Search Documents

By Aziz NI, Beafi EY

In designing for a highly productive new mine during the present declining coal market, a very detailed ò planning is necessary. Attitudes of both management and coal operators may have to be changed, with more initial participation by the unions, governmental agencies, and the coal owners. A considerable number of Australian mines are remote from labour source and this trend is likely to increase particularly in the state of Queensland. Consequently such 'mines must be developed on the basis of the future technological and social changes in order to minimise both the capital and operating costs.

Jan 1, 1988

Modern, high-output, continuous process plant requires heavy capital expenditure and is exroected to achieve a high rate of return upon the investment made, thus its high utilisation is an economic necessity. Downtime is extremely expensive not only in terms of idle capital but also in terms of lost production and revenue. A sound maintenance management system can alleviate the problem of unscheduled stoppages and a key document in the maintenance system is the Work Order because it both initiates work and conveys maintenance control information back to the administrator. This key document must be supported by an information base that provides technical data, job procedures, spare parts, history and costing. To be effective this information must be easily and immediately available to all concerned. Computer technology has developed extremely rapidly over the last ten years and with it a wide variety of on-line computerised maintenance systems. Selection of the most appropriate system for a given industrial plant is not a straight-forward process. Computer requirements for hardware and software must be matched to the requirements of the maintenance system and such matching must be carried out in an ordered and rational way. At Kalgoorlie Nickel Smelter, time was taken to review the existing maintenance system, select, study and test the new computerised maintenance management package and plan its implementation. As a result, the initial target of equipment recognition has been achieved on schedule and within budget.

Jan 1, 1987

Mineral policy is now generally regarded as a function reserved to government. Government is reponsible for the economic health and progress of nations, and must therefore interest itself in minerals as a basic national resource. Government should therefore identify objectives which it sees as suitable and necessary for the mineral industry so that the industry can play its part in achieving national goals. It should provide the legislative framework and policy guidelines to enable these objectives to be achieved. The essential objective of a national mineral policy should be rational development of the nation's minerals resources. To achieve this, it need not be too formal; broad guidelines are enough. But it must be dynamic, to keep pace with the changing circumstances of the mineral industry in the world scene and the changing requirements of government. It should be flexible, recognising that there is no such thing as a "typical" mineral deposit; above all it should represent the outcome of a continuing dialogue between government and industry. Both government policy and corporate planning need to be formulated on the practical understanding of the potential economic value of the mineral sector and what it can contribute to the nation's prosperity. There needs to be a common understanding of the wide range of the costs of risks that may arise through the exploration and development stages and of the uncertainties affecting ventures at the production stage. There needs to be a common understanding that the size and importance of the mineral sector is determined in the long run by the level of investment in exploration. The development of a continuing understanding between government and industry should lead to the formulation of ground rules which ensure the continuance of a strong industry able to adapt to the changing world scene and make its contribution to national growth and wellbeing.

Jan 1, 1986

By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006

Details are given of the excellent performance, outside Australia, of steel slag in road pavement surfacing. Laboratory tests and plant trials have shown Port Kembla BOF steel slag to be a material with properties suitable for producing asphaltic concrete which will maintain a high skid resistance in service under heavy traffic. The high density of steel slag is a factor which will result in a cartage cost penalty likely to restrict usage to close to its source.

Jan 1, 1979

Wrenching between basement blocks is considered to be the mechanism whereby a well developed set of en echelon folds and an associated fracture system are developed in the Fitzroy Depression, Western Australia. The regular geometry of these structures accords with a right lateral regional coupling between high-standing, basement blocks bounding a trough filled with a thick pile of stratified Phanerozoic sediments. The structures developed during or after the Mesozoic Era, but the couple is inferred to have been applied to blocks outlined by old lineaments, which may reflect strains or ruptures in basement that developed during the Precambrian, and which were regenerated during Palaeozoic and Mesozoic time.

