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By Eggins SM, Crawford AJ, Maillet P

The Fiji Islands are remnants of a once continuous Solomon-Vanuatu-Fiji-Tonga volcanic arc (the Vitiaz arc), located at the boundary between the Indian-Australian and Pacific plates. They record a history of (i) arc volcanism the late Eocene to late Miocene, (ii) an extensive magmatic response to arc rifting (5.5-3.OMa) during which volcanism was dominated by shoshonitic to tholeiitic basalts, and as rifting continued, (iii) a transition from arc to intraplate volcanism. The Hunter Ridge-Hunter Fracture Zone separates the inactive South Fiji Basin from the actively spreading North Fiji Basin, and has been considered to be a transform zone, almost parallel to the motion vector of the Australian plate. However rocks dredged during the 1993 `Alize' cruise, from along the northern part of the Hunter Ridge are typical arc tholeiites, and therefore demand that subduction has occurred beneath the Hunter Ridge sometime during the last û 5Ma.

Jan 1, 1995

By Komosa T, Muir D. M

Mixtures of ammonia and cyanide at low concentrations leach gold selectively from copper-gold ores. The effects of various reagent compositions on three different ore types containing between 0.3 - 1.5 per cent Cu are reported. It is shown that the results and optimum compositions vary according to the ore, which is attributed in part to the mineralogy and adsorption of solution species on the mineral surfaces. The solution chemistry of the Cu-NH3-CN system indicates that Cu(CN)a - and Cu(CN)3 species are involved in the leaching mechanism. Rotating disc studies on pure gold and copper are reported which show that the Cu(CN)32- species leach gold at about half the rate of CN but leach copper at the same rate. The presence of ammonia retards the leaching rate further. Mixtures of Cu(CN)a3- and NH3 effectively leach gold from Telfer tailing without leaching copper. The role of ammonia appears to be to control the precipitation of copper rather than the kinetics of leaching.

Jan 1, 1991

Surface geological observations are predominantly two-dimensional but can be expanded into three dimensions using geophysical techniques. These techniques have proved succ- essful in the past and will be utilised more frequently in future mineral exploration. Geophysical training establishments must recog- nize future requirements and teach geophysics as part of a broad earth science course as well as a specialised geophysical course. Central- isation of teaching skills, the use of high- technology in the classroom, and greater interaction between academic and industry staff are recommended as a means of ensuring a vibrant geophysical training base in Australia, for the geophysicist of the future.

Jan 1, 1986

By P Moarefvand, M Osanloo

The anticipated economic life of the mine, which defines the rate of mine production, is dictated initially by the design capacity of the mill/concentrator and the production capacity of the mine relative to the grade and tonnage of ore that can be encompassed by the pit design. A small pit will result in smaller investment and cash flow; in contrast, a larger size of pit will increase capital investment and annual revenue. Since open pit mine design and long-term production sequencing are essentially based on three-dimensional block models, changes in block dimensions leads to different mine sizes, and therefore changes in the mine life. The physical characteristics of the deposit, such as reserve tonnage and ore grade, affect the expected future revenues from the mining project, and consequently they affect the life of the mine. Large blocks will increase the recoverable ore reserves and production rates and hence increase the mine life. This paper discusses the effects of the block dimension on the commercial ore reserve, grade-tonnage curve and its effect on the production rate, ultimate pit size, mining cost and consequently the mine life. The result shows that block height is the most effective parameter governing the economical life of the mine.

Sep 26, 2011

The general theme of the paper is a resume of factors which induce management to explore for oil, gas, coal and uranium in Australia. It is non-technical in the sense that apart from brief references exploration techniques are not covered. The central theme is the interplay of such diverse factors as taxation, mining 'regu- lations, exploration costs, availability of competent personnel, potential markets within and outside Australia, projected prices of sources of energy and their distortion by governmental action including restrictions on international trade for economic or political reasons, the role of the so-called multi- national companies, extreme views by pressure groups on the preservation of the environment, the availability of funds for exploration and the possible returns to the providers of exploration monies.

