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1. Domestic Production and Use: Twelve companies operated 31 primary aluminum reduction plants, three firms accounting for 66% of production. Washington, Oregon, and Montana accounted for 32% of the total production; Gulf Coast States, 25%; Northern States, 29%; and other Southern States, 14%. Output of primary metal in 1973 was valued at $2.2 billion. About 80% of the secondary recovery was from new aluminum base scrap and 20% was from old scrap. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1972, building accounted for 28%; transportation 19%; electrical, 13%; packaging, 16%; and consumer durab1es, 10%.

Jan 1, 1974

By Takeshi Ohgai, Hisaaki Fukushima, Tetsuya Akiyama, Joon-Seo Ki

"Recently, an intensive attention has been paid to the electrodeposition of Zn-Cr alloy in the field of the production of super-highly corrosion-resistant alloy plated steel sheets for the next generation. In this study the electrodeposition of Zn-Cr alloys from the sulfate baths was conducted to investigate the codeposition mechanism of Cr with Zn. As a result, Cr was codeposited with Zn at higher current densities in both polyethyleneglycol(PEG)-free and PEG- containing baths. However, PEG made it possible to reduce Cr+ to the metallic state and Cr existed in the form of Cr(III) hydroxide in the deposits obtained from PEG-free bath. The measurements of the partial polarization curve of Zn and the pH in the cathode layer revealed that PEG acted as a polarizer to shift the cathode potential to the reduction potential of the composited hydroxides of Zn and Cr formed due to the pH rise in the cathode layer.1. IntroductionRecently, much attention has been paid to the electrodeposition of Zn-Cr alloys because of its application to the production of super-highly corrosion-resistant alloy plated steel sheets for the next generation1Hl_ Some researches have already tried to commercialize this type of steel sheet. High corrosion-resistance of this steel sheet is brought about by codeposited Cr in the alloys. According to Piontelli's classification5l concerned with metal deposition from aqueous solution, Cr belong; to an inert metal and its deposition is associated with a large amount of hydrogen evolution. Therefore the current efficiency for Cr deposition is extremely poor. It has been also reported that Cr is unable to codeposit in the electrodeposited Zn film in the absence of a certain additive in the solution. 0-compounds group colloids7l, ether group organic compounds8), 9>, peptide based compounds10l, etc., have been found to be effective additives to induce the codeposition of Cr with Zn. However, few studies have been made on the codeposition mechanism of Cr with Zn. In this research, the fundamental electrodeposition behavior of Zn-Cr alloys from sulfate baths was investigated to clarify the codeposition mechanism."

Jan 1, 1998

By X. N. Hu, X. Shi, V. Vallyathan, N. S. Dalai

"Although silicosis has been studied extensively, the mechanism is still not fully under stood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are thought to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.INTRODUCTIONSilicosis is a debilitating pulmonary disease that afflicts persons (miners, foundry workers, ceramic workers, heavy construction workers, etc.) who chronically inhale silica-containing dusts (Schepers, 1960; Silicosis and Silicate Disease Committee, 1988). Since silica is second only to oxygen in weight percentage of the earth's crust (about 28%) and is found in an enormous diversity of minerals, it is natural that silicosis is one of the Major industrial health hazards all over the world. Although silicosis has been studied extensively, the mechanism by which the dusts exert their toxic actions on cells and the processes by which these-actions progress to fibrogenesis are still poorly understood. The biological characteristics of the dusts are largely unknown, although it is suggested that the dust size, shape, surface charge, roughness, surface chemical composition, trace metal content, and crystallinity; dose of silica in the ambient air of the workplace; duration of exposure; genetic variation in exposed sub¬jects; personal respiratory patterns; and presence of any coexisting dis¬ease (such as tuberculosis or rheumatoid arthritis) all influence the ex¬pression of silicosis (Koskinen et al., 1983; Noweir et al., 1980; Raask and Schilling, 1980; Reiser and Last, 1979; Thorne et al., 1985; Wolff et al., 1981). The actual biochemical mechanisms through which these factors operate are still unclear. However, the experiments do provide evidence that the actions of certain unique properties of silica surface on the cell membrane are the starting point of the silicotic process (Allison et al., 1966; Allison and Harrow, 1971; Bateman et al., 1982; Marks, 1957; Parazzi et al., 1968; Reiser and Last, 1979; Summerton et al., 1977). This article summarizes literature on chemical properties of silica dusts and how silica dusts are thought to interact with the cell membrane, with emphasis on hydrogen bonding and free-radical interactions."