Jan 1, 1967

Every estimate of ore reserves necessarily contains an assumption in regard to the specific gravity of the ore. This assumed figure may be based on experimental data, on textbook data, or on a reconciliation of past tonnage estimates and production figures. Not infrequently it is simply a guess - shrewd or otherwise.Errors in the density factor are not likely to be serious in gold-quartz mines-or, at least, not so serious as in base metal mines. It is to the closer determination of ore density in the latter that this paper is devoted. Moreover, the remarks apply to ores which show no appreciable pore space.Not many ore bodies are sufficiently homogeneous to allow of a truly representative factor being obtained by the simple testing of a few specimens of ore, or by the weighing, after breaking, of a carefully measured block. The empirical figure derived from a comparison of past ore reserves and actual production can never truly describe conditions other than those now past; no real link with ore as yet unmined is provided. The dilution of heavy ore by waste is not exposed by this method, but is effectively cloaked. Anyerrors in past estimations of ore reserves are transmitted, by way of the density factor, as a source of error in all future estimates.ObjectIons may be raised to the practice of weighing measured blocks of ore in the case of any but a very homogeneous ore body. Even then, the exact composition of the block weighed, and an indication of whether its moisture content is representative of the whole, are difficult to determine.

Jan 1, 1940

By K Baskaran, T McKenzie

Sustainability is becoming increasingly important in the mining and mineral processing industries and must incorporate the associated waste products. Acid mine drainage (AMD) is one such by-product and is one of the most serious environmental problems facing the minerals industry today. The oxidation of sulphidic mine wastes often continues for a substantial period of time after mine closure, resulting in difficult and costly remediation and rehabilitation works. Mining companies are often reluctant to spend increasing amounts of money on waste treatment when the mine life is limited or even finished. Hence a simple, low maintenance and low-cost method of treating AMD is required. Whilst this paper does not address the issue of AMD, it does propose methods for removal of individual species from AMD with potential benefits, including raising AMD pH. A novel concept of using biosolids as a biological adsorbent, or æbiosorbentÆ, of metals from AMD is being investigated at a laboratory/pilot scale level. Biosolids are a by-product resulting from the biological treatment of wastewater, and have been previously shown to adsorb metals from aqueous solutions. This could lead to an environmentally sustainable or ægreenÆ method for treating both AMD discharges and disposing/reusing the biosolids. The result of a laboratory-scale study of the biosorption of Zn(II) is presented in this paper. Physical parameters including reaction kinetics, mixing speed and solution pH were investigated. Solution pH also rose an average of 2 pH units over the 24 hour equilibrium time û a valuable side effect when treating acid mine drainage. The outcome of the study highlights the usefulness of biosolids as a biosorbent for the removal/recovery of metal ions from acid mine drainage. A simple, low-cost treatment technology requiring low maintenance would be beneficial to the mining industry to address some issues relating to AMD and would help integrate environmental and economic considerations into sustainable environmental management.

Jan 1, 2002

Record quantities of slag were produced in 1974. Slag usage in this year amounted to 8.5 mega tonnes for granulated blast furnace slag and 7.7 mega tonnes for crushed blast furnace and L.D. slags. Granulated blast furnace slag is mainly used as a hydraulic bonding material in the manufacture of cement and in road construction. These applications give a fuel saving and reduce processing costs. Crushed blast furnace and L.D. slags find application as a substitute for natural aggregates in road construction and in the production of concrete. There is no doubt of ttie interest to utilise to the maximum all the slag produced by the steelmaking industry, thus preventing the build up of slag heaps detrimental to the environment and favouring the disposal of the heaps formed in the past. World wide efforts are being made to achieve this objective.

Jan 1, 1979

International tenders for contract mining opportunities require the Contractor to make an assessment of risk for an operation with a life span of up to twenty-five years usually based on data made available by the Client. This paper seeks to address how the Contractor assesses the data and quantifies the risks associated with the project. The areas of risk are common to most projects, but in the--Lontractor's case, risk assessment is carried out on the Client's data base and within a compressed time frame of usually less than six months. Incorporation of that risk assessment into the contract documentation is also discussed. Practical examples are given in a number of areas.

