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By G. Kleyn

"Sub-standard practices and their adverse impact on safety performance remain a challenge in the South African gold mining industry. The purpose of this study was to investigate the root causes of sub-standard practices and the effect on safety performance in South African gold mines. The focus of the study was on the underground production operations at a gold mine in the Free State. The study consisted of three parts: a personal investigation into the causes of sub-standard practices at the mine, a comparison with the results of a cultural study performed at the West Wits mines, and a behavioural survey.The studies described in this article yielded similar results in terms of the key drivers behind sub-standard practices. It was found that substandard practices had a number of causes, and the origin lies within the habits, attitude, and behaviour of employees. Current methods of addressing sub-standard practices and improving safety performance were found to discourage employees from performing work safely and according to procedure. It was concluded that the lack of critical behavioural habits for the given work environment and job title could possibly be the primary reason for the occurrence of sub-standard practices. IntroductionSince the implementation of the Mine Health and Safety Act, 1996 (Act 29 of 1996) and the Mine Health and Safety Regulations, the South African mining industry has been striving to improve health and safety performance and has placed great emphasis on adherence to mine standards.The Act requires employers in the mining industry to report accidents, incidents, and dangerous situations to the Regional Principal Inspector of Mines in their area. The data provided by employers is captured and analysed by the South African Mines Reportable Accident Statistical System (SAMRASS) and made available for public viewing (Department of Mineral Resources, 2011).A review of the national mine-related accident statistics shows clearly that the South African gold mining industry has improved its safety performance markedly over the past decade, but is still facing major challenges (Figure 1). These include meeting the Mine Health and Safety Milestones (Department of Mineral Resources, 2011)."

Jan 1, 2016

By Sidney Powers

Since the opening of the Wheeler oil and gas field in Carter County and the discovery of oil near Lawton, Comanche County, Okla., in 1904, interest has been aroused regarding the origin of the oil in the Permian "Red Bed" region which lies between the Wichita and Arbuckle Mountains on the north and the Red River on the south. The later development of the Healdton, Loco, Duncan, Fox, and Graham fields south and west of the Arbuckle Mountains has brought the region into prominence. Recent discoveries of Ordovician and of Pennsylvanian fossils in wells in the Healdton field and of Pennsylvanian fossils in the Fox and Graham fields are of such importance from a scientific and a commercial standpoint that the occurrences and the problems arising therefrom are here briefly described. Producing oil and gas sands in the southern Oklahoma fields, with the exception of those in the Cretaceous and underlying rocks in the vicinity of Madill, Marshall County, are associated with the Permian "Red Beds" or with the underlying Paleozoic strata. In the two fields farthest south of the Arbuckle Mountains, Healdton and Loco, production has been entirely confined to sands at depths of 700 to 1400 ft. (213 to 416 m.) and only recently has a producing sand as deep as 1860 ft. (567 m.)l been encountered. These sands are found near and below the base of the red rocks and were supposed by Wegemann and Heald2 to belong in large part to the basal Permian, Wichita formation, or to the immediately underlying formations. Fossils in the blue shales and in the limestones associated with the deeper sands now prove them to be Pennsylvanian and all the producing sands at Healdton are found to be of this age. In the fields nearest the Arbuckle Mountains, the Wheeler sands at a depth of about 700 ft. (213 m.) appear to be of Permian age,

Jan 1, 1918

By Jürgen F. Brune, Liming Yuan, Alex C. Smith

To provide insights and assistances for the optimization of ventilation systems for U. S. under-ground coal mines facing both methane control and spontaneous combustion issues, a computational fluid dynamics (CFD) study is being conducted to investigate the effect of the ventilation scheme on the prevention of spontaneous combustion in longwall gob areas. This report focuses on the flow patterns within the gob under three different ventilation systems; one-entry and two-entry bleederless systems as well as a three-entry bleeder system. The gas flow in the caved gob area is simulated as a laminar flow through porous media while the gas flow in ventilation airways is simulated as a fully developed turbulent flow. The air flow patterns are visualized using flow path lines. Air velocity contours and vector data are also obtained. The possible location of critical velocity zones where the gob is most liable to spontaneous heating is discussed.

