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By I. R. Hanby

A simple but comprehensive method has been developed for the simulation of a mechanical-drive dump truck that enables various parameters to be predicted as a function of time throughout its whole cycle. Uses of the simulation results are indicated with specific attention to environmental and operational or economic planning. The output of a sample run is presented. The method can be easily adapted for the investigation of a wide variety of mobile plants.

Jan 4, 1992

By James Terry Duce

Production of oil in Bahrein for the war years was as follows: YEAR BBL PER YEAR Prior to 1939 . . . . . . . . . . . . . . 22,287,055 1939 . . . . . . . . . . . . . . . . . . . . . . 7,588,554 1940 . . . . . . . . . . . . . . . . . . . . . . 7,073,919 1941 . . . . . . . . . . . . . . . . . . . . . . 6,794,157 1942 . . . . . . . . . . . . . . . . . . . . . . 6,240,627 1943 . . . . . . . . . . . . . . . . . . . . . . 6,571,609 1944 . . . . . . . . . . . . . . . . . . . . . . 6,713,795 1945 . . . . . . . . . . . . . . . . . . . . . . 7,308,938 Total to Jan. 1, 1946 . . . . . . . . 70,578,654

Jan 1, 1946

By D. Hodouin

The paper reviews approaches to estimate in a real time fashion consistent mass flowrates and assays, using data from the on-stream analyzers and flowmeters of a flotation circuit. Results obtained with one algorithm operating on-line with an industrial flotation circuit are presented.

Jan 1, 1996

By D. Duffy, V. Papangelakis

"MgCl2 brines present a number of potential advantages for the processing of saprolite ores for nickel production. With a chloride system it is economically requisite to recover hydrochloric acid, which can be performed in a more energy efficient manner by precipitation and subsequent decomposition, as compared with conventional pyrohydrolysis. In addition, concentrated MgCl2 solutions enhance the activity of acid used, allow atmospheric leaching at elevated temperature and inhibit magnesium dissolution, which reduces acid consumption and increases metal selectivity. Leaching and iron control experiments have been conducted in concentrated MgCl2 brines, up to 4.5 m, to determine the most amenable process conditions. INTRODUCTIONChloride metallurgy has received an increasing amount of attention in recent years, especially with respect to the treatment of nickel laterites. Although the limonitic fraction can sometimes be economically treated by High Pressure Acid Leaching (HPAL), acid-consumption problems are encountered with the higher magnesium content of the saprolite fraction. As magnesium does not hydrolyze under HPAL conditions, as iron and aluminum do, any sulphuric acid used to leach magnesium is subsequently neutralized and wasted. In addition, this magnesium must later be disposed of in some fashion, further complicating the process. The most common method used to process saprolite is the Rotary Kiln-Electric Furnace (RKEF). This uses a kiln to dry and preferentially reduce nickel, before sending the calcine to an electric furnace. Although nickel recoveries are high, and the problems of acid consumption are avoided, the capital and energy costs associated with this process are high (de Bakker, 2011).The problems outlined above have led to the investigation of an atmospheric chloride process for the treatment of saprolite ores. The use of a chloride system presents a number of advantages, but also a few limitations. Metal chlorides tend to be very soluble, with a few notable exceptions (silver, mercury and lead), allowing for smaller processing equipment through more concentrated solutions. This solubility also serves to reduce the potential for scale formation. In addition, a hydrochloric acid leach is more aggressive than a comparable sulphuric acid system, and the activity of the hydrogen ion can be augmented by further chloride addition (Peek, 2011). This activity augmentation in concentrated chloride systems, first reported by Jansz, has repeatedly been referenced as a motivating factor behind chloride hydrometallurgy (Jansz, 1983; Harris and Magee, 2003; Harris et al., 2004; Demopoulos et al., 2008; McDonald and Whittington, 2008; Demopoulos, 2011; Peek, 2011; Verhulst and Lakshmanan, 2011). This activity increase allows a similar amount of acid to perform more in a concentrated solution than in a dilute solution, decreasing overall acid requirements. As such, much focus has been placed on leaching in concentrated chloride systems, or brines, using calcium, magnesium or sodium as the cation (McDonald and Whittington, 2008)."