Jan 1, 1989

Few, if any, reliable thermodynamic data are available for the activity of tin oxide in slags. In this work, the activity of the oxide in silica saturated iron silicate slags has been measured at 1573 K using the equilibrium Sn (alloy) + Y2O2-SnO (slag).Slag and a Ag-Sn alloy were sealed in a zirconium oxide crucible to prevent the escape of volatile tin oxide, and the oxygen pressure at equilibrium measured in situ using the zirconium oxide as a solid electrolyte. Activity of tin was calculated from known data for the Ag-Sn system and activity of tin oxide calculated from free energy data. The results have been extrapolated to predict the industrially important distribution of tin and iron between Fe-Sn alloy and iron silicate based slags.

Jan 1, 1983

1. Domestic Production and Use: In 1980, 13 companies operated 33 primary aluminum reduction plants, with 3 firms accounting for 62% of production. Washington, Oregon, and Montana accounted for 30% of the total production; Texas, Louisiana, and Arkansas 19%; Tennessee, Alabama, and North Carolina 15%; other central and eastern States 36%. Based on published producer prices output of primary metal in 1980 was valued at over $7 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 26% of domestic consumption in 1980, building 22%, transportation 21%, electrical 12%, consumer durables 7%, and other uses 12%.

Jan 1, 1981

By David E. Pearson

"There are many tests that can be used to characterize and classify coals, and describe their quality. One of the easier tests, and most versatile in its application, is petrography. Rank and coal type are precisely defined by petrographic evaluation, and in this paper they are compared with other definitions of rank and coal type. Brief descriptions are given of the various rank tests, and of rheological and coking tests used to describe coking-coal quality in Canada. Similarly, tests used to evaluate thermal coal quality are discussed. Finally, the use of these tests as parameters to classify Canadian coals is examined with reference to four coal classifications.Introduction Among all coals there are two independent variables that are required to evaluate coal quality. These are, coal rank and coal type (or composition), and although coal petrography can be used to precisely define them, other methods are often used to provide values that are, in fact, functions of rank and coal type. For example, volatile matter yield is used as a proxy for rank, and free swelling index is used as a proxy for coal type in the International Classification of Hard Coals by type. Currently, there are a number of methods in use in Canada to define rank. The approach taken here, (obviously the author's bias), is that Romax, the mean maximum reflectance of vitrinite, is both a quick and an accurate measure of rank. It is logical to compare the other techniques employed in the measurement of rank to this favoured method. Coal type is, in theory at least, simply a quantitative measure of the various varieties of coal. In practice, the microscopic entities are assigned to a Reactive or Inert category, and at that point objectivity fades from petrography. Despite this somewhat subjective approach, petrographic composition of coals remains an independent variable of such.importance that its place in the evaluation of coal is essential. In this paper, a variety of me.thods that are used to assess rank and coal type are reviewed and compared; the influence of these variables over other parameters that are used to determine the quality of metallurgical and thermal coals is examined, and their usefulness in coal classifications is discussed."