By Erich U. Petersen

Harbuck et al. (1990) present results of research on sulfuric acid leaching of a germanium-gallium ore and shed considerable insight on possible extraction methods for gallium and germanium. However, the presentation does not give sufficient details to evaluate the research, so some of the conclusions may not be as applicable as stated. The objective of this communi¬cation is to indicate that relevant and easily obtainable geological and technical information was omitted. Consequently, on this basis, alternative explanations for some of the data are possible. Discussed below are the omission of: • pertinent geological, mineralogical and geochemical literature; • details regarding the determination of germanium concentration in quartz by electron microprobe; and • details on the calculation of the amount of germanium locked in quartz.

Jan 1, 1992

By F. Habashi

The Republic of South Africa is a heterogeneous mixture of Black Africans, Afrikaans, British, Indians, Malayans, French Huguenots, and many others from Europe and Asia. A decisive date in its recent history is the collapse of the Apartheid Regime in 1994. For a metallurgist, South Africa is the country of diamonds, gold, platinum, and many other metals. In 1887 Cecil Rhodes (1853-1902) was able to take control of the De Beers Mining Company after the discovery of diamonds at Kimberly in 1866. It was there where the so-called School of Mines was inaugurated in 1896.

Jan 1, 2010

PRESIDENT Mrs Oliver Bowles 5000 Massachusetts Ave N W Washington 16, D. C FIRST VICE-PRESIDENT Mrs David Eugene Park 350 East 57th Street New York 22, N Y. SECOND VICE-PRESIDENT Mrs A B. Kinzel 320 Park Avenue New York 22. N. Y

Jan 1, 1952

By J. Wild, M. Ounpuu, G. Chevalier

"The requirements for a finer grind at Heath Steele have resulted in the investigation of agitated milling as a cost effective alternative to conventional tumbling ball mills.The grinding unit is a vertically agitated, or stirred ball mill. Grinding occurs as the result of the motion of a single vertical rotor equipped with protruding pins which impart a stirring action to the ball charge. A comparative evaluation of a 30 kW SALA Agitated Mill (SAM), and a 1.5 m x 2.5 m copper-lead regrind ball mill has been conducted at Heath Steele.An overview of agitated milling as it applies to the reduction of sulphide ore will be the primary topic for discussion. Specific parameters including energy efficiency, media consumption, operating costs, and the mechanical aspects of the SAM operation will be presented.Evaluation of the agitated mill has shown that improved grinding performance at much lower work indices than those of the conventional ball mill is possible. Media consumption has proven to be comparable on an average g/kWh basis, but the mechanical availability of the mill has been low.INTRODUCTIONConventional tumbling ball mill grinding has proven to be an energy inefficient process. Energy losses occurring within the ball mill itself can be attributed to particle friction without breakage, kinetic and potential energy losses, plastic and elastic deformation and the production of heat and sound (Lynch, 1977). It can be generally stated that a certain amount of the input energy will be converted to another form as a necessary by-product of particle breakage. Theoretical interpretation of experimental results indicate that the energy required for breaking the ore particles in a ball mill varies between I% and 25% of the total energy input (SME, 1985)."

