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By H R. Phillips

The ventilation and refrigeration design of underground mines is an important aspect, when new or existing mines are considered and places a great responsibility on engineers tasked to do so. The current trend for both local and international underground mines is to extend their search for valuable ore reserves deeper below surface. In South Africa, the predictions are that about 40 kt of actual gold still lies in situ, ready for extraction. As mines extend their search for minerals of economic value deeper and deeper into the earthÆs crust, ventilation and refrigeration aspects of such mines become more prominent than before. The planning and design of the required ventilation and refrigeration within these mines, over their expected lifetime is important including the practical implications of such designs. Technology changes and improvements need to be incorporated into ventilation and refrigeration designs, where possible and advances in this specialised field explored. This paper explores ventilation and refrigeration design aspects within the underground mine sphere. Aspects such as mining depth, virgin rock temperature (VRT), mining methods, and different cooling applications available including ventilation supply are reviewed in design applications. Heat generally becomes a significant aspect to counter in these mines and they are not always necessarily deep mines.

Jan 1, 2005

By M B. McKevitt, W J. Shaw

The main task of grade control on a daily basis is to define the material that should be mined to a destination under various categories. This can be determined by grade, lithology, quality and blending criteria. In the case of multi-element deposits or deposits with various blending or other processing criteria the optimum selection of ore block boundaries can be quite complex. In every case the balance between ore loss and dilution must be considered when designing the ore block boundaries and this becomes a risk-based decision when using the conditional simulation model. The use of such systems allows grade control to meet specific targets, such as budget tonnages and grades and blended product specifications. Two case studies are presented: the Prominent Hill copper/gold mine and the Rapu Rapu zinc/copper mine. Mining is based on a rational grade control strategy involving a number of factors, including strong geological control, advanced geostatistical approaches, such as conditional simulation, and optimisation of the ore blocking to meet production requirements. This provides an objective, transparent and repeatable grade control strategy.

Jan 1, 2009

There was a time, in the memory of some here tonight, when the annual meeting of The Institute was a nostalgic occasion. Often, in the 1920s, there was comment on the decline of Australian mining and on the lack of new mineral discoveries. When some of our Presidents prayed then for a new Bendigo, and instead were given a Mount Isa, they were justifiably disappointed because of the vastly different capital requirements.In 1967 the mining picture is very different. The recent mining developments in Australia are certainly as important as several Bendigos and several Kalgoorlies. The mining industry in Australia has never been more dynamic than today (Table 1). And if we ask why it is so dynamic, the answer lies in the role which overseas capital is playing in the industry. The contribution of overseas capital should concern us not only because we are members of the mining and metallurgical profession, but also because we have a duty to make our profession contribute as much as possible to the well-being of Australians. It is not sufficient to argue that overseas capital is good for the mining industry; we must also examine whether it is good for the economy and the nation. In this context the current criticism of the inflow of overseas capital into Australian mining is useful, for it gives us an opportunity to see what has resulted from the inflow.In discussing this question I do not suggest that we emulate Captain Hancock, that legendary Moonta mine manager who, according to Oswald Pryor's cartoon, used to say to his miners: "When I say a thing is, it is, even if it isn't". The question can only be discussed on a factual basis; and I would submit that many of the important facts relating to overseas capital in our mining industry are often overlooked or ignored. I would further submit, on the basis of these facts, that Australia's present day mining industry has been largely built on overseas capital and that the overall benefits of that capital to Australia have been enormous.

Jan 1, 1967

Although most N.S.W. coal mines contain large amounts of combustible materials such as coal and timber, the introduction of mechanisation has extended the range of combustible materials now found underground. The role of combustible material in a fire is not clearly understood and as a result the assessment of these materials for flammability by small and large scale tests is doubtful. Extensive research has been carried out on the toxic and irritating gases evolved during the combustion of plastics. However, most autopsies report death due to carbon monoxide inhalation because the combined toxicity of smoke and fire gases is unknown.

