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"Contained in this chapter is a listing of the publications and reference books which have come about as a result of respirable dust research performed by faculty, staff and graduate students in the Generic Mineral Technology Center for Respirable Dust at The Pennsylvania State University, West Virginia University, University of Minnesota, Massachusetts Institute of Technology, and Michigan Technological University. These publications have appeared in scientific journals, proceedings of the national and international symposiums, and professional meetings. Complete citations of the publications can be found in Volumes 3 through 6 and Volume 8 of this series. The agenda of the last annual GMTC seminar, held at West Virginia University on February 1 - 2, 1988, follows. The project presentations are organized under the five research areas. All projects currently active were presented to the Advisory Committee. New project submissions were not. The authors were allotted thirteen (13) minutes for their presentations; the remainder of the twenty (20) minutes allotted for each project was used for introductions, transitions, and questioning by the Advisory Committee. Each author used a standard format for presentation of his/her materials for review; handout materials were distributed to the Advisory Committee for reference. Opening remarks were made by Dr. Richard Bajura of West Virginia University and Dean Robert L. Frantz and Dr. Raja V. Ramani of The Pennsylvania State University.The Generic Mineral Technology Center for Respirable Dust is funded by the U.S. Bureau of Mines through the Mining and Mineral Resources Research Institute Program. The opinions and conclusions expressed in these papers are those of the authors alone and do not represent the opinions of the Generic Mineral Technology"

Aug 31, 1989

By Paul C. Merritt

Samuel Hopkins, an 18th century inventor from Philadelphia, has been little noted nor long remembered by History, but it was he who on July 31, 1790, obtained what no other man can ever achieve -the first patent issued by the Government of the United States. Signed by President George Washington, the patent guaranteed to Hopkins the protection of the American Government for his "improvement, not known or used before, . . . in the making of Potash . . . by a new Apparatus and Process." The patent itself is no longer important, but it serves as a milestone in the development of an industry that is now rapidly moving to fulfill its role as a mineral to feed the world. Potash ranks as one of the oldest products of Man, having been used as a condiment by the habitants of Gaul a thousand years before Athens achieved its Golden Age of culture. By Hopkins' time, the uses of potash had changed considerably, going primarily into glass-making, tanning, soap, and explosives, yet the same sources and techniques of manufacturing potash used during the earlier 2000 years-that is, leaching of plant ashes in iron pots with water, followed by water evaporation and crystallization of the potassium salts-were still being used.

Jan 10, 1966

By W. N. Marchant

The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduced by hydrogen sulfide (H2S) according to the overall reaction 2H2S + HSO3 + H+ ? 3S + 3H20. The rate-limiting step in the process was shown to be the reduction by H2S of thiosulfate (S2031-) that is formed as an intermediate. Pseudo first-order kinetic measurements were made at room temperature to retard the reaction sufficiently that adequate analysis was possible. These measurements showed the rates of the following net processes to be -d [S02]/dt (pH 4.5) = (0.409±0.050)min-1 [S02]; d [S2032-]/dt (pH 4.5) = (0.199±0.017)min-1 [S02]; -d [S2032-]/dt (pH 4.0) = (0.0437±0.0265)min-1 [S2032-]~1; -dH2S/dt (pH 3.9) = (21.6±3.0) mmoles/min-atm [H2S]g1.4, where [H2S]g is the partial pressure of H2S in the gas phase, in atmospheres, and the rate describes the consumption of H2S, in millimoles per minute; d[S]/dt (pH 4.0) = (38.0±3.4)min-1 [H2S]1, where [H2S] is the concentration of H2S in solution. Hydrogen ion consumption during the slow phase of regeneration was shown to occur at (2.1±0.5) times he rate of thiosulfate consumption, which is interpreted as evidence for the following as the rate-limiting reaction: 2H2S + S2032- + 2H+ ? 4S + 3H20 A scheme consisting of five sequential general reactions is proposed to account for sulfur formation.

