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Great new drilling results! What's so sinful about being a multi-national company? Overseas protestors flown to Australia for a free holiday How to counter the protectionist danger? Our current economic standing Over-regulation puts a convicted paedophile on the payroll The broken window fallacy Mining - A shared history Aristotle and the camels A brighter future? Something over which we do have far greater control, i.e. leadership within our own industry My challenge to you The expanding gold- producing company of which I am proud to be Chairman, Croesus Mining NL, is by definition a æmultinationalÆ. Our shareholders are based in 36 different countries, 77% of our 107 million shares are held in Australia, 23% are held outside Australia, and include New Zealand holdings of 7%. In September, Croesus Mining presented our company at the Mining 2000 Forum in Melbourne, a city caught up with multinational protestors demonstrating against multi-national companies.  

Jan 1, 2000

Marble deposits of dolomitic variety are available in large quantities in India and for extracting these deposits diamond wire saw cutting machine is mainly used. Cutting performance of the diamond wire saw machine depends on rock parameters, machine parameters and operational parameters. Rock parameters related to physico-mechanical properties, such as, compressive strength, tensile strength, shear strength, modulus of elasticity and abrasion resistance of marble play role in determining cutting rate and beads wear rate. Thus, this study was undertaken to determine the relationship between different physico-mechanical properties and cutting performance. This work also aimed at enhancing the cutting performance of diamond wire saw in dolomitic marble deposit. Study was conducted in the field at three different zones having deposit of soft, medium hard and hard dolomitic marble. During the study, cutting rates and wearing of diamond beads were recorded in the field. Physico-mechanical properties were determined in the laboratory. The results obtained were subsequently evaluated by using statistical analysis. Study revealed that these properties of marble play a significant role in the performance of diamond wire saw machine. Predictive equations for the wearing of diamond beads and cutting rate were developed based on regression models. Results of this study will be of ample use for operators of wire saw to achieve maximum cutting performance and for manufacturers in designing the diamond beads.

Dec 6, 2010

By Robson W. D, Irwin D. A

In November, 1932, an investigation of silicosis was undertaken at the, McIntyre Porcupine Mine, Schumacher, Ont., atfer a discussion of the problem with Sir Frederick Banting and his, staff. As a result it was decided to carry on dusting experiments with animals at the mine in a manner that would duplicate as far as possible actual industrial conditions.At that time 50, guinea pigs were placed in the crusher nouse tunnel of the mill where a considerable quantity of fine dust, containing approximately 35 per cent., of free silica, was being constantly produced. These animals lived in this atmosphere for periods up to one year, and, while on autopsy large amounts of dust were found in the lungs, not a single case of silicosis had developed. These negative results suggested, among other things, that the mine gases might be a predisposing factor in the production of silicosis, and the results of this investigation led us to undertake the study of the hydrogen-ion concentration of the condensate of the atmosphere, both in the mine and in various sections of the mill.The C02 combining power of blood serum on a series of 400 miners was also studied at this time. While these results were inconclusive, the variation in the hydrogen-ion concentration of the condensate between the surface and underground atmospheres encouraged us to investigate the effect of neutral, weak acid and alkaline solutions on the solubility of silicious materials. Gye and Purdy were the first to point out that the chemical reaction and not the physical presence of silicious material was responsible for the production of the fibrosis in silicosis. This work was investigated by Gardner and Cummings who showed that the tissue reaction to quartz was definitely proportional to the size of the particle. They found that 1-3 micron particles of quartz produced an acute proliferative fibrotic response while the 10-12 micron particles produced only a foreign body reaction up to a period of three years. It is accepted that the dangerous silica particles retained by the lung are under 5 microns in diameter. We assumed that if the solubility of the silicious material retained in the lung could be reduced sufficiently by the addition of some non-toxic element or compound the usual fibrotic respohse would be modified. We found that the addition of certain compounds to silica would reduce its solubility in the beaker to a slight extent. But these compounds, when mixed with quartz...

