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By Richard E. Hucko

The bureau of Mines conducted a laboratory scale investigation of the process of selective flocculation with the objective of developing a method to effect separations on suspensions consisting predominately of ultra-fine-size (minus 400-mesh) particles of coal and refuse. Selective flocculation of coal from coal-refuse slurries could be achieved with a wide variety of reagents. Typically as much as 15 to 20 weight-percent of high-ash solids (70 to 80 percent ash) could be retained in suspension. The flocculated sediment remained a high-ash product, however, and would require further treatment to be regarded as clean coal. No combination of reagents and conditions led to selective flocculation of the refuse component. The dispersing agent was found to be the critical factor; dosages of 3 to 8 lb/ton2 were necessary to stabilize the suspension for subsequent selective flocculation. In addition, most of the dispersants that worked were most effective at substantially elevated pH (11 or so). It was concluded that this process would be prohibitively expensive and, because of yield and quality constraints, it would be of questionable utility in today's coal preparation industry.

Jan 1, 1977

By J. M. Stuve

Low-temperature heat capacities of chiolite (Na5Al3F14) were determined by adiabatic calorimetry in the temperature range 5.8 to 300 K. The derived standard entropy (S°, 298.15) was 115.6 ± 0.2 cal/deg-mole. High temperature enthalpies relative to 298.15 K were obtained by precision drop calorimetry up to 1,000 K. Tables of experimental data and related thermodynamic functions are given for the temperature range of experimental observations.

Jan 1, 1980

By John W. Finch

The Secretary of the Interior acting through the Bureau of Mines and the Geological Survey is authorized by the Strategic Materials (Public No. 117 - 76th Cong., Chapter 190 1st Sess.) to make investigation concerning essential minerals of which the quantities or grades obtainable from known domestic sources are inadequate. The Bureau of Mines, in carrying out its part of this program, may investigate deposits of such minerals in whatever manner may be necessary, in order to determine (1) the extent and quality of the are, (2) the most suitable method of mining and beneficiating it, and (3) the cost at which it may be produced. The essential objective in doing these things is to determine where and how supplies of minerals and metals of which domestic production is usually inadequate might be obtained in a national emergency, even though at higher cost than usual.

Jan 1, 1939

By T. M. Ruff

The U.S. Bureau of Mines has developed a portable, inexpensive teleoperation system for mobile hard-rock mining equipment. The system was tested on a compact loader-trammer in a simulated stope. The teleoperation system includes radio remote control and computer-assisted navigation. A recent enhancement includes video cameras mounted on the machine to provide visual information to the operator. This system allows the operator to remain in a safe location while operating the machine from a distance, thus increasing both operator safety and mining productivity.

Jan 1, 2010

By R. A. Beall

A series of 45 zirconium ingots has been cast by the consumable electrode arc melting process with the object of analyzing the effects of power input from 50 to 230 kilowatts and reduced pressure furnace atmosphere to improve the quality of regular 8-inch-diameter production ingots made thereby. Electrode consumption rate, molten pool volume, melting efficiency, sidewall quality, arc stability, and yield efficiency are considered. The use of direct current and alternating current is studied. In conclusion, reduced pressure furnace operation is shown to promote electrical efficiency, ingot homogeneity, high metal yield, and are stability. INTRODUCTION Zirconium is a particularly difficult metal to melt because of its affinity for atmospheric gases and its solvent properties when molten. In addition, zirconium sponge as produced by the boll process contains minor amounts of magnesium chloride, which cause severe spattering luring melting, because of these difficulties with zirconium, and its sister metal titanium, near techniques have been developed to permit production of commercial size ingots. Among the more promising is the consumable electrode arc melting method.

