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By Waddell S

A new procedure has been developed for the direct determination of metals loaded on activated carbon. It involves preparation of a suspension of the powdered carbon in water, followed by direct sampling of the suspension with a micropipette,and analyses by atomic absorption spectroscopy using carbon rod atomization. Advantages of the method include the simplicity of sample preparation and the ability to provide a complete metal analysis in 1 - 2 hours. This enables carbon-in-pulp operators to respond quickly to changes in plant efficiency arising from carbon fouling. The successful application of the method has been demonstrated for gold, copper, nickel and iron. Other elements to be surveyed include calcium, magnesium and silicon.

Jan 1, 1984

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

Mere recognition of the need for technic- ally strong human resources in the'extractive metallurgical industries has not prevented the decline in the education base for broad spec- trum metallurgists. The ability of chemical engineers to perform very effectively in many extractive metallurgical positions does not remove from the need for a general metallurgic- al education system. The intrusion of chemical engineers into extractive metallurgy is only symptomatic of the problems facing the minerals industry and its educators. The prospect of a career in the minerals base industries is unattractive to potential students by virtue of perceived inadequacies in the professional basis of the industry and ignorance of its sig- nificance to Australia's future, as assisted by excessive secrecy and a low profile public Image.

Jan 1, 1987

By Seshold P

The cost of capital is the rate at which a project's cash flow should be discounted to obtain the Net Present Value. The cost of capital is a weighted average of both debt and equity funds of a company, on an after tax basis. Two methods are described for calculating a company's cost of equity, the Dividend Valu- ation Model and, more importantly, the Capital Asset Pricing Model. A worked example is presented where the cost of capital was obtain- ed for two resource companies. The application of the cost of capital was illustrated by way of a mining equipment replacement problem. The paper outlines refinements and problems that may be encountered with the use of the cost of capital, and concludes that it is an integral part of any project evaluation.

Jan 1, 1983

By Walton DR

It is self-evident that the availability of well qualified and experienced people to manage mining operations is vital to the success of an individual mine and to the ability to develop new mines either in Australia or overseas. For larger operations the term "mine manager" is here used to denote a range of positions within an individual company. Thus "mine managers" may be people managing individual mines at one geographic location with overall management provided by other "mine managers" in the roles such as mine super- intendents, production managers, general managers, etc. Smaller operations may have only a single level of management nominated as "mine manager".

Jan 1, 1980

By D R. van der Meulen, P Ande, D J. Lunt

Pressure hydrometallurgy is becoming an increasingly common unit operation in the treatment of gold and base metal ores and concentrates. The design of an adequate and appropriate pilot-scale testwork program is, therefore, essential in order to minimise the risks associated with developing a project in which autoclaves form a key part of the operation. This paper identifies the approaches that have been taken in the piloting of oxidative and pressure acid leach operations. Particular emphasis is placed on the determination of scale-up ratios between the pilot and commercial plants and the pilot-plant run durations. The issues, both metallurgical and project-specific, that can impact these key parameters are reviewed.

Jan 1, 2004

The paper discusses how automation is steadily proceeding throughout all areas of the electrolytic zinc industry. Fluid bed roasters with integral sulphuric acid plants are now on -computer control. Highly efficient, continuous leaching and purification stages, with feed-forward predictive and optimisation computer control, precede electrolytic cells with on-stream solution analysers and automatic stripping of deposited zinc. Controlled electric induction furnaces feed continuous casting lines, equipped with automatic stacking and strapping, machines, after computer based metal analysis has confirmed metal purity or alloy composition. The paper also discusses the use of computer models tied to process control systems, and the equipment and solution measurements that could be automated with advantage, using modern micro-based controllers and analysers.

Jan 1, 1985

The short review of hydrogeologic conditions in the three Polish coal basins have been presented as the background for the prevention measures against water inrushes being underta- ken in coal mines. The Polish mine safety regulations concerning water inrush prevention have been discussed, namely: - classification of sources of the potential water inrushes, - levels of water inrush risk and conditions of mining operation in the mines facing particular risk levels, - determination of the -di.mens.ons.of protecting pillars to prevent water inrush to mines, protection of surface water reservoirs and their earth embankments in regions submitted to mining deformations. Three examples of coal mining being carried out under water bodies have been presented.

Jan 1, 1988

The promotion of good standards of reporting of the valuation of mineral assets in- public documents has been of concern to professional mining industry bodies, the securities industry, and. Government regulatory bodies for some time. This concern led to the National Companies and Securities Commission Release 149 (1990b) which laid down standards for Expert Reports on mining and petroleum securities, and other assets. The formation of the Australian Securities Commission provided an opportunity for a timely revision of Release 149 and the Mineral Valuation Committee was established by The Australasian Institute of Mining and Metallurgy in 1991 to review the existing code, and to develop an appropriate new Code and Guidelines.

Jan 1, 1994

An efficient energy management programme can often significantly reduce a company's energy costs. The programme consists of a series of steps, namely a statement of support from senior management, assigning the management team, the energy audit, defining the goals and comwnicating with and training employees. The energy audit provides the information base from which the company can start to control and improve upon energy Usage.

Jan 1, 1983

By Ellis CG

The N.S.W. Department of Mineral Resources commissioned its first Mobile Gas Laboratory in 1973.Although originally intended for diesel exhaust analysis, it has been progress- ively made more suitable for mine air analysis. Currently there are two upgraded units in operation. These laboratories have been used at the scenes of four mine fires, two mine explosions and three recovery operations. The authors' experience jointly covers all of these incidents. In this paper they recount the role of the Mobile Laboratory in each incident - including the difficulties encountered - and trace the development of these units to their present state. Future improvements are foreshadowed, and some comments offered concerning the likely future role of these vehicles in mine Emergencies.