Jan 1, 1945

There are no large rivers in Western Australia capable of supplying water for processing magnetite ores. If sea water is used there are severe corrosion issues and the requirement to wash the concentrates with potable water. If groundwater is used there is a need to treat the water and sustainability is an issue for large projects because of potential drawdown of the aquifer.If sea water is desalinated the cost of the water is high because of the power requirement. At the same time the necessity to conserve water has lead to flow sheets where all of the tailings have to be filtered to minimise the water requirement.Managing the various water qualities and optimising water recovery and quality has resulted in optimising the water balance and issues meeting environmental obligations. Reverse flotation is a critical final step in reducing the silica level in the final concentrate and requires good quality water.

Jan 1, 2009

In 1953, Dr. N. H. Fisher of the Bureau of Mineral Resources, acting on behalf of the Society of Economic Geologists, which is considering the sponsoring of a uniform system of nomenclature for ore reserves, enquired from the Australasian Institute of Mining and Metallurgy whether it had ever considered this subject and particularly whether it had ever set up any standard definitions or specifications with regard to ore reserves.As this had not been done, but was thought to be desirable, the Council of the Institute appointed a Committee consisting of H. H. Dunkin, Associate, Professor of Mining Engineering, University of Melbourne (Convenor), E. A. Rudd, Professor of Economic Geology, University of Adelaide, I. N. Campbell, Chief Geologist of Western Mining Corporation; and the writer to consider and report on this supject.In December 1953, the Committee submitted its first report to the council and this report (reproduced here as an Appendix) was widely circulated among member companies, and engineers, with an invitation to comment on the proposal. A large number of, replies was received and studied.After studying the replies the Committee issued a second report in part as follows:-From these replies we have learned that the suggestions made in the first teport of the Committee are unacceptable to most of those interested, on one or all, of the following grounds;-(a) number of categories,(b) definition of categories;(c) nomenclature.

Jan 1, 1955

Following extensive trials on a 100 000 tpa Research and Development facility at Kwinana, Western Australia, Hismelt Corporation (wholly owned by Rio Tinto) are confident of the future commercial success of this technology. The Hlsmelt process uses iron ore fines and non-coking coals to produce molten pig iron suitable for feeding to BOF and EAF steelmaking vessels. The unique process configuration combines direct injection of raw materials into the molten iron bath, high rates of metal and slag mixing, and effective post-combustion of the bath gases to achieve efficient coal utilisation. This is the key to the strong economic performance of the process.

Jan 1, 1999

THE ore treated is almost pure copper pyrites (chalcopyrite) in a gangue of quartz and quartz-felsite. Very little free iron sulphide (pyrite) occurs, and at the time of the erection of the flotation plant the stopes in the oxidized zone had been almostentirely depleted. This zone only extends to a shallow depth, and, below the l00-ft. level, the sulphide for the most part is clean and bright but in the crushed and brecciated parts of the ore channel, where surface water has circulated freely, the gangue is decomposed and kaolinized, and the copper sulphide badly tarnished. This class of ore gave considerable trouble at the mill, but unfortunately, was very limited in quantity. A sample of rich ore assayed-Copper, 21.2 %; iron, 24:.3 %; silica, 28.9 %; sulphur, 25.1%.The concentration in the original mill was effected by handpicking, jigging, and tabling. A considerable portion of the copper mineral arrives at the surface in the form of large lumps of very pure quality, eminently suitable for sorting out by hand.The rich ore is tipped over a grizzly at the shaft bins; the oversize hand-picked, and the undersize bagged direct.

Jan 1, 1912

When asked to lecture at Bendigo on the geological factors that determine the depths of ore deposits, I hesitated for a little before agreeing to lecture on the theory of deep ores in the city world famous as the pioneer of deep gold mining. If there be one place, wherein the conditions of deep-seated ore deposits should be sufficiently well understood, it is the city where the 180 mine made its bold plunge to previously neglected depths; and where the record of that famous mine has been broken by the skill of the managers, and the pluck of the proprietors, of the New Chum Railway and Lazarus mines.In the face of such practical triumphs, theoretical discussion may seem a waste of time, especially since it is often dedared that the existence of such deep-seated ores was denied by geological theory. This assertion is, however, startling since the oldest and best supported geoiogical theory of ore deposits, has taught for more than a century tliat ores must descend far below the regions of practical mining. This charge against Victorian geologists is generally based on opinions attributed to the late Sir Fredrick McCoy. It has been repeatedly affirmed that he declared that gold cannot occur pelow a depth of 300 feet. But so far I have not been able to discover that McCoy ever made any such assertion or ever held such a view.

