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By Don Masson

MUCH has been written and many prophecies made on the subject of plastics as a replacement for metal, and the extent to which these materials will compete with each other for peace- time markets. (Metal is used in a broad sense to include all types.) But although certain synthetic resin materials have made considerable headway in war production, this change to plastics can hardly be regarded as a serious threat to the mining and metallurgical industries. Even today, the total yearly tonnage of plastic materials is approximately only 1 per cent of that of steel, and only a small fraction of this might be considered as actually replacing steel. However, these figures must not be taken as indicating that the importance of plastics in fields hitherto considered exclusively the territory of metals is negligible-far from it. Considering the comparatively minute tonnage of plastics now being produced in comparison to the output of metals, the number of applications where plastics have augmented or aided the sale of metals is considerable.

Jan 1, 1944

By P. LaRochelle, K. Y. Lo, A. L. Tamuly Phukan

In many civil or mining engineering works, the stresses and deformations of natural or excavated slopes due to the combined effect of self-weight and initial stresses are of interest. Because of the mathematical complexities of this problem, however, no complete exact solution exists for the simplest case, that of assuming the stress-strain relation of the rock to be perfectly elastic. Efforts have therefore been directed toward numerical and experimental technique. The stresses within an elastic slope have been obtained by LaRochelle,1 using the photoelastic and finite difference method to determine the difference and sum of principal stresses. Subsequently, Finn,2 Hoyaux and Ladanyi,3 and Duncan and Dunlop4 attempted to solve the same problem by using the finite element method. The problem was also investigated by Brown and Goodman5 and Brown and King6 who emphasize the importance of the effect of loading or unloading procedure on the stress distribution within the slope. Although the geometry of the slope and the boundary conditions involved are identical or similar, the results obtained by these various authors by no means agree. It is therefore necessary to review briefly the results of elastic analysis in order to lend credence to the methods used in the solution. Although the stress-strain behavior of some rocks may be reasonably approximated by the elastic modrl, other rocks generally exhibit an elasto-plastic behavior with strain hardening or strain softening as shown in Fig. 1. Experiments show that for most rocks, the stress-strain relationship is approximately linear from the origin to the point P (neglecting the small concave region under low stresses). At P, the curve deviates

Jan 1, 1970

By Juniper LA

ERM Consultants Pty Ltd was established in 1980 for the purpose of introducing a disciplined coal technology and power station planning service, to support Australia's efforts in establishing a major export steaming coal industry. At that time, major coal exploration programs were mounted on more than 50 potential export coal deposits with proven open-cut reserves to export 200 Mt/a of coal. The fact that Australia achieved an export trade of only 30 Mt/a, equivalent to the energy requirements for a population of around 5 million people, illustrates the very small achievement to date. The main reasons for this small export steaming coal growth have been: 1. Failure to convince potential overseas coal buyers of the benefits of coal-fired power generation, and the ability of proper power station design to overcome environmental problems, and achieve reliable operation and long life when burning Australian coals. 2. Failure to promote Australian power engineers to advise on the use of Australian coals, resulting in Northern Hemisphere power station experience dominating in market countries. 3. Failure of governments to draw on privately practising Australian power engineers and coal technologists in technical workshops, presentations and assistance to overseas countries, to ensure that personnel whose business it was to serve the follow-on needs of countries were readily available. The result of these failures has been that: 1. Only a fraction of prospective overseas coal-fired power projects have proceeded. 2. Australia has had no influence in the design of overseas power stations to ensure that potential customers would be confident that Australian coals could be reliably burnt in their boilers.