Jan 1, 1993

By P. Kobylin, K. Haavanlammi, K. Valkama

"Base metals and precious metals can be recovered from a nickel matte or nickel concentrate using the Outotec nickel chloride leaching process. The raw material is leached with hydrochloric acid and the metals are recovered by solvent extraction, where ammonia is used to control the pH. Ammonium chloride is regenerated to ammonia and the side product of this step is calcium chloride solution. The regeneration utilizes either calcium oxide or calcium hydroxide. The calcium chloride solution is used to convert sulfuric acid into a hydrochloric acid solution while producing pure gypsum as a side product. The regeneration and reuse of ammonia and hydrochloric acid in this process will have a positive impact, from the point of view of both operating costs and environmental sustainability. This paper concentrates on the test work and technical concept development performed by Outotec to implement and develop chemical regeneration and recycling into a vital part of the nickel chloride leaching process.INTRODUCTION According to a nickel market analysis, the nickel market is expected to grow in the future. Main driver for this growth is the increase in stainless steel consumption as the living standards are equalizing globally. The expected increase in the amount of electrical cars and the need for nickel in the batteries of electrical cars also gives potential for the increased need for nickel in near future. At the moment the use of nickel in nickel-cobalt-manganese (NCM) and nickel-cobalt-aluminium (NCA) Li-ion batteries is in the range of 14 ktpa. It is estimated to increase to the level of 90 ktpa by 2025. In every era of the nickel industry, Outotec has been constantly developing new processes to create environmentally sustainable and economically viable processing routes. The Outotec® Nickel Matte Chloride Leaching process is a great example of a process that is flexible regarding raw material and could also treat nickel raw materials that are difficult for smelters. Outotec’s main options for pyrometallurgical nickel treatment include the Outotec® Direct Nickel Flash Smelting process (DON) and the Outotec® Ausmelt TSL process. The DON process is operated in Boliden Harjavalta Nickel Smelter in Finland. Ausmelt process is in use for example in Daye nonferrous plant in China. In the Outotec® Direct Nickel Flash Smelting Process, a sulphide nickel concentrate is processed in an Outotec Flash Smelting Furnace (FSF). Producing concentrates and processing them by Outotec Direct Nickel Flash Smelting to matte followed by hydrometallurgical refining offers a reliable route from concentrate to product. In the DON process, high-grade matte with low Fe content is produced in the FSF and the valuable metals in the slag are recovered in an electric furnace (EF). The Outotec® Ausmelt TSL process can use a large variety of raw materials (concentrates, secondary material and scrap metal) as feed. Fuel and oxygen are injected into the furnace through TSL (Top Submerged Lance) and this enables efficient smelting. Both Flash Smelting and TSL plants produce nickel mattes, which can be refined with Outotec hydrometallurgical processes."

Jan 1, 2017

By T. J. Batchler, T. M. Barczak

The Code of Federal Regulations (CFR) requires that the transverse load capacity of stoppings be equal to or greater than traditionally accepted in mine controls, which for block stoppings is generally accepted as 39 psf as referenced in the preamble to the CFR standard. This measure is based on physical testing of a freestanding wall in accordance with ASTM E 72 specifications, where our past research has shown that the dominant parameter is the tensile strength of the sealant. A new protocol based on rigid arch loading of the structure is proposed to determine the true transverse load capacity of block stoppings. Arching is achieved by the restraint of the stopping against the mine roof and floor, whereby compressive forces are developed within the wall. A laboratory procedure using the NIOSH Mine Roof Simulator (MRS) to simulate rigid arching of block stoppings was developed and results verified through full-scale in-mine tests. The rigid arch tests have demonstrated transverse load capacities more than an order of magnitude higher than the ASTM E 72 evaluation method from which the 39-psf requirement is derived. More importantly, the rigid arch tests have shown that the load capability is dependent on the physical properties of the block and geometric properties of the wall and not the sealant.