Jan 1, 1902

Particles of a complex nickel sulphide concentrate (containing pyrite, pyrrhotite, pentIandite, and violarite as the major mineralogical constituents) were entrained in a stream of hot gas the temperature of which was varied from 500 to -1000°C. Chemical analysis of the particulates collected from the furnace was used to detect the rapid change in sulphur content which accompanied the ignition temperature jump. X-ray diffraction analysis was used to characterize the oxidized material.These techniques showed that ignition was dependent on the mineralogical composition and occurred over the temperature range 500-900°C. Pyrite ignited first in the range 500-600°C; pyrrhotite was the least reactivemineral and required temperatures in excess of 800°C for ignition. The nickel minerals <pentIandite and violarite decomposed before ignition and ignited at temperatures intermediate to those required for the pyrite and pyrrhotite. The ignition temperature for the pyrite was found to be independent of particle size and concentration of oxygen in the atmosphere.Ignition temperatures determined by the simulated flash smelting method were compared with the results of differential thermal analysis (DTA) measurements performed on the same concentrate. Temperaturesdetermined in the DTA test as corresponding to the start of exothermic activity were shown to be at least 100°C below those determined by the simulation test.

Jan 1, 1978

For tax purposes a mining company is a New Zealand company whose principal source of income is from the business of mining, or exploring for certain specified minerals in New Zealand. New Zealand tax law distinguishes between a non-resident mining operator and a mining company, with the only major difference in tax treatment being the corporate tax rates. New Zealand mining companies are taxed at 28 per cent, whereas non-resident mining operators are taxed at 33 per cent of taxable income. These provisions also apply to the petroleum mining industry. Individuals who carry on the business of mining are also specifically defined in the Act. They are termed as 'resident mining operators'. Non-resident mining operators are non-residents of New Zealand who carry on mining ventures as a business in New Zealand. Mining ventures are defined as the exploring, searching and mining of specified minerals, including development work carried out for profits. Similar provisions apply to the petroleum mining sector. Specified minerals are defined in the Income Tax Act 1976 ('the Act') and while no useful purpose is obtained by listing them in the paper, they include a larger number of industrial and commercial minerals. The Minister of Finance is also empowered to add to the list by publishing his determination in the Gazette.

Jan 1, 1988

A predicted 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. Browncoal char, with a lower ash content and with an elemental purity similar to petroleum coke, was produced by leaching in hydrochloric acid, washing with water, and charring at 1,150°C. The cost of processing is estimated tobe 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 andthe 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 consumptionon a theoretical basis, in performance tests gave up to 17 per cent better carbon consumption per weight of aluminium produced and 21 per cent better electrical current efficiency than the electrodes based on petroleum,coke alone.It is suggested that larger scale tests are warranted.

Jan 1, 1971

The following paper on the development of processes for the treatment of crude ore, accumulated dumps of tailing and slime at Broken Hill, has been prepared by a committee of the Broken Hill Branch of the Australasian Institute of Mining and Metallurgy, with the object of recording, in chronological order, the developments of the various processes which have led up to the metallurgical practice of the present day.