Jan 1, 1987

By M. A. Hardie

"CASES and mixtures of them are so common and so much a part of everyday existence that they become so taken for granted that their individual characteristics and idiosyncrasies rarely become of curiosity to others than those involved in tl1eir production, processing, treatment, transportation, and for utilization. The use of the most common and universal mixture of gases -air -is begun at birth by ail living creatures and their discontinuation of its use terminates existence. Modern man rides on air in his tires, rides through it for high-speed transportation, and uses it for his comfort in the heating and air conditioning of his domicile. It is neither the aim nor the in-tent, in the next few moments, to provide a panacea for even a portion of the problems inherent in the gas industry nor to delve deeply into any particular facet of its diversities. The purpose is primarily to touch upon some of the peculiarities and generally to consider approaches to employ in the pursuit of solutions."

Jan 1, 1959

By Kavanagh M. E, Henley R. W

The Meekatharra mining district lies in the northern pan of the Murchison Province of the Archaean Ynlgam block of Western Australia. Since dis- covery of the Paddy's Flat belt in the district in 1897 total gold production has been 67 tonnes and a further 33 tonnes in resources have been defined by drilling. The Paddy's Flat gold deposits occur within the Gabanintha Formation, a basal formation of the Murchison greenstone sequence containing komatiitic basalts, ultramafics and minor banded iron formations. The regional control on the distribution of deposits is an anastomosing shear belt which extends over 350 km and incorporates the Mt Magnet, Reedys and Meekatharra deposits. The following gold deposit styles may be recognized based on lithological association and alteration: Albite porphyry hosted, Carbonate-fuchsite- quartz alteration hosted deposits, Banded Iron Formation hosted sulphide replacement gold deposits and quartz vein deposits. With the exception of the banded iron formation hosted deposits, the Paddy's Flat alteration zone shows strong similarities to the alteration styles at Kerr-Addison (Ontario).

Jan 1, 1991

By E. Bélisle, Christopher W. Bale, S. Petersen, C. Robelin, K. Hack, J. Melançon, G. Eriksson, A. D. Pelton, P. Chartrand, S. A. Decterov, I. H. Jung, A. Gheribi

The FactSage® package consists of a series of information, database and calculation modules that enable one to access pure substances and solution databases and perform thermochemical equilibrium calculations. FactSage was originally founded by process pyrometallurgists and has since expanded its applications to include hydrometallurgy, electrometallurgy, corrosion, glass technology, combustion, ceramics, geology, environmental studies, etc. With the various modules one can perform a wide variety of thermochemical calculations and generate tables and graphs of complex chemical equilibria and phase diagrams for multicomponent systems. This paper presents examples of recent and current developments in FactSage in areas of particular interest to Dr. David Robertson. These include both ferrous and non-ferrous processing, as well as solidification and refining simulation. The paper also includes reference to the Internet Fact-Web education package.

Jan 1, 2014

By John V. Beall

When a mine has ore averaging 5% lead, 7% zinc, 0.60% copper, 1/4 oz gold, and 6 oz of silver, adequate reserves, power and water, easy access to market, and is situated in beautiful natural surroundings with the advantages of a big city within a few hours drive, there is little left to be desired. Such a mine is the Mayflower mine of the New Park Mining Co. situated 30 miles from Salt Lake City in the Wasatch Mountains near Keetley, Utah.

Jan 1, 1949

By d&apos, L. R. Fletcher, Andrea. D. V., M. A. Peltier

The Bureau of Mines analyzed coal mine blasting accident data obtained from the Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The data were examined to determine the causes, frequency, and severity of accidents in an effort to point out the most dangerous aspects of coal mine blasting. Accident data for the 14 years from 1971 through 1984 show that there has been a total of 43 fatal and 926 nonfatal blasting accident victims in surface and under- ground coal mining. This is an average of 3.1 fatal and 66.1 non- fatal injuries each year. Underground coal mining accounted for 60.5% of the fatal and 78.7% of the nonfatal accidents involving explosives and breaking agents in coal mining. In addition, since 1970 there have been 53 fatal and 20 nonfatal injuries that occurred when explosives were the ignition source for dust and/or methane explosions in underground mines. Abstracts from 297 accidents that occurred from 1978 through 1984 were also examined to determine accident causes. Most accidents occur during scheduled blasting, and failure of the blast area security system is the leading cause. Blast area security problems in surface mining are failure to clear the blast zone, failure of personnel to follow instructions, inadequate guarding, and failure to retreat to a safe location and/or take adequate cover. Other common causes in surface mining include premature blasts, excessive flyrock, and misfires. In addition to the above causes, accidents in underground coal mining can be due to rockfalls triggered by the blast, unexpected breakthroughs, fumes, and incidents associated with Airdox-type systems.

