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By Smith P

The past 20 years have seen the replacement of hydraulic control of longwall mining systems by the neater. smaller and better controlled electronic units.Early problems of moisture and other effects on reliability were overcome to see electronically controlled supports chosen for Corrimal Colliery ten years ago. Lessons from Corrimal and elsewhere, with following improvements and sophistication led to wider use as exemplified by Meco and other electronically controlled supports used in more recent installations in New South Wales, Queensland, USA and Czechoslovakia of the total of over 80 electronically controlled support installations worldwide in the past decade. Present work is toward a fully "integrated face" of British Coal by 1993, incorporating the Meco automatic face straightening system already due for practical use in the UK later this year. However the manless face still appears to be some way off although the present minimum crews and close monitoring, including early warning, are promising stages.

Jan 1, 1991

The Cleveland Mine has an annual ore production of 400,000 tonnes at a grade of 0.79 per cent tin and 0.30 per cent copper. It is achieved by an open stoping method, mechanised overhead sub-level benching. The operation is trackless with a ramp access from all working places to the surf- ace. Broken material is loaded from the stope and development headings into diesel trucks and hauled to the surface crushing plant.

Jan 1, 1977

New Zealand Steel Limited is nearing completion of the environmental reporting and planning procedures for its proposed fivefold expansion to steelmaking at Glenbrook, and supporting mining operations at Waikato North Head. A report on the proposal to transport concentrate from the mining operations to Glenbrook has also been prepared and is awaiting release. This paper draws from these events, and by discussing some of the problems encountered, gives some guidelines for the preparation of an Environmental Impact Report.

Jan 1, 1981

Reconnaissance geochemical exploration in the vicinity of low angle detachment faults which bound the core of the Paparoa metamorphic core complex yielded Au up to 14 ppm, with 35% of greywacke, granitoid and quartz vein samples in the northern range exceeding the 0.01 ppm detection limit. Au is associated with Ag, As, Sb and Cu anomalies consistent with epithermal-type mineralisation. The Ag and Cu anomalies also distinguish this mineralisation from older, mesothermal Au deposits widespread in the Ordovician 'slate belt' greywackes, which comprise much of the upper plate of the core complex. Baryte, molybdenite, fluorite and stratiform U mineralisation in the northern Paparoa Range may also be related to hydrothermal activity along the detachment fault zones.

Jan 1, 1995

Consideration was given to the.applicab on of a solvent extraction circuit to be'included in the process'for the-recovery of a high grade product from.:-the Rum Jungle Creek.South uranium ore body.The economics of two alternative processes, firstly the Eluex process which uses an ion exchange process followed by solvent extraction.-of a.high grade sulphuric acid eluate, and secondly a process using direct solvent' extractioh of pregnant leach liquor, were studied. There was a small cost advantage favouring the Eluex process but when other factors were considered, the installation of a direct solvent extraction process appeared the better long term investment. A solvent extraction plant was installed at Rum Jungle in 1962.

Jan 1, 1963

By R G. Barker, N Mortimer

In New Zealand, platinum group metals (PGM) occur in three main geological environments of economic interest: layered mafic igneous complexes, the Dun Mountain Ophiolite Belt, and in association with placer gold deposits. Most of the layered mafic complexes with PGM potential occur in the Median Batholith. These include the Longwood (Permian), Bluff (Permian), Riwaka (Devonian) and Rotoroa (Jurassic) igneous complexes. Exploration of the Longwood Complex discovered PGM associated with gabbroic rocks. Best assays to date include a 1 m drill intersection of 1 g/t Pt + Pd and float rock with 3.0 ppm Pt and 3.3 ppm Pd. The Greenhills complex at Bluff consists of basal dunite overlain by wehrlite and gabbro. PGM occur with chrome spinel in the basal dunite and Pt geochemical anomalies have been identified associated with the wehrlite-gabbro contact zone. The Greenhills complex has some similarities to Alaskan-Ural type complexes.Reconnaissance exploration in the Dun Mountain Ophiolite Belt has identified PGM geochemical anomalies, but no follow-up work has been carried out. During the late 1800s and early 1900s, PGM were recovered as a byproduct of placer gold mining in Southland. Placer gold prospects with PGM potential include the Waiau River, deposits flanking the Longwood Complex and some Southland beaches.

