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By R. J. Fantel

The Bureau of Mines investigated the resource availability of titanium minerals from 63 mines and deposits in 12 market economy countries. These mines and deposits contain, at the demonstrated resource level, an estimated 438 million metric tons (mt) of titanium dioxide (TiO2) in the minerals rutile, ilmenite, leucoxene, and anatase. An additional 314 million mt of TiOz is available from inferred resources. If all titanium minerals and other recovered heavy minerals are sold at total costs at least equal to the January 1984 market prices, approximately 200 million mt of contained TiO2 could be recovered in total. In terms of mineral concentrates, this equals approximately 11 million mt of rutile concentrate, 187 million mt of ilmenite concentrate, 3 million mt of leucoxene concentrate, 13 million mt of synthetic rutile concentrate (in addition to the ilmenite), and 89 million mt of titanium slag. The study indicates that world resources of low-cost rutile are declining. In order to maintain future supply for high-grade titanium resources, alternate sources will need to be developed, which may include higher cost rutile mines, Brazilian anatase deposits, increased production from slag operations, or more synthetic rutile capacity from ilmenite resources, which are abundant.

Jan 1, 1986

By A. M. A. Mohamed, F. H. Samuel, S. Alkahtani

"This article was undertaken to investigate the effect of nickel and zirconium additions on the strength of 354 aluminum cast alloy. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 ºC for 2 hr. High temperature tensile tests were conducted at various temperatures from 25ºC to 300ºC. Optical microscopy and scanning electron microscopy were used to study the microstructure of the samples. The results revealed that the intermetallics phases of (Al,Si)3(Zr,Ti), Al3CuNi and Al9NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300ºC compared to the base alloy.INTRODUCTIONThe task of improving the mechanical properties in an aluminum alloy at high temperatures should include the knowledge of several factors which are related principally to a decrease in the strength of the metal with increasing temperatures. This behavior is linked to the change or deterioration in the principal metallurgical parameters of the specific cast aluminum alloy during its performance at higher temperatures. Most of applications of Al-Si casting alloys are generally used at temperatures of no more than 230°C (Lee & Chen, 2002). This recommendation is made in view of the fact that, for certain applications such as those required by the automotive industry, these alloys must operate over a wide range of temperatures and stress conditions where temperatures are liable to rise even higher than 230ºC (Robson & Pragnell, 2003).Aluminum-silicon-copper-magnesium alloys such as the 354 alloys show a greater response to heat treatment as a result of the presence of both Mg and Cu. These alloy types display excellent strength and hardness VALUES (although at some sacrifice of ductility and corrosion resistance. These alloys are used for a wide range of applications, such as engine cooling fans, crankcases, high speed rotating parts, structural aerospace components, air compressor pistons, fuel pumps, compressor cases, timing gears, rocker arms, machine parts, and so forth (Cáceres, Svensson, & Taylor, 2003; Rurrxia, Rong-de, Yu-hua, Cherrxi, Xiao-feng, Heng-rong, & H. Zhuang-qi, 2004)."

Jan 1, 2012

By L. Z. Wojno

Tunnels in South African gold mines are developed at depths down to 3 600 m below surface where the virgin rock stress approaches 100 MPa and, on occasions, through rock where the field stresses exceed 150 MPa. In addition, many tunnels are subjected to increases in field stress of over 50 MPa during their useful lifetime. As a consequence, the walls of most tunnels are fractured causing the rock to dilate into the tunnel. Quantitative data on the extent of this fractured zone are presented. The function of support in these circumstances is to reinforce and maintain the integrity of the fractured rock. In 80 per cent of the 800 km of tunnels developed annually, the support methods used are capable of maintaining the stability of the tunnels. However, the remaining 20 per cent of tunnels is subjected to severer conditions where dilation in excess of 250 mm occurs and/or where the probability of strong seismic ground motion is high. In these tunnels, additional support is required. The type and pattern of support for both normal and severe conditions is described. In spite of the improved support used, damage to tunnels may occur. To minimize this damage, the concept of a rock reinforcing tendon that will yield and do work, when subjected to quasi-static or rapid deformation, has been put forward. Specifications for such a tendon are presented and the development of certain yielding tendons are described.

