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By Oboso A, Nakahiro Y, Takenaka Y, Wakamatsu T

As part of the fundamental studies on the recovery of Au by solvent extraction, the synergism of combined extractants on the extraction of An from the sulphuric acid solution containing thiourea was investigated. Extractants tested were di-(2-ethylhexyl)phosphoric acid (D2EHPA), tri-n-octylamine (TOA), tri-n-butyl phosphate (TBP), and trioctyl phosphine oxide (TOPO). Four kinds of extractant combinations, D2EHPA/TBP, D2EHPA/TOPO, TOA/I'BP, and TOAITOPO, were tested to clarify the synergism on the extraction of Au in terms of various concentration ratios, diluents, the concentration of sulphuric acid, and the concentration of thiourea.

Jan 1, 1993

The various functions of public relations are playing an increasingly important part in the activities of the many companies now engaged in oil exploration in Australia.Several of the larger exploration companies, notably West Australian Petroleum Pty.Limited, Ampol Exploration Limited, Caltex Oil (Australia) PtSr: Limited and Australian Oil and Gas Ltd. (and its American Associate Union-Kern), employ staff or consultant public relations specialists. In, most of the other companies now exploring in Australia, public relations are handled within the company, directed from the highest executive level.The object of public relations in.the oil industry is. to create in the public mind an impression favourable to the industry as a whole and'the company -or group of companies with which the public relations officer is associated.

Jan 1, 1962

The mineral resources of Hamersley Iron are structurally complex with fluctuations in mineral chemistry. Besides orebody charact- eristics, mineral recovery is also affected by stringent product quality demands from the competititve steel industry. Under such conditions, a geological ore reserve estimate has little meaning because it is unqualified and presupposes the defini- tion of ore. A system was developed in Hamersley - the Mine Planning Technique - to optimise recovery from available resources. This incremental planning method reduces a geological reserve statement into a simple, logical sequence of events. While there are limitations in the method used, the benefits are enormous. Among its' numerous applications, the schedule - the end product of the technique - plays an important role at Management level in decision making and policy formulation on all aspects of resource exploitation.

Jan 1, 1979

I have spent most of the past thirty-five years working as an economic geologist in the area of exploration and development of base and precious metals. Most of this period has been as an employee of Trans-National-Corporations (TNC's). I presently act as a consulting geologist to a joint venture company, bringing together two such TNC's: Anglo American' Corporation and affiliated companies De Beers (Diamonds) and Minorco (Metals mining outside of Southern Africa), and Normandy Mining Limited of Australia. Normandy is presently through its gold arm PosGold, Australia's largest gold miner and Anglo American can claim to be the world's largest gold company producing over 280 tonnes of gold a year, more than twice its nearest rival Gold Fields of South Africa. In addressing this topic, the role that Government can, and should play in mineral development, I will be drawing heavily on some examples from these and other TNC's experience in recent offshore mining Investment.

Jan 1, 1995

Fluid bed sulphation roasting of bismuth concentrates began at Warrego in 1980 in con- junction with the recommissioning of the Tennant Creek Smelter. This process, develop- ed by Peko Mines, is used to separate copper and bismuth by converting copper minerals to a water or weak acid soluble form and then leaching. Pilot scale testwork conducted at the Australian Mineral Development Laboratories (AMDEL) and by Dorr Oliver Pty Ltd in the USA indicated that close control of bed teaper- atures and exhaust gas composition was required to ensure high levels of soluble copper. After overcoming some initial problems, the plant now achieves typically 89 percent copper extraction. Plant capacity is 2.7 tonnes/h by design but in practice this is limited by feed analysis, air requirements, cyclone operation and calcine particle size Consideration.

