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By Clayton M. Rumsey

In 1984, the U.S. Bureau of Mines conducted a mineral survey of a 26,598-acre study area which includes the 23,702-acre Mt. Limbo Wilderness Study Area (NV-020-201). The study area is 65 miles northeast of Reno, NV, and is underlain mainly by Cretaceous granodiorite that comprises the Selenite Range. Tertiary basalt, rhyolite, and sedimentary rock as well as Quaternary alluvium and lake deposits are exposed near the study area boundary. Mines just north of the area in the Hooker mining district produced tungsten ore in the 1940's and 1950?s. Similar deposits are not known in the study area. Disseminated gold is in sinter about 6 miles west of the study area and at several other locations regionally.

Jan 1, 1986

By Philip W. Holland

This Bureau of Mines report discusses the results of three independent reconnaissance geochemical surveys conducted in the vicinity of the Bush Dome reservoir in the Bureau-owned Cliffside field near Amarillo, Tex. The surveys consisted of (1) determining the helium content of area ground waters, (2) determining the helium content of area soil gases and ground waters, and (3) determining the helium content of soil gases collected on a grid sampling pat- tern in the Cliffside field area. The native natural gas in the Cliffside field contains about 1.8 percent helium. To date, approximately 54 billion cubic feet of gas containing approximately 39 billion cubic feet of helium has been injected into the center of the Bush Dome structure. The research work, which was completed under contracts, was done to determine if helium concentration levels in ground water and soil gas could he used as an indication of the presence of helium in a subsurface natural gas accumulation. Results of the surveys were positive in that helium-in-water and helium-in- soil-gas anomalies were detected in portions of the Cliffside field area. All helium analyses were performed by mass spectrometric techniques.

Jan 1, 1979

By W. R. Hardwick

This paper describes mining methods and practices of the Chino Mines Division, Kennecott Copper Corp., Grant County, N. Mex. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program was conducted from 1928 to 1939, which helped to improve the efficiency of mining operations. The primary purpose of the program is to promote development and conservation of our mineral resources by disseminating technologic information on methods, practices, and related features in mining mineral deposits. It is expected that the program will: (1) Promote efficiency in operating mines; (2) assist operators and engineers in evaluating and developing new mineral deposits; (3) provide data for engineering curriculums in mining schools; and (4) furnish performance and cost data for revising engineering handbooks and for inclusion in engineering textbooks.

Jan 1, 1958

By J. Howard Bird

The purpose of this publication is to describe the power-distribution system of the mine and refinery of the Duval Sulphur & Potash Company at Carlsbad, N. Mex. This distribution system has been excellently predesigned to meet requirements and fit special conditions encountered at the property. In presenting the material, the authors point out various features that would be desirable for incorporation in other systems under similar conditions. Central location of switchgear in pressurized vaults and ventilation of such equipment with filtered air prevent salt accumulations and contribute to trouble-free operation. The simplification of power-distribution circuits and overload protection, as a result of centralization of switchgear, the use of individual control circuits enclosed in conduit (which aids troubleshooting), and central location of control panels, are factors which contribute to efficient, safe operation. Those features are applicable to many operations where fire or explosion hazards are encountered, or where dusty conditions may exist, as well as in operations where numerous individual drives are involved.

Jan 1, 1959

By G. B. Shea

Among the many engineering problems directly related to conservation in the petroleum industry, that of crude-oil emulsions continues to be important. Emulsions of water and oil always have constituted one of the most serious forms of waste in the oil fields, and the necessity of dehydrating emulsified crude petroleum to obtain marketable or pipe-line oil confronts operators in many fields with a major operating problem. In 1926 the Bureau of Mines published a comprehensive treatise s on oil-field emulsions dealing with field conditions, practical methods of dehydration, and physicochemical characteristics of the formation and resolution of emulsions. Although this bulletin is still available and may be obtained from the Superintendent of Documents, Washington, D. C., and although its contents are a valuable reference on the subject of emulsions, knowledge regarding the physical properties of emulsions and the phenomena of dehydration has increased greatly within the last decade. With the information gained through continued scientific research, substantial improvements have been made in the art of resolving petroleum emulsions. Moreover, in recent years there has been a growing realization of the importance of emulsion-preventive measures that has led to more critical examination of the causes of emulsions and methods of eliminating or at least reducing the degree of emulsification. Conditions causing agitation and commingling of oil and water and the formation of "cut oil" often are within the control of the producer, thereby making it possible to utilize preventive or remedial measures by which emulsification may be minimized or avoided. In fact, many companies have materially reduced their treating costs as a result of careful studies in emulsion prevention and proper handling of "wet" production. Of course, in many instances preventive measures or the correction of conditions causing emulsification cannot be achieved practically or economically, and the emulsions that form must be treated regardless of the care exercised or the money spent in attempting to prevent their formation.

