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Relationships between lead blast furnace performance and the composition and size distribution of sinter were determined from analysis of lead blast furnace operating data. Sintering plant practice was subsequently modified and substantially improved furnace performance resulted.

Jan 1, 1971

By Kovscek P. D, Thimons E. D

The Bureau of Mines equipped a longwall shearer with a water- jet-assisted cutting system and measured dust levels during the cutting of a simulated coal block. The block was cut dry, at a conventional water spray pressure of 1 MPa and with water-jet-assisted cutting pressures ranging from 7 to 40 MPa. At water pressures of 20 MPa and higher, dust concentrations were reduced by as much as 85 % via water-jet-assisted cutting in comparison with conventional water sprays. This reduction was achieved without any increase in the water flow rate.

Jan 1, 1988

By Sheng X. L

The Jurassic coals at Datong are characterised by their strong, massive sandstone and conglomerate roofs which fail suddenly over large areas, crushing pillars and creating destructive windblasts. collapsed areas have exceeded 180,000m2 and windblasts have extended over one km underground and 200m on the surface and have been accompanied by subsidence troughs on the surface. Scientific analysis has researched premonitory signs of caving and the nature of windblasts leading to considerations of alternative mining methods and ways of dissipating the energy of windblasts to reduce their damage and danger..

Jan 1, 1992

Robe River Mining manages a large open pit iron ore mine in the Pilbara region of the North-West of Australia. The mine is managed for various joint venture participants.In July 1986, Robe River Mining made various changes to its management philosophy, which were heavily publicised in the media at the time.As a result of those changes to its management philosophy, Robe River Mining has been able to dramatically increase its production output, productivity, and safety performance without having to resort to major capital outlays and without the benefit of restructuring of applicable industrial awards.

Jan 1, 1992

By B Tadesse, L G. Dyer, B Albijanic, M Jung

The presence of high concentrations of dissolved ions in groundwater, sea water or recycled water may alter the water structure, particle surface wettability and colloidal interactions between bubbles and particles and can have a significant effect on mineral flotation. While the impact of water quality on the flotation of precious and base metal minerals is well established, no relevant published study exists currently regarding the effect of water salinity on the flotation of rare earth bearing minerals. This paper attempts to quantify the effect of water quality variation on flotation recovery and grade of rare earth minerals and gain an understanding on which ions existing in saline water affect flotation behaviour. Specifically, it is aimed at investigating the effects of water quality on the flotation of monazite in the presence of cations such as Ca2+, Mg2+, K+, and Na+. Flotation tests, zeta potential measurements, and adsorption tests were performed to explain the flotation behaviour. It was found that monovalent ions such as Na+ and K+ have negative impact on rare earth minerals recovery and grade. The result of single mineral flotation tests showed that the floatability of monazite was significantly depressed in the presence of Ca2+ and Mg2+. The result of single mineral flotation test showed varying depression levels in the presence ions in the order of Ca2+ > Mg2+ > Na ~ K.

Aug 24, 2022

The advancements achieved in rapid tunnelling in the 60's and 70's have been notable. It is unfortunate that shaft sinking has not enjoyed equivalent advances and there are many good reasons why this is so. Technical and commercial considerations have held back development and continue to do so despite the increasing urgency in the search for minerals and energy. By the careful selection of an appropri- ate project and the application of specialist engineering the Bdard took advantage of a unique opportunity to apply a mechanised shaft borer in field conditions.

Jan 1, 1981

Any project carries a number of challenges and risks. Inappropriate design, poor project management, time, industrial disputation and capital over runs are all areas which can impact on a project cash flows and return on investment. In the resource Industry you have the added complexity and risk of geology which is difficult to predict and sometimes unforgiving. The Dartbrook Mine was designed and constructed as a high output longwall mine and has overcome a number of hurdles to produce over 2.3 million tonnes for the first year of operation. A number of problems were encountered during construction which resulted in the inseam development being delayed for six months. Dartbrook people have demonstrated they can manage adversity and produce world class results. The mine has been through a very steep learning curve during 1997 and with this experience behind the mine is now producing at an annualised rate of 3.4 MTPA.

Jan 1, 1998

The genesis of the Bulong Laterite Ni/Co deposit spans some 60 per cent of earth history: from development of the parent rocks in the Archaean to lateritic weathering in the Cainozoic. In a man's term, the discovery and evaluation history of the deposits has also been protracted and, at any given time, the perceived value of the deposits has depended upon the available technology and world markets.