Jan 1, 1981

By Nyamekye GA, Subramanian S

Adsorption tests have been carried out to elucidate the interaction mechanism between dextrin and sulphide minerals. Sulphides such as galena and heazlewoodite exhibit high affinity adsorption over the pH range that coincides with the iep of lead and nickel hydroxides, and is suggestive of chemical interaction. The adsorption behaviour with respect to the sulphides of copper is of the low affinity type, and follows a different pattern. The adsorption studies on graphite, support the chemical interaction mechanism, with the metallic impurities serving as adsorption centres. In conformity with the proposed mechanism selective separation of galena from chalcopyrite and heazlewoodite from chalcocite has been Achieved.

Jan 1, 1993

Modern minerals projects face serious challenges in earning and maintaining acceptance by their key stakeholders. Factors which underpin effective response to managing these challenges include consideration of public affairs issues from the earliest planning stages, building robust alliances with a range of influential partners, developing a level of transparency in all operations and decision-making and integrating activities towards resolving key strategic issues. Effective community relations is vital and there are a number of elements common to the best approaches. These include senior management support and involvement, appropriate involvement in project decisions and activities by community members and company responsiveness to community expectations. The project's operations manager and executive team must fully commit to developing the capability and processes to meet these challenges. They require a whole of project response and it is not an option to manage them peripherally.

Jan 1, 1997

By Denholm WT

Current control practice is reviewed for agglomeration processes, including pelletising, sintering and induration; and for smelting processes, including blast and reverberatory furnaces, flash smelting, the intensive bath smelting processes together with converting. The importance of sensors for on-line control and the status of mathematical modelling is discussed.Future progress in automatic control will require improved component specific sensors and the use of validated mathematical models running in parallel with the process. The possibilities in both these areas are reviewed in light of the trends towards more intensive smelting processes.

Jan 1, 1985

By J J. Cilliers

The aim of this paper is to give an overview of the FrothSim flotation simulator and to demonstrate its ability to predict the performance of real flotation circuits. Example simulations are presented in which the feed rate to the circuit is varied, followed by simulations in which a cleaner section and recycle loop are added to the rougher bank.The simulator is able to predict both the recovery and the grade produced by the cells at all locations in a circuit and the simulator is shown to produce plausible grade recovery curves. It also demonstrated that the performance of banks of cells improve as the feed rate to the bank increased (improved grade for a given recovery), but that more cells are required to give the same overall recovery.

Jan 1, 2005

By Miskelly N

Construction of the Ranger uranium project located 230 kiss east of Darwin in the Northern Territory commenced in January 1979. Energy Resources of Australia Ltd (ERA) was incorporated in February 1980 to acquire all the rights in the project. The total cost to ERA of these rights was $407 million, made up of $125 million in cash to the Federal Govern- ment and the issue of 125 million $1.00 shares at par, plus a payment of $16 million in cash to each of Peko-Wallsend Ltd (Peko) and EZ Industries Ltd (EZ).

Jan 1, 1983

The Professional Standards Act responds to the growing problem of professional liability by introducing a mechanism whereby professional associations can have schemes approved. Those schemes include a cap on liability; a requirement for compulsory insurance; the development of risk management strategies; and the establishment of a complaints and disciplinary system. The Act is also designed to support and develop the concept of self-regulation by the members of occupational associations who provide services to the community by providing them with those tools. It implicitly accepts that self-regulation is preferable to statutory regulation and that self-regulation serves the interest of the community and of the providers of services. The Act arose from a review of professional liability commenced in 1988. The Attorney General's Department produced an Issues Paper, released in September 1989, which outlined in detail the extent of the problem. This was widely circulated and an extensive number of comment were received.

Jan 1, 1995

By Siemon J. R

It is possible to use compacted anodes formed at low pressure for the direct electrowinning of lead from sulphide concentrates. An anode containing 5.5 per cent graphite, formed into a compact at 34 MN m-2, enables lead to be won at a current efficiency of about 80 per cent; the power consumption .at 150 A m-2 current density being 0.4 kWh per kg lead. It would be necessary to use diaphragm cells to obtain a sufficiently pure product. A conceptual design for a full-scale plant is presented, together with a cost estimate for the production of lead by a process based on direct electrolysis of compacted concentrates. It is unlikely that the proposed process will be economically competitive with the conventional lead smelting.

Jan 1, 1976

By A R. Butcher

Gold deportment and ore characterisation studies are key tools in gaining an appropriate understanding of complex gold ores for process development and optimisation. These studies have historically involved imprecise chemical methods with slow and costly optical microscopy for gold identification. The traditional approach requires highly skilled petrographers, is prone to human error, and is not scalable, reducing the usefulness in practical analysis. The proposed methodology utilises a decision tree and knowledge base in a staged approach to gold ore characterisation, building up progressively more detailed information about the sample mineralogy, gold deportment and key mineral properties, as the process is followed. Whilst the automated QEMSCAN« system is used for mineral and gold identification, interactive and focused data analyses are used to give more efficient and accurate results. This is complemented by smart sample preparation and chemical methods to enhance and validate the data, making the staged approach methodology reliable, scalable and therefore practical and economical.

Jan 1, 2007

GRD Macraes Limited, owners and operators of the Macraes and Reefton Gold Project in New Zealand, have taken up the challenge of sustainably producing in excess of 300 000 ounces per annum within five years.GRD Macraes is well on target to achieve the forecast of 170 000 oz at a cash cost of A$310/oz for the 2002 financial year, with our Reefton operation set to add about 70 000 û 80 000 ounces per annum from late 2003.At the end of 2001 GRD Macraes Limited had resources of 5.5 million oz with reserves at 2.8 million oz.

Jan 1, 2002