Jan 1, 1987

By C. A. Komar

Renewed interest in the underground gasification of coal evolves from comprehensive studies of earth fracture systems that indicate that the movement of fluids can be controlled in the coalbed. In particular, directional property studies of natural microfissure occurrence, permeability, ultrasonic velocity, tensile strength, and orientation of intervals of inherent rock weakness, together with geologic structure setting and fracture trace analysis, can predict the gaseous flow paths in the coalbed. Having this information, the dominant direction in which gases generated and/or liberated by heat would move can be determined so that appropriate well patterns can be developed. Together with advances made in drilling technology that permit long horizontal holes to be drilled through the coal seams, tests can be conducted to determine whether directional control will permit devolatilization of the coalbed and gasification of the remaining hot coke in a systematic manner to produce a low-Btu gas suited for the generation of electricity.

Jan 1, 1973

By Joseph J. Wallace

1. The investigation shows that there are two coal beds of major importance in Perry County from the standpoint of present production -Flag and Fire Clay -and two beds of minor importance -Haddix and Hindman. The Flag and Fire Clay beds contain the largest remaining known reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, are estimated at 840 million short tons as of January 1, 1954. Of this total, 720 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, these should be added to the total estimated reserves.

Jan 1, 1954

By X. Xu, J. K. -W. Wong, J. -Y. Delenne, K. Soga

Hydraulic fracturing (HF) is a mulit-scale and multi-physics process which makes numerical modelling challenging. Conventional numerical models focus on multi-physics nature of HF but the multiscale nature is compromised by idealization of reservoir to be continuous, homogeneous and isotropic. However, natural fractures take a significant role in the success of HF for exploration of unconventional resources like Shale gas. Advancement in microseismic monitoring provides useful data for simulation in a much greater details. There is an urgent need to develop a suitable numerical tool for multi-scale threedimensional simulation to better understand the roles of discontinuities and heterogeneity in reservoir and its interaction with HF, especially to address the environmental concerns such as induced seismicity. In this paper, a simple discontinuum numerical method – Lattice Element Method (LEM) is proposed to model HF in a large scale three-dimensional model. A reservoir is modelled as a lattice network composed of 1D Hookean’s spring. Fracturing is modelled simply by removing lattices that meet a specified threshold as determined by the critical energy release rate of the rock. By introducing disorder in the model, mesh dependency in modelling fracture growth is minimized. Fluid flow is simplified as flow in pipe network and the permeability of pipe is related to fracture aperture by cubic flow law. Therefore, fracture flow and rock deformation are fully coupled. In this paper, four simulations of the same configuration except with different degrees of reservoir heterogeneity are presented. Fractures formed are diffusive and two groups of fracture are identified – connected fractures and isolated fracture without clear spatial correlation. The former forms a ‘fracture cloud’ and contributes to fluid flow and modeled by pipe network. The flow of fluid is highly tortuous and pipe network is sparely connected. The degree of reservoir heterogeneity controls the growth of ‘fracture cloud’ and pipe network. Microseismic monitoring often shows diffusive fracturing during HF on site and hence the outcome of the proposed model can be compared to such monitoring results.

Jan 1, 2015

By B. J. Buys

Rock bolt integrity is a critical issue for the mining industry because of its influence on the safety of mining operations. Guided ultrasonic wave testing of the defects associated with resin-anchored rock bolts was investigated. Axisymmetrical and three-dimensional finite element models were built, one of a partially encapsulated bolt and the other of a bolt with a simulated local corrosion crack. Experimental bolts were then installed in a testing block and typical responses were compared to finite element models of different defect scenarios. Encouraging results were obtained for the smaller axisymmetrical and three-dimensional finite element models, as well as during the experimental investigation. It is recommended that software with energy-absorbing elements should be utilized to consider higher frequencies and longer bolts. Once the integrity of models such as these has been established, the models could in principle be used to train neural networks for use in commercial equipment to determine the integrity of the installed bolt.

