Search Documents

By John O. Atkins

[Experiments were conducted by the Bureau of Mines on five types of simuated lunar rock (dacite, tholeiitic basalt, vesicular basalt, pumice, and uluth Gabbro) to study the effects of various simulated lunar environments n their strength and deformational properties. Specimens were tested in an ltrahigh vacuum (UHV) system at pressures ranging from atmospheric down to 0-11 torr and at temperatures of -130°, 20°, and 135° C. All tests were onducted with a servocontrolled testing machine. Rock specimens tested at 0° C in UHV exhibited significantly higher compressive strength and Young's odulus than those tested at 20° C in atmospheric pressure. The magnitudes f increase are related to the porosities and permeabilities of the rock pecimens; high porosity and permeability allow better outgassing and thus nprove surface cleanliness in UHV. The compressive strength generally ncreases but Young's modulus decreases as test environments change from 20° C i UHV to 135° C in UHV. No significant difference was observed in the iysical properties measured at 20° C in LTV and -130° C in UHV. Anisotropy i strength and Young's modulus exist both in UHV and at atmospheric condi¬'.ons with the same symmetry pattern. The orientations of the principal axes iy, however, change from the atmospheric to UHV condition. The results idicate that rock fragmentation in lunar environment will require more ergy than that at 20° C in atomospheric pressure.]

Jan 1, 1974

By G W. Swana

Elastoplastic parameter is a parameter that describe how much materials behave elastically up to certain stress states and plastically thereafter (Hudson and Harrison, 1997). In the continuum analysis, two main parameters of the elastoplastic parameter are modulus elasticity and Poisson’s ratio. In the slope, elastoplastic parameter holds the main role for stability related to deformation in ductile type of rock. There’s a limitation to determine elastic or plastic deformation at the field for ductile rock type. Field manifestation commonly showed that there was no accumulation zone during and after the sliding failure mechanism, in other hand, at the research area, manifestation of deformation at the toe of slope only indicated by bulging shape. This paper will focus at the sliding failure occurred at Coal mining Pit Y owned by Arutmin Indonesia, which according to failure investigation report similar with the condition described above. This paper also will be based on two hypotheses, first hypothesis is claystone rock mass has not been reached plastic deformation yet and the second hypothesis is there is a chance that elastoplastic parameter of the rock mass has been changed during the deformation/sliding failure process. Research method of this paper are back analysis using probabilistic analysis in Finite Element Method (FEM), which conducted before and after failure. Then, the result of the displacement or deformation of the analysis will be checked with the actual deformation shape. Meanwhile, the change of the elastoplastic parameter will be analysed and interpreted. This paper hopefully able to be developed to study about elastoplastic behaviour of rock mass in actual condition and the influence of another uncertainty factor which determine the slope stability.

Nov 29, 2022

[Aalde, Kaare, ('40) New Mexico School of Mines, Socorro, N. M. Abadesco, Enrique A., ('39) Univ. of the Philippines, Manila, P. I. Abdul-Ahad, A., ('39) Montana School of Mines, Residence Hall, Butte, Mont. Abreu, Ovidio M., ('38) Univ. of Nevada, Reno, Nev. Acker, Voscoe, . ('39) Agricultural & Mech. College of Texas, College Station, Tex. Acosta S., Gonzalo, ('40) Univ. of Texas, Univ. Sta., Box 1785, Austin, Tex. Adams, Albert, ('38) New Mexico School of Mines, Socorro, N. M. Adams, Charles W.,' ('39) Michigan College of Min. & Tech., Houghton, Mich. Adams, Hugh T., Jr., ('39) Univ. of Oklahoma, Norman, Okla. Adams, Jack L., ('39) Univ. of Oklahoma, Norman Okla.]

Jan 1, 1940

By B. E. Davis

Over 80 pct of domestic phosphate rock, which is the starting material for phosphorus-containing fertilizers, comes from central Florida deposits. As K-her grade deposits are depleted, lower grade phosphate ores containing 'Mg0 in the form of dolomite are encountered. Treating high MgO ores with present beneficiation technology will not yield a concentrate meeting specifications for acidulation. The Bureau of Mines conducted research on three high-MgO phosphate samples from south Florida. The sales contained, in percent, 5.4 to 10.2 P205, 1.9 to 7.6 MgO, and 35.3 to 60.1 acid insolubles. A technique of sizing, grinding, desliming, scrubbing, and redesliming was used to produce a feed suitable for continuous flotation studies, A conventional fatty acid-fuel oil rougher flotation followed by two to three cleaner stages resulted in concentrates containing, in percent, 30.7 to 31.3 P205, 0.6 to 1.3 MgO, and 2.5 to 4.8 acid insolubles. The P205 recovery from the flotation feed ranged from 55.1 to 89.7 pct.