Jan 1, 1981

By Sinha NH

ICI Australia and CSIRO have developed a novel process for extraction of zirconia from zircon sands. The two stage process involves a high temperature step and a wet chemical processing step. A pilot plant has been operating since November 1985 at CSIRO Division of Mineral Chemistry, Port Melbourne and construction of a full scale plant isplanned at Kwinana, WA.The plant has a high degree of flexibility and is capable of producing high purity zirconia up to about 99.99% and withinspecific particle size ranges. The products are being marketed by the joint company, 2-TECH Pty Ltd.

Jan 1, 1986

An extensive study was carried out to evaluate the performance of Outokumpu OK50, OK38 and Maxwell MX14 cells at ComincoÆs Red Dog flotation concentrator in Alaska. Tests were conducted by varying operating conditions of the cells installed in different circuits in the plant. The hydrodynamic and gas dispersion properties were measured and the metallurgical performance of the cells was evaluated for each condition used in the tests. This paper highlights the importance of superficial gas velocity, bubble surface area flux, gas hold-up, power consumption, residence time distribution and froth flow behaviour in optimising cell performance. The findings of these tests provide valuable insights into selection of the best cell operating conditions to optimise circuit performance.

Jan 1, 2000

By C R. Headley, S O. Hille, N P. Jacob

The redevelopment of the Telfer Gold Mine in the Pilbara region of Western Australia was primarily based on the construction of a 17 Mtpa dual train concentrator coupled with open pit and underground mining operations. The unique copper-gold orebody at Telfer requires the application of complex flotation conditions normally reserved for base metal concentrators, where two competing minerals are managed into separate products. This paper describes the commissioning of the flotation circuit, the process modes and the master/slave relationship that flotation has with a variable orebody.

Jan 1, 2007

In this paper the reactions which may lead to particle hydrophobicity/hydrophilicity as a function of grinding environment-are reviewed. The results of pulp chemical investigations related to a Cu-Pb-Zn ore on a pilot plant scale and laboratory tests with a Pb-Zn ore to evaluate the effect of some inhibitors on grinding/flotation are presented. The flotation recoveries of the ores treated by conventional and autogenous grinding methods show only a marginal difference and the results favour autogenous grinding. Iron originating from several sources manifests in the form of insoluble hydroxy complexes in the pulps. Such metal hydroxy complexes are hydrophilic and coat the mineral surfaces indiscriminately. On the other hand, selectivity is a problem for pulps ground by autogenous milling. Some corrosion inhibitors used in the laboratory grinding/flotation tests on a Pb-Zn ore showed maximum reduction in the wear of the grinding media ranging from 25 - 36 per cent, depending on the type and concentration of the inhibitor.

Jan 1, 1993

For decades strip mining with discon tinuously operating 'draglines and shovels has been the most economical operation method in the shallow hard coal opencast mines of Aust- ralia, North-America and some other countries. Continuously operating equipment such as bucket chain excavators and bucket wheel excavators in combination with conveyor belt systems, conveyor bridges and stackers had been deve- loped in Germany; during the last 25 years this type of equipment has been further developed in order to allow a high degree of rationaliza= tion as to opencast mines in unconsolidated overburden in Germany, in many European couh- tries, in India and in Victoria. The differing compactness of the layers to be mined, the increasing mining depth, the adverse over- burden to coal ratio and geotechnical con- ditions account for the combined use of con- tinuously and discontinuously operating equip- ment and systems. This paper is to demonstrate some projects showing the combination of continuously and discontinuously operating equipment which aims at optimizing opencast mine operations. It will be reported on the following combinations: - combined use of bucket wheel excavator/