Jan 1, 2009

By L. Price, R. Hortie

Movement of ore and waste from the Hilton Mines pit is accomplished by truck haulage. With the aim of reducing costs, a study of truck fleet replacement was initiated. The study included on-site short-term tests and longer-term rental purchase agreements for haulage trucks. The operation and maintenance characteristics of different trucks, along with projected haulage conditions, were used to prepare cash flows, from which the most advantageous trucks were selected. The results of the study and implementation of the recommendations gave a cost saving greater than had been estimated. The study also indicated areas where improvements could be made, and resulted in much more attention being paid to road conditions, the training of operators and mechanics, and the development of a practical preventative maintenance scheme.

Jan 1, 1971

By J. W. R. Rayner

THE conventional method of making water gas involves individual plants for the separate carbonization of coal to coke and the subsequent gasification of coke with steam. The process demands lump coke, preferably made from the best quality of coking coals. The ash in the coke should have a high melting point and the gasification process suffers a loss of efficiency when cokes with low ash-melting points are used. In Britain, these coals are generally the most expensive and they are readily available only in certain localities. The coals not suitable for making lump coke, or yielding only poor quality coke, are much more widely available and are generally cheaper. DEVELOPMENT OF ALTERNATIVE PROCESSES In Germany, processes have been developed and operated commercially for the production of water gas from very low-rank coals such as brown coal and lignites, but much less effort has been spent on processes to use coals of intermediate rank, which are widely available in Britain. The brown-coal processes use coal in the form of either dust or briquettes. The most successful of the dust-gasification methods is the Winkler process, which made a substantial contribution to German oil production during the war. It uses coal in the size range 0 to 8 mm and the fuel bed is blown with a mixture of oxygen and steam at a rate high enough to give it a characteristic boiling motion or, in present-day phraseology, at a rate more than sufficient to fluidize it (Fig. 1). Air cannot be used to provide the heat required for gasification, for vari¬ous reasons. In the first place, to make the process continuous by mixing air and steam would involve the production of a lean gas containing much nitrogen. If a separate blow were used, a large amount of potential heat would be lost because the blow gas in such a process would contain a very high percentage of carbon monoxide. Oxygen is necessary therefore and oxygen remains relatively expensive for use in gasification. In the Winkler generator, formation of clinker caused by local overheating does not occur, because of the mobility and high heat transfer of a fluidized bed. These properties of fluidized dusts have been used most successfully.

Jan 1, 1953

The Main Seam occurs in two 'pods', termed North and South, separated by an east-west oriented 'want' zone (most probably a palaeo-channel). The seam on either side of the 'want' area reaches thicknesses of over 30 metres but the North Main Seam adjacent to the 'want' zone has been split into multiple seams of 10 to 15 m thickness. Rock types in the inter-burden of this area are characterised by inter-bedded sandstones and carbonaceous mudstones varying in thickness from 0.5 to 5 m. In the South Main Seam, an area of un-split coal exists and is characterised by few inorganic partings. Overburden in this area varies geographically from relatively thick mudstones in the south and east part of the coal deposit to inter-bedded sandstones and carbonaceous mudstones adjacent to the 'want' area. The sandstone/mudstone overburden probably represents a splay or splay-channel complex emanating from the larger 'want' area palaeo-channel. Modelling lithological variability is of use because it is one of the factors used in predicting cavability and roof support system design. The coal in both the north and south deposits were found to exhibit highly predictable quality and breakage parameters in relation to the coal geometry. Although ash yield and sulphur are mostly low and not variable, volatile matter and thus fixed carbon, varied in relation to seam thickness. In general, volatile matter (dat) decreased and moisture increased with decreasing seam thickness whereas moisture increased with decreasing seam thickness. In addition to these parameters it was found that the energy needed to crush the coal was lowest at the top and bottom of the seam and, on a whole seam basis, decreased with seam thickness. All of these parameters were found to vary in relation to the vitrain band content of the coal which itself was controlled by seam geometry. These parameters can therefore be modelled and inputted into mining plans and quality control operations.