Jan 1, 1930

By L Avalos, F Melo Miranda, J Misle, M Ingwersen

"Los Pelambres, majority owned by the Chilean company Antofagasta Minerals, is one of the leading producers of copper and molybdenum in the country. It is located high in Andes Mountains, over 3000 metres above sea level, 316 km from the nation's capital, Santiago.The maintenance service supplied to Los Pelambres over the past 13 years has evolved to the point that FLSmidth now provides an integrated service crucial to the management of their customer's assets. The contract initially involved specialty mechanical, electrical and instrumentation maintenance and has developed to encompass maintenance planning and plant control systems.The integrated partnership has delivered excellent results in the areas of improved availability, reliability and return on investment. The operation is now amongst the industry leaders in plant availability.The integrated maintenance service has delivered: An increase in plant availability from 93%, in the first year, to 96.5% today, generating approximately $50 million additional income per year, Quality work procedures, Process and equipment improvements, Major shutdown planning involving more than 700 personnel, 6000 parts and over 2 000 discrete activities.The ongoing success of the partnership requires a high level of understanding between both companies. A commitment to maintain a long term sustainable relationship, based on a ""win - win"" culture, is the key to this success. In this regard Los Pelambres has been a pioneer in establishing and developing such relationships.This case study will share the lessons learnt, the measures taken to improve performance and the best practices adopted during the 13 year evolution of the maintenance service partnership.CITATION:Misle, J, Melo Miranda, F, Avalos, L and Ingwersen, M, 2013. Integrated maintenance services at the Los Pelambres Mine in Chile - The lessons learnt and best practices developed from a long-term sustainable relationship, in Proceedings MetPlant 2013 , pp 296-331 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

The metallogenic map of New Zealand shows the distribution of metallic mineral deposits, according to type and size, in relation to their geological setting. The major purpose of the map and accompanying 200-page monograph is to summarise the distribution, modes of occurrence and origins of the metallic mineral deposits of New Zealand. The map demonstrates the prospectivity of New Zealand for metallic minerals, particularly gold, silver, iron, and titanium. Information on each deposit is summarised in index tables based on major geotectonic units or deposit/commodity type. The mineral deposits are arranged and discussed in relation to tectonostratigraphic and tectonomagmatic units or terranes, under broad geotectonic divisions of the Paleozoic to Mesozoic Western Province, the late Paleozoic to Mesozoic Eastern Province, the mid Cretaceous to early Tertiary rifting phase, and the late Cenozoic Kaikoura Orogen. Regions or areas of marked concentration of mineralisation are recognised as metallogenic subprovinces or districts, namely: eastern Northland (Hg), the Hauraki Goldfield (epithermal Au-Ag-Pb-Zn-Cu), the west coast of the North Island (shoreline placer Fe), east Nelson (podiform Cr), west Nelson (porphyry Mo), the West Coast of the South Island (shoreline placer Ti), west Nelson-Westland (placer Au), Reefton (mesothermal Au-quartz veins), and Otago (placer Au and mesothermal Au-W quartz veins).

Jan 1, 1993

By Bohrn W, Milionis K, Tessmer G, Reidetschlager J

The share of electric arc furnace based steel production is increasing - New technologies for the production of virgin raw materials for EAF production are under development and on the market - VAI has a strong position in the field of scrap substitution technologies with their COREX«-, COREX«-DR and FINMET«-technology. In late-1998 the steel plant SALDANHA was started up successfully. This integrated compact mill is using the COREX«-technology as hot metal and a combined DR-plant as DRI production unit. Also in 1999 the BHB FINMET« plant Port Headland went on Stream.

Jan 1, 1999

By P. S. B. STEWART

As part of a continuing study of mechanisms of breakage, the grinding at Nairne Pyrites Pty. Ltd. was traced by the addition of barytes and the results compared with parallel small scale laboratory tests. It was confirmed that the same basic mathematical functions described the behaviour of the full scale ball mill as those established in the small scale mill. However, an additional classification function was required to define the behaviour for the rod mill and was evaluated as a function of size from the experimental data. The classification and grinding of the pyrites ore was assessed from steady state size distributions around the circuit.

Jan 1, 1971

The need for the hydraulic transportation of coal in the New South Wales coal industry, both from the coal face to the surface and from the coal mine to the consumer or the port for export, is explained. Details of research projects currently in'progress and involving the hydraulic transportation of New South Wales coals are given together with information on the hydraulic transportation of coal in the United States of America.The potential of hydraulic transportation as a viable alternative to the proposed expansion and upgrading of the New South Wales railway system to meet the projected New South Wales coal production to the year 2000 is described.

