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By James D. Eklund

Towards the goal of improving safety, economy and efficiency of scaling in underground metal/nonmetal mines, Battelle developed a combination prying/hammering scaling tool. A prototype was subjected to limited testing 1) to verify its operational functions and 2) to assess its potential capability in future underground testing.

Jan 1, 1983

The term slag has been used to define a wide variety of material including mine spoil and slag produced at steel plants. The present paper is concerned only with the non-metallic alumino-silicates developed simultaneously with iron in blast furnaces.The control of iron quality by slag has long been appreciated but here aspects of slag control based on concurrent iron production are indicated. Consideration is given to the basic composition of slags relative to the type of allotrope required. Up to a point, the plant conditions, under which a particular slag type is processed, have some effect, but these conditions only widen the range of a given allotrope.They do not convert one slag type into another. The nature of the slag types and experiments with additives to convert one slag type into another are discussed.The various uses for allotropes of blast furnace slag are considered.Their use in air cooled slag, foamed slag, slag wool, cements, soil stabilization, glass bottles, and building bricks and blocks, is explored in some detail.INTRODUCTIONWithin recent memory, blast furnace practice has been solely concerned with the production of iron. The slag make at this time had not reached embarrassing proportions. In Britain, unlike Germany, no legislation existed to prevent the growth of unsightly slag banks. Generally slag found limited use as fill and road material in the immediate plant vicinity. This is broadly the case in Australia today. In Europe and America, where the slag make is of the order of several million tons annually, the room problem and the cost of dumping slag has stimulated commercial and scientific research on the disposal problem. Currently, most iron plants in Europe can profitably dispose of at least 95 per cent of their slag make.

Jan 1, 1964

By W. M. Bangert, F. S. Boericke

"INTRODUCTION Previous investigations of the Boulder City station of the Bureau of Mines have demonstrated that low-grade domestic chromite concentrates can be roasted with carbon to obtain selective reduction of the contained iron, and that the reduced iron can be removed by acid leaching of the roasted products to produce residues with higher chromium iron ratios. Thus, some chromite ores or concentrates that originally contain too much iron to be acceptable for the production of ferrochrome can, by this treatment, be rendered marketable as ""high-grade"" chromite. 3/The present report supplements the earlier work of the Bureau and re¬cords the results of small-scale laboratory tests investigating the effects of:1. Temperature and time of the reducing roast.2. Chromite and carbon particle size.3. Ratio of carbon to chromite in the initial roast mixture.4. Variations in the alumina and silica content of the ore.5. Back-oxidation of the roast product.6. Temperature and time of leaching .of roast product.This work differs from that done previously in that particular emphasis was placed on roast mixtures containing just enough carbon for the reduction of the iron in the chromite, whereas some two and one-half times this amount of carbon was used in the earlier work.In addition to these tests, the mechanism of the production reactions was examined for the purpose of explaining the precance of acid-soluble chromium, which occurs under certain conditions of chromite reduction."

Jul 1, 1945

By Bibby P. A, Leupen R. A

A 24,300 tonnes per year state of the art Silicon smelter is being constructed for Barrack Silicon Pty Ltd at Kemerton, 20 kilometres north of the City of Bunbury in Western Australia. The plant is designed for the reduction of high purity quartzite lump to metallic silicon in two 27MVa Demag submerged arc electric furnaces. The primary reductant, a high purity charcoal, will be manufactured at the plant from locally sourced jarrah wood waste (Eucalyptus Marginata). Commercial silicon production is scheduled to commence in October 1989. Keywords: Silicon, Smelter, Quartzite, Furnace, Charcoal, Jarrah, Wood, Eucalyptus Marginata.

Jan 1, 1989

By Rao P. K, Sahoo P. K

The main constituents of ferromanganese slags are silicates of Mn, Ca and AI. Factors affecting the recovery of manganese from a low manganese content ferromanganese slag (about 16 per cent MnO) during acid leaching were studied. These included time, temperature, agitation, sulphuric acid addition, solid:liquid ratio and particle size. Agitation rates greater than 300 rev/min. leaching periods greater than 30 min and temperatures above ambient were found to have no effect on Mn recovery. Dissolution of Mn was found to be highly dependent on the amount of acid added.About 90 per cent of the Mn was recovered when 5·5 times the stoichiometric amount of acid was used. About 28 per cent of the Mn was recovered when the stoichiometric quantity of acid (with respect to Mn alone) was used. However, the recovery increased to about 75 per cent when the total stoichiometric requirement of acid with respect to Ca, Al, Mg and Fe as well as Mn was used for leaching. The extent of Mn dissolution also depended on the particle size of the slag. The percentage of Mn recovery (using 5·5 times the stoichiometric amount of acid) increased from about 60 per cent to about 92 per cent when particle size decreased from -36 +52 to -150 +200 mesh (B.S.S.). When the results of this study were compared with those in a previous study involv,ing the leaching of a high manganese content slag (containing about 40 per cent MnO) results were similar except that there was a gr-eater consumption of acid in the present case (i.e. low manganese content slag).