Jan 1, 1986

By J. L. Ellenberger, P. W. Jeran

A deep longwall coal mine was instrumented with a three-dimensional microseismic system in order to help determine the exact strata mechanics associated with the rock failure, redistribution of stress and the associated gob formation from the longwall. Overall, 5,000 well calibrated seismic events were recorded during the mining of the panel. Analysis of these events showed a close correlation between the seismic activity and advance rate, and that the majority of the recorded seismic activity occurs in the immediate area of the advancing longwall face.

Jan 1, 2002

By Harold Paredes D

El presente texto señala el comportamiento químico de las principales impurezas de los iones metálicos y no metálicos provenientes de los efluentes líquidos de la industria minera durante el proceso de potabilizacion de agua. Es importante que el tratamiento aplicado a los micro u oligoelementos de dicha potabilización del agua, garanticen que los contenidos de sus concentraciones no sean nocivos para la salud, así como que la calidad del efluente líquido de las plantas de beneficio se corresponda a un bajo precio y garantice una óptima potabilización del agua.

Nov 8, 1984

By Charles Prasky

This report describes and appraises recent progress in the development of a differential sulfatizing process for recovering a ferrograde manganese oxide from low-grade manganiferous ferruginous materials in the Cuyuna range. Individual process steps were carried out successfully using a 20-inch-diameter shaft for continuous countercurrent sulfatization of the manganese, a multiple-compartment rotary drum for leaching the water-soluble manganese sulfate, a submerged-combustion evaporator for the recovery of monohydrate crystals of manganese sulfate, and a shaft furnace for the thermal decomposition of sulfate crystals for production of a ferrograde manganese oxide and a sulfur dioxide gas suitable for sulfatization of fresh are. Of the two general kinds of Cuyuna manganiferous materials--the carbonate slates and the oxidized ores--only the slates were studied at pilot scale.

Jan 1, 1963

SCOPE AND APPLICATION The rules cover the installation and use of electrical equipment in coal mines.- For generating stations, substations, lines, and equip¬ment aboveground, reference is made to existing rules covering such locations, viz, the National Electrical Code and the National Electrical Safety Code and any existing State or municipal regulations. The purpose of the rules is to set forth methods for safe electrical installation. In preparing the rules five basic measures for safe¬guarding the use of electricity in mines have been followed, viz 1. Remove the contributory causes of accidents or danger. 2. Remove from the vicinity of electrical apparatus all elements susceptible to the influence of electricity. 3. Keep the electric current where it belongs, if possible; if not, limit the area of its activity by protective devices. 4. Use a. large factor of safety in the selection, installation, and in¬ spection of equipment. 5. Have full control of the operation of electrically driven machines. Each rule that is given is proposed as necessary or helpful to the accomplishment of one or more of these measures. DEFINITIONS OF TERMS USED Alive.-See definition of " live." Approved.-The term " approved " means accepted as suitable by a competent committee, board, or organization designated by those adopting the rules. Authorized person.-The term " authorized person " means a per¬son appointed or permitted by the official designated by the State mining laws as the one in charge of the operation of the mine to carry out certain duties incident to the generation, transformation, and distribution or use of electric energy in the mine, such person be-

Jan 1, 1926

By William O. Vanderburg

This paper gives the results of a reconnaissance of the mining districts in Humboldt County, Nev., made during the month of June, 19373/. During the field work, virtually all the mining districts in the county were visited and many data were obtained on a number of active and inactive properties. No attempt has boon made to include in this report all the properties in the various mining districts, and it should be emphasized that whether or not a property is mentioned herein has no being on its merit. The report covers the location of the various mining; districts, types of deposit, information on past operations and current activity, and general information likely to be useful to operators, investors, and others interested in mining. The geology of the deposits is discussed only briefly. The names of the various mining districts mentioned in this report are those generally used when they were organized for purposes of record and regulation. As organized, the districts embraced largo areas with no definite boundaries, and the names have little significance.