Jan 1, 1939

By E. Owens, R. Gudavalli, D. Wilder, T. Xia

As mechanical shock and vibration environments evolve, it is important to understand their potential effect on human operators. Human beings are sophisticated mechanisms comprised not only of passive components with mass, damping, and stiffness characteristics, but also of components that can actively affect apparent mass, stiffness, and damping. Because the lumbar spine can exhibit local, short-column buckling, stability of the human trunk depends on the responsiveness of the neuromuscular control system.1-2 We have been evaluating the ability of patients with back pain to respond to a series of sudden loads. We believe the results have implications for isolation design and standards development. Methods 153 patients, aged 21 to 55, presenting with back pain agreed to enroll in a research study that randomly assigned them to one of three treatment arms: high velocity low amplitude spinal manipulation, low velocity variable amplitude spinal manipulation, or wait for 2 weeks and then be randomized to one of the above groups. Response to sudden load testing was one of a battery of baseline evaluations performed upon entry into the study and prior to treatment. EMG electrodes were attached to the skin over the paraspinal muscles of the standing participant bilaterally 3 cm from midline at the L3 level. While standing upright on a force plate (Bertec), participants were fitted with a strap around their back and hooked to a load cell in front of their chest. An accelerometer was rigidly attached to the load cell. Impact was applied to the chest using a cord attached to a falling weight. The weight’s fall distance was varied between 9 and 13 inches to account for the size of the subject. The subject was blindfolded and wore headphones playing white noise to prevent cueing of when the weight was dropped to apply the load. Hence, although the participant knew a load was about to be applied, he or she did not know the instant it would occur. Just before the weight was dropped, a 4 second data collection process was started for the two EMG electrodes, load cell, accelerometer, and force plate. The load drop was repeated 6 times, at irregular intervals, over a period of 2 minutes. The raw data thus collected was reduced to obtain several values: 1) length of time from the pull on the harness to the beginning of the response of the left and right paraspinal muscles (LES, RES), 2) time and magnitude of the maximum response, 3) force and acceleration experienced at the chest, and 4) the time and magnitude of the center of pressure location (COP). A general linear model was used to evaluate the results. Results For the EMG data, of the 1,824 observations made, 90% of them indicated a response. Prior to the sudden load, resting muscle activity was different between left and right sides (p=0.0001) and between males and females (p=0.0001). Female subjects began to respond to the sudden load within 92 to 110 ms and males from 101 to 109 ms. Females exhibited more variation in starting

Jan 6, 2006

[1.1. The provisions of this code are minimum provisions and are designed to minimize hazards to life and property in and about underground coal mines where electrical equipment and circuits installed used. They indicate the Steps necessary in the selection, installation, operation, inspection, and maintenance of electrical equipment and circuits to obtain proper safeguards in reducing electric shock, fire, explosion and other hazards. Surface as well as underground installations were considered in formulating the code and, unless otherwise stated, each provision applies equal to both underground and surface installations. This code does not apply to buildings and installations not directly connected with mining operations, nor does apply to strip-mining operations.]

Jan 1, 1952

By Kenneth R. Maser

This report describes a research and development program sponsored by the United State s Bureau of Mines. The purpose of the program was to develop reusable explosion-proof bulkheads for a cross-cut emergency shelter, and to study the implementation of such bulk-heads, and the resulting shelters, as part of an emergency escape plan in a normal coal mining environment. The first part of this report reveals a number of significant conclusions regarding the application of emergency shelters. A study of the cause s of, and the conditions prevailing during a mine emergency indicate s that ideal placement of the shelter s would be midway along developing entries, and at the inter section of butt and main entries. The proper spacing of shelters is based on the travel capability of trapped miners, which is in turn dependent on the height of coal. The life of a given emergency shelter, based on an analysis of the above information, will be anywhere from 6 months to 10 years. Consequently, some shelters are regarded as "temporary?, while others "permanent?.