Jan 1, 1984

This short paper outlines the authorÆs views regarding the present ability of the resources industry to manage its mining assets. It represents a personal view û but one founded in fact-based observations of mining companies and of the mining industry in general. It contends that whilst a great deal has been learnt about the management of mines over the last 500 years since the seminal work of Agricola, observations suggest that best practice management is the exception rather than the rule across our industry. Although insights regarding the successful management of mines have become apparent, we still witness unnecessary errors in our industry that lead to the loss of shareholdersÆ funds. By highlighting some aspects of current best practice, particularly in the arena of operations improvement, it is hoped that this short paper contributes a small step along the next 500-year-long learning curve. At a time of key skill shortages in our industry as mineral producers attempt to ramp-up production to capture historically high commodity prices, achieving best practice operations management has seldom been more critical.

Jan 1, 2006

Field investigation of surface subsidence events associated with both active and abandoned underground coal mines in the United States has established criteria that enable the prediction and classification of mine-related subsidence. The key was establishing the role of geology in all types of subsidence and the recognition of beam subsidence in specific geologic settings. The classification is based on overburden thickness, variations in stratigraphy, topography and mine plan. Types of subsidence are Pit, Room, Sag, and Beam. Pit subsidence is associated with three geologic settings: shale overburden, seasonally wet unconsolidated overburden, and perched water table in unconsolidated overburden. Room subsidence occurs where the roof across the width of the room fails to the surface and a shallow depression develops.

Jan 1, 1992

This subject of paramount importance in many modern plants employed in the extraction of gold from ores by cyanidation, involves several considerations.With the old-type "slimes decantation" process, using several tanks of large dimension, installed at high capital cost, it was frequently possible to obtain good settlement over a protracted period, but the disability of indifferent response to subsequent filtration and washing of the residual pulp, after decantation of the supernatant pregnant solution, was often present.In modern cyanidation practice, the tendency is to reduce capital expenditure by continuous processing of the ore pulp in a plant of less volume, but capable of handling more tonnage through-put and yielding, coincidently, less residual dissolved gold in the final pulp residues.INHIBITORY FACTORS.These involve a study of the effect of the circuit water or solution employed in milling and treatment, the amount of "primary" slime occurring in the ore broken underground, the constitution of the "walls" underground, the inherent occurrence of colloidal slime in partially decomposed ore, and the presence of kaolinised and ferruginous clayey structures carrying payable infiltrations of gold values, to mention some of the troubles encountered in practice. Practically all the difficulties occurring are due to the presence of colloids (using the metallurgical as apart from the chemical definition of the term), either...

Jan 1, 1935

By S Morrell, D Clark

æMine to MillÆ improvement involves optimising the chain of rock breakage processes from the in situ rock in the mine to the output of the concentrator. A growing number of paper studies and case histories from metalliferous mines (AusIMM, 1998; JKMRC, 1998; Clark and Scott, 2002) demonstrate that generating more breakage in the pit and the primary crusher can lead to benefits to milling that result in significant improvements to the economic performance of a mining project. However, unless the ævalueÆ of doing this (benefit over cost?) can be appropriately quantified, the approach cannot be effectively managed and the increases in blasting and monitoring costs cannot be justified.Mining operations have traditionally been organised into the separate departments of geology, mining and processing based on the specialist skills required and the different professional disciplines involved. Process optimisation across these boundaries has commonly been frustrated by management requirements to minimise the costs incurred by each department without adequate reference to the ævalueÆ being created. Companies have tended to discard positions that provide a technical over-view of the value chain, reducing the number of people with the opportunity to influence practices across these process boundaries.This paper discusses these issues and identifies measures required to quantify and manage the ævalueÆ provided by æMine to MillÆ improvement generated by the intense blasting of ore.