Jan 1, 1984

By J. A. González-Anaya

This laboratory work presents a study of the effect of ultrafine grinding on the gold recovery of a highly refractory gold concentrate. The particle size of the concentrate was P80 = 46 µm and the main species present were quartz (28.58%), dolomite (25.63%), pyrite (20.93%), arsenopyrite (15.39%) and 112 g/t gold. After optimizing hydrated lime and lead nitrate additions, standard cyanidation with 1% NaCN, pH = 12.3, 25% S/L permits to recover only 9.4% of the gold. Different particle sizes were submitted to cyanidation. When the concentrate was ground to ultrafine sizes (P80= 4.6 µm), the gold recovery for the same cyanidation conditions increased to 67%, with cyanide consumption of 66.7 kg NaCN/t. Additional tests were performed in order to reduce the cyanide consumption. The reduction of the cyanide concentration in the leaching solution from 1 to 0.5% and the addition of 100 g Pb(NO3)2/t allowed the reduction of the cyanide consumption to 27.6 kg NaCN/t (58% reduction), while maintaining the same gold recovery of 67%. The remaining gold could be present as very fine inclusions or in solid solution in the matrix.

Jan 1, 2011

By S. Flewelling, M. Scobie, G. R. Baiden

"SynopsisA feasibility study to develop a research program, the Mine Automation Plan (MAP), was recently completed. This was undertaken by a team comprised of Inco Ltd., Falconbridge Limited, the Canadian Centre for Automation and Robotics in Mining (CCARM) and the Centre for Resource Studies (CRS). The study was sponsored by PRECARN Associates, which is a consortium of thirty-six Canadian companies focussed on research and development in artificial intelligence and robotics. PRECARN Associates was formed in 1987 when a number of research proposals were funded in the fields of process control systems, robotics systems and intelligent engineering systems. In July 1991, PRECARN accepted the next round of proposals for research. The MAP project was one of the successful proposals, being awarded $100,000 for the development of a feasibility study defining a long-term R&D plan for underground hardrock mining automation.The development of the feasibility study started by addressing the fundamental structure of the mining process, and its relationship to the metallurgical process, over-all infrastructure support and management systems (Fig. I).Mining may be considered as comprising five subprocesses: (I) delineation; (2) development; (3) production; (4) backfilling; and (5) infrastructure support services. Within these subprocesses many applications for artificial intelligence and robotics exist. The mining process is dependent upon the interaction between the physical mining process and information. For example, the delineation process is dependent on geomechanical, geochemical and geophysical techniques to develop a model of the orebody based upon access to such data. This same relationship between the physical and information models holds true through the development, production, backfill and infrastructure support systems.The foundation for the MAP study has been the recent development by Inco Ltd. of an underground communications system (Fig. 2). The system has the ability to supply high bandwidth communications, over voice, data and video to mobile and stationary locations within the mining operation. It is seen to be the future backbone of a comprehensive, automated information system which should permit the application of the concept of Computer Integrated Manufacturing (CIM) to underground mining. CIM, through the automated flow of information, has been successful in integrating the engineering, production and various support groups in manufacturing."