The great philosopher, Marshall McLuhan, is said to have stated that the use of forecasting as a means of guiding future actions is akin to driving an automobile through observations made in the rear-view mirror! In effect, in forecasting it is assumed that there will be an orderly progression from the past into the future, and that the model will be sufficiently unvarying for use to gauge both the directions and the rates of change. The concepts of forecasting have served man well in disciplines in which the relationship between causes and effects can be clearly demonstrated; such as between rainfall and crop yield, for example. These are of no value, however, when conditions change rapidly and unpredictably, or when there is no model at all. Even worse, under such circumstances our preconceived notions may cause us to make some horrendous errors in judgement. Such are the risks at present in attempting to make an assessment of the educational needs of the minerals industry for the coming century! The model, and the conceptions that we have had of the linkages between cause and effect are in disarray. Minerals markets are chaotic, and there is almost no ability to forecast trends in metal values. Linkages between supply and demand seem tenuous. Internationally, producers are struggling for survival. Mine closures, temporary shutdowns, and reopenings are frequent occurrences. Decision-making under uncertainty is probably one of the most certain things about the world mining industry Today!

Jan 1, 1986

By C. Okay Aksoy

In Turkey, the increasing demand for lignite has necessitated an increased emphasis on both lignite production and recovery. This emphasis has resulted in a gradual increase in the application of the retreat longwall mining method for both its product recovery and productivity benefits. Also, in order to maximize the recovery of the natural resources and to increase total production, it is necessary to take advantage of underground reserve before abandoning the mine. This means that at the end of the life of the mine, the main drift safety pillar and the shaft pillar will generally be extracted. This investigation a preliminary study of the stability of the main drift and the shaft at the Hustas Mine as the safety pillars are extracted. In this study, field surveys belonging to the underground colliery of Hustas Co. in Soma have been investigated with the help of LAMODEL working under the Laminated Displacement Discontinuity principle for the models calibrated as a results of physical model and finite element analyses. The convenience of Laminated Displacement Discontinuity Analysis has been researched in such studies. The results out of the models have been coherent with the previous studies.

May 1, 2004

By V. A. Khartcenko

As the environment conditions deteriorate with the intensification of mining, the problems of mineral resources protection and the development and introduction of various bio- technologies are becoming more pressing This paper is devoted to the description of an ecological simulation system, related to the exploitation of a mine in a given region. We suggest mathematical tools for solving the main problem, namely an expert system, providing the simulation of ecological models for the mining complex. On the basis of the suggested models, algorithms, and software facilities, numerical modeling was carried out, as well as systematic investigation and processing of the mining activities of the complex. AS a result of this work we have obtained more effective parameters of technological and economical measures of environmental protection.

Jan 1, 1992

By J. W. Horne

The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the non-condensable gases evolved when crude shale oil is distilled under pressure. Hydrogen sulphide is one of the components found in the complex mixture of Gases produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills. The study required a complete extraction of all the hydrogen sulphide from the gas stream after it left the water-cooled distillate condensers and before the gas stream entered the charcoal absorber for removing the light naphtha. In devising the method it was necessary to take into account a constant variation of velocity, pressure, and percentage of sulphide in the total gas stream coming from the still. Ordinarily, the quantitative determination of hydrogen sulphide in gas is made by analyzing small samples taken at regular intervals. This estimation can be accomplished by use of the Bunts gas burette as modified by Tutriler, or by a similar method. In the industries where the flow of gas is constant and of uniform composition, this practice is sufficiently accurate for plant control. For experimental work where many variables have to be taken into consideration, as in the case at band; these methods are not applicable.