Jan 1, 2002

The Mount Lyell Company's concentrating mill is situated about a quarter of a mile westward of the portal of the North Lyell tunnel, which serves the North Lyell, Royal Tharsis and Crown Lyell mines, being on the 1100-ft. level of the first named. The Comstock mine is connected with the tram system at this level by five and a half miles of steam tramway, two-foot gauge being standard throughout.The plant is well placed with regard to all essential services and has an excellent water-supply from a series of three dams on the West Queen river.MILLING ORESThe mill feed is a mixture of the outputs from the foUr mines mentioned, each of which has its characteristic ore, but, generally speaking, about half of the ore consists of siliceous schists and the other half of hard grey quartzite. The schisty ores are easy to crush, but, on grinding, while the schist slimes readily, the quartz granules are hard, resulting in the handling of heavy loads on the secondary classifiers. The quartzite ores are both hard to crush and difficultto grind.The principal sulphide materials are bornite, chalcopyrite, and pyrite, chalcopyrite being the main copper-bearing mineral.The crystallization is coarse in the schisty ores, but it has been shown that even the 200 mesh (Tyler) material contains included sulphide particles. At the present time the sizing of the final tailing averages 80% through 200 mesh.

Jan 1, 1932

By S Johnston, L Howe, S Stevens

Regulators have an important role to play in fostering and enabling reliable, effective, environmental management. Given this, it is perhaps surprising that there has been relatively little debate on exactly how regulators can enhance their own approaches, in order to promote improved outcomes overall. The authors argue that applying research on High Reliability Organisations, as well as the University of Pennsylvania’s Penn Program Framework for Regulatory Excellence, to regulators has the potential to facilitate positive environmental results across the mine life cycle.

Aug 2, 2023

By F

Ore reserve estimation has been described as the most individualistic, the most prickly and even the most controversial of all the technical aspects of the mining profession. This symposium is a great opportunity to look at the present state of the art and full marks must go to the Sydney Branch for organi- sing it at this time. The first essential of good ore esti- mation is probably an awareness of the uncertainties involved, and the possible impli- cations of these uncertainties.

Jan 1, 1979

By Hamilton LH, Campbell PB

Since fundamental research in applied coal petrography is carried out mostly on polished surfaces, backscattered electron microscopy is most applicable for studying coal in the SEM. By employing this technique coal macerals can be easily identified , and information on the relations between maceral groups, mineral matter and trace elements are highlighted by grey level contrasts. This type of information is valuable in coal technology and cannot by normally revealed by the light microscopy (e.g. the distribution of inherent mineral matter).

Jan 1, 1989

The BHP Steel Group embarked on a Total Quality Control (TQC) programme in 1984 in response to enquiries from a major customer regarding procedures for quality in materials supply.The TQC initiative has been adopted by all seven Divisions of the Steel Group and covers a broad and comprehensive range of management and workforce improvement initiatives.The development of the TQC initiative in the Collieries Division of BHP Steel over the past eighteen months has resulted in important experiences and leanings.

Jan 1, 1991

The purpose of any feasibility study is to determine whether a particular investment or management program will enhance shareholder wealth by, for example, producing an economic return in excess of the cost of equity capital.The threshold rate of return conventionally used in gold feasibility studies is higher than the cost of equity capital, meaning that some viable projects are wrongly described as being sub-economic with their development deferred.Is the industry failing to fully realise its potential? Aside from important technical considerations that determine the cost of exploiting inground inventories, feasibility studies need to incorporate expectations about future gold prices, exchange rates, interest rates and tax rates.Rather than revert to speculation, insights from capital markets give a rigorous framework in which these parameters can be determined for feasibility purposes. Separate questions sometimes, and then inadequately, addressed by feasibility studies include: ò Is it optimum? Many projects are expanded soon after project commissioning - what does this say about the quality of the initial feasibility study? Moreover, does the rate of extraction really matter? ò What is it worth? Although feasibility studies are designed to address viability rather than valuation, such studies are never- theless used by the industry as further evidence that the equity markets have got it wrong again! More likely the problem is with the financial slide rule being used. ò Can it be debt financed? The bankable feasibility study has entered the vocabulary of the gold mining industry but what does it mean? Does it matter anyway how the project is to be Financed?

