources of the United States. Ilmenite (FeTi03), an iron-titanium oxide, is the major titanium-bearing mineral consumed in the titanium pigment industry. Rutile (Ti02), titanium oxide, is used mainly in producing welding-rod coatings and titanium metal. The fieldwork was conducted during the first half of November 1959. Seven holes, totaling 304 feet of bore, from which 64 samples of cuttings were taken, were drilled in the north-central part of the county; and two holes, totaling 172 feet of bore, from which 34 samples of cuttings were taken, were drilled in the southeastern part.

Jan 1, 1961

By Allen D. Look, Alan A. Sharp

"Churn drills for blast-hole drilling are important to the operation of most open-pit metal mines, but certain hazards are created through their use that cause fatal and nonfatal accidents.2/ The purpose of this circular is to present a code of safe practice prepared and followed at a large Arizona open-pit copper mine, where safety is recognized as a definite operating problem. Such a code, based upon a thorough study of available published information as well as practical experience gained from accidents and near accidents, is the result of considerable effort and monetary expenditure. It is hoped that other operations using churn drills may benefit by the code presented, either in comparison with existing rules or in the preparation of new operating instructions.The code presented is in use at the Morenci Branch of the Phelps Dodge Corn., Morenci, Ariz. Similar codes are used at the New Cornelia Branch, Ajo, Ariz., and in the waste-pit operation at the United Verde Branch, Jerome, Ariz.The authors gratefully acknowledge the cooperation of the Phelps Dodge Corp., whose personnel made: possible the collection of information included in this circular. Special acknowledgment is due Paul Simmons, safety engineer, and 3. U. Larsen, general drilling and blasting foreman, Morenci Branch, Morenci, Ariz.The importance of churn drills in Arizona mining is apparent when it is realized that at all the open-pit copper mines blast holes are drilled with this equipment. At Morenci, approximately 98 percent of the ground is broken by primary blasting of churn-drill holes.There has been a growing tendency in Arizona's copper-mining industry to change from underground to open-pit mining, with consequent increase in the use of churn-drill blast holes for primary blasting.3/Thirty-three churn drills are in use at Morenci for blast-hole drilling. The drills operate with 440-volt alternating current, and trailing drill cables, in 500-foot sections, connect with the portable drill transformer station.4/ Three Diesel-driven churn drills for drilling prospect holes also are in use. About 25 churn-drill shifts are operated currently on a three-shift basis. Ordinarily, a two-man crew is assigned to each drill; however, with prospect-drill crews a third man is added to handle the sampling.Benches are carried at a uniform height of 50 feet. Churn-drill holes are 9 or 12 inches in diameter and about 60 feet deep. The holes are 18 feet apart in hard waste and 21 feet in soft waste and ore, with toes from 11 to 13 yards at the shovel grade. Both the hole spacing and the toe have been increased gradually, until they are now 2 yards longer than in 1940. The average ground broken per hole is 3,500 tons, or 60 tons of ore per foot of hole drilled. The holes are drilled 10 feet below the bench to avoid leaving hard bottom, which requires secondary drilling and blasting.Starting with a 12-inch casing, the prospect holes average 1,200 to 1,500 feet in depth and terminate with 6-inch casing; the deepest hole drilled to date went to 1,735 feet.In addition, churn-drills are used at Morenci to drill blast holes in the silica pit, limestone quarry, and the tailings dam. Other irregular applications are the drilling of holes to set trolley roles and for concrete piling in building foundations."

Jan 1, 1950