Jan 1, 1955

By J. G. Croeni

The titanium-iridium alloy system was investigated to determine whether alloys of this system would merit further development as control-rod material for nuclear reactors. A study was made to determine the titanium-iridium phase diagram by using melting-point, thermal analyses, X-ray diffraction, dilatometric, electrical resistivity, and metallographic techniques. The titanium-iridium alloy system was investigated between 500° and 2,400° C. Results indicate the formation of two intermetallic compounds, Ti3Ir rind TiIr3, and one intermediate solid solution centered about the 50 atomic percent iridium composition. A eutectic reaction occurs at 1,475° C, and 19 atomic percent iridium. The Ti3Ir decomposes peritectically at 1,520° C. The intermediate solid solution exhibits a maxima of 2,140° C. at 50 atomic percent iridium. This phase is also believed to undergo an order-disorder transformation at 1,750° C. Another eutectic reaction takes place at 2,000" C. and 60 atomic percent iridium. The compound TiIr3 formed at 75 atomic percent iridium decomposes peritectically at 2,115° C. Further increases in iridium content result in the formation of an iridium-rich terminal solid solution. Information obtained below 900° C. in titanium-rich alloys indicates that iridium acts as a beta stabilizer in titanium, and the authors believe that a eutectoid decomposition of beta-titanium occurs near 500° C. and 10 atomic percent iridium.

Jan 1, 1962

By F. P. Haver

The Bureau of Mines developed a process to extract about 90 percent of the sulfur from molybdenite flotation concentrate by compacting the concentrate with one-quarter of its weight of aluminum powder, heating it at 800° C for 30 minutes, and then allowing the product to react with water. This thermite reduction yields an impure molybdenum alloy plus aluminum sulfide. The latter readily hydrolyzes, to yield pure hydrogen sulfide which can be converted to elemental sulfur by the Claus process. At least 95 percent of the molybdenum can be subsequently recovered as 99.95-percent-pure molybdic oxide.

Jan 1, 1968

By Ryron O. Pickard

"The Berkeley safety station of the U. S. Bureau of Mines was recently informed that a geologist was killed through entering an abandoned 90-foot exploratory shaft without making a preliminary test of the shaft atmosphere. He was one of a geological party which was investigating coal lands in California. The only light that he carried into the shaft was an electric flash light. After he had descended a short distance, one of his associates on the surface heard him exclaim, ""This place is full of gas, I am coming up"", He had no more than finished the remark when he was seen to lose his grip on the ladder and fall down the shaft. He was apparently weakened from impure air in the shaft, and could no longer suppers himself on the ladder. When his body was recovered, it was found that his neck had been broken by the fall.This is the ;second recent accident that has been called to the writer's attention where a life has been lost in abandoned exploratory workings; the other fatality being in Minnesota where a mining engineer was overcome while sampling a shallow pit in iron-ore formations. This engineer was on the bottom of the shallow pit and died before help could reach him. It was generally supposed that each of these deaths were due to poisonous gases, but the writer believes, after reviewing the information available, that death in both instances may have been directly caused by deficiency in oxygen.Frequently in the daily press there are items relative to lives being lost through cleaning out old wells, and as a general rule such accidents are also caused by impure atmospheres.In every abandoned shaft or pit, or in fact, any old working where the air has been stagnant for a considerable time, there is always danger of oxygen deficiency, as the oxygen which originally comprised one-fifth of the atmosphere may be appreciably replaced by gases that do not support life, usually by carbon dioxide (black damp) or methane (fire damp). Much valuable information on the subject of mine atmospheres, mine gases, and the effect of oxygen deficiency onthe human system is contained in Miners' Circular 14, ""Gases Found in Coal Mines"" by G.F. Burrell and F. M. Seibert; Technical Paper 122, ""Effects of Oxygen Deficincy on Small Animals and Men"", by G. A. Burrell and G. G. Oberfell; and ''Chit of Properties of Mine Gees"" by G. A. Burrell. These publications of the Bureau of Mines should be rent by all who are interested in the subject of this paper."