Jan 1, 2002

By Seedsman R. W

Good roads are essential in moving men and materials to and from the underground workplace. Coffey Partners International Pty Ltd (Coffey) has recently completed a underground coal industry funded project on underground mine road construction and maintenance. This paper discusses practical approaches to construction and maintenance of underground mine roads using transferrable civil technologies and innovative techniques. Mine pavements are generally low-cost (relative to civil roads), constructed to varying standards using locally available materials to best meet the mobility needs of the mine. Performance of pavements is thus largely dependent on the environmental conditions, quality of the available road making materials, maintenance policies and available resources. The paper will detail `what causes bad roads?' in various underground environments, available management strategies, construction and water control techniques, road maintenance and vehicle considerations.

Jan 1, 1995

A large scale distributed process con-trol system has been successfully applied to the automatic control of aluminium reduction cells at Boyne Smelters. A three stage hierarchy of minicomputers and microcomputers is used to continuously monitor and control conditions in each cell and to manage the data generated during the process.The automation hardware was purchased on the basis of low cost, high reliability, prior use in the aluminium industry and a high level of backup under failure conditions. The hardware has met performance criteria to date.The process control strategies have continually been updated to minimise the energy and raw material consumptions in each cell. A major change to systems software has recently been made to decrease the development time for-future changes. Various low energy potline retrofit alterations are currently being investigated requiring significant changes to the process control strategies.

Jan 1, 1985

The Coke Ovens Laboratory at Australian Iron & Steel, Port Kembla has been involved in the analysis of seam gases and mine airs for approximately twenty (20) years. This period has seen many developments and changes in the techniques used to the point when the current techniques are equal to other labora- tories involved in similar analyses. The laboratory has NATA registration for the analysis of mine airs and gases. Apart from routine testing of seam gases, ventilation airs and gases emmitted from coal bore cores a number of projects have been undertaken. These have served a twofold purpose, one to provide information to the customer, generally Collieries Research and Technology and secondly in developing the skills and capabilities of the Coke Ovens Laboratory. This paper discusses the development and services available at the Coke Ovens Laboratory for the analysis of gases and airs from collieries.

Jan 1, 1983

A comparison is made between bord and pillar and longwall coal mining. Longwall mining presents a challenge to raise the level of management and engineering practice. To maintain a competitive position in the world export market, the Australian coal mining industry must continue to use and develop the most advanced, cost benefiting, safe mining systems.

Jan 1, 1987

By Taylor RN

A simple apparatus for delivering pulverized coal as fuel to a SIROSMELT lance is described, and its performance in smelting tests is evaluated. Using the pulverized coal as fuel, the SIROSMELT furnace performed well in both oxidative copper smelting and reductive smelting (zinc fuming). In both cases the evidence suggests that part of the combustion occurred by indirect oxidation of coal particles entrained in the bath. Oxygen potential measurements made during the zinc fuming tests confirmed the general features of the the non-equilibrium mechanism for zinc fuming proposed by Richards and Brimacombe. The zinc level in the slag during continuous fuming was lower than was predicted using an equilibrium model.

Jan 1, 1987

By Bowden MW

Sintering of lead-zinc concentrates is practised by Sulphide Corporation to provide both desulfurised lump sinter feed, for simultaneous reduction to zinc and lead in the Imperial Smelting Process blast furnace, and sulfur dioxide gas for sulfuric acid manufacture.Moisture control of feed mixes is of paramount importance in the sintering operation and improvements in this area have realised increases in overall plant performance.