Jan 1, 1975

By Heine Kenworthy

"INTRODUCTION In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral content of this ore was considerably higher than in, the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently, tailing losses, especially with respect to lead, were high. A few years later, in order to study the possibilities of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill, feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Sta¬tion for testing-. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values was present.A résumé of the ore-dressing treatment used in the Shenandoah-Dives mill follows. After crushing, the ore passes through a ball mill, the minus 5-mesh discharge of which is distributed to three tables. A finished lead concentrate is made on the tables, and the table tailing goes to the classifier which is in closed circuit with the ball mill. The classifier overflow is treated -by flotation to obtain a bulk sulfide concentrate at a relatively coarse size. The bulk concentrate is thickened and reground to about 95 percent minus 325-mesh before flotation treatment to separate a lead-copper and a zinc concentrate. A typical monthly average showed that the table concentrate contained about 45 percent lead, 1 percent copper, 4 percent zinc, 12 ounces of gold, and 40 ounces of silver; that the lead flotation concentrate contained '35 percent load, 6 percent copper, 7 percent zinc, 3.5 ounces of gold, and 50 ounces of silver; and that the zinc flotation concentrate contained 2 percent lead, 0.5 percent copper, 60 percent zinc, 0.15 ounces of gold, and 4 ounces of silver. Recoveries in salable products were roughly b5 percent of the lead, 70 percent of the copper, 45 percent of the zinc, 85 percent of the gold, and b5 percent of the silver."

May 1, 1948

By Lester G. Morrell

While developments in Australia dominated the minerals industry of the South Pacific area, New Caledonia's nickel, manganese ore from New Hebrides, gold from Fiji and New Guinea, and phosphate rock from several small islands were significant in world supplies of those materials. The total value of mineral commodities produced in this area in 1965 has been estimated at about $763 million an increase of nearly 16 percent over the value reported in 1964. Increases were recorded in mineral production value with respect to that of 1964 for all of the countries except Papua-New Guinea where lower gold output resulted in a drop of about $300,000 and in the several phosphate-producing islands that collectively recorded a value decline of around $1.3 million. Exploration and development activities continued at an intensified level, not only in Australia and New Zealand but also in the British Solomons, Bougainville, and Fiji. Substantial additions to world supplies of iron ore and bauxite are assured and recent discoveries of natural gas, manganese ore, and nickel combine to give Australia a brilliant mineral outlook. Important discoveries of copper on Bougainville Island and on Vanua Levu, the north island of the Fiji group, and a gold mine on Misma Island were being developed during the year, with plans for early production underway. In New Zealand progress has been made on the New Zealand Steel Company project, and preliminary appraisal of a new titano-magnetite beach sand resource on the South Island has aroused considerable industrial interest. Extensive geophysical investigations were carried out in the British Solomon Islands and on Fiji's goldfields. The expansion program that will double output of products by New Caledonia's Société Le Nickel continued through 1965, and several foreign private companies have expressed a desire to initiate additional industries based on nickel prospects in New Caledonia.

Jan 1, 1967

By David P. Conover

The U.S. Bureau of Mines (USBM) has developed a computer-assisted Ground Control Management System (GCMS) for near realtime evaluation of underground coal mine ground conditions. The GCMS combines existing mine-monitoring system and sensor technology with automated computer analysis techniques to enhance the acquisition, analysis, and display of geostructural data. The GCMS, which combines mine structure data with other information, such as geologic conditions and mine layout, has provided information on mining-induced stress transfer and pressure buildup associated with several ground control events. The GCMS collects and analyzes shield-leg pressure, ground pressure, and strata movement data to evaluate the structural behavior of an active Western U.S. Iongwall coal mine. Field data are transmitted over a dedicated phone line to the USBM Denver Research Center (DRC) mine monitoring laboratory, 240 km (150 miles) from the mine site. Real-time collection, processing, and analysis of mine structure and shield pressure information has proved to be an effective method for near-face ground conditions while mining progresses. The GCMS provides the mine operator with information to rapidly identify and manage potentially hazardous ground conditions while mining is in progress.