Jan 1, 2012

By M. H. Kline

Round Mountain is one of a number of locations investigated by the Bureau of Mines in its search for manganese deposits during the early phases at the strategic minerals program. The Suiter mine, on Round Mountain, had provided some 5,000 tons of manganese concentrates during the period 1917 to 1919, and early in 1941 prospecting by the Virginia Hardwood Lumber Co. in this same area had discovered manganese on what later became known as the Hall Pit. These promising indications encouraged the Bureau to begin an exploration project in search of additional reserves of manganese on Round Mountain in January 1942 (fig. 1).

Jan 1, 1948

By Leo J. Vogel, E. D. Hummer, David J. Akers

INTRODUCTION An efficient refuse-disposal system is a necessary part of the modem cleaning plant. The large-scale refuse system and disposal area, engineered for the lifetime of the plant, has become more important due to the greater tonnages of refuse produced from increased quantities of mechanically mined and prepared coal. Laws and increased government regulations have affected the design and operation of disposal systems. THE EFFECT OF MINE AND PLANT OPERATION Refuse disposal starts at the mining face. The mining system, the type of roof support, the machinery used, and the degree of discipline at the face contribute to the amount and type of refuse that must be removed through the disposal system. Economies gained through modification of the mining system or mining machinery may be partially offset by increased dilution of the mined coal with impurities from associated rock formations. In some cases the change in the mining system and equipment has reduced the dilution. In all cases the ratio of impurities that must be removed from the raw-coal feed to the plant not only affects the maintenance and

Jan 1, 1979

By J. H. Welsh

This Bureau of Mines report presents guidelines to be considered in the design, installation, and operation of environmental mine monitoring systems in underground coal mines so as to enhance safety in the U.S. mining industry. A review of the current status of mine monitoring in the United States is also provided.

Jan 1, 1987

By L. E. Djingheuzian

"IntroductionDURING the past two decades an enormous amount of empirical data has been accumulating on grinding. These data have been obtained by mill operators on grinding ores with a diversity of characteristics, and generally they have been published. However, whenever an operator, who has started milling on a new ore, has tried to find a case in literature which would exactly fit his particular grinding problem, he has failed. Evidently, something fundamental has been lacking in all these empirical data, and, as a consequence, each new operator has had to undertake his own experimenting, get the best results he can, maybe publish these results, and let it go at that. This, in the writer's opinion, has been• due to the fact that even the ablest and most inquisitive millman has been forced to look on grinding as an art, and so, except very rarely, has not been able to find the time to stop and think; if he did so, it was rather in a philosophic way, that grinding is a fundamental process, a process that takes place in river beds, on the sea shore, etc.Nevertheless, when all the data so far published are correlated and examined as a whole, one is struck with the advances that have been made in grinding. The writer (7) had made such a study in 1949, and, when the correlation was completed, it showed that there was nothing heterogeneous about the accumulated data and that when brought together they were in harmony with each other. The writer's conclusion was that, if grinding criteria were defined and were expressed in such a way as to make integration of any data into basic formulae possible, grinding would be established as a mathematically exact science, and grinding worries of the harassed mill operator would be at an end!The first attempts to rationalize comminution were made by Rittinger and Kick. However, their theories led to endless disputes which did not accomplish much, except possibly clearing the path for subsequent investigators."

Jan 1, 1952

By H. S. Price, F. N. Kissell, R. C. McCulloch, J. C. Edwards

"The methane em1ss10n from deep coalbeds which are actively mined is a serious problem facing the mining industry today. Pinpointing the source of methane and predicting the emission of this gas from these coalbeds is necessary if preventive techniques are to be effectively used to control methane emission. In general, because most coalbeds have water associated with them, the system to be studied may be either single-phase (methane gas) or two-phase (methane and water). Because coal mine geometry is complex and the fluids have variable properties as functions of pressure and methane concentration, the differential equations describing the flow of methane and water are not amenable to analytic solution, but must be solved numerically using high-speed computers. This paper presents the development of such a complex mathematical model along with some preliminary applications of the model to methane emission from one- and two-dimensional coalbeds with and without water present."