Nov 1, 1921

By Robert C. Hickman

"INTRODUCTION The Big Four fault and the Sandy Creek fault, with several cross faults, traverse the Stalion-Curnel fluorspar prospect in a northeasterly direction. The Big Four mine, about three-quarters of a mile northeast of the prospect, is the only active mine in the immediate area.A resistivity survey was made of a portion of the prospect by the Division of Geophysical Exploration, Bureau of Mines, in May and June 1946. As a result of this survey, five holes were drilled by the Bureau of Mines during the period from October 8 to December 16, 1946. Two Longyear No. 12 Junior Straitline diamond drills were used for the work.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Division, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests.The project was under the supervision of Mitchell H. Kline, chief, Raleigh Branch, Mining Division."

Mar 1, 1948

Reduce costs of surface mine reclamation by improving bulldozer operating efficiency. Approach A draft power indicating system helps bulldozer operators adjust blade height and other controls for maximum load movement, by continuously indicating the rate at which work is being done. How It Works This system continuously measures both the push of the blade against the overburden, and the true ground velocity of the bulldozer. It multiplies those quantities to determine the real work rate of the machine. The system consists of a velocity sensor, a blade load sensor, processing circuits, and a work-rate indicator. The processing circuits include an analog multiplier which has an output signal representing the draft power (velocity x load = power). The draft power, or pushing power is a measurement of the work rate at that moment.

Jan 1, 1979

By A. L. Service

The four periods of test operation described in Report of Investigations 5219 indicated that planer mining of phosphate rock was feasible. Corrective measures proposed for design deficiencies indicated in test 4 had to be evaluated, however; and, before the attempt to design a prototype production model, it was considered advisable to test the original machine under more severe operating conditions. Planer A was modified, therefore, during the latter half of 1955, and one additional period of experimental operation was conducted in the Anderson mine of the Montana Phosphate Products Company near Garrison, Mont., during the first 4 months of 1956. Test 5 was made in a stope, where the phosphate bed had been offset in a number of places by minor faults. Considerable difficulty was found in negotiating the irregularities caused by these faults, and productionwise the test was not as successful as some of the previous ones. Information obtained, however, was valuable in designing model B.

Jan 1, 1959

By G. B. Atkinson

The Bureau of Mines, in cooperation with McDermitt Mine, investigated a method for recovering mercury metal from mercury sulfide flotation concentrate by a hydrometallurgical technique. This preliminary report shows the feasibility of leaching mercury with a cupric chloride solution and electrowinning mercury from the solution. Proposed chemical reactions are shown in equations 1 through 3: 2CuC12 + HgS + 2CuCl + HgC12 + S°; (1) electrolysis HgC12 ?Hg + C12; (2) 2CuC1 + C12 ? 2CuC12. (3) A bench-scale leaching-electrowinning apparatus capable of treating 2.36 kg of sulfide concentrate in 11 days was operated continuously. An acid chloride solution containing, in grams per liter, 70 Ca, 60 Cu, 30 Fe, and 80 Hg was used as both leachant and electrolyte; 99.5 pct of the mercury was solubilized from the sulfide concentrate. Electrolysis of the leaching solution recovered mercury metal at an average current efficiency of 32 pct and an average energy consumption of 1.2 kwhr/lb Hg. Results from a preliminary economic evaluation indicated that a plant producing 31,500 flasks of mercury per year would have a capital cost of $3.7 million and an operating cost of $62 per flask of mercury.

Jan 1, 1983

By Barbara Fotta, Lynn Rethi

Within the Mine Safety and Health Administration's (MSHA's) classification of metallnonmetal (MAM) mining, the number of independent contractor' employees has increased significantly in recent years. In 1985 independent contractor employee hours reported to MSHA accounted for 4.5% of all M/NM mining employee hours (excluding office workers); by 1994 that proportion had doubled to 9.0%. As a result, these workers now account for an increasingly significant proportion of fatal and nonfatal mining accidents. According to MSHA's statistics, annually computed fatality incidence rates (the number of fatalities per 200,000 employee hours) for independent contractors working in M/NM mining are consistently higher than those for operator employees. Over the five-year period from 1990 through 1994, 53 independent contractor employees were fatally injured while working on M/NM mine property (See Table 1). More than one third of these fatalities (36%) were due to accidents involving powered haulage; 21% were machinery accidents; and 11% percent were falling material accidents. Combined, these three accident classifications accounted for 68% of all independent contractor fatalities occurring on M/NM mine property during these years. Clearly, current efforts to increase the safety of the mining workforce must also address the safety of the independent contractor employee. This report is a preliminary attempt to identify trends in the employment and safety of independent contractor workers by identifying which segments of M/NM mining are experiencing the greatest increases in the number of independent contractor employees and by examining changes in the rates and types of accidents in which these employees are involved. The employment and accident data used in this report were obtained from the MSHA database. [ ]