Jan 1, 1994

By E. C. Wright

FOR many years the cost of making pig iron and steel in the Birmingham district has been about the lowest in the United States. The close proximity of the important raw materials such as coal, iron ore, limestone, and the large available scrap supply made it possible to assemble all of the important ingredients necessary for steel- making with only nominal costs for transportation. Both iron ore and coal were being mined in this district at one time for about $1 per ton from underground operations. At that time mining wages were low everywhere and the labor rate in the South was considerably below that of other mining districts. This situation persisted until the emergence of labor unions as an economic and political force, emigation of southern labor to northern plants, and continued growth of industry in the South in the years following the depression of 1932. Since that time union organizing of miners and steel workers throughout the nation has increased labor costs in mining and steelmaking. This influence has been felt particularly in underground mining operations since the proportion of labor cost to total cost is still high. The previous advantage in basic labor rate in the South has been almost entirely eliminated by the equalization of labor rates in basic industries by national unions. Since 1945 these influences have been especially noticeable in increasing the cost of mining coal and iron ore in the South. The northern steel districts are still being largely supplied with iron ore from the Minnesota open-pit mines and the cost of this ore has not increased nearly as much as the cost of ore obtained from underground mines in Birmingham. A similar situation exists in coal mining; the thinner seams in Alabama are not so amenable to mechanization as the northern mines and, as a result, the output per man-day in southern mines is only about three tons of coal as compared to five or six tons per man-day in the large captive mines of West Vir-

Jan 1, 1950

By W Patton, I Minniakhmetov, H Talebi, U Mueller

The sustainability of mining projects is linked to informed investment decisions based on public reporting of exploration and mineral resource estimation results. In Australia, public reporting guidelines are established by the Joint Ore Reserves Committee reporting code through the JORC Code (2012). Although the assessment of uncertainty in the results reported is a requirement, this is often communicated qualitatively and evaluated subjectively. This can become a liability particularly in the early stages of mining projects when spatial domains of geological interpretation and mineralisation envelopes inform resource estimations’ reliability. A recent review of JORC reports found no reports used quantitative assessments of the geological interpretation or mineral resource estimation envelopes, and 27 per cent of reports did not address the question of quality of geological interpretation. Reports that did address the quality used 19 different terms to communicate quality. This work presents methodologies for quantitative uncertainty assessment and communication and explores how they could be applied in public reporting practice. Quantitative uncertainty reporting would benefit mine planning and financial modelling as they normally assume the geology is 100 per cent right (since no error is reported or only a single deterministic model is provided). The complexity, cost, and additional work of doing a quantitative assessment could hinder a straightforward implementation. This could be overcome if mining companies budget for quantitative uncertainty assessment and associated professional development. A compulsory requirement for the inclusion of uncertainty assessments in public reporting or adopting standardised subjective language would improve industry practice.

Mar 22, 2022

By A. E. M. Warner

Inco Limited has long and extensive experience in converting nickel-copper primary smelting mattes over a broad range of nickel/copper weight ratios and combined nickel-copper-cobalt contents. At the Copper Cliff Smelter, the composition of the converter product matte has to meet the requirements of the matte separation process; at the Thompson Smelter, converter matte of a different composition is cast into anodes for nickel electrorefining; and in Soroako, Indonesia, a very low copper product matte is granulated for the Japanese market. Recently, Inco has conducted pilot plant testing of three possible nickel-copper matte continuous converting routes, namely flash converting, oxygen top blowing-nitrogen bottom stirring, and tuyere blowing. This test work has generated substantial new information on nickel-copper matte converting chemistry. This overview paper reviews the metallurgy of nickel-copper matte converting, in particular the behaviour of cobalt and the operating conditions required to meet the iron and sulfur specifications of the product matte. The relevant thermodynamic information is used to discuss the industrial data.

Jan 1, 2003

By J. Seiter, S. Cox, E. Kim

Mining has always been among the most hazardous of occupations, and with the increasing demand for coal and minerals, safety in mines assumes even greater importance. Worldwide, underground miners are being exposed to noise and respirable dust hazards associated with roof bolt drilling. These hazards are now being understood to cause irreparable damage to the health of miners. The objective of this research was to discover if a polycrystalline diamond compact (PDC) drill bit generates less respirable dust and hazardous noise than a competing tungsten carbide (WC) bit in dry vacuum drilling. In order to control the drill parameters the drilling tests were conducted in a laboratory setting. The results were obtained by determining the quantities of dust and noise generated using each drill bit and analyzing those levels, using monitoring devices and software to collect the data. This paper includes information on the experimental setup, equipment used, drilling parameters, and data collected. Our results indicate that PDC bits produce significantly less noise and dust than WC bits. Our findings can contribute to improving the working conditions of rock bolter operators by reducing noise and dust generation.