Jan 1, 1973

By R. S. Dean

The function of the Metallurgical Division is to conduct investigations relating to the treatment of mineral products from the state in which they are mined to the refined metal or other unfabricated product. These investigations include scientific and practical studies of ore dressing, covering the crushing and grinding of ores, separation by gravity, flotation, and magnetic methods; the hydrometallurgical treatment of ores, including cyanidation and amalgamation of the precious metals; the smelting and refining of copper, lead, and zinc, as well as the rare metals; and steel-melting practices from the raw ore to the finished steel. The object of this work is to conserve natural resources and eliminate waste by furnishing information on current methods of metallurgical practice, making fundamental studies of metallurgical processes, and developing new processes to the point of demonstrating their practicability. The Division is made up of sections devoted to the several phases of this work, each section being beaded by an investigator capable of supervising his particular work. The work is carried on at the experiment stations and field offices or in the field, whichever seems test suited for the work in hand. The following projects should be mentioned as particularly outstanding among those consummated successfully during the year: 1. Application of the type of chemicals known in the textile industry as wetting-out agents to flotation and agglomeration of ores, particulary soluble salts such as sodium and potassium chloride which must be treated in saturated brine. 2. Demonstration of a linear relation between surface and coercive force in magnetic minerals and its application to magnetic separation and to the determination of grinding efficiencies and other metallurgical data which require surface determination at very fine sizes. 3. Pilot-plant demonstration of the practicability of the reduction of iron ore by natural gas and conversion of this direct iron into steel by direct melting and by forging and rolling before melting. The structure and properties of the iron so produced were studied in detail. This report covers the fiscal year July 1, 1934, to June 30, 193b.

Jan 1, 1936

By A. B. Campbell

The Bureau of Mines is developing alloys using ion implantation as an alternative to bulk alloys that consume large quantities of strategic materials such as chromium and nickel. These alloys are formed at the outer layer of relatively common materials. To more fully understand the corrosion characteristics and physical properties of this outer layer, it was necessary to deter-mine the alloy concentration as a function of depth into the substrate material. Also, since many of the ion-implanted alloys would be utilized at elevated temperatures, it was necessary to determine the diffusion behavior of the implanted element. Proton-induced X-ray emission and inert gas ion sputtering have been utilized to generate composition depth profiles for Fe-Cr, Fe-Ni, and Fe-AI ion implanted alloys fabricated by implanting 25-kev Cr+, Ni+, or AI+ into iron substrates. The data were fitted (utilizing a computer program) with symmetrical Gaussian profiles yielding values for the range and range straggle of the ions. These parameters were then compared with those calculated from theory. Changes in the profiles due to annealing were investigated and values for the diffusion coefficient were obtained assuming diffusion according to Fick's Law. For the Cr+ and Ni+ implantation, the profiles as-implanted agree reason-ably well with theory and exhibit ?norrmal" diffusion characteristics at 500° C. For the Al+ implantation, the profile as-implanted is much broader than predicted and exhibits substantial enhanced diffusion at temperatures up to 500° C.

Jan 1, 1979

By G. L. Neumann

"INTRODUCTION Mining in this area is inactive. The entire region is now comprised of small farms. Because approximately 1,500,000 tons of magnetite ore had been shipped from this area between 1855 and 1915, it was deemed probable that geophysical surveying and core drilling might indicate other ore bodies or sizable extensions of the previously mined ore bodies.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has, as its primary objective, the most effective utilization of our mineral resources, thus fortifying our 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 beneficiatien tests.The chemical analyses and beneficiation tests included in this report were performed at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, head of the laboratory service unit.The Mineral exploration Was under the general supervision successively of G. D. Jermain, district engineer, C. B. White, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch.The geophysical section of the exploration was performed by G. B. Botsford, engineer of the Bureau of Mines. Assistance was given by the Division of Geophysical Exploration of the Bureau of Mines, Dr. F. W. Leo, chief."