Jan 1, 1979

The results of self potential geophysical surveys conducted over base metal prospects near Orange, Goulburn, and Wellington, N.S.W., indicate that this rapid and inexpensive exploration procedure merits wider application within eastern New South Wales, and in similar environments elsewhere.

Jan 1, 1973

By Bruno Bussière, Michel Aubertin, Anne-Marie Dagenais, Johanne Cyr

A five steps remediation program was commissioned in 1998 for the acid generating Lorraine mine site, located in the Témiscamingue region, Quebec, Canada. It included, as the main expenditure, a cover with capillary barrier effects (CCBE) used to limit oxygen migration. After construction of the cover, instruments were installed on site to monitor the CCBE performance. Modified oxygen consumption tests were also done to measure the oxygen flux through the cover. Results from water content and suction data, measured from 1999 to 2003, show that the capillary barriers effects are effective and that the water retention layer stays near saturation throughout the years. Oxygen fluxes estimated from monthly water content measures are generally below 10 g/m2/year. Results from modified oxygen consumption tests made on the site give almost similar oxygen fluxes. A two dimension numerical model of the Lorraine mine site was also constructed to verify that mathematical models could predict realistically the in situ conditions on such a large scale site. Numerical results obtained for three years show a good concordance between measured and calculated values. The results obtained form these different evaluation methods for the performance of a CCBE concur and confirm the efficiency of this cover in limiting acid mine generation.

Jan 1, 2005

By F. D. Sutterfield

This study was conducted to provide experimental evidence on the effect of modifications of gasoline front-end composition on the photochemical specific reactivities of automotive emissions. Evaporative and evaporative-plus-exhaust emissions from an automobile operated with four fuels of different volatility and varying levels of C.-C5 olefins were irradiated in a 10040 environmental chamber at three sets of initial hydrocarbon-nitrogen oxides concentrations. Reactivity was measured and expressed in terms of rate-of-NO2 formation and dosages of oxidant, peroxyacetyl nitrate, and formaldehyde. The compositional changes that were necessary in reducing fuel volatility were found to have no significant effect on the reactivity of the emissions. However, replacing C4-C5 olefins with saturated components resulted in sharp decreases in all reactivity manifestations observed for the evaporative emission samples. A lesser influence (of C4-C5 olefin replacement) was found with the composite exhaust-plus-evaporative samples; the effect that was observed could be attributed to the evaporative emission portion of the sample. The data therefore suggest that saturation of front-end fuel olefins had no large effect on exhaust emission reactivity.

Jan 1, 1971

By Akira Usui

The details in small-scale variability of the geological occurrence and chemical composition of ferromanganese crusts are not yet well understood, although the northwestern Pacific seamounts are believed to be among the most promising areas for rare metal resources. Our belief is that geological observations and geochemical analyses are still insufficient for economic evaluation or for discussion of depositional processes and environments. Our team, composed of geologists, mineralogists, geochemists, physical engineers, and microbiologists has attempted to utilize an ROV for in-situ measurement and for sampling of undisturbed and uncontaminated ferromanganese crusts at three typical seamounts in the NW Pacific near the Japanese Exclusive Economic Zone. The first ROV geological survey of ferromanganese crusts was successfully completed, and the ROV proved to be the most powerful, efficient and elegant method to date. The collected samples (more than total 1 ton of crusts, at more than 100 sites along a total of approximately 10 km of survey lines) were most suitable to analyze water-depth dependency and secular variation of their composition. The intact surfaces of crusts, collected without the usual abrasion caused by dredging, were also valuable for microbial study of Mn oxidizing bacteria. The ROV sampling devices, however, can be improved with further sophisticated drills or rock saw blades in the future.

Jan 1, 2011

By J Parnell, B Manson

Bitumen occurs in the basins in reservoir sandstones, in veinlets close to hydrocarbon source rocks, in veins through lava beds and in sulphide-mineralised veins where it is closely associated with, but predates, the sulphides. The role of organic matter was probably in enhancing metal reduction by creating a low-Eh environment rather than in metal transport. Coeval euhedral quartz crystals or albite in sulphide-bearing carbonate veins provide evidence of an aqueous component to the hydrocarbon fluid