Jan 1, 1938

By George Hunt

THE first practical treatment of wood to prevent decay was devised early in the 19th century. At that time the oaken navy of England, when . the nation was fighting for its very existence, seemed doomed to annihilation by the swift ravages of decay. The acute situation inspired a desperate search for preventive measures and resulted in the development of the Burnett, Bethel and Kyan processes for impregnating wood with zinc chloride, coal-tar creosote and mercuric chloride, respectively. In the century that has elapsed, their use has spread throughout the world and the three original preservatives are used today in enormous quantities. Meanwhile, improved processes have been developed, new preservatives discovered, and the practice of impregnating wood to make it last longer has attained a position of major importance in the field of structural materials. USE OF PRESERVATIVES BY- THE RAILROADS In the application of wood preservatives in the United States the railroads have been the leaders for the past 50 years or more.. Having found, that decay is the chief cause of the early destruction of wood and that preservative treatment is the remedy, they have treated their ties and timber in increasing amounts(1) ?-in 1925 about 220,000,000 cubic feet. By preservative treatment the Santa Fe Railroad saves annually 1,500,000 ties in its 18,000 miles of track, and many other railroads effect similar savings. (2) In like manner the life of wooden bridges and trestles,(3) poles, marine piling, water tanks and other wooden railroad structures has been greatly increased, reducing the amount of timber required annually to maintain them.(5),(7)

Jan 2, 1927

By P. T. Brooks

Semipilot scale tests were made to demonstrate a newly developed electrorefining process which could be extrapolated to commercial scale in producing high-purity nickel and cobalt from crude nickel metal and high-grade ferronickel. The new process comprises application of solvent extraction techniques to remove and separate cobalt and iron from nickel and the electrodeposition in diaphragm cells of pure nickel and cobalt from chloride-based purified electrolyte. Using water insoluble organic amines, the solvent extraction operations enabled production of commercial-sized nickel and cobalt cathodes of higher purity than that of commercial electrolytic metals. The solvent extraction operation for separation of cobalt from nickel was made simpler than the conventional method. Furthermore, the solvent. extraction operation for iron removal made possible the electrorefining of ferronickel without the prohibitive loss of nickel resulting from the method ordinarily used for iron removal.

Jan 1, 1970

By K. R. Dorman

To further investigate the potential of precast concrete sets as a support medium for underground mines, the Bureau of Mines designed a five-piece precast concrete drift set for a small opening and tested it to destruction in a straining frame. Twenty-seven tests were made with three sizes of members using three loading conditions. In addition, six tests were made with sets in a distorted configuration, Test results and typical failure patterns are presented. A comparison of results with those previously reported for the three-piece set shows the five-piece set supports considerably larger total loads than does the three-piece set of equivalent cross section designed for the same size of opening. Recommendations are made for improvements in design.

Jan 1, 1969

Iron removal using biologically produced organic acids was investigated as a treatment option for the production of refractory grade bauxite. A leaching solution containing 98mM oxalic and 67mM citric acid was prepared from a sucrose medium using for fermentation the fungus Aspergillus niger. The leaching capacity of the metabolic product was tested on a bauxite sample containing 16-19% iron (as Fe2O3). Aerobic and anaerobic leaching tests were carried out at pH 3, 50°C and in the absence of light. Results indicated that more than 80% of total Fe can be removed from the ore, when the sample is finely ground and applying a two stage treatment. The presence of oxygen was seen to affect adversely the kinetics of the process, suggesting that leaching follows a reductive mechanism. Experiments that were carried out with different particle size fractions indicated that for obtaining efficient removal of iron particles should be finer than 0.63mm. Reduction of the operating temperature from 50 to 30°C caused a decrease in the rate of iron removal by more than 10 times.