Dec 1, 1947

By M. Carrales, C. J. Jirik, W. D. Dietzman

In view of the developments and recent interest in recovering heavy oil , this report was prepared to present general information on more than 2,000 heavy oil reservoirs in more than 1,500 fields in 26 states . Information given on each heavy - oil deposit includes the following items : Field and formation , location , average or range of depth , average API gravity of oil , average thickness of formation , areal extent of field , total productive wells drilled in field , discovery date of field , field status in 1963 , cumulative production to Jan. 1 , 1964 , and all known types of secondary - recovery operations initiated ( active and terminated ) in the reservoirs . The geographical location of heavy oil accumulations in the United States is shown by a map , and a brief discussion of 14 different areas is given in the text . As of Jan. 1 , 1964 , 75 percent of the heavy oil reservoirs in the United States had produced more than 10 billion barrels of oil and are estimated to contain over 90 billion barrels of oil in place . It is also estimated that if the deposits which have had little or no production history , such as the one in Missouri , were included , the total remaining heavy oil in place would be in excess of 150 billion barrels . To find economical ways of recovering this vast reserve of heavy oil , industry is developing technology in several types of thermal - recovery methods . Some of the general considerations and more suitable limitations in selecting a prospect to study for thermal - recovery techniques are : Lithology , depth , viscosity of reservoir fluids , gravity of oil , reservoir thickness , oil in place , and permeability and porosity .

Jan 1, 1965

By L. John Minnick

A revised and expanded edition of a previous paper** dealing with reactions of calcium and magnesium oxides and hydroxides with pulverized coal fly ash is presented. Lime-fly ash specimens were cured at constant temperature and subjected to X-ray diffractometry, differential thermal analysis, pozzolanic reactivity tests, and microscopical investigations. Bars of limefly ash were subjected to cycles of wetting and drying, and measurements of length change were recorded. A discussion of variations within and among types of lime and types of fly ash is presented. The nature of the pozzolanic reaction is reviewed, particularly as related to compounds which are used up and formed during the aging process. The relationship between the pozzolanic reaction and the resultant physical properties of the mixtures is examined.

Jan 1, 1968

By Ronald S. Conti

This U.S. Bureau of Mines (USBM) report describes various fire-fighting resources available to the mining industry and examines the fire preparedness of four western coal mines. Information regarding fire-fighting equipment indicates that an inadequate maintenance program may cause component failure of fire extinguishers, damage to waterhoses is usually a result of improper care, and foam may be a convenient means of conveying water to the fire. Performance data relative to water nozzles (throw distance) and specific practices to improve the state of preparedness in many of these areas are discussed. Studies also indicated that a high-expansion foam plug, will travel down an entry, with a 1% rise in elevation, 207 m (680 ft) before a plywood stopping separating the generator and plug failed. The advance rate of the foam plug decreased when the entry is dry, requiring more foam concentrate and as the foam spread further down the entry. An examination of the mines showed state-of-the-art monitoring systems were common at the minesites. Fire safety was also stressed, including early detection and rapid response of the miners to evacuate the mine. However, the mines placed little emphasis on performance of water nozzles, or personal protective clothing for the underground firefighters.

Jan 1, 1994

By Thomas M. Barczak

This U.S. Bureau of Mines report chronicles the historical development of longwall mining in the United States and speculates on future developments to the turn of the century. The involvement and contributions made by the Bureau during these developments are also discussed. Two major periods of history are analyzed: (1) from 1875 to 1950 when small advancing faces were operated manually, and (2) from 1950 to 1990 when mechanized extraction and powered roof supports provided a system to efficiently extract large coal panels. Five eras of technological development during the modern period are described and analyzed. These eras discuss the development of (1) mechanized extraction, (2) powered roof supports, (3) high-capacity roof supports, (4) shield supports, and (5) system automation. Current trends are analyzed in terms of longwall utilization, face production, support capacity, face widths, and new technological developments. From these analyses, the future of longwall mining to the year 2000 is speculated. It is concluded that longwall mining will continue to grow in importance during the next decade and that the next major technological milestone will be the realization of a fully automated longwall mining system.