Jan 1, 1996

By Chilman G. F, Lean P. J

The New Broken Hill Oonsolidated LImited (NBHC) concentrator was commissioned in 1952 and underwent a number of expansions over the next 25 years. In 1978, the decision was taken to expand further from 1.20 million tonne/yr to 1.43 million tonne/yr. This increase necessitated a substantial modification to an already over-taxed grinding circuit. The circuit consisted of rod mills, ball mills and rake classifiers. Plant data of grinding mill performance was obtained to develop mathematical models of individual units that could be combined to simulate total circuit performance in a number of configurations. The data provided further illustration of the validity of the perfect mixing model for relatively small increments of ball mill scale-up.

Jan 1, 1983

The resources industry is unique in that the finite nature of resource deposits requires a participant to be constantly locating and developing new ones to replace those that are depleted. An effective growth strategy that enables new project developments to be brought on line in time and within budget is therefore of fundamental importance to any mineral resources company. This paper seeks to identify the role of the development project in the company's overall growth strategy and the key performance criteria that a development project must achieve in order to allow a company to meet its growth objectives.

Jan 1, 1997

By Graham JW, Cullen GV

edicted increase in, Aluminium production and the possibility of a diminishing supply of petroleum coke for anode electrodes in alumina reduction cells makes it desirable to find alternative electrode materials. Brown coal char, with a lower ash content and with an elemental purity similar to petroleum coke, has been produced by leaching in hydrochloric acid, washing with water and charring at 115000. The cost of processing is estimated to be competitive with petroleum coke. Without further processing the bulk density and real density were undesirably low, but. by briquetting the coal before charring and crushing, the bulk density was improved to 92 per cent of the petroleum coke value and the Particle density was improved to 92 per cent of the density of petroleum coke by water-displacement or 75 per cent by mercury displacement. Pre-baked electrodes were prepared from the char alone, mixtures of petroleum coke and char and from petroleum coke alone, all bonded with coal tar pitch. The electrodes were tested for the usual physical properties and were, evaluated for performance in a laboratory size alumina reduction cell. Electrodes based on brown coal char alone were found to be inferior in physical properties, and performance, but mixtures of the char and petroleum coke, despite poorer density, electrical resistivity and carbon consumption on a theoretical basis, in performance tests gave up to 17 per cent better carbon consumption per weight of aluminium produced and 21 percent better electrical current efficiency than the electrodes based on petroleum coke alone. It is suggested that larger scale tests are warranted.

Jan 1, 1970

By Deverux M

Heavy mineral deposits accumulate on shorelines with interrupted sediment input. Beach deposits, which form on shallowly dipping coastal plains, are most favourable. However, shallow shelves seaward of cliffed coastlines are known to contain economic deposits. Significantgeologicalconditions are defined, from review of the stratigraphic and geomorphic controls on known deposits , for heavy mineral accumulation on the Swan Coastal Plain.

Jan 1, 1986

The purpose of this paper is to present a detailed account of the development of the Blasthole Diamond Drilling method of stoping now used at the property of Big Bell Mines Limited, in Western Australia.The ore body is one of the large low grade gold deposits of this State, being a continuous lens 1,850 ft. long and ranging in width from 15 ft. at the ends to 120 ft. at the widest part, the average width being 59 ft. It was first worked in 1913 by a local syndicate, and up to 1924, when operations ceased, 64,448 tons of 3.4 dwt. ore were mined from a shallow open cut. Between 1928 and 1932, 15 deep diamond drill holes were put down to test the ore body at vertical depths ranging from 100 to 700 ft. On the information gained from these drill holes, Premier Gold Mining Co. Ltd. began underground explQration. A level was driven at a depth of 253 ft. and crosscuts put out to the full width of the, orebody at intervals of 100 ft. along the strike, all ore broken being put through a sampling plant. On completion of this sampling,' Big Bell Mines Limited was formed as the operating company, and a plant with a capacity of 1,000 long tons per day was erected and mining and milling operations were commenced in 1937. Ore was first mined from glory hole stopes, 65 ft. long, separated by 35 ft. pillars, by benching using conventional steel with changes up to 20 ft., all broken ore being hauled to the main shaft on the...

Jan 1, 1948

By Golosinski T. S, Jorgenson J. D

Several methods are available for inspections of mine shafts. These involve use of inclinometers, moving beams, inertial platforms and decelerometers. Inspections which use decelerometers are of most interest since they allow assessment of conditions of shaft steelwork, conveyances and the shaft itself. This assessment is based on recording and analysing dynamic behaviour of shaft conveyances. Sample inspections of several WA shafts confirm feasibility of using this method for periodic shaft Inspections.

