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By T. T. Tomimatsu

This? Bureau of Mines paper discusses the corporate structure dynamics, methods of financing, and financial assessment approaches that should be utilized to evaluate the economic health of the coal industry. It suggests rates of return and other measures of corporate economies necessary to attract capital required to finance emerging coal demand, plus impact of coal sales to total revenues. The study illuminates the activities of 30 selected coal-producing companies, including their subsidiaries or affiliates, that were responsible for approximately 60 percent of the total U.S. production in 1974. The selected firms are not all primary coal producers; many of the larger producer's are classified by the financial institutions as petroleum, metal, and steel producers, public utilities, or chemical industries. The bituminous coal industry is highly competitive as to price, service, and quality of pronuct and is subject to competition from other noncoal energy sources. The top 15 bituminous coal-producing companies mined about 46.6 per-cent of the Nation's total production in 1974, and the balance of approximately 3,885 companies were responsible for the rest of the production. Thus, the U.S. bituminous coal industry is not an oligopoly. Today, about 65 percent of the Nation's total coal production is consumed by electric power utilities and 26 percent by steel, space heating, and other industries; the balance of 9 percent is exported.

Jan 1, 1976

By Merwin H. Howes

In constructing the NORAD Combat Operations Center, controlled blasting techniques were employed to achieve smooth walls and to avoid shattering the rock beyond excavation lines. Extraordinary measures were taken to stabilize the rock to permanently preserve the openings. Rock stabilization was accomplished by means of reinforced concrete and gunite linings, rock boltings, installation of chain-link fabric, and epoxy resin and cement grouting. A particular zone of weakness at a vital location was supported by exceptionally thick reinforced concrete lining, rock bolts, and cement grout.

Jan 1, 1966

By Arno C. Fieldner

The determination and publication of data o the chemical and physical properties of American coals have been primary functions of the Bureau of Mines since its creation in 1910. In recent years this program has been expanded to meet increasing needs for information on the suitability of coals for the production of coke, gas, and byproducts, and within the last year an experimental coal-hydrogenation plant has been completed. With this addition, the Bureau is able to cover every phase of coal utilization, including combustion, carbonization, liquefaction, and complete gasification. The need for this information is increasing not only to meet the requirements of consumers but also to give the data required to establish the classification and minimum selling price of coal by the National Bituminous Coal Commission.

Jan 1, 1938

By A. D. Marcy

The Midnite Mine is an inactive, hard-rock uranium mine in Stevens County, WA. Oxidation of sulfide-containing minerals, primarily pyrite, in the ore body produces large quantities of acidic water. An interception system installed by the mining company limits the discharge of contaminated water from the mine. The U.S. Bureau of Indian Affairs (BIA) and the U.S. Bureau of Land Management (BLM) have been actively involved in planning remediation of the disturbed areas. To assist in remediation, the U.S. Bureau of Mines (USBM) initiated research to determine water quality and to define ground water flow characteristics. USBM personnel designed a monitoring network, supervised installation of sampling wells, and collected and analyzed water samples. This Report of Investigations describes interpretation of data collected between December 1989 and April 1992. The computer program WATEQ4F was used to identify aqueous species distribution and to calculate potential solid phase controls of solubility. To assist in interpretation of changes in water quality between sampling locations and to develop models describing proposed flow paths, the computer program BALANCE was used. Using output from these programs and field observations, a description of the chemistry along proposed ground water flow paths at the mine is presented.

Jan 1, 2010

By J. A. Brothers, M. R. Foran

"AbstractThis paper reviews the progress made in the manufacture of hydraulic cement from iron blast-furnace slag by simply grinding the granulated material with other constituents. The influence of the chemical and mineralogical composition of the slag, the conditions of granulation, the manner of drying, and the fineness of grinding, on the hydraulic properties of the cement, is discussed. The effect of additions of lime, portland cement, and anhydrite, alone and in combination, on the physical and cementing qualities of the mortar and concrete made from Sydney blast furnace slag, is shown in tables of data and is reviewed in some de- tail. The work at the Nova Scotia Technical College has shown that a cement equivalent in every respect to portland cement can be made from basic blast furnace slag- by the us2 of certain quantities of portland cement as an activator.IntroductionBlast furnace slag is a potentially valuable material for the manufacture of hydraulic cement. It is a by-product of the manufacture of iron in the blast furnace, and is formed by the combination of the silica and alumina .of the iron ore with the limestone flux. The metallurgist terms a slag .acid or •basic according as the percentage of lime is less or greater than the percentage of silica plus alumina. The basic slags have the •more pronounced hydraulic properties."