Jan 1, 1985

By R. L. Benner

The Bureau of Mines investigated the ZnO-Fe2O3-Fe3O4 system at 1,000°, 1,300°, and 1,400° C, with oxygen pressures between 1.0 and lx10-4 atmospheres. The results, divided into the thermodynamic properties as related to the spinel structure, and the thermodynamic properties as related to zinc concentrate roasting, were used to calculate the activities of ZnO, Fe2O4, and Fe3O4 within the spinel solid solution region of the ternary system, and the pseudo-binary activities of ZnFe2O4 and Fe304. The activities of both systems show large positive deviations from Raoult's Law, especially at high Fe3O4 concentrations. The free energies, the enthalpies, and the entropies of mixing for the binary system were calculated from the binary activities, and the entropies of mixing were compared with two statistical models, one representing an ideal solution, and one representing the mixing of a normal with an inverse spinel. The binary entropy of mixing seemed to be better represented by the latter statistical model, indicating that the tetrahedral and octahedral cations of the reactants tend to remain in the product, even at the high temperatures of the study. This comparison also indicated that the cations of the components are the major contributing factors to the thermodynamic properties.

Jan 1, 1966

This paper endeavours to lay as concisely as possible, before the members the salient features of local gold milling practice, and to point out in what respects this practice differs from that of other large mining camps. This is essentially a free milling ore the gangue being quartz and the gold occurring in a coarse form. At times the ore crushed contains a good deal of slate, the latter imparting to the tailings a somewhat leaden hue.Small amounts of sulphides, chiefly iron pyrites, and at times smaller quantities of arsenical pyrites, zinc blende, and galena are contained in the stone. The average amount of sulphides contained in the ore cannot well be ascertained, as the concentrate obtained in all cases contain too much silica to form a basis of calculation...

Jan 1, 1902

1. Domestic Production and Use: In 1979, 12 companies operated 32 primary aluminum reduction plants, with 3 firms accounting for 64% of production. Washington, Oregon and Montana accounted for 32% of the total production; Gulf Coast States 20%; other Northern States 32%; and other Southern States 16%. Based on published producer prices output of primary metal in 1979 was valued at over $6 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1979, building accounted for about 24%; packaging 23%; transportation 22%; electrical 11%; consumer durables 8%; and other uses, 12%.

Jan 1, 1980

1. Domestic Production and Use: In 1984, 12 companies operated 27 primary aluminum reduction plants, with 3 firms accounting for 57% of production. Washington, Oregon, and Montana accounted for 35% of the production; Indiana, Kentucky, Missouri, and Tennessee 25%; Alabama, Arkansas, Texas, South Carolina, and North Carolina 20%; other States 20%. Based on published producer prices, output of primary metal in 1984 was valued at $7.2 billion. Aluminum consumption by 25,000 firms was centered in the east-central United States. Packaging accounted for an estimated 35% of domestic consumption in 1984, transportation, 20%; building, 18%; electrical, 9%; consumer durables, 8%; and other uses, 10%.

Jan 1, 1985

1. Domestic Production and Use: In 1974 twelve companies operated 31 primary aluminum reduction plants, three firms accounting for 64% of production. Washington, Oregon, and Montana accounted for 32% of the total production; Gulf Coast States, 24%; Northern States, 33%, and other Southern States 11%. Output of primary metal in 1974 was valued at $3.4 billion. About 80% of the secondary recovery was from new aluminum base scrap and 20% was from old scrap. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1974, building accounted for about 27%; transportation 19%; electrical, 13%; packaging, 15%; and consumer durab1es, 9%.

Jan 1, 1975

1. Domestic Production and Use: In 1983, 12 companies operated 27 primary aluminum reduction plants, with 4 firms accounting for 65% of production. Washington, Oregon, and Montana accounted for 35% of the production; Indiana, Kentucky, Maryland, New York, Ohio, and West Virginia 35%; Tennessee, Alabama, South Carolina, and North Carolina 14%; other central States 16%. Based on published producer prices, output of primary metal in 1983 was valued at over $5.7 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 37% of domestic consumption in 1983, transportation 19%, building 17%, electrical 9%, consumer durables 8%, and other uses 10%.