Jan 1, 1931

By T. Karlkvist, H. R. Kota, F. Andreas, B. I. Pålsson

"Separation of different calcium minerals have long been an interesting and challenging problem. In this investigation calcium mineral separation is examined by: microflotation, zeta potential measurement and adsorption, using novel collectors having two functional groups instead of one. In theory, by varying the distance between the functional groups, it could be possible to preferentially target one calcium mineral by matching the spatial distance between the sites on the mineral surface. In this investigation two new surfactants have been tested to estimate their ability to float apatite and/or calcite. Preliminary findings show that an increase in distance between the functional groups favors one mineral over the other, and this might be due to differences in the mineral surface structure. INTRODUCTION Apatite is a strategically important mineral which has both great value for industrial use as a precursor to phosphoric acid; and in the agricultural industry as an important source of phosphorous in fertilizers. This has led both the European Union and the United States to recognize it as an important resource for the future. Currently there is no lack of apatite in the world, but it is important to develop the beneficiation to ensure future supply. A common problem in apatite flotation is the selectivity towards calcite, which it is commonly associated with. Although calcite is an important industrial mineral its abundance makes it not usually worth to extract from apatite ores unless it is easy to separate1,2. Both apatite and calcite are semi soluble minerals with calcium as one of their constituents. The most common way to separate apatite and calcite is to use flotation. A process that involves making the mineral particles to extract from the system hydrophobic by adsorbing a collector on the mineral surface. One way to study collector adsorption on a mineral surface is by zeta potential measurements. The zeta potential is the charge at a slip plane a short distance from the surface. By measuring the zeta potential with and without the presence of collector it is possible to investigate if the collector is present at the surface or not, a change is indicative of collector adsorption. The zeta potential of fluorite, apatite and calcite without collector can be seen in Figure 1. The small difference in zeta potential between apatite and calcite shows the similarity in their surface properties and gives an indication of their separation difficulty. One additional problem with semi soluble minerals is their tendency to slightly dissolve in the pulp and thereby change the ionic composition of the solution. This makes separation and research problematic as the freed ions may readsorb on the mineral surface and interfere with the collector adsorption on the mineral surfaces3–5."

Jan 1, 2016

By Tae Hwan Lee, Jun-Shin Lee, Daejin Kwag, Sangchul Bang, Gerard T. Houlahan, Moo Sung Ryu

"Geotechnical engineers have been installing innovative, permanent underwater foundation systems utilizing suction buckets for the offshore industry since the early 1980s (Senpere and Auvergne, 1982). This foundation system has been successfully used on numerous and various types of offshore structures in a wide range of environments. Suction buckets have numerous advantages compared to conventional underwater foundation systems. The more notable advantages include easy installation, large loading capacity, low noise and retrievability. The application of reduced water pressure inside the bucket facilitates the installation of the suction buckets, where a suction pump attached at the top of the bucket can accomplish the entire driving operation. Because of this efficient operation, very large suction buckets can be driven into the seafloor, which eliminates the use of a large number of small piles.In Korea, one of the most economical and reliable renewable energy sources is wind power; however, onshore wind power generation has encountered many problems, such as the lack of favorable sites and public concerns about noise and environmental damage. Consequently, offshore wind power generation has attracted increasing attention due to its abundant potential, high efficiency of grid connection, and availability of easy expansion.In November 2011, the government of Korea announced a national offshore wind power development roadmap, which targeted its offshore wind power generation with the goal of becoming one of the top three nations in the world for offshore wind power generation. Korea Electric Power Corporation Research Institute (KEPRI) is the main research arm of the Korea Electric Power Corporation (KEPCO) and conducts research and development on electricity, power generation, renewable energy and other energy-related matters. KEPRI ultimately provides forefront knowledge and leadership to KEPCO with respect to energy and related areas for its near- and long-term needs. Financial support for the overall project, of which the suction bucket foundation system installed for the pilot phase wind turbine is described below, was provided from the New and Renewable Energy Program of the Korea Institute of Energy Technology Evaluation and Planning funded by the Korean Government Ministry of Trade, Industry and Energy"