Jan 1, 1950

By M. L. Whisman

The Bureau of Mines developed and tested in the laboratory several innovative techniques for reclaiming used lubricating oil. These processes included percolation through both chemically treated clay and ion-exchange resins, distillation through batch and continuous wiped-wall vacuum apparatus, treatment with solvent extraction systems, and chemical removal of impurities with chelating agents. In each treatment, the criteria of evaluation was oil recovery and reduction of acidic and metallic components. Both vacuum distillation and solvent treatment ranked high in their abilities to remove acidic and metallic components of the used oil with good oil recoveries. A combination of the two techniques gave the best overall results in terms of quality evaluations made by established bench tests. The methods were not ranked according to economic practicablity.

Jan 1, 1974

By M. Nagamori, A. J. Plumpton

"Commercial HCl-leaching of magnesite and serpentine yields highly concentrated aqueous solutions containing 25 mass % to 33 mass % MgCl2. The partial molar enthalpies and heat capacities, the ionic activities of Mg2+ and Cl–, and the Raoultian activity of H2O have been assessed for the concentrated MgCl2-H2O solutions at temperatures of 348 to 373 K. These thermodynamic data are used to calculate the pH of aqueous MgCl2 solutions saturated with a Mg-bearing mineral such as magnesite, serpentine, brucite, forsterite, enstatite or talc. On the basis of these thermodynamic data, technico-economic aspects are discussed as to neutralization with pulverized MgCO3, water evaporation from the MgCl2 solutions, and ore composition including such minor constituents as CaCO3, FeCO3 and Fe3O4. IntroductionA major magnesium electrolytic reduction plant operates in Quebec, where another will begin its production in the year 2000. One uses imported magnesite ore as raw material, while the other will utilize local asbestos tailings (serpentine). Both processes produce a concentrated salt solution of 25 mass % to 33 mass % MgCl2 by leaching the ore with concentrated hydrochloric acid. Thus, the two processes differ mainly in the HCl-leach and related operations. After the HCl-leach of the ore, the serpentine process yields about 25 times more wet cake to filter and wash than the magnesite counterpart. A comparative cost-engineering study with respect to slurry filtration and cake washing has been published elsewhere (Blackburn and Nagamori, 1994). By contrast, the present study considers the thermodynamics and technicoeconomics of the HCl-leach itself for both ores."

Jan 1, 1999

I have headed this paper with a question and for the impatient among you ûthe answer is no we have not run out of developments but, and it is a big æbutÆ, we need to be innovative and ahead of the game or ænoÆ will be æyesÆ before we know it.Why do I believe that our future lies in innovation? Thirty years ago, knowledge doubled every 14 years. It is now doubling every seven years. In 1965, Gordon Moore, one of the founders of the chip maker Intel, made an observation that growth in memory chip performance is doubled every 18 months which became known as MooreÆs Law. Now there is fibre law, where the transmission line capacity doubles every nine months and storage capacity, under disc law, doubles every 12 months. What does this mean? Well, firstly there is a massive rise in information flow and availability with no limits in growth for at least the next ten years. Secondly, unlike our grandfathers, we are most unlikely to be employed by the same firm for our working career - we may not even have the choice to stay with the same company. In a phenomenon Richard Foster and Sarah Kaplan (2001), borrowing from Schumpeter, termed æcreative destructionÆ, companies are unable to sustain market-beating levels of performance for more than ten to 15 years. In the 1920s the turnover rate of companies in the United States was 1.5 per cent, so a company could employ almost three generations from the one family. A company had a half life of 60 years. In other words, you could well be in the same working environment as your grandparents. Today the churn rate is estimated to be eight to ten per cent. A company has a half life of five to six years. So for large companies, as an employer or employee or as a contractor, your working environment has a 50 per cent chance of changing in five years. Innovation is the driver of this rapid rate of change. Innovation is not for the faint hearted (Cutler, 2001) but it is the core for success in the global economy. The rate of change in our world is not going to decrease. We must learn, not only to manage change, but to enjoy the process of changing û to ride the tsunami of the knowledge economy.