Jan 1, 1996

By J. F. McIlwain

The Bureau of Mines has investigated fumes generated by selected welding electrodes used in mines in order to help determine their relative health hazard potential. Fumes were generated and collected in an enclosed chamber for subsequent generation rate and chemical constituent determination. Shielded metal arc electrodes from the following groups were tested: AWS types E308-16 and E310-16 stainless steel, ECoCr-A Co-Cr hardfacing alloy, ENiCr Ni, an Mn-Cr buildup alloy, E7018 carbon steel, and EII018-M low-alloy steel. Flux-cored wire electrodes of this last group also were tested. Fume generation rates and the chemical composition of the fumes were measured. From these data, exposure in-dices were determined, which give a relative measure of the health hazard potential of using the electrodes. The effect of welding onto build-up alloy layers on the fume composition also was examined for five of the higher alloy groups.

Jan 1, 1987

By Stanley Davidson

Introduction The ore deposit mined by Falconbridge Nickel Mines, Limited, is one of the numerous nickel-copper sulphide bodies marginal to the large oyster-shaped mass of differentiated norite in the Sudbury district, famous as the world's most important nickel producing field. The unique character of the ore deposits of the district has resulted in its intensive geological study over a period of more than fifty years. The results of these studies have given rise to a voluminous geological literature and to a great deal of controversy as to the genesis of the ores. This description of the structural geology at the Falconbridge mine is presented in the hope that it may form a small part of the chain of evidence leading to a reasonably satisfactory explanation of the ore genesis. The mine, named after Falconbridge township in which the deposit occurs, lies along the southeast margin of the norite mass which, however, is here concealed beneath a deep mantle of glacial sands and gravels averaging over 100 feet in thickness. As a consequence, the deposit was not discovered by the early prospectors, and it was not until 1916-17 that E. J. Longyear, of Minneapolis, located the ore by drilling. The discovery was foreshadowed in 1899 by the work of Thomas A. Edison, who found indications of the deposit by what is believed to have been a combination of magnetic and electrical geophysical surveys. He sank a prospect shaft over what has to date proven to be the largest and richest ore section in the mine. A wet quicksand layer at the rock surface proved impenetrable, however, and the "Edison' shaft never reached bed-rock.

Jan 1, 1946

By Zbigniew Lubosik, Andrzej Walentek, Stanislaw Prusek, Sylwester Rajwa, Aleksander Wrana

"Underground coal gasification (UCG) provides a solution to supply electricity from high ash coal or deep deposited seams. The coal is consumed in situ, and, accordingly, the ash is left underground. UCG could play a major role in the future of coal, which is expected to fuel 44% of the world’s energy in 2030, in a more environmentally friendly and commercially viable manner. Nevertheless, it is known that the UCG can impact the environment. One of the most important factors in safe UCG process should be the evaluation of rock mass quality and the monitoring of its behaviour. The changes of rock mass parameters and quality have an influence on numerous aspects, such as subsidence and the stability of underground workings in georeactor vicinity, however, they also increase the possibility of pollutant migration through fractures and pores. These issues are especially important in cases of gasification conducted in an operating mine or on areas of high ecological vulnerability. This paper details observations made in two underground trials of UCG performed in Poland recently. The first of which is the Experimental Mine Barbara (under the project entitled HUGE-2 Hydrogen oriented underground coal gasification for Europe – Environmental and Safety aspects, (Wiatowski et al., 2015). The other trial has been conducted at an operating mine, Wieczorek, which is in the framework of a research project on the development of coal gasification technology for highly efficient fuel and electricity production (Czaplicka-Kolarz et al., 2013). During these trials, investigations were carried out aimed at assessing geomechanical parameters of rock mass and support behaviour in surroundings of UCG geaoreactors. Investigation comprises assessment of geomechanical parameters of coal, floor and roof strata, roof displacements, and concrete support strength parameters variation, as well as standing steel support load. Hydraulic penetrometer, endoscopic camera, Schmidt hammer, pull-out method, telltale, and ground penetration radar (GPR) were used in the investigation. Research conducted at both EM Barbara and Wieczorek Collieries revealed that the UCG process did not adversely affected the competency of rock mass (expressed by number of fissures and strength parameters of rocks), the stability of roadways and the support performance in the areas located in the vicinity of the georeactors."