Jan 1, 1984

By L. R. Burdick, J. F. Barkley

The inherent heating value or the amount of heat that will be produced when a coal is completely burned is measured in British thermal units (B. t. u.) per pound of coal . This standard heat unit is the quantity of heat required to raise the temperature of 1 pound of water 1 °F . at about 60 °F . The amount of inherent heat is determined by burning a small quantity of the coal in a heat meter or calorimeter , which gives results in British thermal units . The exact manner of making this test is standardized by the American Society for Testing Materials.4/ The value so determined is the total heat developed by complete burning, with all the products of combustion cooled down to the temperature of the calorimeter . The calorimeter is kept at about room temperature . This total heat is sometimes called the " high" or gross heat value , because it includes the latent heat given up by the water vapor in the products of combustion when the vapor condenses to water in the calorimeter . The heat as measured is reported as the heat of combustion at constant volume , since the burning is carried out in a tightly closed calorimeter chamber whose volume does not change . In actual use , coal is usually burned in an open - end chamber at constant pressure , generally somewhere near atmospheric . As the heat of combustion of coal at constant pressure is very slightly higher than the heat of combustion at constant volume , it might be considered that the heat at constant pressure should be used as the standard reference base . For an ordinary eastern coal the heat at constant pressure is about 16 B. t . u. per pound higher than the heat at constant volume . Calorimeter corrections , ordinarily not considered , that could have been subtracted from the heating value before reporting , may amount to about as much . Hence , the value reported is apt to be more nearly the true heating value at constant pressure than at constant volume .

Dec 1, 1941

A stronger U.S. economy stimulated the domestic mineral sector in 1994. Metals demand was spurred by robust U.S. motor vehicle sales, while demand for major industrial minerals rose in response to highway and building construction. Domestic mineral and material demand is expected to increase in 1995, particularly if interest rates do not restrain the building industry and international monetary exchange rates remain advantageous to U.S. automobile manufacturers. Additional information on events, trends, and issues in the mineral and material sector is presented below and in the commodity sections that follow. Overall Performance Processed materials of mineral origin produced in the United States during 1994 increased to an estimated value of $360 billion. Domestic output of raw nonfuel minerals in 1994 was estimated at $34 billion, about 6% more than that of 1993. The value of U.S. minerals production has increased in 29 of the last 34 years.

Jan 1, 1995

By Chris A. Fleming

"The ability to recover cyanide from gold plant tailings has been known almost as long as the cyanidation process has been practiced, but there has been little incentive to process tailings in this way in the past. With the development of technologies that make it possible to recover and recycle free or complexed cyanide directly from gold plant slurry tailings, which indicates, on paper at least, significant cost savings compared to cyanide destruction, coupled with the introduction of legislation to seriously limit the discharge of cyanide to the environment in most gold-producing regions of the world, many companies are evaluating the cyanide-recovery alternative.There is arguably an even more compelling reason for mining companies to consider cyanide recycling. With the growing storm of negative public opinion that the use of cyanide in the mining industry is attracting - following several highly publicized spills over the last couple of years - the time has come for the gold industry to demonstrate environmental diligence and stewardship in the use of this commodity that is so vital for their industry. There is no doubt that the widespread implementation of cyanide recycling will reduce the impact of the cyanidation process on the environment, both by reducing the risk of spills (with less cyanide being transported from manufacturing plants to gold mines), and by reducing the loading of toxic and nontoxic metals and ions in the tailings.This paper briefly discusses the pros and cons of the different processes that are available for the treatment of gold plant tailings to regenerate and recovery cyanide for recycling, and presents a techno-economic argument for the incorporation of this technology into many gold plant flowsheets today."