Jan 1, 1992

By H. A. Watson

The introduction and use of synthetic materials in various applications may lead to potential hazards from toxic, gaseous, decomposition products if these materials are subjected to conditions abnormal to their intended use, such as high temperatures or burning from accidental causes. This report covers an investigation of such possible hazards from toxic gases produced by the burning or thermal decomposition of some low-density, expanded, synthetic materials, three of which consisted of polyvinylchloride and one of acrylonitrile. In the production of certain expanded plastic materials, Chemical blowing agents frequently are used to produce a cellular structure. One of these blowing or foaming agents contains azo-bis-isobutyronitrile, which is designated in this report as PN. Information indicates that a product of decomposition of this blowing agent, formed in the blowing operation, is tetra-methyl-succino-nitrile, designated as TSN, Which is significantly toxic. Decomposition of the blowing agent, with release of its azo nitrogen, is represented by the following reaction:

Jan 1, 1951

By S. K. Ash

In arriving at economic losses in coal mining due to accidents, a statistician is confronted with many difficulties on account of the lack of information relative to nonfatal accidents. For comparative purposes the ex¬ perience of those countries, States, or companies that keep complete records can be drawn upon and an extimate can be arrived at whereby one State can be compared with another, or one mine compared with another in the same district. Such a comparison for the United States has been compiled by the United States Bureau of Mines. It will be observed in Table 1 that the cost per ton for accidents in the State of Washington for the year 1927 is higher than for any other State, with the exception of Georgia and North Carolina, with a small combined tonnage of 130,089 tons. (The figures for coal production in Table 1 are taken from Bulletin 319, 1930, of the United States Bureau of Mines.) The reasons why the cost of accidents in Washington might be higher than the average are on account of physical conditions such as steep pitches, faults, igneous intrusions, highly explosive coal-dust, extremely friable coals, presence of gravel and water, very gassy coal beds, rugged topographic conditions, inherently bad roof and floor, thick beds, and heavy cover. The nature of the coal beds requires the use of preparation machinery. The mines are often deep, and topographic conditions are such that long and fast haul¬ age becomes necessary. All of these factors not only tend to cause high cost of production, which is manifested largely in a. lower than average daily pro¬ duction, per man, but..they.also affect to some degree a tendency toward a higher than average cost for accidents.

Nov 1, 1931

This manual covers the operation and lubrication procedures for the Eimco Pumpable Roof Bolting Machine. This machine meets U. S. Bureau of Mines Schedule 2G Approval. This manual is divided into three major parts: 1. Machine dimensions; 2. operating instructions and; 3. Lubrication. Whenever front or rear, right or left arc mentioned it is assumed that the reader is standing behind the machine looking toward the boom. The boom is at the front of the machine. Safety When leaving machine parked on an incline turn wheels into the rib or block wheels. Do not run over power cables. Make sure your power cable is up out of the way so others can't run over it. Machine has a fire suppressor system for the power unit. The remote actuator (pressure cylinder) is located at the operator's station. Components and service procedures on page 59.

Jan 1, 1976

By Andrew J. Freyman, George S. Barry

"Mineral endowment in northern British Columbia and the Yukon Territory was assessed on the basis of geological opinion which was gathered in a quantitative framework of subjective probabilities. The survey area encompassed 364,000 square miles and was divided into 310 cells having dimensions of one degree of longitude by one-half degree of latitude. The response solicited related to tonnage, grade and number of deposits of a particular mineral in each cell. The questionnaire sought an expression of mineral endowment down to mine-able depth as distinct from economic expectations. Details on the questionnaire and responses are presented in a series of contour maps on individual commooities, which illustrate the collective occurrence picture of the respondents. The approach is largely dependent on the cooperation of an adequate number of geologists familiar with the region being examined. This approach to an assessment of the mineral endowment of a region has a wide range of applicability, from the focusing of exploration effort to aiding government and development bodies in the formulation of regional strategies and the planning, for example, of road, rail and power facilities."

Jan 1, 1970