Jan 1, 2002

By G. L. Oldright

In the first paper of this series (R. 1. 4333) on the cooperative work with the Eagle-Pitcher Mining & Smelting Co., changes in the nature of the sinter feed were measured by corresponding changes in the retorting temperatures necessary to distill zinc at the best rates; the firing schedules summarized such changes. In this paper, third of the series, are noted same of the changes in practice that were brought about by the need to treat more fused, glassy, and "hard" sinter, as the operators qualify it. Losses of uncondensed zinc were increased by adding zinc-bearing materials from which? the zinc was readily distillable to hard sinter requiring higher-temperatures for zinc distillation. The rates of zinc distillation were increased by grinding the fuel finer; there were few benefits and loss of dust on grinding the sinter finer, unless the fine ?coal and fine sinter were brought into contact by pelletizing, and the pellets made but little dust.

Jan 1, 1948

By Joseph A. Cavallaro

This report describes the timed release analysis technique that was developed to serve as a tool for assessing the froth flotation cleaning potentials of fine-size coals. Using this developed technique, 16 coals from 10 different coalbeds were tested. All of the coals included in this study were quite amenable to froth flotation with float coal yields ranging from 80.7 to 99.5 percentage points. Float-and-sink analyses of the coals tested are shown to be of limited value in predicting froth flotation cleaning potential. Generally the float-and-sink analyses indicated a better product could be obtained than froth flotation could provide; although, in four of the coals tested froth flotation results were superior to those expected from the gravimetric analysis. The fixed carbon content of the samples collected was found to correlate with the floatability of the coals. The higher rank coals were the most readily floatable coals while the lower rank coals did not respond quite as well to flotation.

Jan 1, 1965

By Pamela J. Watson

The U.S. Bureau of Mines has demonstrated in laboratory tests that drilling with surface-charge-neutralizing concentrations of polyethylene oxide (PEO) polymer solutions simultaneously improves penetration rates and extends bit life. The applicability of this additive to improve drilling performance in coal measure rocks was demonstrated under field conditions at an abandoned mine land site in Pennsylvania and a producing coal mine property in Ohio. Penetration rate improvements ranging from 15 to 50 pet were obtained when core drilling through a variety of coal measure lithologies. Drilling cost analysis indicates that the small added cost of using the polymer is more than offset by the savings that result from demonstrated increased drilling penetration rates, which translate into drilling cost savings of about 10 to 30 pct. This report also gives chemical analyses of a variety of coal measure rocks and some corresponding local drilling water samples, obtained from a wide geographical base, along with threshold concentrations of PEO required to effect the improved drilling performance in these rocks. From these data, the threshold PEO concentrations needed to ensure improved drilling performance can be estimated for any coal measure rock suite. Proper techniques for mixing PEO solutions are also presented.

Jan 1, 2010

By D. N. Nilsen

A mathematical modeling method was developed by the Bureau of Mines for the prediction of the principal equilibrium species in the solvent extraction of copper. The use of models for predicting the amount of metal extracted can reduce the amount of experimental work required to characterize a system for purposes such as optimization studies. Models were developed for the extraction of copper from ammoniacal sulfate and carbonate solutions with commercially available extract ants commonly used by industry. Results from laboratory shakeout tests compared well with predictions of the equilibrium concentrations of copper and pH values. For example, the loading of copper onto the solvent was predicted for most cases within ±S pct of the measured values, and the pH to with-in ±O.l pH unit in sulfate systems and ±O.2 pH unit in carbonate systems. Both mechanistic and empirical extraction equations were developed from laboratory data for copper and ammonia. The empirical-based models were slightly more accurate than were the mechanistic-based mod-els. Industrial level concentrations of the aqueous and organic constituents were used in this work. Independent variables included copper concentration, ionic strength, and initial pH of the aqueous phase; extractants, diluents, and their concentration in the organic phase; and temperature.