Jan 1, 1981

Geologists often classify ore textures on the basis of the origin of the rock in which they form and the grade of one or more minerals within the ore (Sinclair and Blackwell, 2002, pp 32-36).  Metallurgists, on the other hand, need to know how best to process the ore in order to extract the valuable minerals from it (Petruk, 2000). Geological classification has the following disadvantages:it requires the services of skilled economic geologists, of whom the supply has been dwindling for many years;it is subjective, depending on the perceptions of the individual geologists who make the classification; andit may relate only weakly to processing requirements of the ore. We describe methodology for automatic classification of ore textures from images of drill core. The images analysed are æclassifiedÆ images, in which a particular mineral (or mineral group) is assigned to each pixel. The new methodology is intended to:provide a quantitative and reproducible alternative to traditional geological texture classification,relate to process mineralogy of the ore, andimprove the ore-texture-related input to orebody domaining and geostatistical block models.

Jan 1, 2008

Efforts to stabilize international markets in commodities have gradually intensified during the course of this century in keeping with the grow- ing complexity and interdependence of the world economy and the increasing involvement of government in economic activity. Successive Australian Governments have con- sistently supported the concept of commodity agreements and arrangements in an effort to lessen short term fluctuations in price and to moderate the boom/bust conditions which tend to charac- terize production and trade in many commodities. The objective is to stabilize price at a level which equates supply and demand over the life of the arrangement. Such action involves a degree of market inter- vention and government involvement in the inter- national trade in the commodity concerned; the acceptability and desire to foster such arrange- ments varies from country to country depending upon attitudes to market intervention and man- agement. However attitudes, even among those opposing commodity agreements, have under- gone a major reversal in this century. Before the first world war, such intervention as existed almost entirely involved the physical producers. There was almost no government involvement and at that level most regarded commodity agree- ments as neither desirable nor practical. However government regulation of such activities as pro- duction and marketing of food during World War I, coupled with post-war shortages, followed by overproduction and the crash in prices during the Great Depression, stimulated producer gov- ernment interest in commodity market regulation. Consumer governments took a little longer and with a few exceptions, it was not until the post World War II period, that the fear of shortages of basic commodities brought some consumer countries to accept the concept.

Jan 1, 1978

By J L. Merritt

Effective minesite water management requires that this issue be treated as a risk management exercise. The management process is generally far from simple and by necessity must involve a range of personnel covering a siteÆs commercial, operational and environmental interests and responsibilities. The challenge to be collectively faced by these stakeholders is to strike the correct balance between risk and cost. On the other hand, the challenge to be faced by technical services support personnel is to provide stakeholders with information in a format that they can use with confidence. This paper presents the application of continuous operational simulation (OPSIM) modelling techniques to establish appropriate risk profiles for minesite operations. It is necessary that the format of these risk profiles be generic and equally applicable for defining the risk of occurrence for a relatively comprehensive range of activities û eg from of a non-compliant discharge, to the risk of failure to meet production targets. What is more, the profiles need to be quantitatively based and capable of reflecting change in system response to varied operational or management strategies. The techniques presented in this paper are based around a key assumption that long-term records of the climate contain within them sets of sequences that are representative of what can be expected in the future û that is, the droughts, floods, cyclones, good years and bad, long or short, and everything in between. Therefore, if these historical records are run through an OPSIM model for a particular site, then the simulated operational characteristics can be taken as being representative of what can be expected in the future, in the long-term. This lends itself to statistical analysis and translation into the required risk based format. Water Solutions Pty Ltd have been working with Capricorn Coal Management to develop a relatively comprehensive OPSIM model of their operations at German Creek Mine, Central Queensland. Outcomes from the modelling have been used in recent times to provide mine management with risk-based guidelines for both securing and containing mine water inventories. One of the more interesting tasks has been to establish risk based inventory levels that, if reached, would trigger the immediate implementation of a contract for the desalination and re-use of mine water, at predefined rates. Also, lead-time warning of the occurrence of a possible trigger is of importance to operational and commercial planning. To service this requirement the OPSIM model is regularly used to produce lead-time estimates to defined levels of confidence. Case studies of these, and other, applications of the OPSIM model at German Creek Mine are presented in this paper and serve to demonstrate an effective methodology for practical risked based water management.