Jan 1, 1986

By Beattie T

For many years explosive sensitized explosives were assessed using the ballistic mortar. The standard test used lOg of explo- sive initiated with a detonator. Over the past 30 years many non- explosive sensitized explosives and blasting agents have been developed. Most of these new explosives and blasting agents cannot be tested in the ballistic mortar as they are not initiated by a detonator. It is also known that all explosives have a criti- cal diameter. When the cartridge diameter is less than the criti- cal diameter a stable detonation cannot be produced and the explosive fails to propagate. For many blasting agents the criti- cal diameters are greater than 50mm and such large diameters cannot be tested in the ballistic mortar. The underwater test allows explosives to be tested in diameters greater than the critical diameter and to be adequately initiated with suitable boosters. The effects of the explosive on the water are easy to measure and the test provides a safe, convenient and reproducible means of assessing explosive performance. The reaction products are allowed to expand to a low final pressure. The underwater test can therefore be used to give a measure of the total expansion work of explosives. The detonation of an explosive induces a shock wave in the surrounding water. The profile of the shock wave can be meas- ured 3-6m from the charge and the energy in the shock wave cal- culated. Measurements over a range of distances show that the shock wave is attenuated as it travels through the water and the attenuation is different for each explosive. This makes it difficult to estimate the energy dissipated in the water between the charge and a single gauge. The reaction products continue to expand and displace water. The bubble continues to expand until the kinetic energy of the water is zero. The gas pressure in the bubble is now lower than the hydrostatic pressure and the bubble radius is a maximum. The higher external hyrdostatic pressure causes the bubble to implode. The bubble energy is the work done displacing the maxi- mum bubble volume against the hydrostatic pressure and can befound from the bubble period. It is not always easy to find a large enough pond for the bubble to expand undisturbed by the water surface and the containing boundaries. This makes it difficult to determine the bubble energy accurately in shallow Ponds.

Jan 1, 1988

Comalco's Bell Bay smelter produces some 94 000 t.p.a. of primary aluminium in the form of foundry alloys, extrusion billet and rolling blocks. The extrusion billet and rolling block are produced by a process, in which molten aluminium is poured into an open ended water cooled mould of the required shape. The bottom of the mould is initially closed off by a dummy or starting block. Primary cooling takes place at the mould wall and secondary cooling is achieved by direct water sprays onto the out side shell of the product. Careful preparation of the molten alumin- ium is essential if stringent alloy specific- ation limits are to be met. Optimum casting temperature must be maintained within a narrow range and metal cleanliness is important to ensure a consistent product. Increased demands of recent years for larger product and higher standards of surface quality and dimensional control have been instrumental in forcing improvements in furn- aces, casting machines and in mould and dummy Doq,

Jan 1, 1977

By Warner B. D

Smelting at Mount Morgan started in 1906 with blast furnaces which were replaced by a reverberatory furnace in 1939. The second reverberatory, commissioned in 1944, was replaced by a copper flash smelter in 1972. Flotation concentrates, dried to 0.05 per cent moisture, were oxidised under accurately controlled conditions and produced 45 per cent Cu matte and a slag in the flash smelter. The matte was converted to blister copper and the slag was slowly cooled before grinding and retreatment in a flotation concentrator.

Jan 1, 1974

The paper presents an algorithm for calculating the natural air distribution in a ventilation network (sub-network) on the basis of following data: - for each network branch: labels of starting and ending nodes, label of the branch, resistance and natural depression; - for each fan: the characteristic in the form of a second order equation and initial flow.

Jan 1, 1977

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

The subject of government involvement in industry is, to say the least, a touchy one. For many it conjures up thoughts of socialisation or nationalisation. For others it is a desirable objective and is seen as a means of social reform by giving government a greater say in the control and distribution of human, financial and natural resources for the betterment of the community. Whatever your point of view, it is difficult to deny that government involvement exists to lesser or greater degrees in all industries. The mining industry is no exception and the degree of government involvement is probably greater than it is in other industries. I think it is important to remember when talking about government involvement in industry to recognise that there are different types of involvement and that all governments have a right, if they so desire, to become involved in whatever way they choose. The decision of a government to increase its direct or indirect involvement must, of course, be taken in the national interest. Governments, if we are still old fashioned enough to believe in ministerial and electoral responsibility, must make up their own minds about whether their actions are in the national interest and they must be prepared to accept the consequences of that action, good or bad. For instance, they must decide