Jan 1, 1988

By C. L. Peng, F. F. Min, S. X. Song

"Using a parameter representing the degree of hydration of particles in a liquid called hydration index I, which we derived based on Einstein’s viscosity equation, we evaluated the degree of hydration of fine montmorillonite particles in different aqueous solutions by measuring the viscosities of the montmorillonite dispersions and plotting relative viscosity against volume fraction of dry montmorillonite particles in the dispersions. We investigated the effects on the hydration of montmorillonite in aqueous solutions of (1) the type and (2) the concentration of electrolytes in the solutions and (3) pH. For the same concentration of electrolytes, the hydration index I of montmorillonite was found to increase in the order of Na+ > K+ for monovalent cations and Mg2+ > Ca2+ for divalent cations, and to decrease with increasing valence of cations in the order of Na+ > Ca2+ > Al3+. For both Na+ and Ca2+, the hydration index I first increased with increasing concentration of electrolytes and then decreased after a certain concentration. The hydration index I increased with increasing pH. IntroductionClay minerals have the distinctive ability to adsorb water molecules and hydrated cations in aqueous solutions, resulting in hydration on their outer surfaces and in their interlayer spaces. Many investigators (Jurinak, 1963; Anderson and Tice, 1971; Costanzo et al., 1982; Israelachvili, 1992) had found evidence of ice-like structures of water on clay minerals.This phenomenon of hydration plays an important role in the dispersion and sedimentation of clay minerals in aqueous solutions. To understand clay hydration, numerous experimental and simulation studies have been carried out since 1933, including the recent ones of Hawkins and Egelstaff (1980), Skipper et al. (1995), Karaborni et al. (1996), Salles et al. (2013) and Morrow et al. (2013). Among the factors that can influence a clay mineral’s hydration characteristics are chemical composition, type and degree of isomorphous replacement in its structure, and number and nature of associated exchangeable cations."

Jan 1, 2015

By Maria Sílvia Camarão de Sousa

Nesse estudo foi fabricada uma matriz hipoeutética de Al-2%Ni e adicionado nela a concentração 1,0 % de nanotubos de carbono de paredes múltiplas (NTCPM). A fabricação do material estudado aconteceu por fundição e resfriamento unidirecional brusco originando grãos predominantemente colunares. Os ensaios mecânicos mostram que concentrações maiores de nanotubo na matriz provocam acréscimo na propriedade mecânica e que em áreas mais distante da base extratora de calor a microdureza aumenta. As curvas de tensão-deformação, para os materiais estudados, evidenciaram que o acréscimo de 1% NTC na liga de Al-2%Ni teve como resultado, uma alta deformação plástica. No entanto, o endurecimento do material não afetou o aumento da resistência à tração.

Aug 17, 2017

By Rustu S. Kalyoncu

A major goal of the Bureau of Mines is to conserve the Nation's mineral resources by developing improved performance materials. In support of this mission, a survey of the state of the art of chemically bonded refractories has been made, covering the scientific literature, government reports, and patents. This review includes research and development results for phosphate, silicate, oxychloride, oxysulfate, and other bonding agents used in refractories manufacture. A significant finding of the review was that references on bonding mechanisms, bond formation kinetics, and other important process parameters and conditions were few and universally vague. As a result, recommendations are made to expand research efforts to investigate the kinetics and mechanisms of reactions in chemically bonded refractories.

Jan 1, 1982

By Benjamin W. Haynes

This research was conducted as part of the U.S. Department of the Interior, Bureau of Mines program to recover metals, glass, and a combustible fraction from municipal solid waste (MSW). The objective of this analytical study was to determine the concentration of antimony, arsenic, and mercury in samples taken from various sampling areas in the Bureau of Mines raw refuse recycling plant and to compare these values with those for coals used in the generation of electricity. To provide the necessary analytical data, sensitive reproducible ashing-chemical digestion-atomic absorption procedures were adapted from published procedures. It was determined that antimony and mercury concentrations in the combustible fraction of MSW are approximately an order of magnitude higher than those found in coals presently used for power generation;' the arsenic concentration is similar in both fuels.

Jan 1, 1978

By Larry A. Haas

The Bureau of Mines is investigating the use of complex gas mixtures, such as would be produced by coal gasification, for reducing iron oxide pellets. A semiempirical model was developed to predict a priori the reduction rate of an iron oxide pellet in a laboratory tube furnace with simulated coal gases at a total pressure of 1 atm. The model uses partial pressures of H2, CO, CO2, CH4 (methane), water vapor, and a temperature-dependent term to predict the rate of reaction. The reduction rate (weight loss per unit of time) was determined with a thermo-gravimetric apparatus (TGA) in the temperature range of 800° to 1,100° C. The ranking of the reductants, in order of decreasing reducing potential, is H2, CO, and CH4 at temperatures between 800° and 1,000° C; however, CH4 became a better reductant than CO at 1,100° C. Water vapor did not decrease the reduction rate as much as did CO2, Carbon deposition was observed at temperatures below 1,000° C with gas mixtures with high CO and low H2 concentrations. With low-Btu gas at 900° C, over 90 pct of the iron oxide was reduced to iron in less than 3 h. This com-pares with a reduction time of 1.5 h with medium-Btu gas and 1 h with reformed natural gases.