Jan 1, 1981

By A. J. Kraemer

This report on the physical and chemical properties of crude oils of California is one of a series on the producing districts of the United States. It includes a short discussion of results, tabulated data, and individual analyses of California crudes. Analyses of crude oils from the fields of Fresno, Kern, Los Angeles, Orange, and Ventura Counties have been published in Serials 25952 and 26083. The analyses reported in this paper corer samples that were obtained subsequent to the publication of Serials 2535 and 2608. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting of samples was facilitated by the courtesy of representatives of oil companies in California.

Jan 1, 1927

By Richard L. Sanford

The generalized rail haulage simulator described in this paper is an outgrowth of the need to expand a previously developed single level simulator to permit analysis of production problems where intermediate car storage is used. Many of the ideas of the former single level simulator, which is an integral part of an Underground Generalized Materials Handling Simulator (UGMHS), have been used in model development. In addition, experience gained in applying the earlier model to a variety of operating conditions has been heavily relied on. The generalized rail haulage simulation model can operate as an independent system and, as such, can be used to analyze rail haulage systems using production distributions as data input. In addition, this model is designed to replace the present rail haulage sub-assembly in the UGMHS model and the linking procedure has been integrated into the model. The flow of coal from production sections in UGMHS, for example, fill the mine cars and a condition of no empty cars at a loading station will shut down in by production systems.

Jan 1, 1974

By M. K. Alam

Chemical Vapor Deposition (CVD) processes are currently attracting special attention in materials processing. CVD processes are now used to produce special materials in the form of thin films, coatings, composites, and optical fibers. This process produces material of high purity, in complex shapes, and in a variety of microstructures. It is a capital intensive process, involving use of high cost raw materials. Modeling simulations have the potential of reducing the time for CVD . process design, and the need for experimentation. Modeling would, therefore, appear to be an attractive option for producing a product of acceptable quality. At Ohio University, progress has been made in modeling of CVD processes, specially in the areas of optical fiber preform fabrication, and fiber coating.

Jan 1, 1990

By D. V. J. W. Groenewald, T. M. Louw, L. Auret, S. M. Bradshaw, A. V. Cherkaev

Unexpected equipment failures lead to financial losses due to production disruption. Time-based maintenance, based on checks over regular time periods, has been employed to minimise disruption. However, the improvements it can offer are limited as it may lead to unnecessary service of healthy equipment or missed failures occurring between service intervals. Condition-based maintenance (CBM) provides a further improvement to equipment reliability by detecting faults and predicting remaining useful life (RUL) based on equipment health monitoring. Its application in the mineral processing industry is hindered due to the high cost of health monitoring equipment. In this study, two stochastic process models, the adaptive auto-regressive model and the gamma process, are compared in their ability to forecast the degradation state and to provide RUL prediction. The gamma process model was found to be effective in both tasks. Due to its simplicity and minimum hyperparameters requirements, it is proposed to use the gamma process as a baseline for comparison with other models. Keywords: Condition-based maintenance, remaining useful life, slurry pump, adaptive autoregressive mode, gamma process

Jan 1, 2020

By Robert Howard

With the rapid depletion of the Peerless Coal Co.'s mine in Spring Canyon, it was necessary, if the company was to remain in the coal-producing business, to look to the development of a new property or to acquire a mine already developed. After careful investigation of several operating properties it was decided by the officials of the company to take over the lease on an undeveloped acreage held by a private party in Price Canyon, about 3 miles north of Castle Gate, Utah.