Jan 1, 1985

Taiwan is situated between Ryukyu and the Philippines with 35,960 sq. km of area, being slightly larger than Belgium It has roughly a spindle-shaped outline with a longitudinal axis extending in a roughly north-south direction. Geologically, Taiwan is extremely complex in terms of its tectonic setting in the convergence zone between the Asian continent and the Philippine Sea Plate. To the east of Taiwan, the Philippine Sea Plate subducts beneath the Ryukyu island arc, and to the south of Taiwan the Philippine Sea Plate overrides the Asian plate along the Manila Trench. Taiwan, therefore, occupies an unstable region between these two well-defined subduction systems of opposite polarity (see the following block diagram).

Jan 1, 1987

China has large amounts of iron ore reserves, but iron ore in China, with low-grade, small disseminated particles and many other associated minerals, is difficult to dress. In recent years, with the fast development of China's steel industry, the demand for iron ore has increased markedly. The new technologies in iron ore dressing in China are very effective in processing haematite and other difficult to dress iron ores. The iron ore grade and recovery rate has been improved. This result alleviates the difficulty in iron ore supply in China.

Jan 1, 2007

By McHaina D. M, Hardcastle S. G

A description is given of an investigation into the feasibility of using controlled recirculation of warm exhaust air into the cold intake air of underground mines during winter. Canadian mines can experience inlet air temperatures of minus 30 ¦C and less, requiring them to pre-heat their intake air. The use of controlled recirculation would reduce the inlet air quantity and thus reduce heating costs which exceed $1M on some mines.

Jan 1, 1988

By Just G. D

Performance of draglines in large scale overburden stripping operations is critical to the efficiency of a major section of the Australian Coal Mining Industry. Optimisation of dragline productivity requires an understanding of a range of operating conditions and constraints. One of the least understood of these operations is the process of bucket filling and how this may vary with respect to variable operating conditions.Studies conducted at The University of Queensland over a number of years into this problem have enabled the mechanics of excavating to be assessed for different types of fragmented rock. In relation to bucket filling, factors such as fill volume, digging time and energy consumption have been found to be significant factors in optimising bucket design, bucket rigging and operational techniques.

Jan 1, 1992

By Ralph AM, Deakin JJ

A quantitative knowledge of underground mine ventilation requirements and conditions has become increasingly important, both to meet statutory requirements and to ensure high levels of safety and productivity within mines. The ACIRL Mine Ventilation System MINVENT was designed to provide a flexible means of analysing the behaviour of an underground mine ventilation system under a variety of conditions. It is not sufficient to rely solely on the analytical tools such as ventilation network analysis computer programs - these must be supported by the expertise necessary to conduct an accurate underground ventilation survey as well as experience of typical conditions to be expected in the evaluation of proposed extensions to a new or existing mine. When planning a new mine, the ventilation engineer can use the program to draw on a set of typical ventilation parameters, seam and proposed mining methods. These have been assembled as a result of numerous ventilation surveys conducted by ACIRL in New South Wales and Queensland.

Jan 1, 1983

By Yokozawa K, Yamamoto T, Kameoka Y

Japan Construction Method and Machinery Research Institute has been conducting various field surveys of tunnel works and other excavation works, and the cost and efficiency of these two excavation methods have been studied. Based on these data, the costs of blasting excavation and mechanical excavation represented by roadheaders were calculated. The costs were calculated and compared for rocks of various hardness. When the total construction cost is considered, the degree of overbreak becomes one of the most influencial factors, because the overbreak area must be filled up with expensive shotcrete in NATM. So, in the next step, the relation between the excavation costs considering overbreak and the rock hardness was studied using the data on overbreak obtained by the field survey.

Jan 1, 1987

The evolution of Hall process alumina reduction technology is des- cribed with particular attention to the pot lines. Future directions of tech- nological change are considered. It is predicted that the Hall process will continue to be the avenue for aluminium production for some time to come.

Jan 1, 1982

The foundation of our industrial welfare lies in the success of our primary industries, and, so far as mining is concerned, it is hoped that for many years it will be a most important primary industry in Western Australia.

Jan 1, 1927