Jan 1, 1985

By Davis M. Lapham

Ore bodies at Cornwall, Pennsylvania, have been mined since 1742 principally for iron from magnetite, but also for copper (in chalcopyrite), silver (in chalcopyrite), gold (in chalcopyrite), cobalt (in pyrite), sulfur, and crushed limestone aggregate. Metallization occurs as a limestone replacement above the essentially conformable, south dipping portion of a discordant saucershaped diabase sheet. Pre-Triassic and Triassic faulting have emplaced host Cambrian limestone and two Ordovician(?) hornfels units, now for the most part resting above diabase. Thermal metamorphism of carbonate-bearing country rocks largely to calc-silicates, is ubiquitous. Metasomatism, particularly of potassium, is unique to ore zones. Associated magnetite- actinolite mineralization replaces, in a preferential sequence, all earlier metamorphic and metasomatic minerals and rarely diabase chilled margin. Mineralogical (diopside, actinolite, mica, sulfides, oxides) and chemical (Fe, Cu, S, Co) zoning of the eastern ore body is focused down dip, near its western edge, along a major vertical fault through diabase. This zoning is spatially related to magnetite veins in diabase, to an ore body within diabase, and to a shear zone that probably extends through the sheet.

Jan 1, 1968

By Eduardo Reis de Oliveira

As ligas fundidas de Alumínio são uma excelente opção para substituir os materiais convencionais devido às suas excelentes propriedades mecânicas. Assim, o uso destas ligas nas indústrias aeroespacial e automobilística estão em uso crescente. As propriedades mecânicas finais das peças são muito dependentes da macro e microestrutura, que são resultantes do processo de solidificação. Portanto, o controle dos processos de solidificação de ligas permite maximizar as propriedades mecânicas de um componente mecânico. Os parâmetros de processo que podem interferir na estrutura final de uma liga são amplos. Tem-se como exemplo: composição da liga, taxa de resfriamento, modo de extração de calor, condições de fusão e tratamento do metal líquido e temperaturas envolvidas durante a fundição. O objetivo deste trabalho foi estudar uma liga binária de Al-Mg usando a técnica solidificação unidirecional. As macroestruturas e microestruturas obtidas foram correlacionadas com parâmetros térmicos tais como: velocidade de deslocamento da isoterma liquidus (VL) e taxa de resfriamento (?). E os espaçamentos dendrítico secundários (?2) com a microdureza HV. A composição da liga analisada foi Al-Mg com 3% de Mg e com patamares de superaquecimento (?TV) variando em 20, 40 e 60ºC.

Oct 30, 2017

By Frfas C, Parrilla F, Regife J. M

A project to develop the Zinclor electrowinning cell to industrial size is being conducted at Tecnicas Reunidas' Research and Development Centre with Spanish Ministry of Industry support. This project is the final development phase in zinc electrowinning from a chloride medium, the highest ZINCLOR technology development level prior to the industrial scale having already been reached. This paper covers the outcomes and conclusions corresponding to project Phases 1 and 2: Process Selection and Industrial Electrodes (1 m2) design and testing. The most important achievement reached is that there are presently available industrial cathodes and anodes for the Zinclor diaphragm cell giving an optimum response for zinc chloride electrowinning with unit power consumptions between 2.65 and 2.80 kWh/kg Zn, depending on the diaphragm type. Standard electrolysis conditions were: 65 g/L ZnC12, 3 g/L HCl, 160 g/L NaCl, 350 g/t Zn arabig gum as the addition agent, 36¦C, and 400 A/m2 current density. The selection of electrodes, diaphragms and organic additives for the industrial scale tests have been optimised. The complete electrowinning cell development, with electrodes having an active area of I m2, enables the evaluation of Zinclor Technology application for industrial processes.

Jan 1, 1993