Jan 1, 2017

By Janet M. Epps

The international climate regulating environmental management in mining is rapidly evolving through the combined influences of the development of international guidelines, resolutions, protocols, treaties and conventions; the influences of the international lending and aid institutions who seek a consistent but constantly evolving standard of environmental performance from their clients; the legal precedents being developed in courts al over the world; and the activities of multinational countries who tend to rapidly upgrade technological performance through their international activities (particularly influencing developing countries). In this rapidly evolving regulatory environment, the more 'models' available to this international pool of resource materials that demonstrate practical. cost-effective and (most desirably) incentive based regulatory mechanisms, the better will be the eventual body of 'international standards' we will al have to work with. Australia can make a significant contribution to this process, however, it has only been on the margin of this dynamic, North American and European led process, up to this time. It is in the Australian minerals and energy industry's best interest to take an active part in the evolution and direction of this process.

Jan 1, 1996

By Frank L. Hess

"New England" and "granite" if not synonymous are at least associated terms. Where there are granites that are not deeply eroded there are usually pegmatites, the most erratic of rocks, and of them New England has a full portion. Many of the New England pegmatites contain the rare alkalis - lithium, rubidium, and cesium. however, the same in homogeneity of the earth's crust that has made the New England pegmatites unusual, in that so many of them contain the rare alkalis, has likewise made the distribution of the rare-alkali minerals sporadic even in those pegmatites, and most contain only enough to furnish collectors with more or less ornamental and uncommon minerals. New England has long had numberless collectors of minerals, and the mineralogists of its various schools have published many papers on the pegmatitic minerals, including those of the rare alkalis, but none of the papers have dealt with estimates of quantities. In this paper we have tried to place the emphasis on quantity rather than on mineralogy.

Jan 1, 1943

By Segundo Bejarano R

Durante mucho tiempo los métodos tradicionales utilizados en la ejecución de los proyectos en el sector minero han sido insuficientes. Por ello, la minería optó por emplear técnicas modernas de planificación y control que ahorren tiempo y minimizen recursos como mano de obra, maquinarias, energía y otros. En este sentido, el objeto del texto es describir el uso del método PERT-CPM en la ejecución del proyecto minero, así como señala su aplicación práctica en el proyecto de ampliación que viene ejecutando la compañía de minas Orcopampa.

Nov 24, 1986

By W. Drummond

The cooling of smelter gases by air dilution, adiabatic evaporative cooling and indirect heat exchange is discussed with reference to the process, to the subsequent cleaning of the gas. and to the use of the heat extracted from the gas. The method of reducing the effect of acidic sulphide formation on the corrosive properties of the gas and the dust and the development of surface cleaning mechanisms?are discussed. The development of indirect recuperators using air, water or steam cooling, made possible by the control of surface fouling is traced. The application of the modern Waste Heat Boiler to the new sulphide smelting processes is discussed with respect to the natural and forced circulation concepts. Case histories are presented to illustrate mistakes made with respect to designs produced without recourse to sensitivity analysis and without an appreciation of "worst process? conditions".