Jan 1, 2014

By Juliana Satie Watai

Foi estudado o efeito do método de incorporação de pó de serra em PP/EPDM/talco, nas propriedades mecânicas e térmicas do compósito final. Os três métodos de incorporação foram: pré-mistura, por tamboreamento, de todos os componentes com injeção subsequente; alimentação em separado da fibra, da matriz polimérica e compatibilizante em extrusora dupla rosca co-rotacional, com injeção subsequente; pré-mistura, por tamboreamento, de todos os componentes, alimentação conjunta em extrusora dupla rosca co-rotacional, com injeção subsequente. A adição de fibras conferiu maiores valores de temperatura de deflexão ao calor (HDT), resistências à tração e à flexão, módulo de Young e menores resistência ao impacto e deformação em relação à matriz. Para o mesmo teor de fibras, o método de alimentação conjunta apresentou os maiores valores de resistência à tração e flexão, módulo de Young, e HDT, e maior queda na resistência ao impacto. O método com dois alimentadores apresentou maior deformação e maior resistência ao impacto. Análise termogravimétrica revelou menor teor de fibra incorporado, para o método com dois alimentadores em relação aos outros métodos. A análise de micrografias obtidas por MEV não revelou diferenças significativas na adesão entre fibra e matriz, quanto ao método de incorporação.

Aug 8, 2018

By O. Kökkilic

This study covers the tests to develop separation process for production of clay and colemanite rich concentrates, and aims to serve the clay and colemanite concentrates extracted from the tailing dams to the industrial applications. For this purpose, samples from the tailing dams in Kestelek Boron Plant (Turkey) with an average B2O3 content of 8%~11 % were subjected to the investigations. The separation process of hydrocyclone--to make clear the way to obtain either clean clay or cole-manite--was initially discussed. Therefore, following the gentle scrubbing (to keep the bimodal size distribution between clay and colemanite) of the tailings to disperse the slurry, two alternative multistage hydrocyclone processes; allowing to recycling the overflows or underflows to concentrate clay and colemanite were respectively tested. As a result of the preliminary tests, the multistage hydrocyclone separation in direction to the clean colemanite concentrates (recycling the underflows) gave the better separation efficiencies. So, all the parameters such as apex and vortex finder diameters and feeding pressures were examined with the multistage hydrocyclone process allowing the recycling the underflows. The detailed multistage hydrocyclone separation process of the tailing dam wastes yielded with colemanite concentrates (approx. 12 % of the feed, w/w) with B2O3 content of 35.0 % and the clay concentrates (approx. 42 % of the feed, w/w) with B2O3 content of 2.1 %. Colemanite concentrates were found good enough either to re-feed in to the separation process or to keep upgrading for final product ready to use in Industry whereas the attempts on production of light bricks from clay concentrates has failed. But it is worth to point out that these clay concentrates can be used for agricultural purposes just in the form as it is.

Jan 1, 2014

By William A. Beck

"INTRODUCTION Mica is found in Georgia from the Fall Line in the central part of the State to the Valley and Ridge Province in the northwest. During the past 3 years, Georgia has been one of the chief producers of dielectric mica in the United States. Since January 1945, when prices were reduced, mining has decreased until practically no sheet mica is being recovered at present.The main mica-bearing regions in the State may be classified into three districts: The Thomaston district comprising Upson, Lamar, and Monroe Counties; the Ball Ground district, comprising Cherokee and Pickens Counties; and the Hartwell district, comprising Hart and Elbert Counties. There are numerous mines and prospects in all of these districts. All have been visited from time to time by engineers of the Bureau of Mines and by members of the Federal Geological Survey. The Federal Survey has made detailed maps and reports on all of the most important ones.This report will deal with five of these properties on which the Bureau of Mines has diamond-drilled.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Division, I. B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, O. C. Ralston, chief, analyzes samples and makes beneficiation tests."

Apr 1, 1948

Esso-BHP have installed a Production Supervisory Control System that is presently controlling the offshore oil and gas facilities on the Barracouta and Marlin platforms from an onshore master station. This control is achieved with a computerized master station onshore which uses a UHF radio system for telemetry and control. The system is designed to control, monitor, and gather data from a large number of oil and gas production platforms and has flexability to handle future variations in operating conditions. Thn -etom ..ill kn nvt,,ndnd to thn I-lalihn+ rJ,+f, rr , Into +hie -- -A +n the lei...,fieh .,lo+fnrmc A.,;- 1071

Jan 1, 1970

By Raúl Daniel López

Ternium-Siderar steelmaking has been focused in permanent improvements and process optimization. At present the Slab Continuous Caster N°1 has been totally transformed after 20 years of uninterrupted work. The authors of this paper summarize and comment on aspects which were the main changes and place emphasis largely on those technological developments in which they have been active during that period. Productivity and quality have been our goals during the last 20 years; it has led us to improve process and to achieve better control tools. In the development of this presentation, the authors will put special emphasis on the explanation of those works that were made following their own experiences through the technical personnel who belong to the staff of the company.