Jan 1, 2003

The Greenvale Joint Venturers, Metals Exploration Queensland Pty. Ltd. and Freeport Queensland Nickel Incorporated, use ten Herreshoff roasters, for the reduction of ground lateritic nickel and cobalt containing ores.Initially the roasting section of the plant limited production, due to high down time.The use of technology developed and adapted over a number of years has achieved significant increase in on line time and a minimization of costs.

Jan 1, 1985

The aim of the study was to determine the ranges of stability and instability of the metal hydroxides and metal cyanide species that may be formed during the gold extraction process, Merrill-Crowe gold precipitation, and Inco S02/Air or ferrous ion cyanide removal processes.Following cyanide detoxification by the Inco S02/Air process, the main components of concern in the tailings will be:

Jan 1, 1997

There are a number of methodologies which can be used for the preparation of environ- mental impact statements. Selection of a method depends upon the type of project and the environmental characteristics of the area where it is to be built. Most methods are satisfactory for assessing impacts on the physical environment but less so for the biological. Major problems may arise in deal ing with sociological issues because value judgements are involved. Several methods of approaching problems of this nature have been tried with some limited success.

Jan 1, 1976

Only West Australian entrepreneurs and Queensland politicians generate more debate than the uses and abuses of expert reports. Indeed, there are 300 of us here today to debate the very issues that, in general, have been unsatisfactorily managed by regulators and industry to date. I imagine Trevor Sykes will have some interesting stories to tell tomorrow morning in describing "Mines that weren't quite".

Jan 1, 1989

By Brown D. N, Troth D. A

Large blast furnaces demand high standards of preparation of feed materials which must meet tight specifications of chemical and physical quality. Measurement of these factors must be expeditious but the nature of the coke, sinter, ores and fluxes and the large tonnages involved requires substantial mechanical sampling plant. The equipment, its operations, and its problems, associated with the 5000 t.p.d. No.5 blast furnace at Australian Iron and Steel Pty. Ltd., Port Kembla, are described and the efficacy of chemical blending achieved in the ore blending yards and sintering operation, is reported.

Jan 1, 1976

By Jones

Extractive metallurgy in the mining industry in Western Australia has diversified and increased in the last 11 years. Before 1980, the industry mainly produced alumina, nickel, mineral sands and iron ore, with the gold industry restricted to five operating plants using Merrill-Crowe technology. In 1981 Carbon-in-pulp (C]P) plants were commissioned at Kambalda, Kalgoorlie and Meekatharra.Currently, the gold industry has some seventy CIP plants in operation, production of synthetic rutile has increased tenfold to 500 000 tpa, alumina production has doubled and production of copper, lead and zinc concentrates has begun. Other extractive metallurgy plants recover tin, niobium and tantalum, silicon, titanium dioxide and zirconia. Current proposals include vanadium, steel and rare earths.

Jan 1, 1992

By R Uken G P Whitmore

The coastal dune cordon of northern KwaZulu-Natal is amongst the highest in the world reaching heights in excess of 180 m and up to 2 km in width. It comprises a complex system of Quaternary stacked dunes of various geomorphologies, types and ages. The dunes contain economic heavy minerals which are currently exploited ~20 km north of Richards Bay. Although mining of these ore sands has been in operation for the last two decades, little work has been undertken on the clay-fraction (

Jan 1, 2001

Some fundamental aspects of recent single-particle fracture studies are reviewed. Findings from this research shed new light on the utilisation of energy during comminution operations and provide useful pointers to new research directions that could lead to significantly better comminution machines. Two methods for quantitatively predicting mineral liberation during comminution are reviewed. These methods have been developed into useful practical procedures, but they are almost unknown in the mineral processing community. Their use should promote the consideration of mineral liberation as an important variable to be considered during the design and operating control of comminution circuits.

Jan 1, 1993