Jan 1, 1991

All minerals contain radioactive elements, from the uranium ores of the Gabon, which contained sufficient uranium to initiate a natural nuclear reactor, to the very low levels of some recent evaporites. The commonly occurring heavy minerals such as ilmenite, rutile and zircon are no exception to this and contain varying qualities of radionuclides, depending on the source. With recent changes in legislation many natural minerals may become officially classed as radioactive. Such moves can inhibit the sales and exploration of many minerals in the heavy minerals suite. The many negative perceptions associated with the word radioactivity can produce an over cautious reaction from regulators and users. This paper presents a method of managing the radioactivity issues associated with minerals such that the safety aspects of workers and public are not compromised, whilst allowing the commercial use of such minerals to continue in a sensible manner. The paper focuses mainly on the mineral zircon and its uses. However the legislation changes particularly in Europe and the USA have the potential to affect all minerals imported into or produced in those countries. The model developed for addressing the issues of zircon radioactivity may be readily applied to other minerals since legislation governing such matters is not mineral specific. There is a strong need for education of both regulators and users of minerals. Regulators are usually not aware of the specific properties or uses of individual minerals. Similarly mineral users are not aware of the radioactive nature of their materials or how to manage this property. The paper concludes by recommending strong cooperative action by both producers and users of minerals to protect the future of their industry.

Jan 1, 2001

Prospecting in arid terrain can produce substantial environmental impacts, comparable to or greater in magnitude than the impacts associated with actual mining or petroleum production. Impacts are likely to be particularly severe where prospecting involves intensive geophysical exploration, especially in areas which have escaped degradation by other land uses such as pastoralism. With appropriate environmental planning and management, however, the environmental impacts of prospecting in arid terrain can be greatly reduced and mitigated, at low cost. In many countries, prospecting licences, exploration leases and associated tenements now carry a range of conditions relating to environmental protection. The assessment, avoidance and mitigation of environmental impacts is therefore an important component of and-zone exploration. My aim here is to give an overview of some of the main aspects of an environmental planning and management (EPM) programme for prospecting in arid terrain (PAT). Detailed operational prescriptions for environmental protection procedures are necessarily specific to particular areas and types of prospecting: see. e.g., Buckley (1982a, 1984, 1985a, 1986a), Klepacki et al. (1985) and Stone (1986). The intention here is to provide a checklist rather than a recipe book: as an aid in incorporating environmental aspects into the overall planning and management of an exploration programme, and in liaison with company environmental staff, consultants and regulatory bodies. I also hope to show that whilst some of the techniques used in particular environmental disciplines certainly require specialist expertise, the overall design of an EPM programme is not in the least esoteric, but simply an exercise in straightforward common sense. Perhaps this paper could be subtitled: "Demystifying environmental Planning".

Jan 1, 1988

By T Christopher

The Campamento Au/Ag deposit, discovered by Linear Gold in 2004, is located in Chiapas State, southern Mexico. The deposit is hosted by a sequence of Pleistocene-Pliocene andesitic volcanic rocks that have been intruded by a feldspar-phyric porphyry complex. Measured and indicated resources are 852 000 oz Au and 3.46 million ounces Ag with inferred resources of 374 000 ounces Au and 920 000 oz Ag. Resources were estimated at a 1.0 g/t Au equivalent cut-off. This is an ABSTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Prior to the 20th century much of our infrastructure was provided by the private sector. This included toll roads, tunnels and bridges, power supply, transport and water.With the depressions of the 1890s and 1930s and the world wars, much of this infrastructure passed into public ownership. This was certainly the case in Australia as well as many other Western countries.In the last quarter of the 20th century we are seeing a swing back to private sector provision of infrastructure,-resulting'from increased needs for investment in infrastructure due to changes in

Jan 1, 1993

By Collins L

The commercial success of a mining project can be strongly influenced by the business activity which takes place away from the mine site. The project revenue is determined by marketing success which results from persistent research and full realisation of suitable products and by-products and appropriate upgrading achieved in conjunction with proper material security and insurance. Significant costs of transport can be optimised, protection of the environment carefully managed and skilled employees acquired as a valuable asset. Working capital requirements are often substantial and should be carefully established and financed, possibly by special contractual arrangements for product sales.

Jan 1, 1997