Jan 1, 2017

By Neil J. Dahmen, Howard J. Handewith

INTRODUCTION Tunneling machines were introduced into civil con¬struction in the 1800s, but their practical applications were not realized fully until the 1950s. As of 1977, tunneling machines were being used on most tunneling projects of substantial size. As in civil construction, the mining applications of tunneling machines have included long drives such as tunneling for long ore-body develop¬ment drifts, long haulage tunnels, longwall access drifts, and long crosscut developments. Tunneling machines ranging from 1.75-m (5.7-ft) to more than I1.0-m (36-ft) diam are available from several manufacturers; machines for mining applications generally have ranged between 1.75 and 6.0-m (5.7¬and 20.0-ft) diam. Tunneling machines usually operate at or near horizontal grades and are supported by a rail-haulage backup system. However, declines and inclines have been made using alternative backup equip¬ment. Either circular or shaped tunnels may be bored, depending upon the particular equipment used. Using tunneling machines to bore openings through rock offers several advantages over the use of the drilling and blasting technique. These advantages include a rapid advance, continuous operation, uniformity of the opening size, smooth walls, and safe working conditions. Compared to drilling and blasting, boring reduces the disturbance of adjacent rock, thereby reducing the ground-support requirements and the exposure to water inflows. The smooth walls provide natural arching and present minimum resistance to the flow of air. A tunneling machine should be considered a spe¬cialized mining tool that is well-suited to certain mining applications. Properly applied and sustained, a tunnel¬ing machine contributes to realizing substantial econo¬mies in the development of underground mines. All costs herein are expressed in 1977 US dollars, unless otherwise noted. The mention of trade names and manufacturers is not intended to imply an endorse¬ment of any specific equipment. TYPES OF TUNNELING MACHINES As listed in Table 1, five principal types of tunneling machines were being manufactured in 1977. Each type of machine offers a special solution to a specific mining problem. Although each of these types of machines is described herein, most of this chapter is devoted to the full-face rotary rock-tunneling machine that has demon¬strated the greatest production in both civil construction and mining applications. Full-Face Rotary Rock-Tunneling Machines As shown in Fig. 1, a full-face rotary rock-tunneling machine consists of a rotating head that is fitted with rock-cutting tools and is forced into the tunnel face. This head is supported by a bearing on a structural support member that, in turn, is held in place by a hydraulically positioned wall-gripping mechanism. Both torque and thrust are reacted from the cutterhead, through the structural support and gripper mechanism, and to the tunnel wall. The rock cuttings fall to the invert at the tunnel face, and they are removed by means of cutterhead buckets or scoops that transfer the cuttings to a conveyor belt. After advancing the cutter¬head through a preset boring stroke, the tunneling machine is advanced by hydraulically pulling the gripper mechanism in from the tunnel walls, stroking forward, and resetting the gripper to the new forward position on the wall; the machine then is set for the next advance stroke. Full-face machines cut only circular openings. Ma¬chines with diameters as small as 1.8 m (6 ft) and as large as 6.1 m (20 ft) have been used in mining applica¬tions, excavating rock with unconfined compressive strengths in excess of 276 000 kPa (40,000 psi). Although special machines have been designed to turn on a radius of 30 m (100 ft) in both horizontal and vertical directions, the conveyors and backup sup¬port equipment generally limit tunneling machines to turns with a radius of more than 60 m (200 ft). The full-face rotary rock-tunneling machines have provided the fastest and most reliable production of any mining method or machine. These machines can be equipped to place any of a variety of ground-support systems, and they can be provided as "open" machines, as shown in Fig. 1, or as "shielded" machines, as shown in Fig. 2. The open machines have the advantage of allowing the ground to be supported as near to the tunnel face as possible. The shielded machines have been designed principally to allow placing precast con¬crete segments. The shielded machines completely pro¬tect the equipment and personnel at the heading, but they are economically limited to permanent long-life haulageways where full lining is required. Partial-Face Rotary Rock-Tunneling Machines As shown in Fig. 3, the partial-face rotary tunneling machine is equipped with a cutterhead that rotates slowly at about 0.21 rad/s (2.0 rpm). The single-disk cutterhead produces the tunnel section shown in Fig. 4 by means of an oscillating motion. These machines work on the undercutting principle, and they are avail¬able in spring-line dimensional increments of 0.1 m (0.32 ft) from 1.5 to 2.1 m (5.0 to 7.0 ft); the vertical dimensions are 2.4 to 3.2 m (8.0 to 10.5 ft), respec¬tively. Depending upon the tunnel width, the cutterhead disk may be fitted with from 8 to 16 drag-bit cutters. Penetration is achieved by means of hydraulic rams that force the tungsten-carbide bits into the rock mass. The operation is cyclic, with cutting occurring only on the upstroke. On the downstroke, the rotating cutter¬head draws the fallen muck from the invert into the panzer-type conveyor for rearward transfer. This feature allows time to either reposition ore cars or to exit the tunnel with muck trains while the machine is cutting, as shown in Fig. 5. Boom-Type Rotary Excavators The boom-type rotary-excavator tunneling machines commonly are known as boom-type continuous miners