Jan 1, 1930

By Willard J. Tesch

The borehole surveying system described is used to measure ground movement over and near operating mines. The magnitude of any movement is con-trolled by the ground conditions, the mining method, and the mine progress. By correlating these factors with the measured movement, equations can be determined for predicting the effect of mine progress on the surrounding ground. These equations can also be used to predict the effect of mining a similar deposit with similar ground conditions. The borehole surveying system is used in cased boreholes to measure the inclination of the hole in two perpendicular planes. Grooved casing with an inside diameter of 3 inches is grouted in the hole. Two probes are used to obtain the data necessary to calculate the hole position versus depth. One of the probes contains a gyroscope, and the other contains a biaxial force-balance [s]ervoaccelerometer. Readings from the transducers in the probe are punched on paper tape by an automatic data acquisition system as the probe is pulled up the hole at 30 feet per minute by an electric winch. Readings from the inclinometer probe containing the accelerometer are used as input data to an on-line programmable calculator as they are punched on tape. The calculator computes preliminary results of the survey being made. The paper tapes obtained during the survey runs are later used as input to a computer that computes the offsets of the drill hole versus depth in true north-south and east-west planes. These offsets are printed for each foot of depth. Changes in these offsets between the first survey and subsequent surveys are a measure of the horizontal ground movement between the surveys.

Jan 1, 1976

By Greg Nutson, Jeremy Butkovich, Bill Perkins, Hollie Ellis, Paul Bott

"Dynamic soil-structure interaction (DSSI) analyses are becoming more common in bridge designs, especially in seismically active areas. Because of its proximity to two active fault zones, the Evergreen Point west approach bridge replacement will be base isolated, and will be designed using DSSI. The project team completed two independent bridge designs to satisfy peer review requirements. The designs required substantial characterization of the soil dynamic behavior using both laboratory and in-situ testing. The analyses made use of earthquake time histories spectrally matched to conditional mean spectra. This led to reduced, and more realistic seismic demands on the structure, compared to conventional uniform hazard spectrum matching. The bridge analyses suggest that the preliminary bridge design is relatively conservative. This will allow the design team to potentially reduce shaft/column diameters and reinforcement. The design team estimates that the dynamic analysis design could represent a net savings of around $60 to $90 million compared to a conventional design.INTRODUCTIONThe Evergreen Point Bridge conveys State Route (SR) 520 2.6 miles (4.2 kilometers [km]) from Seattle to Medina across Lake Washington. The bridge is located in a seismically active area, and the Washington State Department of Transportation (WSDOT) has determined that the western half of the 1960s-era bridge (the “west approach”) is vulnerable to earthquake damage. WSDOT has begun preliminary design to replace the west approach bridge.The west approach extends about 6,100 feet (1,900 meters [m]) east from Seattle’s Montlake neighborhood, over Union Bay and Foster Island, then into Lake Washington proper (Figure 1). Approximately 5,600 feet (1,700 m) of the replacement bridge would be constructed over water. Subsurface conditions along the bridge alignment consist of 5 to 80 feet (2 to 24 m) of very soft peat and clay, over very dense/hard sand and clay. Multiple pile supported columns support the existing bridge. The new bridge would be supported by 8- to 10- foot-diameter (2.4 to 3.0 m) drilled shafts that extend about 50 feet (15 m) into the underlying very dense/hard soil. To reduce seismic demands on the bridge superstructure, WSDOT has decided to incorporate a base-isolation system into the bridge design."

Jan 1, 2017

It is widely accepted that particles stabilise flotation froths and that stable froths result in improved flotation performance. Predicting the effect of particle addition on froth stability is, however, challenging. Dynamic surface tension measurement using maximum bubble pressure presents an attractive technique to investigate the effect of surfactant and particles at the air-water interface. The range of bubble lifetimes that can be studied (typically 0.1 to 60 s) is analogous to variations in air rate in flotation cells, and the corresponding changes in surface tension give an indication to the diffusion and adsorption rates of particles at the interface. In this paper, we use dynamic surface tension measurements to investigate the effect of particles on bubble surfaces at the microscale and link this to bulk froth stability measurements carried out using a froth column. Using the maximum bubble pressure method, the results show that the addition of particles results in lower surface tension, both at the dynamic (i.e. short) bubble lifetimes and towards equilibrium (i.e. 60 s bubble lifetime). This corresponds with the bulk froth stability measurements, where the three-phase system yielded more stable froths than the surfactant only system. Furthermore, increased particle loading at the air-water interface, whether through higher surfactant concentrations or lower air rates (longer bubble lifetimes), gave lower surface tension and higher froth stability. This demonstrates the link between bubble loading and froth stability. It is proposed that the maximum bubble pressure technique can be used to predict froth stability for two- and three-phase systems, enabling the effect of particle loading to be accounted for and quantified. Moreover, the technique has the potential to allow rapid determination of particle and surfactant diffusion at the air-water interface and prediction of the corresponding effect on bulk froth behaviour.