Jan 1, 2003

1. Domestic Production and Use: In 1982, 13 companies operated 30 primary aluminum reduction plants, with 3 firms accounting for 55% of production. Washington, Oregon, and Montana accounted for 34% of the production; Texas, Louisiana, Missouri, and Arkansas 18%; Tennessee, Alabama, South Carolina, and North Carolina 14%; other central and eastern States 34%. Based on published producer prices, output of primary metal in 1982 was valued at over $5.5 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 39% of domestic consumption in 1982, transportation 20%, building 14%, electrical 8%, consumer durables 8%, and other uses 11%.

Jan 1, 1983

By R. F. Rolsten

VAN Arkel 1 prepared ductile tantalum by the thermal decompoiition of tantalum pentachloride on a resistively heated wire (2000° C) in an evacuated bulb maintained at 100°C. Burgers and Basart2'3 observed the formation of a mixture of tantalum carbide and free metal when a carbon deposition base was used. campbel14 suggested the thermal decomposition of the iodide if a lower decomposition tem- perature was desired. To date, the details for preparing high-purity iodide tantalum have not been disclosed. EXPERIMENTAL The tantalum to be purified was symmetrically placed around the clear quartz deposition surface centrally located within a 64 mm cylindrical Vycor bulb. The deposition vessel usually employed5 was modified6 by incorporating a reentrant fin,mer in place of the customary metal filament in the head

Jan 1, 1960

By Ralph Husack, J. W. Eckerd, G. A. Brady

The effect of gamma radiation on Pennsylvania anthracite and on reactions between anthracite and other materials was studied using a shielded , selfcontained 23,000 - curie cobalt 60 source . When anthracite was exposed to air at 65° C the reaction with oxygen was greater in the presence of radiation. than in its absence . Although drop- shatter tests indicated that exposure to radiation decreased the resistance to breakage of anthracite , this evidence of structural weakening was not supported by the results of grindability or particle- size studies . Irradiation caused definite changes in the gases evolved from evacuated samples of anthracite ; the percentages of hydrogen and carbon dioxide were increased, and the methane concentration remained unchanged . Carbon monoxide was evolved only from the unirradiated samples . Electron paramagnetic resonance (EPR ) measurements indicated large differences between evacuated samples and those exposed to air . There was little or no difference between irradiated and unirradiated samples , except that the free- radical content of unirradiated samples of anthracite increased progressively with higher temperatures of evacuation , but in the case of irradiated samples , no such behavior was found . Attempts to produce carbon disulfide and calcium carbide by reacting anthracite with sulfur up to 120 ° C , and with calcium oxide up to 400 ° C , were unsuccessful .

Jan 1, 1964

I. Domestic Production and Use: In 1981, 13 companies operated 32 primary aluminum reduction plants, with 3 firms accounting for 58% of production, Washington, Oregon, and Montana accounted for 32% of the total production; Texas, Louisiana, and Arkansas 16%; Tennessee, Alabama, South Carolina, and North Carolina 17%; other central and eastern States 35%. Based on published producer prices output of primary metal in 1981 was valued at over $7.5 billion. Aluminum consumption by 25,300 firms was centered in the East Central United States. Packaging accounted for an estimated 30% of domestic consumption in 1981, building 21%, transportation 18%, electrical la%, consumer durables 8%, and other uses 13%

Jan 1, 1982

By G. S. Hill

A large amount of the stereological error associated with liberation studies can he eliminated by assessing areas instead of linear intercepts. The presentation of a simple geometrical model as a stereological 'worst case' allows calculation of the worst possible grade/recovery curve for a given assemblage of areas. The true results are expected to lie in the window between this worst case and the hest possible case, represented by uncorrected data. The width of this window typically corresponds to an error margin of about 5% grade at a given recovery. An indication of where the data lies within the range of possible grade/recovery results may he obtained from a qualitative analysis of the locked section complexity. Assemblages consisting of texturally complex locked sections (ie. containing many mineral nuclei) are likely to exhibit minimal stereological bias and therefore will tend to lie close to the uncorrected side of the grade/recovery window.

Jan 11, 2011