Jan 1, 1974

The author describes 1. The classification and characteristics of various thick seam mining techniques in various Japanese coal mines. 2. Practices of thick seam mining methods experienced in Taiheiyo Coal Mine. Currently, thick single lift, simultaneous multi lift and non simul- taneous multi lift mining methods are adopted as underground flat thick seam excavations in Japan. These are now reliable and effective in increasing the extraction ratio. At Kushiro Colliery of Taiheiyo Coal Mining Co., these three thick seam mining methods have been used. According to the results, if solidification of the top lift goaf is essential, the non simul- taneous multi lift mining method is the most effective in increasing the extraction ratio without minimising productivity of each lift and it points out that further development of this method is necessary.

Jan 1, 1976

The treatment of beach sands in'' the Bunbury/Capel' area for the extraction of ilmenite is a very recent development in the mining industry in'J7estern Australia. Nevertheless since the commencement of production in 1956, ilmenite has become the sixth most important mineral produced. The increasing world recognition of W.A. as a major' Iiroducer of ilmenite is due primarily ' to its low chromic oxide. ; (Cr203 content,, 0,03% to 0.04%, combined with a medium to high grade TiO2 content, 54% - 6 , supported by large reserves, a'. stable government with close access to good shipping facilities.. Ilmenite is produced from-these deposits at low-costs, enabling the industry to compete on world markets despite high rates for sea freights because of the distance from.major markets.

Jan 1, 1964

By Mercer JK

This paper gives a description of the research undertaken by an explosives manufacturer to give better technical advice to the Mineral Industry. Blasting Physics is defined as giving a systematic and coherent account of the initiation and subsequent effects of high explosives upon the surrounding medium. As a result of this work a mathematical model based on the gener- ally accepted mechanism of blasting has been developed. The mechanism and the resulting model are briefly outlined. IFrom'this model the effects of burden, spacing, blasthole diameter, rock and explosive properties upon fragmentation and heave can be calculated. Using these calculations it is then possible to see how variations in frag Imentation and heave can affect the overall production costs of a mine whether it is surface or underground. The overall costs are made up of a number of individual costs - drilling, blasting, loading, hauling and crushing. ach of these operations influences or is influenced by fragmentation and heave s these costs are inter-related, the

Jan 1, 1975

Over the 20 years to 1990 the Australian mining industry, presently worth some $A60 billion, generated a negative real rate of return (McDonald, 1992); not surprisingly under-performing the returns from bonds and industrial equities. Over this same period more than $A70 billion was invested in expanding the Australian mineral industry.

Jan 1, 1993

Current mine ventilation systems have evolved from simple, limited energy, series or multi split layouts motivated by low suction, slow running, surface fans. Concentration of coal production from fewer working places and ventilation splits, and varying needs, hazards and challenges, however, have led to substan- tial changes. Modern ventilation systems, therefore, are more complex, sometimes more interdependent on others, more energy intensive, and are founded on the use of multiple airways and greater suction, higher speed surface ventilators and often booster fans. Intensi- fication of output has resulted also in higher gas emission rates, the wide adoption of fire- damp drainage, and sometimes in particular problems such as spontaneous firedamp emissions. Some coal mines are subject to spontaneous outbursts of coal and firedamp. These and related matters and current practices and developments are leading to discernible trends, potential advances, and further changes in Practice.

Jan 1, 1983

Gentlemen, you heard the good Doctor has commissioned me to make a'summary of the proceedings to date and also to close the said proceedings. It seems that over the years the business of making a summary alternates between'Mr. Pearce and myself, also I,think that w~oever is around onthe day in question 'obtains the task and apparently I drew it this, year. It is hoped you will be patient as previous experience in this capacity'indicates that the best way to proceed is to have a brief summary on each paper and then do a summary of summa~ies. This makes the approacha little cumbersome but it is felt to be fair to each author and it brings'back to the audience some recollections of what transpired at the time and they can make their own decisions, which may not necessarily agree with those of the 'sum'marisor.