Jan 1, 1980

By P C. Couper, P C. Keall, S J. Mathews, A Francis

An epithermal gold-silver deposit is presently being developed at the Golden Cross Mine in the Waitekauri Valley, 8 km northwest of Waihi, New Zealand. Highest grade mineralisation underground is mainly confined to an elongate zone of strongly banded quartz veining on the hangingwall. Footwall veining is irregular, flatter lying, and of lower grade. Hydrothermal breccias in the ore zone may have economic grades where clasts of vein quartz are present. Jigsaw breccias, shingle breccias, and layered breccias with sedimentary type structures such as layering, crossbedding, and graded bedding have been identified proximal to, and within, quartz veins. Mineralisation in the open pit occurs in and adjacent to stockwork quartz veining.   Three alteration zones are recognised: a central silicic zone enclosing Au-Ag bearing quartz veins, an argillic zone above the stockwork zone and in the footwall of the underground ore zone, and a propylitic zone which is gradational with argillic zone. Intense shearing is confined to the less competent argillic zone.   Precious metal mineralogy consists of electrum (65% Au; 35% Ag) and argentiferous tetrahedrite, polybasite, pyrargyrite, argentite, and native silver. Pyrite is the dominant sulphide mineral. Marcasite, arsenopyrite, and rare chalcopyrite and sphalerite also occur. Oxidation ranges from a few metres in the argillic western stockwork zone to 100 m in fractured rock in the footwall of the stockwork.   The open pit contains a proved and probable reserve of 2.1 million tonne grading 3.5 g/t Au and 17 g/t Ag. The underground mine will produce 2.7 million tonne grading 7.8g/t Au and 27g/t Ag.

Jan 1, 1991

By Cadman S. J

( The central part of the Gippsland Basin is surrounded by existing major Petroleum accumulations and although six exploration wells have been drilled in the area, none are significant petroleum discoveries. Post drilling analyses indicate that the wells were drilled off structure due to the presence of high-velocity Miocene channels. These channels contain carbonates of significantly higher interval velocity than the surrounding sediments. Problems with seismic interpretation were thus encountered in the development of prospects in the central part of the Gippsland Basin as part of a BMR prospectivity study. The seismic interpretation problems associated with the Miocene channels are two-way time pull-ups at the underlying top of Latrobe Group and deeper levels on the seismic sections. Interpreted seismic sections passing through some of the exploration wells and the Miocene channels are presented to illustrate the configurations of these channels and the pullup effect associated with them. Two different methods of depth conversion were applied, one for the area below the high velocity channels and the other for the area away from the channel. The application of these two methods of depth conversion were found to be reasonably successful in correcting for the pull-ups caused by the high velocity Miocene channels. Mapping of the events near the top of Latrobe Group and near Base Lower L balmei seismic horizons has led to the identification of several potential structural closures. Further exploration efforts are necessary in this area to test these closures.

Jan 1, 1992

Draft tube circulators are now widely used instead of Pachucas for suspension of slurries in large tall tanks.Precipitators in the alumina industry are an example.Draft tube/tank diameter ratio is critical. Two independent criteria are given for optimum ratio. The hydraulic and energy relationships are defined. These require an impeller of very high specific speed. For a stable and efficient system the impeller should have aerofoil blades with a pitch angle which decreases from hub to tip.The draft tube must be matched to the impeller with inlet baffles above the impeller and flow control vanes below it. Tip recirculation must be suppressed. The tank itself should have a filleted flat bottom.Such a system exhibits the behaviour of axial flow devices with the characteristic undesirable behaviour at low flow.Installed and operating power requirements depend critically on hydraulic design and to a lesser extent on speed reducer efficiency.The problems of re-suspension have been overcome by a patented slot system which also improves behaviour at low flow to permit a more economic design. A number of other practical operating considerations are also discussed.

Jan 1, 1982