Aug 1, 1995

By W. C. Winegard, A. Galibois, C. J. Beingessner

The effects of solutes on the distribution of two-dimensional configurations of grains in zone-refined tin have been studied. When solutes with partition coefficients (ko) greater than unity are added, three-sided pains become more prevalent and the growth law changes. It is shown by electron-Probe micro-analysis that a solute buildup occurs ahead of a moving grain boundary when ko > 1. It has been found recently1, 2 that solutes with partition coefficients greater than unity have a larger retarding effect on grain growth than solutes with k, less than unity. ko is defined as the ratio of the concentration of solute in the solid to the concentration of solute in the liquid with which the solid is in equilibrium. Niessen and winegard2 have suggested that this effect is probably due to the complex shape changes which occur during the process of grain growth and that no theory based on single boundary motion3-5 can explain the results. They suggested that the dissociation of the unstable fourfold junction was delayed in alloys where ko was greater than 1 because the boundaries at the junction had to move into a region of high solute concentration. If indeed this mechanism were correct, it was felt that not only would the dissociation of fourfold junctions be affected by the solute buildup ahead of the boundaries, but the collapse of three-sided grains would be impaired. These combined effects would naturally lead to a modification in the distribution of the number of sides per grain seen on a two-dimensional section. The present investigation was undertaken to test these hypotheses by examining the grain-growth process in detail. EXPERIMENTS The Distribution of Grain Configurations in Zone-Refined Tin as Seen on a Two-Dimensional Section. Following the method of Bolling and Winegard,6 zone-refined tin was cast into button-shaped specimens and, subsequently, plastically deformed under a drop hammer at room temperature. The resulting flat coin-shaped samples were annealed at 200°C, some for 50 sec and others for 100 sec. The specimens were then examined to determine the distribution of the number of sides per grain, i.e., the num- ber of crystals adjacent to any particular grain in the section. For simplicity, the grains were classified as three-sided, four-sided, and so forth; this concept is schematically illustrated in Fig. 1. As indicated by smith,' it was necessary to examine every grain within an enclosed area to obtain a proper distribution of the relative frequency of each type. The distributions for the two annealing times are illustrated in Fig. 2. The total number of grains examined is also indicated on the figure. It is evi-

Jan 1, 1965

By J. H. East, D. Harrington

"INTRODUCTION Considerable interest has been shown in the prospective use of Diesel-powered haulage equipment in both coal and non-coal mines. Foreign technical magazines have devoted considerable space to discussions of the use of Diesel locomotives in European mines and some mention of it has been made in technical papers in the United States. The Bureau of Mines has extensively tested the gases produced in the exhaust of the Diesel engine under various atmospheres and conditions of use; it has established a schedule of tests for permissibility of Diesel engines for use in underground coal mines, including, gassy or dusty mines.This publication provides information as to the successful use of Diesel-powered equipment underground workings in the United States and Europe, briefly discusses the characteristics of some of the toxic gases found in the exhaust of Diesel engines, and points out that Diesel-powered equipment can be used with reasonable safety in underground minus if necessary and entirely feasible precautions are taken."

Apr 1, 1947

During the construction of storage caverns, and during their lifetime if the use to which they are put so requires, it is necessary to provide adequate ventilation to ensure the safety and comfort of the underground workforce. An analysis of likely contaminants during construction has indicated that where a large facility is situated in a rock mass of even moderate temperature climatic conditions are likely to be the limiting factor during most of the mining operation and atmospheric pollution when blasting is undertaken. Possible options for improvement are increased air flow, cooling of intake air and reduction of the heat source by altering the number and type of haulage units employed in the cavern. Local solutions are an alternative approach where heat problems are confined to a few specific locations

Aug 1, 1994

By A. M. Gaudin

Jan 1, 1962

By G. van Aswegen

Seismic monitoring became commonplace in the deep South African gold mines in the early 1990’s. The discipline has, to a large extent, developed beyond the ‘research’ stage, and a ‘Guide to Seismic Monitoring in Mines’ has been accepted by the Department of Minerals and Energy1. Although ongoing research is a requirement for the achievement of all the objectives of seismic monitoring in mines, sufficient knowledge exists to apply seismic monitoring for routine seismic hazard assessment as an aid to risk management. The design and management of seismic monitoring systems can be tested against requirements spelled out in the ‘Guide’. Assuming the seismic monitoring system performs as per requirement, the best practice for routine seismic hazard assessment in mines includes • Long term seismic hazard assessment: through back analysis of seismic data and correlation with numerical modelling output, reasonable tests for planned mine designs are possible. • Medium term seismic hazard assessment: o Spatial analysis through contouring of seismic strain related parameters, with superimposed contours or event plots of stress related parameters allow the delineation of potential instabilities in space. o Quantitative and statistical analyses of seismicity in smaller spatial units (usually encompassing production sites) allow the comparative seismic hazard rating of different areas/sites so that rock engineering input and risk management can be optimised • Short term seismic hazard assessment relies mainly on time history analyses of particular seismicity parameters. The temporal patterns are controlled by a combination of temporal and parameter filters, the optimisation of which determines the success rate.