Jan 1, 1983

By Bruce See J

Oxidation of artificial Imperial Smelting Furnace lead bullion was performed during cooling between 1180 and 820°C in order to attempt to produce a tin-rich dross.The addition of sodium carbonate together with stirring increased the tin content of the dross when oxidation was carried out with air or PbO on zinc-free bullion.Zinc in the bullion during oxidation resulted in a decrease in tin concentration of the dross due to zinc oxidation and copper entering the dross.

Jan 1, 1987

By Smith M, Milton T, Pitt G

High levels of contamination (non magnetics) were present in the magnetite medium of the D.M. cyclone circuit. Attempts were made to minimise the amount of undersize (-lmm) material in the D.M. cyclone feed by improving initial desliming and examining those factors that contributed to any overall reduction in desliming efficiency. Circuit density control was improved and a system of continuous contamination monitoring implemented. A brief description is included of the major alterations to circuit control philosophy. The significant improvement in overall D.M. cyclone circuit performance is outlined.

Jan 1, 1987

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

The facilities used and techniques employed in the manufacture of steel and iron rolls at the Steel Foundry, B.H.P., Iron & Steel Works, Newcastle are described.

Jan 1, 1972

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 Williams RE, Ralston DR

Acid mine drainage is a serious environmental and economic concern, resulting in regulation of the mining industry and significant water treatment costs. An interdisciplinary approach is needed to analyze the many aspects of a complex acid drainage problem. This paper describes the integrated application of techniques from the following fields to the characterization of acid drainage at a large underground lead-zinc mine: 1) hydrogeology, 2) surface stream analysis, 3) structural analysis of fracture distribution, 4) hydrochemistry, 5) geostatistics, and 6) multivariate statistics. The Bunker Hill Mine in northern Idaho, is developed in highly fractured and faulted quartzites and discharges 95 L/sec of water with an average pH of 2.8 and an average zinc concentration of 120 mg/L. Research has been conducted on all aspects of the acid water production and drainage problem. Recharge to the mine has been investigated using geophysical techniques and tracer studies. Fracture mapping and geostatistical analysis of the fracture data have been used to determine characteristics of inflow to the mine workings. Hydrograph analysis techniques have been applied to water flow data within the underground workings. Chemical sampling and analysis have been used to identify acid producing workings, and better understand mechanisms controlling acid water production. Multivariate statistical techniques have been applied to analyze the quality and flow data. Research results from the many subprojects of the Bunker Hill study reveal the importance of an interdisciplinary approach to the analysis of acid mine drainage problems.

Jan 1, 1988

Twelve years ago, Jeffrey Mining Machinery Division of Dresser Industries Inc. developed the 120H HELIMINER. This machine was the world's first fixed-drum continuous miner and soon became the standard among manufacturers of continuous miners throughout the mining machinery industry. This paper will first outline a brief history of continuous miner development, then discuss significant parameters which are essential to a successful continuous miner design, and finally describe a number of specific applications of Jeffrey continuous miners in a variety of materials, such as coal, potash, iron ore, and trona, around the world.

Jan 1, 1978

By Jackson D. G

Iron ore mineralisation in the Paraburdoo environs is known to extend almost continuously over a strike length of 55 kilometres. Six formations of the Mount Bruce Supergroup con- tain high grade mineralisation in varying degrees of importance. Ore is currently being mined from the Joffre and Dales Gorge Members of the Brockman Iron Formation, with smaller, less significant amounts, occasionally taken from the lowermost units of the Weeli Wolli Formation and the upper parts of the Mount McRae Shale. Regional mapping has demonstrated the existance locally of a major unconformity at the base of the Wyloo Group sediments out- cropping south of the minesite. The basal con- glomerates at the unconformity are sometimes mineralised at Paraburdoo. A supergene enrich- ment process controlled by structure, strati- graphy and topography is the only one which can satisfactorily explain the disposition and chemistry of the Paraburdoo iron orebodies.

Jan 1, 1979

In the face of intense global competition and other business pressures on coal miners, ongoing quality initiatives and continuous process improvements are needed to enhance business performance. By viewing a minesite in terms of key processes, rather then departments, and employing innovative technologies and better applying organisational resources, there exists enormous potential to achieve reductions in process cost and time.

Jan 1, 1998