By John B. Shutack

In an effort to improve the performance of the explosive-anchored rock bolt, the Bureau of Mines studied the effect of the detonation velocity of the explosive and type of charge (linear or nonlinear) on the fracturing tendency of the anchor tube. Also, different types of tubing were compared to determine the one most suitable for use as an anchor tube. The Bruceton up-and-down method was applied in tests in which steel shooting blocks having boreholes ranging from 1-3/8 to 2-1/8 inches in diameter were used. Of the four types of tubing evaluated, a welded A-178 tubing that was drawn over a mandrel and renormalized gave the most promising results. The A-179 seamless tubing that is normally used with the explosive bolt was the most inferior. Both types, however, gave significantly better anchorage than the conventional shell when tested in both laboratory and underground experiments. Within the range of velocities studied (5,000 to 7,000 m/sec), the type of explosive showed no significant effect on anchor-tube performance. In general; linear explosive charges provided better anchorage than nonlinear charges.

Jan 1, 1968

By W. S. Wright

"INTRODUCTION The Ward copper deposit was brought to the attention of the Bureau of Mines in September 1943 by John J. Knob, 217 E. Penn Street, Long Beach, N. Y. At that time all Bureau of Mines work on Seward Peninsula was being directed to the exploration of deposits of tin, a metal high on the strategic list. It was not until September 1946 that the Bureau could make a preliminary examination of the Ward prospect.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.Acknowledgment is extended to Robert S. Sanford, acting chief of the Alaska division, under whose supervision all exploratory work of the Territory is conducted."

Aug 1, 1947

By W. J. Wenger

Results of the analyses of 151 crude oils from 123 oilfields in the Williston basin are presented. Production statistics are compiled by geographical areas within the basin, by geological age of the producing zones, by States, and by field for the nine fields with the greatest production. Characteristics of the oils are tabulated, and correlations are included to show relationships between properties of the oils and some factors in the environment. Properties of the oils in some instances imply that there has been migration and mixing of the oils between productive formations of different geological time periods.

Jan 1, 1968

By L. H. Johnson

"INTRODUCTION The Pennsylvania anthracite industry produced 53 million net tons of anthracite during 1945. Fifty-one million tons was prepared for the commercial market (3), 3/ and 2 million tons (consisting of fine sizes) was used for colliery power consumption. Of the number of tons prepared for market, 17 million tons (33 1/3 percent) was prepared by the use of acid mine water treated with lime.Mine water from underground workings is pumped, drained, and stored in huge quantities. The mine-drainage systems in the anthracite region handle over 200 billion gallons of water annually, of which 150 billion gallons is pumped to the surface. More than 69 billion gallons of water is impounded in underground pools (1). Much of this water is employed for breaker use, dust-control installations; hydraulic backfilling, combatting mine fires; and aiding in the transportation of anthracite in gently dipping places where sheet iron is used Roos(4) estimates that 1,100 gallons of mine water is utilized in the preparation of anthracite mined."

Nov 1, 1946

By G. S. Rice

The recommendations of the Bureau of Mines on rock-dusting practices are embodied, except in a few details, in the Recommended American Practice for Rock-Dusting Coal Mines to Prevent Coal-Dust Explosions,5 approved by the. American Engineering Standards Committee,6 December 30, 1925 It is specified that the dust to be used is of a size that all will pass through a sieve having 20 meshes per linear inch and that 50 per cent or more will pass through a sieve having 200 meshes per linear inch.