Jan 1, 1994

By John C. Machisak

This publication, for the calendar year 1959, contains statistical data on injuries and employment pertinent to metal mines, ore-dressing plants, and primary nonferrous smelters, refineries, and reduction plants. The Bureau of Mines is authorized to request data on injuries and employment in the metal-mining industry, and the information, voluntarily submitted by the operators, contributes immeasurably to the promotion of safety in the metal-mining industry. Every effort has been made to make the annual canvass as complete as possible. The data presented are classified according to the hind of ore mined and includes information on copper, iron, lead-zinc, gold-silver lode, placer, uranium- vanadium, and miscellaneous metals. A breakdown of miscellaneous metals by commodity is shown in tables 17 and 18.

Jan 1, 1963

By Robert J. Timko

This U.S. Bureau of Mines study examined spontaneous heating episodes in coal mine pillars in an active underground coal mine. The information obtained from these incidents was then analyzed to learn which sampling methods provided the earliest indication of pillar heating. The objective of this study was to discover if the location of future events of pillar spontaneous heating could be inferred from the available information. The spontaneous heating-prone area in this evaluation involved pillars located just inby the mine portals. Several detection methods were used to determine gas levels outside as well as inside the affected pillars. It was hoped that, by incorporating external and internal sampling methods into an organized pro-gram, locations undergoing spontaneous heating could be determined more readily. This study found that by drilling small-diameter boreholes into the pillars, then obtaining gas samples from the affected pillars, the ability to locate early spontaneous heating episodes was improved. However, the ability to accurately predict future spontaneous heating events remains in question.

Jan 1, 2010

By Wendell L. Reich

Percussion drilling dates back to the hand operated star drill and hammer. Eventually steam and compressed air were substituted for muscle power and the mechanical percussion drill was born. From the hand held jack hammers, driving a forged steel bit into the rock, there evolved the jack leg, the rubber tired and crawler mounted drill carrier with automatic feed, increasing power and reducing man?s muscle requirements. Because the reaction of a blow on one end of a piece of steel has to be transmitted to the other end there is a limit to the depth or length of drill steel that can economically be used in out of the hole percussion devices. During the late 1800?s there is evidence that designers were attempting to put the percussion tool at the bottom of the hole, directly on the bit, in order to avoid the long drill steel which absorbed much of the blow, leaving little to be applied to the bit and the rock being drilled.

Jan 1, 1972

By S. R. Zimmerley, C. H. Schack

"INTRODUCTION The pilot-mill concentrator at Boulder City, which has a nominal capacity of 40 tons per day, was planned and built to investigate further the beneficiation of domestic manganese ores that have been concentrated successfully in the ore-dressing laboratory. As milling of manganese ores in general is a new field, it is necessary to prove the success of laboratory processes by means of large-scale operations employing standard milling equipment, and thus to obtain engineering and metallurgical data essential to designing and operation of full-scale concentrating mills.The first ore tested in the pilot plant was the Three Kids Annex manganese ore from the Las Vegas Wash area 15 miles southeast of Las Vegas, Nev. The deposit was worked for its high-grade ores during the First World War From 1930 to 1939, 4,500 feet of diamond drilling was completed by a private company. Diamond drilling started by the Bureau of Mines in November 1940 and completed in July 1941 aggregated 6,600 feet. Exploration by the private company and the Bureau outlined reserves of about 1,000,000 tons of ore assaying plus 28 percent manganese. A much larger tonnage of lower-grade ore also was outlined by the drilling.Because of its physical nature, the Three Kids Annex ore had long proved unamenable to concentration by ore-dressing methods. The ore is a mixture of manganese oxides (wad) filling the pores and to some extent replacing a silt composed of very fine grains of volcanic tuff, quartz, feldspars, other silicates, and clay. Some gypsum occurs as fillings along fracture planes. The ore is light and very porous. Upon wetting, it disintegrates into granular but friable particles and a large amount of slime. It is these characteristics that make the ore so difficult to concentrate."

Sep 1, 1947

By Albert S. Konselman

This paper describes the mining methods and operating costs for 1938 at the South Burns shaft, situated in the Cripple Creek district, Colorado. The shaft is operated by Golden Conqueror Mines, Inc., through which portions of the properties of the Acacia Cold Mining Co., The Free Coinage Gold Mining Co., and The United Gold Mines Co. are worked under lease. During 1938, 30,773.61 dry tons of ore averaging $9.59 in gold per ton was mined. Of this, 10,138.439 tons averaging $10.65 per ton was produced on company account, and 20,635.171 tons averaging $9.05 per ton was produced by "split-check" lessees.