Jan 1, 2006

Jan 1, 1879

By Fernando Zúñiga y Rivero

El presente texto describe los principales métodos usados en las etapas de prospección por petróleo para así establecer la inversión en la búsqueda de petróleo. La exploración de petróleo es una de las más riesgosas dado que los estudios geológicos previos a la zona, no siempre se corresponden las espectativas de la inversión. Pese a estos inconvenientes, el petróleo se sigue consolidando como la principal fuente de energía del país, tanto por su Es bajo costo, poder calorífico y las ventajas para el transporte y manipuleo. De forma que la provisión de productos de petróleo, como su abastecimiento nunca ha representado un problema en el país, sobrepasando los 15 000, 000 barriles de petróleo hacia 1958. De otro lado, el circuito de prospección de petróleo comprende la roca reservorio, la roca madre y la roca sello, cuya acumulación de capas genera irregularidades y forma las trampas petrolíferas. Reunida estas condiciones para la acumulación de petróleo, hay posibilidades de que la zona a explorar contenga algún yacimiento petrolífero. Sin embargo, existen casos donde se hay una superposición de estratos a manera de reservorio que ocultan la posibilidad de un yacimiento, como es el caso del desierto de Sechura o la montaña del Perú. En estos casos, se emplea los métodos geofísicos de prospección que verifican el indicio de las condiciones estructurales del subsuelo. Entre los distintos métodos utilizados, tenemos a los gravimétricos, basados en la medición de variaciones de la atracción de la gravedad sobre la superficie de la tierra; los métodos magnéticos, que miden las variaciones del campo magnético terrestre, generados por las propiedades magnéticas anómalas del subsuelo; los métodos sísmicos que son los más usados dado que informan de forma precisa sobre la condición geológica del subsuelo, y los métodos eléctricos, que son los menos usados puesto que otorgan datos superficiales sobre las condiciones geológicas del subsuelo. Finalmente, para el costo de exploración del petróleo se tiene que equilibrar los siguientes factores: los métodos de prospección, costo de materiales y equipo, sueldos del personal, número de puntos de observación, facilidades de transporte y las clases de terreno y clima.

Jul 20, 1959

By G. R. Speich

RECENT studies by Smith and Olney,1,2 Olney,3 Greifer and Salli,4 Rys etal., and Olney and smith 6 have established that graphite is the first decomposition product to format the surface of hypereutectoid plain-carbon steels when they are austenitized in a vacuum or inert atmosphere and slowly cooled. This graphite evidently forms directly from the austenite and only at the surface of the specimen. The interior of the specimen is found to be free of graphite. The graphite layer can almost completely cover the specimen surface and the rate of its formation is markedly sensitive to the orientation of the austenite. The present work was undertaken to study this phenomenon further, especially with regard to the effect of temperature and austenite orientation. The material studied in this work was a high-purity iron-carbon alloy containing 0.88 pct C, 0.005 pct Mn, 0.016 pct Si, 0.005 pct S, and 0.002 pct P. Specimens were heat-treated in a commercial hot stage modified for rapid quenching.7 This permitted direct observation of the formation of the surface graphite. A vacuum of 10"" to 10-5 mm of Hg prevented oxidation or decarburization of the specimens. Specimens were austenitized for 30 min at 1100°C and quenched to a series of lower temperatures where they were isothermally transformed. Surface graphite was observed to form at 700°, 750°, and 780°C but not at 825°, 900° or 1000°C. Since the maximum solubility of austenite for graphite is 0.88 pct C at 800°C,8 surface graphite only forms at tem-

Jan 1, 1962