Jan 1, 1930

By T. E. Purcell

(a) Moisture. - Moisture, "as fired," is specifically significant in pulverized-coal firing because of its effect upon the continuity of raw-coal feed to the pulverizer, pulverizer capacity, flame stability, and speed of ignition. The extraneous moisture content is a rough index of potential difficulties in unloading and maintaining the flow of raw coal to the pulverizer and of pulverized coal to the furnace, with the troubles increasing geometrically as the percentage increases. Sticking or other stoppage of coal flow at any point between the bunker and the furnace is especially serious with pulverized-coal firing because there is danger of immediate loss of output. Where moisture is a problem, the designer must exercise great care in the design of coal-handling and preparation apparatus.

Jan 1, 1951

By John J. Sammarco, Janet S. Flynt

This report (Independent Functional Safety Assessment Guidance 7.0) is the last in a nine-part series of recommendations and guidance addressing the functional safety of processor-controlled mining equipment. It is part of a risk-based system safety process encompassing hardware, software, humans, and the operating environment for the equipment’s life cycle. Figure1 shows a safety framework containing these recommendations. The reports in this series address the various life cycle stages of inception, design, approval and certification, commissioning, operation, maintenance, and decommissioning. These recommendations were developed as a joint project between the National Institute for Occupational Safety and Health and the Mine Safety and Health Administration. They are intended for use by mining companies, original equipment manufacturers, and after-market suppliers to these mining companies. Users of these reports are expected to consider the set in total during the design cycle. • 1.0 Safety Introduction (Part 1).—This is an introductory report for the general mining industry. It provides basic system/software safety concepts, discusses the need for mining to address the functional safety of programmable electronics (PE), and includes the benefits of implementing a system/software safety program. • 2.1 System Safety (Part 2) and 2.2 Software Safety (Part 3).—These reports draw heavily from International Electrotechnical Commission (IEC) standard IEC 61508 [IEC 1998a,b,c,d,e,f,g]and other standards. The scope is “surface and underground safety-related mining systems employing embedded, networked, and nonnetworked programmable electronics.” System safety seeks to design safety into all phases of the entire system. Software is a subsystem; thus, software safety is a part of the system’s safety. • 3.0 Safety File (Part 4).—This report contains the documentation that demonstrates the level of safety built into the system and identifies limitations for the system’s use and operation. In essence, it is a “proof of safety” that the system and its operation meet the appropriate level of safety for the intended application. It starts from the beginning of the design, is maintained during the full life cycle of the system, and provides administrative support for the safety program of the full system. • 4.0 Safety Assessment (Part 5).—The independent assessment of the safety file is addressed. It establishes consistent methods to determine the completeness and suitability of safety evidence and justifications. This assessment could be conducted by an independent third party. • Safety Framework Guidance.—It is intended to supplement the safety framework reports with guidance providing users with additional information. The purpose is to assist users in applying the concepts presented. In other words, the safety framework is what needs to be done and the guidance is how it can be done. The guidance information reinforces the concepts, describes various methodologies that can be used, and gives examples and references. It also gives information on the benefits and drawbacks of various methodologies. The guidance reports are not intended to promote a single methodology or to be an exhaustive treatment of the subject material. They provide information and references so that the user can more intelligently choose and implement the appropriate methodologies given the user’s application and capabilities. The guidance reports comprise parts 6 through 9 of the series and are listed below: [< 5.1 System Safety Guidance (Part 6).—This guidance supplements 2.1 System Safety. < 5.2 Software Safety Guidance (Part 7).—This guidance supplements 2.2 Software Safety. < 6.0 Safety File Guidance (Part 8).—This guidance supplements 3.0 Safety File. < 7.0 Independent Functional Safety Assessment Guidance (Part 9).—This guidance supplements 4.0 Independent Functional Safety Assessment.] [ ]

Jan 4, 2006