Jan 1, 1992

By William A. Beck

Since bauxite mining began in the Irwinton District, Wilkinson County, Ga., in 1912, it has been on a small scale, as most of the deposits of high-grade ore are small. The bauxite has a high silica content, and its use has been largely limited to the chemical industry. Drilling under this project did not disclose any bauxite deposits of commercial value: However, numerous holes penetrated high-alumina clay deposits, but no attempt was made to delimit them, as the project was solely an exploration for bauxite. Bauxite was first discovered near Irwinton in 1907. The district covers virtually all of Wilkinson County and extends into the adjoining counties of Washington, Baldwin, and Twiggs. Mining was begun in 1912 by the Republic Mining & Manufacturing Co. on the Honeycutt, Parker, and Daniel properties, which are 1.5 miles from Wriley on the old Irwinton to Milledgeville Road.

Jan 1, 1949

By Joseph W. Richards

THIS method of briquetting flue-dust, or flue-dust mixed with fine ores, or, in a few exceptional cases, coke-dust, has come into large commercial use in Europe, and a small plant is already in operation in the United States. It promises to become of such great importance to the iron industry of the United States that the following description will certainly interest the majority of our pig-iron producers. Discovered in 1908, the process rests upon the observation of Dr. Schumacher that blast-furnace flue-dust, while possessing of itself no binding or cementing properties, acquires strong cementing properties if mixed with a very small amount of certain salt solutions, the amount of which is so small that the resulting cementation appears to be rather by catalytic action of the salts added than by the mass-action of such chemicals. To be more specific, fresh blast-furnace flue-dust mixed with from 5 to 10 per cent. of its weight of magnesium chloride or calcium chloride solution-that is to say, with from 0.25 to 2 per cent. of its weight of magnesium chloride or calcium chloride-acquires the property of setting within a short time, from 15 to 60 min., and forming a hard cemented briquette. Alkaline solutions appear to have no action such as described, and they even interfere, if present, with the action of the magnesium and calcium solutions. When treated in this way the flue-dust briquette sets very hard, apparently from pure excess of cementing- and setting-power. It is, therefore, possible to . mix with the flue-dust a considerable proportion of inert ore or like material, which has no setting-power by this process, and thus to make a compound briquette containing large quantities of ore mixed with flue-dust, but in which the flue-dust may be regarded as the cement or binding-material. A particularly strongly cementing flue-

May 1, 1912

By A. S. Bayne

WITH the great increase in the use of power-driven machinery in industry, and consequent large-scale operations, the hazards to which , workmen are exposed have become much more numerous than at the beginning of the century. This is especially noticeable in mining. In the past thirty years or so, improvements in methods of excavation and metallurgy have made possible the exploitation of deposits which would have failed to make ore in previous years. This improvement, together with the in-creased use of machinery, has facilitated the mining of tremendously greater tonnages with a marked decrease in unit cost of production. This 'speed up' in mining creates numerous problems demanding close attention of operators and necessitates careful prep;tratory planning, as well as diligent supervision of actual operations. Underground openings increase in size so fast, and all phases of mining, mucking, and transportation proceed at such a rate, that a short period of reduced vigilance on the part of operators . results in disaster, both from the standpoint of safety and economies. Happily, the challenge of increased hazards has been successfully met by a general application of the slogan 'Safety First'. Today, we have large manufacturing concerns devoted entirely to the development and production of safety equipment for the protection of workmen in various branches of industry. Machinery manufacturers, in co-operation with their mining customers, have included the best possible in foolproof devices in the manufacture of hoists, compressors, boilers, electric motors, and equipment of all kinds. Mining companies and private individuals spend thousands of dollars and devote a great deal of time to research with the single object of preventing accidents and combating miners? diseases. Governments throughout the world have written regulations into their statures for the protection of miners and operators. Staffs are appointed to enforce these laws and investigate accidents to ascertain means of preventing them for the future benefit of the industry.

Jan 1, 1938