Jan 1, 1975

Sampling systems are never perfect. They all have some bias and give variable sampling errors. The ways of thinking about bias and precision should be different before and after construction (or reconstruction) of a sampling system. Before a sampling system is constructed, the fundamental error variance can be estimated using GyÆs formula or by doing test work on the material to be sampled. The component of sampling variance which varies with the number of sample increments can be computed for the expected patterns of grade variation. The smallness of the bias can be checked using discrete element modelling, by checking that the proposed design complies with clauses in standards, or by copying an existing sampling system that performs well for similar material. After a system has been constructed, sampling precision can and should be monitored directly. Anyone claiming to take responsibility for a sampling system should know its precision. Bias could be checked by comparison to a more accurate sampling system, such as stopped-belt sampling, under conditions where bias seems most likely. However, it is more practical to conduct regular checks that the system is still operating as designed, that the design is still appropriate despite any changes to material flows, and that sample masses are consistent with the correct operation of the sampling system. If precision is not regularly assessed then it should be assumed to be very poor. If a sampling system is not regularly inspected then it should be assumed to be biased.

Jan 1, 2008

In the last eight years inclined conveyor haulage systems have established themselves in the mainstream for hard rock underground mine haulage. This leaves the question; what else might be on the horizon for mine haulage and how do we address the process of selecting haulage systems for new mines? This paper considers the identification of viable haulage technologies for underground mines and explores an approach for assessing existing and potential technologies. The example of a large deep mine is considered here. The evaluation of existing haulage systems relies on precedence and the assessment of the system capacity to meet the haulage requirements envisaged for a particular mining project. The assessment of potential technologies for mine haulage relies on the capacity to deliver a viable production-scale system within the timeline envisaged for developing a mining project. The haulage technologies addressed in this paper include: shaft hoisting,conveyor haulage,truck haulage,vertical conveyors, andhydraulic hoisting. This paper does not consider rail haulage out of a mine. This is simply because Australian topography typically has insufficient relief to bring them into consideration. However, rail haulage is a widely used and effective haulage solution in situations where significant topographical relief is present. The assessment of haulage system capability focuses on the following fundamental questions: How reliable are they? What is the degree of technical risk in a business context?What levels of flexibility do they offer?How capital effective are they? What returns are indicated by the balance of capital and operating cost estimates?

Jan 1, 2008

My paper presents a discussion of the legislative and departmental requirements in connection with the acquisition of exploration rights for minerals (other than petroleum and coal) in the Independant State of Papua New Guinea, the Solomon Islands and Queensland and he practical problems associated with land entry and land ownership associated therewith. In general there are many similarities in the methodology and philosophy behind the legislation in each country and the contractual requirements established thereby between the exploration company (the explorer) and the government and the mines department or equivalent in each place. There are also a number of differences. I have prepared the paper on the basis that my audience will largely consist of -experienced explorers and the paper is intended to act as a brief refresher and a guide to the philosophy and the practicalities behind the legislation and practices in ground entry in each case. I will deal in turn with New Guinea, the Solomon Islands and then Queensland.

Jan 1, 1987

The classic description of Project Finance as "the reliance by lenders on the cashflow of a project, supported by the assets of the project with no recourse to the project sponsor's corporate balance sheet" has, like most other terms in the finance industry, evolved through recent usage. The area now under most scrutiny is the sharing of risks between parties either most able to take them or prepared to accept payment for them. Creativity in, and flexibility of financing structures have enabled project lending to continue under a dramatically different economic outlook. The diminishing competitiveness of the Australian producers in a global market place of uncertain commodity prices has discouraged the advancement of many large scale resource projects. The majority of new project financings has been designed to assist the relatively small company promote and develop its first projects. New trends- are emerging in four areas: sources of capital; borrowing structure; financing instruments (securitisation); and risk underpinning. As project financing becomes more widely used, the range of interested financiers grows. New initiatives contribute to its development and evolution with a view to increase effectiveness to the sponsor of any new venture.

Jan 1, 1987