Jul 30, 2018

By P. Nos, L. Kolbeinsen, M. W. Kennedy, A. Filzwieser, R. T. Jones, A. MacRae

Modern furnace designs often incorporate extensive use of cooled elements to achieve long campaign lives at high operating intensities. However, contact between water and high temperature fluids can result in powerful Boiling Liquid Expanding Vapour Explosions (BLEVEs). Therefore cooling such elements with water carries inherent risks when used under slag and particularly below molten metal or matte. Alternative cooling media exist that can reduce or eliminate the risk of BLEVEs. These media are analysed and discussed in the context of deeply cooled furnace elements. Important factors in selecting alternative coolants are explored including: critical heat flux, thermal limits, toxicity, flammability, unit cost, etc. Key cooling system design criteria are reviewed in the context of both traditional and alternative coolants. Results of Computational Fluid Dynamics are presented for an example tap-block cooler design using a number of selected coolants. Research needs to advance the safe use of alternative coolants are presented.

Jan 1, 2015

By Franklin B. Woodbury

As part of its goal of helping maintain an adequate supply of minerals to meet national economic and strategic needs, the U.S. Department of the Interior's Bureau of Mines is evaluating alternative technologies to treat oxidized taconites. Since process control is an essential element in the application of these process technologies, research was performed with a prototype monitoring system. A Californium-252 neutron source and a thermal neutron capture- gamma ray spectra analysis method was utilized to measure the amount of iron and the percent solids in the process slurries. The concentrate and tailing streams in a 410-kilogram-per-hour (900- pound-per-hour) pilot plant employing a selective flocculation and cationic flotation process were monitored. The results obtained showed that the thermal neutron capture-gamma ray reaction can be used to provide process control parameters.

Jan 1, 1979

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 Peter Zhang, I. BERK TULU, Morgan M. Sears, Mark Van Dyke, Heather Dougherty, Ted Klemetti, Gabriel S. Esterhuizen

Ground falls in longwall gateroad entries remain a concern in modern longwall operations. The gateroads are subject to changing horizontal and vertical ground stress induced by longwall extraction. These stress changes can result in failure of the strata around an entry leading to large deformations of the entry roof, floor, and ribs. The gateroad support systems are required to control the failed strata while maintaining safe access to the longwall face and unimpeded ventilation. This paper presents research that was conducted to better understand the stability issues in gateroad excavations and to develop procedures for evaluating support and layout alternatives for longwall gateroads. Using the results of a field-monitoring program and numerical model analysis of case histories, a conceptual model of gateroad support needs was developed. The conceptual model formed the basis for developing a set of equations that can be used to estimate likely roof sag and support loading for given roof geology and longwall-induced loading conditions. The developed equations were used to compare predicted gateroad stability to field study results, showing satisfactory agreement. The calculation procedures are used to demonstrate their application in assessing support alternatives at a case study mine. It is concluded that the developed analysis procedures provide realistic assessments of likely ground stability and can be used to evaluate alternative gateroad support systems at operating longwall mines.

May 13, 2021

By Brenda Marise Oliveira Custódio Pereira

Este trabalho apresenta uma análise fluidodinâmica de um leito granulado, utilizando-se partículas sólidas de diferentes característica em um leito de área de secção transversal circular. Os materiais utilizados foram aqueles comumente utilizados em um alto-forno a carvão vegetal. Os dados experimentais foram obtidos em um leito fluidizado fixo, de escala piloto, medindo 1,20 x 1,00 m. A fluidodinâmica foi estabelecida pelas medidas da perda de pressão no leito e vazões de ar crescentes. Os valores de velocidade de fluidização foram obtidos a partir dos gráficos de perda de pressão x velocidade do ar.

Aug 1, 2018