Jan 1, 1995

Major discrepancies between mine estimates and estimates from plant metallurgical balances are a common problem in many gold and base metals mines around the world. Many existing practices are based on practical protocols that often fall short

Jan 1, 1998

By G MacSporran, I Sheppard

The practical application of LaneÆs theory on optimum cut-off grade policy has to date proved difficult for selective stoping in large-scale underground mining. The key to determining an optimum cut-off grade is the ability to rapidly perform complex mine layout designs combined with rapid output of multiple potential schedules. This paper describes aspects of the detailed investigation into estimating a practical static cut-off grade for the two main orebodies in Mount Isa MineÆs Enterprise Mine. Rule based automated scheduling software was used to evaluate thirteen different stoping layouts (including design infrastructure and capital development) of the Enterprise MineÆs two main orebodies, with over 200 schedules generated. The investigation illustrates the application of commercially available software to solve the problems of generating multiple cut-off grade stope designs and achieving the otherwise insurmountable task of rapidly generating and valuing multiple scenarios for each stoping layout. Each scenario was evaluated using modelled net cash flows of the mining, concentrating and smelting operations of the company and calculating NPV. The cut-off grade for each orebody was selected based on the cut-off grade that achieved maximum NPV û with an appropriate production rate. Underground mine scheduling is a complex task involving the adherence to a number of simple scheduling rules and the balancing of several competing drivers. The study also found that: while each scheduling rule itself is simple, the compounding complexities of their interaction preclude manual scheduling from being a realistic option. there is a maximum sustainable rate of production possible for any given stoping layout, and that the actual maximum production rate is also a function of the required number of years of sustainable production. the optimal cut-off grade was different for each orebody û a recognition of the impact of the different characteristics of each orebody.

Jan 1, 2003

By M E. Rakidjan

The DOZ underground mine at PT Freeport Indonesia is a copper and gold mine in Indonesia with current ore production of 42 000 tpd. Because of the mine expansion into the West DOZ more ventilation raises are needed to create a safe and healthy work place. All ventilation raises that connect the extraction levels to the underlying gallery exhaust drifts at DOZ are now developed using drop raise techniques. This paper describes the improvements undertaken to increase blasting efficiency, to decrease cost and reduce safety risks. This was achieved by using deck loading and presplitting, changing of stemming materials and prevention of excessive raise collar cratering (blow up).

Jan 1, 2005

By Mazandarani M, Chabot L, Vichion K

Pitch-steering models have been developed for discretely advanced mining machines (such as heading machines and coal shearers) using small-angle geometry and there are illustrative examples of simulator predicted performance. Although simple linear models result from the analysis of open-based machines, sledge mounted machines require execution of a Linear Programming energy minimisation to determine the attitude of the machine base at each advance over the previously cut floor steps. An analytical approach is based on elastic beam concepts developed for such applications as longwall face conveyors, caterpillar tracked machines such as continuous miners and longhole drills. Simulation results for longhole drills show the expected performance of an automatic guidance system and the destabilizing effects of sensing deviation too far behind the drill bit. Certain drill bit boundary conditions are expected to assist TBM. steering studies in three dimensions.There is a real role in mining machine steering for the mathematical models used in flight simulators.

Jan 1, 1991

By Kyle J. H, Misra V. N

The most recent development in gold processing is the increasing use of heap leaching for the extraction of gold from low grade ore, and old tailings dumps. The reason for this trend is mainly to do with economics. The advantage of heap leaching is the considerable saving in both capital and operating costs. However, not all ores are amenable to heap leaching. It is only applicable to well oxidized ores that have suitable permeability char- acteristics, and the gold recovery is poorer than by conventional process. In this study, an attempt has ben made to ascertain the heap leaching characteristics of Western Australian gold ores on the bench scale using multiple, appropriately sized leach columns. The influence of particle size, flow rate, column depth and leaching time on the rate of gold extraction was determined. The percolation rate of cyanide leaching solution was deter- mined with and without gypsum additions. Efforts were also made to minimise particle segregation, fines migration and solution channelling during leaching, so as to improve solution percolation, gold extraction rate and recovery.

Jan 1, 1991

By Rajan S, Mainwaring P, Gould WD, Beaulne M

Polished discs of a complex sulphide ore were leached with three lixiviants; a mixed culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, Thiobacillus ferrooxidanalone, and ferric sulphate. At either one or two week intervals the discs were examined by scanning electron microscopy, and the amount of soluble metals released from the discs were determined. The mixed culture solubilized more Cu, Zn and Pb than did either ferric sulphate or T. ferrooxidans alone. However, no differ-ences were observed between the three treat-ments by scanning electron microscopy during the first 44 weeks. The minerals were attacked in the following order: pyrrhotite, cubanite, sphalerite, pyrite and chalcopyrite.

Jan 1, 1990