By Warren D. Longwill

The Bureau of Mines inventoried Federal lands in the State of Oregon and classified them in detail, section by section, according to their availability for mineral exploration and development as affected by legal status and agency management practices. The Bureau determined areas of the State having past mineral production and/or known metallic mineral resources and areas favorable for coal, oil, gas, and geothermal resources, and prepared maps that spatially compare the availability of Federal mineral land with these mineral areas to demonstrate the extent of restrictions to mineral entry. Oregon contains 62.1 million acres, of which 33.9 million acres or 55% is Federal mineral land. About 2.3 million acres of Federal land is favorable for selected metallic mineral deposits, of which 64% is available, 13% is restricted, and 23% is unavailable. Of the 21.1 million acres of Federal leasable land favorable for oil and gas, 68% is available, 11 % is restricted, and 21 % is unavailable. Of the 146,720 acres favorable for coal, approximately 71% is available, 13% is restricted, and 16% is unavailable. Federal leasable land favorable for geothermal resources amounts to 458,968 acres, of which 42% is available, 34% is restricted, and 24% is unavailable.

Jan 1, 1988

By J. B. Hedrick

Rare earths were not mined in the United States in 2008. However, processing of intermediate rare-earth concentrates continued throughout the year at the Mountain Pass Mine in California. Consumption of refined rare-earth products increased. U.S. rare earth imports were primarily from China, with lesser amounts, in decreasing order, from France, Hong Kong, Japan, Austria and Russia. The United States imported 100 percent of its supply of yttrium metal and compounds primarily from China. United States In 2008, lanthanide concentrates were processed by Chevron Mining Inc. (previously Molycorp Inc.) at its mine site at Mountain Pass, CA. Chevron Mining sold its entire holdings in the rare earths mine to Molycorp Minerals LLC in September and operations continued at the site through-out 2008. Major uses for these mineral commodities were in automotive catalytic converters, petroleum fl uid-cracking catalysts, permanent magnets, glass-polishing compounds, ceramics, metal-alloying additives, phosphors and recharge-able batteries. Three domestic companies produced and sold lanthanide intermediate concentrates and refined products. Chevron Mining sold its interests in the Mountain Pass Mine to Molycorp Minerals LLC on Sept. 30, 2008. Molycorp Minerals LLC is an investment company owned by Resource Capital Fund IV L.P., Pegasus Partners IV, LP, The Goldman Sachs Group Inc., Traxys North America LLC, Carint Group LLC and Mark Smith. The Molycorp operation previously mined the rare earth fluocarbonate mineral bastnäsite by hard-rock surface methods, and the mine remained on care and maintenance in 2008. Molycorp maintained significant stocks of bastnäsite concentrates, intermediate concentrates and high-purity rare earth compounds at its operations at Mountain Pass. In October 2007, Chevron Minerals completed phase one of its three-stage plan and restarted the rare earth separation plant at Mountain Pass. The company also processed intermediate rare earth concentrates from existing stocks during the first three quarters of 2008. Molycorp Minerals LLC maintained production in the last quarter of the year. The mine at Mountain Pass has been closed since 1998. Future plans are to restart processing of stockpiled bastnäsite concentrates followed by reopening of the mine.