Jan 1, 1940

By Leonard Obert

The ultimate object of this investigation is to develop a method for determining the pressure, in- situ, on rock mine pillars, arches, end other mire structures. The preliminary investigations of Bureau of Mines engineers, as well as those of other investigations4/ have shown that, the velocity of sound depends on the pressure if it is dependent to such an extent that a measurement of the velocity might be used as a means of determining the pressure, a sonic method of measuring the pressure on rock mine columns is possible. Briefly the method would require, first, laboratory determination of the variation of the velocity of sound with pressure in samples of rocks taken from mine pillars to establish a. velocity-pressure relationship for the type of rock and, next, measurements 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. Obviously the success of the method depends on the extent to which the velocity of sound varies with pressure in rock.

Jan 1, 1939

By R. A. Egen

The purpose of this book is to provide an indication of what good hoisting practice is and how it might be achieved. To this end the book contains discussions of equipment and inspection and maintenance procedures developed and used by mining people in striving for safe, reliable hoisting equipment. Most of this information comes from domestic practice; the rest is foreign, notably from Canada. Most things discussed have long proved their general worth, and others promise to; a few are beginnings. However, nothing is conjectural or theoretical; the practices described herein are in use somewhere in the mining world. The stress is on equipment in use; it is not a design-guidelines manual. Nevertheless, there are some sections dealing with design material since it may be of value in a maintenance/ replacement sense. Mine hoisting installations encompass such a wide variety of equipment and conditions that it is impractical to specifically cover them all. This book mainly treats conventional systems using conventional components with some discussion of the more common unconventional (special) systems in use. There is no recognized definition for a "conventional" mine-hoisting system. Herein the term means those systems most commonly used in daily operations for transporting men, materials, and product-electrically driven drum and friction hoists, with guided conveyances running in vertical or inclined shafts. Beyond this, what "conventional" means is probably best illustrated by the topics discussed.

Jan 1, 1975

By V. A. Cammarota

In this report, the effects of anode-production variables, such as aggregate coke sizes, pitch binder content, and baking cycle, were investigated. A small alumina reduction cell proved effective in evaluating anodes prepared from commercial materials and from lignite coke and pitch. Compressive strength was found to be the physical property most significantly influenced, but it did not appear to affect anode consumption. Specific carbon consumption, that is, the ratio of carbon in the anodic gas to carbon theoretically oxidized at the anode, was used as an index of anode consumption. It was found that an anode made with lignite coke and commercial pitch was very low in consumption; however, anodes made completely from lignite but by a different fabrication method showed high consumption and anode deterioration. Microscopic examination of anodes after electrolysis showed evidence of higher consumption at low current densities, and was useful in judging overall anode quality. Based on the physical properties of the anodes and their consumption during electrolysis, lignite can be a suitable material for anodes, provided the proper fabrication conditions are used.

Jan 1, 1970

By Peter Grandstone, D. A. Jessup, D. B. Taliaferro

"INTRODUCTION Water flooding of oil sands in Texas as a means of secondary recovery of oil has been practiced mainly in the north-central part of the State, which includes the old shallow fields in eight counties, extending south through Wichita and Clay Counties on the Red River into Brown County.The Texas Railroad Commission, is empowered ""to promote conservation and prevent waste in the drilling, completion, operation, and abandonment of oil wells"" and ""to issue regulations necessary for fulfillment of these ends,"" granted The Texas Co. the first permit to inject water into the oil-bearing sand on December 7, 1935. The permit was granted after the Commission had conducted a number of hearings, which were attended by many operators interested in that method of secondary recovery. Through December 31, 1944, the Commission had granted 50 permits for water flooding. Of that number, 45 permits were issued for projects in north Texas, the remaining 14 being distributed throughout west and south Texas. By the end of 1944, there were 33 active and 5 abandoned water-flooding projects in the North Texas area, as is in figure I.Oil production in the North Texas area started in 1904 from the shallow sands (ranging from 100 feet to 800 feet in depth) of the Petrolia (or Henrietta) field in northern Clay County. Development was rapid and unrestricted during the boom period from about 1911 to 1918, and considerable waste of both produced oil and reservoir energy resulted."

Jul 1, 1946