Jan 1, 1982

By Donald S. Macdonald

"I AM thankful for this opportunity to address the Toronto Branch of The Canadian Institute of Mining and Metallurgy. The Members of your Institute can have a great influence on the direction in which the mineral policies of Canada will evolve, and to assure that optimum benefits from our country's vast mineral resources will accrue to the nation as a whole and to all its citizens. Today, I want to: (1) offer an outlook on the mineral industry for 1973; (2) talk briefly about the role of minerals in the total economy; and (3) outline some of our thinking with respect to a national minerals policy for Canada."

Jan 1, 1973

By B. Jensen, R. Davis, P. Golledge, A. D. S. Gillies, W. Urbanik Urbanik

A current program of research on the explosibility of coal dust/methane mixtures is described. During the study an explosion test chamber based on a novel design has been developed. This 20 litre open chamber uses a rotating drum concept for dust dispersion and infra-red sensors for dust concentration measurement. The chamber design allows different initiators to be tested while varying methane gas and coal dust concentrations. A new approach to the determination of coal dust concentration is included with a description of a dielectric dust probe. The measurement technique is based on the change in dielectric constant as the proportion of coal dust in air between probe capacitor plates increases or decreases. Characterization of coal dust samples is of vital importance. The particle size distribution, coal proximate analysis and elemental analysis were studied. Coal dust was sourced from airborne collected samples, settled dust from mine sources and seam channel samples crushed and sized. Explosibility test results indicate that a very low concentration of coal dust can form an explosible mixture when dispersed in methane concentration of just below five percent. With low temperature initiators, the coal dust lean limit concentration rises rapidly as the methane concentration is reduced. An accurate knowledge of the potential explosion hazards of coal dust and coal dust/methane mixture is necessary to establish safe operating conditions in underground mines. The research results outlined extend knowledge in this area.

Jan 1, 1989

By D A. Cuello, G B. Sharrock

The Prince Lyell orebody at Mount Lyell Mine has a rich mining history commencing with the open pit in 1935, which transitioned underground in 1972. Between 1972 and 2014 a total of 64 Mt was mined underground as the mine extended from 210 m to 1100 m below surface. As the depth increased, three separate transitions in the mining method occurred to meet the changing geotechnical conditions, ore grade, mining costs and metal prices. The first was open stoping with pillar recovery in 1972, followed by front caving and longitudinal sublevel caving (1995), and finally transverse sublevel caving (2004 to 2014). This paper provides an overview of key geotechnical and planning milestones relating to the evolution of the mining method including underground stability, gravity flow, cavability and subsidence. Key aspects of the mine design, geotechnical parameters and rock mass response are described and critiqued with reference to observational, numerical and empirical methods.CITATION:Sharrock, G B and Cuello, D A, 2016. Geotechnical milestones at Mount Lyell Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 427–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Brennan D. J

The trend worldwide is for increasingly stringent control of sulphur dioxide emissions to the environment. It is therefore likely that Australian industry will be placed under increased pressure to restrict such emissions, and this will have implications for Australian smelters of mineral sulphide ores. Traditional outlets for sulphur dioxide emissions have been in sulphuric acid manufacture, but Australian demand for sulphuric acid has declined markedly in recent years. This paper examines the balance of supply and demand for sulphur and related products in Australia, the shifts occurring in that balance and the underlying causes of those trends.

Jan 1, 1994