Jan 1, 2009

By Mateus Sotelo Menezes

Uma ferramenta de trefilação deve suportar as altas tensões a que fica submetida durante o processo sem apresentar deformações. Para isso, o projeto da fieira deve iniciar com a escolha correta do material de fabricação e um dimensionamento adequado. Tais fatores podem minimizar a ocorrência de falhas, tanto na fieira, quanto no produto trefilado, assim como diminuir as tensões e desgaste na ferramenta. Portanto, este estudo visa analisar as regiões de uma ferramenta de trefilação industrial que estão sujeitas as maiores amplitudes de tensões ao longo de um processo de trefilação. O método de elementos finitos foi utilizado para simular a trefilação de uma barra de aço utilizando uma ferramenta de carbeto de tungstênio. O perfil da fieira foi inserido no software e então analisado em diferentes etapas ao longo do processo de trefilação e após o seu término. Observou-se a ocorrência de tensões compressivas superiores a 600 MPa na região de trabalho e as maiores tensões trativas foram visualizadas na região de saída, com valores próximos a 200 MPa. A presença de tensões residuais não foi registrada na fieira, como esperado.

Aug 17, 2017

By Anderson Azevedo Agra

A geração de resíduos siderúrgicos é um problema que abrange dois cenários: o ambiental, no que diz respeito ao descarte de resíduos no meio ambiente e também tange o econômico, pois trata-se de material não reaproveitado que deve ser destinado a aterros industriais, gerando custos. Tendo isto em vista, a reciclagem desses possíveis coprodutos para a reutilização como matéria-prima do processo torna-se uma alternativa pertinente. Uma das formas de recuperação do pó de aciaria elétrica (PAE), resíduo abordado neste trabalho, é através da pelotização. Para o reaproveitamento de metais de interesse do pó foi utilizado um agente redutor, o coque de petróleo. No entanto, para formação das pelotas um aglomerante se faz necessário. Este, em associação com as partículas do óxido, tem como objetivo conferir resistência mecânica adequada às solicitações que o processo de fabricação do aço exige. Neste trabalho, são feitas considerações acerca do uso de seis composições diferentes de aglomerantes com o objetivo de avaliar o desempenho destes, através de ensaios de resistência a compressão, testes de queda e tamboramento. Como resultado, pode-se verificar o melhor desempenho da combinação da cal com cinza de casca de arroz.

Aug 16, 2017

By Victor Zavodinsky, Sergey Rogov

"Pseudo-potential fully relaxed total energy calculations are used to predict a hypothetical Si1-xCxO2 (x<0.5) compound formed from SiO2 ß -cristobalite by substitution of some SiO2 complexes by CO2 molecules. The simulation shows that the Si1-xCxO2 compound can be quasi stable if the CO2 content is less than fifty per cent. It is assumed that six-molecule Si6-nCnO12 (n=3) rings can play a role of nucleuses for formation of the Si1-xCxO2 compound from SiO2 and CO2 molecules. Thus, silicon dioxide can be considered as a possible solid store for gaseous CO2.IntroductionThe problem of increasing of CO2 in the Earth atmosphere is one of the main modern problems of mankind. One of conceivable ways to decrease the harmful value of CO2 is to convert a part of it to solid state. Iota et al. [1] reported a polymeric (quartz-like) phase of CO2 solid synthesized at high pressure (~40 GPa) and at high temperature (~1800 K). Shortly after this experimental work, Serra et al. [2] reported a total energy calculation of several possible phases of CO2 using plane wave pseudo-potential density functional theory. They concluded that there should be a transition from a molecular phase to a phase isostructural to SiO2 -quartz in the range of 35 to 60 GPa. The latest calculations by Dong et al. [3] have shown that the more favored solid CO2 phase is ß -cristobalite. Recently, Kume et al. [4] have demonstrated the polymerization of CO2 even at room temperature at high pressures up to 80 GPa. Transformations of gaseous CO2 to different solid phases were studied recently experimentally and theoretically [5-8]. The main obstacle for using synthesized CO2 solid as a solution for the CO2 problem is its pressure instability. However the SiO2 ß -cristobalite with the same structure is stable.The question is whether a silicon-oxide system in which a part of atoms of silicon is replaced by atoms of carbon will be stable? If the answer is positive, this system can be considered, in our opinion, as a possible store for CO2."