Jan 1, 2003

By B. P. Watson

The Bushveld platinum group metal deposits are two distinct, shallow-dipping stratiform tabular orebodies which strike for many hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 300 m. The mining method is a variation of planar open stoping. Pillars are widely employed to support the open stopes. In the deeper levels, in-stope pillars are required to fail in a stable manner soon after being cut, and the residual pillar strength is used to stabilize the hanging wall. These pillars are commonly known as crush pillars. Little work has been done in the past to determine pillar peak and residual strengths, and pillars have been designed using experience and formulae developed for other hard-rock mines. This has led to over and undersize pillars with consequential loss of ore, pillar bursts and potential collapses. This paper describes a crush pillar design methodology, and provides design charts. Three mining environments were incorporated in the investigations, which included underground and laboratory measurements, analytical solutions, numerical model sand back analyses. The results of the study are suitable for the areas where the research was carried out, and may also be applied with caution in other similar environments.

Jan 1, 2010

By J. E. Cleveland

The major health concern for uranium miners is the release of radon gas and the resultant ingrowth of the short lived daughters in the mine atmosphere. Present methods of control are the utilization of mine ventilation systems for dilution and control of ingrowth time to maintain working levels below those set by regulations. This study examined pressure cycling efforts on the radon emanation. The mechanical ventilation systems were altered to allow pressure changes throughout the mine to increase radon influx during the off shifts and thus deplete the sources of radon gas. Continuous radon working level and environmental monitors, developed by the Bureau of Mines, were employed to monitor radiation and physical parameters in the mine workings. The mine ventilation system was then varied to induce radon flows during off shifts, thus, depleting the radon sources during normal production shifts. Electro-static precipitators were also tested to determine radon daughter collection efficiencies. Both radon and radon daughter concentrations were monitored and evaluated. Major problems were found in the simple mechanical operation of cleaning these units.

Jan 1, 1982

By Edgardo Fogli, Mario Lampiano, Antonio Nicola

The project is located in the northern region of the People’s Republic of China and was awarded to Impregilo, as sponsor of the Wan Long Joint Venture, in September1997. The project consists of four tunnels for a total length of 88,700 m, with an excavation diameter of about 4.9 m. The lining is made of honeycomb pre-cast segments, connected by PVC dowels and the joints are sealed with elastomeric gaskets. The geology is mainly Limestone, Dolomite and Sandstone. Karst cavities are abundant and are often in-filled with plastic red clay. This has adversely affected the TBM’s progress. Four double shield telescopic TBMs were mobilized to cope with the very tight construction schedule and, at the end of November 2000, more than 80% of the tunnel has been bored. The article analyses the TBMs’ productions in the various geological conditions and the results of different technical solutions adopted at the project.

Jan 1, 2001

By Joseph J. Feiler

Fires in underground coal mines are persistent problems anywhere in the world that coal is mined. Coal fires pose safety and health hazards in the form of mine subsidence, loss of energy reserves, destruction of property and surface improvements, and air pollution. In 1995, the US Bureau of Mines (US-BM), in cooperation with the Colorado Division of Minerals and Geology (CDMG),entered into a contract with Goodson & Associates Inc. (GAI) to design and field test the effectiveness of a new foamed grout technology called ThermoCell. GAI is a Lakewood, CO geotechnical and mining reclamation engineering firm. The company developed ThermoCell to control and extinguish underground coal fires. The viability of the special grout and the technology of application were established during a full-scale field demonstration at the abandoned IHI Coal Mine fire, near Rifle, CO. Following acquisition of additional funding by CDMG in 1999, Goodson returned to the site in April to continue the grouting to fully extinguish the IHI fire.

Jan 1, 2000

The goal of the Bureau of Mines diesel engine research program is to reduce exhaust emissions and minimize the risk of fires and explosions caused by the use of diesel- powered equipment in underground mines. This program has led to a fundamental understanding of the problems and to solutions that allow diesel equipment to be used safely and effectively. This volume contains reports of the presentations made at the Bureau Technology Transfer Seminar on Diesels in Underground &fines given in Louisville, KY, and Denver, CO, on April 21 and April 23, 1987. It also contains three reports of related research, not presented at the seminar, which highlight the significant achievements of a joint US.-Canadian research program on diesel emission control technology for underground mines. Topics covered in this volume include discussions of industrial hygiene problems associated with the use of diesels, accident statistics, fire and explosion control systems, measurement of diesel pollutants, emission control techniques including engine maintenance, fuel additives, diesel particulate filters, and ventilation of diesel sections. An alternative to diesel power, the hydrogen-powered mine vehicle, is also described.

Jan 1, 1987