Jan 1, 2009

By J. Arango Gonzales, J. Vela Portilla

Este estudio se basa en un probable nuevo descubrimiento de un yacimiento de Au, en las rocas del volcánico Llallahui (Grupo Tacaza – Terciario Medio a Superior), que podría estar ligado a la ocurrencia de yacimientos epitermales de Au del sur del Perú. Se trata de un yacimiento epitermal de baja sulfuración, emplazado en autobrechas y tobas donde mediente los análisis químicos de los muestreos realizados se dete rminó valores de leyes en Au 0,10g/TM a 0,81g/TM, estimandose recursos inferidos de 70MT @0,10-0,80 g/t de Au, lo cual convierten en un prospecto de gran potencial.

Sep 1, 2017

By Roy J. M. van Lier

In industrial aqueous solutions, germanium generally occurs in trace amounts amid high concentrations of other metals, such as zinc, copper and iron. Separation of germanium from these metals as well as its isolation from gallium and indium pose a real challenge to the hydrometallurgist. After a brief discussion of the aqueous chemistry of germanium, this paper reviews the flowsheet of the Apex Mine in Utah. The Apex property was the only mine in the world to be operated primarily for production of gallium and germanium, but apparently closed due to great operating difficulties. Several process variants proposed for the treatment of the Apex ore, including bioleaching methods, are addressed. Following a more general description of the behavior of germanium in hydrometallurgical zinc processing streams, available technology for its recovery from aqueous solutions is summarized. Precipitation, solvent extraction, ion exchange, electrowinning, ion flotation and liquid-membrane separation are all outlined in terms of the aqueous chemistry of germanium. Finally, the production of high purity germanium dioxide and metal is briefly discussed

Jan 1, 1995

By Daniel de Carvalho Silva

O presente trabalho estuda a evolução microestrutural e mecânica ao longo do processo de produção de um aço baixo carbono com micro adição de molibdênio, destinado a produção de chapas de aço dual phase galvanizadas. Para realização do estudo foi feita a caracterização microestrutural e mecânica ao longo do processo produtivo de amostras (placa, chapa laminada a quente, chapa laminada a frio “full hard”, e galvanizada) deste aço via microscopia ótica e eletrônica de varredura das amostras, avaliação da dureza via microdurômetro, do comportamento mecânico via ensaio de tração, este último somente nas amostras de chapa laminada a quente e galvanizada. Os resultados obtidos revelaram um aumento significativo na resistência mecânica do material conjugada uma alta ductilidade, devido principalmente ao refino de grão e a formação de dispersão de martensita.

Aug 17, 2017

By J. E. Udd, S. Bharti

"ABSTRACTMonitoring of stability conditions in underground mines permits management to assess the response of the rock mass to mining strategies. Monitoring of movements, if sufficiently early, may also permit operators either to avert potential failures or to develop alternative approaches to extraction.The Falconbridge organization has been a leader both in the uses of rock mass stability monitoring techniques and in the development of instrumentation.In this paper, the authors review the Falconbridge approaches to monitoring, and present case history examples to illustrate the application of the various instruments used.RESUMELa surveillance des conditions de stabilité dans les mines souter-raines permet aux chefs d&apos;enterprises d&apos;évaluer les réactions de la masse rocheuse aux méthodes d&apos;extraction minière. Si le contrôle des mouvements du terrain est effectué assez tot, l&apos;exploitant pourra prendre les mesures qui s&apos;imposent, soit pour éviter les détériorations possibles ou pour mettre au point de nouvelles méthodes d&apos;extraction.Le groupe de la Falconbridge a ére le premier a utiliser des techniques de vérification des conditions de stabilité de la masse rocheuse et a mettre au point l&apos;appareillage requis.Ce document présente une revue des méthodes employées par la Falconbridge pour assurer la surveillance active de la stabilité de la masse rocheuse et illustre au moyen de cas concrets la manière d&apos;utiliser les divers appareils."

Jan 1, 1987