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At the Nikkel og Olivin nickel mine near Narvik, Norway, Outokumpu has been the operator since 1993. The mine was opened in 1989 and in 1992 Outokumpu commenced operations to secure concentrate deliveries to Harjavalta's nickel smelter in Finland. Annual production is about 740 000 tonnes of nickel ore grading 0.5 per cent Ni, about 25 000 tonnes of nickel concentrate and about 2800 tonnes of nickel metal. All production comes from underground operations which makes Nikkel og Olivin AS perhaps the lowest grade underground nickel mine in the world today. Production is currently from one of two orebodies, which is known as the Western orebody. The Eastern orebody was worked out by 1995. During Outokumpu's operational period the Western orebody has been delineated and taken to production. The underground exploration and definition drilling involved about 15 000 in of diamond drilling, which was carried out during a nine-month period. Following this a feasibility study was undertaken and production commenced. Improvements were made to the mining methods. Previously the mine utilised open pit equipment underground and this resulted in an enormous amount of additional tunnelling. Grade control and ore delineation were previously based on sparse diamond drilling and all geological information was processed manually. The improvements included the use of underground sludge drilling to increase the amount of geological information, the of a new computer system for grade control and mine planning, new automated underground longhole drilling equipment and the of underground mining equipment which reduced the size of the drives. These changes produced a marked increase in the efficiency of the underground Mine.

Jan 1, 1996

A methodology is described to integrate heap leaching into a CIP operation. The paper firstly describes what is meant by a 'systems approach'. A broad view of the objectives of integration of heap leaching into CIP is given, followed by the components of the system, and then a description of the methodology for integration. The seven stages of integration are given as determination of distribution of gold, sampling, metallurgical testwork, conceptual study, pilot heap operation, pit modelling and pit optimisation. The final result is a series of optimised curves which determine the maximum value of the orebody, and the optimum cut-over grade from CIP to heap leaching.

Jan 1, 1992

A major problem in the continuous casting of aluminium killed strip steel is the incidence of black and grey lines in the strip surface caused by the alumina inclusions. One place for limiting the number of alumina inclusions is by providing favourable fluid flow conditions in the ladle so that the inclusions float out to the surface or adhere to the ladle wall. In laboratory equipment 20 kg of steel was melted in an alumina crucible of 14 cm diameter in an induction furnace. Deoxidation was carried out while the melt was constantly stirred by argon bubbling. Bubble frequencies were measured at the lance tip using a microphone technique. High speed cine photo- graphy was incorporated to measure melt top surface velocities. Experimental results indicate that the rate of removal of inclusions is a function of both the gas input and the power input. However due to unfavourable surface area to volume ratio, reoxidation of the melt took place. Some other experimental difficulties in working at high temperatures are also discussed such as lance design, melting arrangement and sampling techniques.

Jan 1, 1984

To counter depressed world nickel prices, a continuing effort is being made at Kalgoorlie Nickel Smelter to reduce unit production costs. One major area in which production costs can be reduced is the substitution of coal for fuel oil. Two areas where this has been achieved to bring about a saving are, the addition of coal to flash furnace flux to reduce supplementary fuel oil requirements in flash smelting and the replacement of two oil-fired air preheaters with a coal-fired unit. These actions have resulted in coal replacing 67% of the current fuel oil requirement in flash smelting at the Kalgoorlie .Lckel Smelter.

Jan 1, 1987

Kalgoorlie Consolidated Gold Mines Pty Ltd (KCGM) is a management company, formed in 1989, to manage the assets and operate the Kalgoorlie joint venture for the owner companies Gold Mines of Kalgoorlie Limited (GMK) and Homestake Gold of Australia Limited (HGAL). Mining is still in progress on the 'Golden Mile' and surrounding areas more than 100 years after Paddy Hannan's discovery adjacent to the active Mt Charlotte mine. From 1893 until 30 June 1995 the Kalgoorlie Goldfields has produced approximately 45 million ounces (-1400 tonnes) of gold from mining and treating about 179 million tonnes of ore. This production equates to about 20 per cent of the total Australian gold production and about one per cent of the world's

Jan 1, 1996

Although the last decade has seen the growth of many new licencing and approval requirements for the exploration and mining industries, there remains in each State of Australia and the Northern Territory a predominant "Mining Act" containing provisions for the grant of exploration and mining tenements. What then are the rights and duties of tenement holders either by virtue of a Mining Act or through other approval and licencing mechanisms? What rights and duties does a person acquire when he is granted an exploration licence or a mining lease? In this paper I will attempt to cover these types of questions using in particular examples from New South Wales. I will also refer to a range of other subordinate approvals and licences which today's society requires and the need for ethics and recognition of liabilities.

Jan 1, 1995

By Tomlinson R. C

There are two main aspects of coal preparation to which the operational Research Executive of the National Coal Board has applied computer models. The first is in the planning of preparation plants and the first part of this paper discusses Simprep, a computer package that was designed to help on these calculations. The other is the development of control schemes to improve quality control, and the second part of the paper deals with the development of simulation techniques for this purpose.

Jan 1, 1977

During the past five years there has been a transformation in the operating costs which apply to narrow vein mining. Mechanised methods including sublevel uphole retreat and narrow vein cut and fill are now proven. Other methods, such as vein mining by horizontal drilling from a raise platform are currently being tried in Australia.The important factors which affect the cost and appropriateness of each method include: ore continuity, the planarity of the wall contacts, relative hardness of ore and wall rocks and the dip bf the deposit.Drawing on current operating costs from a number of mines and on recent feasibility studies, a methodology for estimating the costs of narrow vein mining is presented. These costs are then placed in their economic context with regard to ore grade and mining rate.

Jan 1, 1993

By Goldstone A

The paper introduces a newly developed multi-function test rig for fracture grouting. This test rig has many functions and its performance is consistent. It can control and adjust accurately the opening degree of fissures and static pres- sure; it can measure automatically the quantity of grout injected; it can measure precisely pressure drop of grout in fissures; it can test the results of injection, including effective dispersed distance, anti-filtration capacity of consolidated body, mechanical strength, etc. It can inject a single or two grouts into one or several fissures at a pressure of 16 MPa. Therefore, it is an ideal test rig for fracture injection. The paper depicts all the components of the test rig, its performance and application of the results obtained from fracture grouting tests. Examples are briefly described.

Jan 1, 1988

By Baohm C, Barker T

There have been significant changes in the Australian mineral sands industry in recent years due to changing supply and demand conditions, new product opportunities and opportunities for rationalisation of operations. Earnings within the industry have typically been volatile and this has been reflected in the share prices of listed mineral sands companies. Apart from the effects of variations in the state of the economy on the industry, share prices have also reflected the extent to which a company's earnings volatility is due to capital structure, the relative proportion of fixed costs to total costs and the nature of th'- sales mechanism. At the time of writing, the high prevailing share prices for industry participants and the current outlook for the industry would suggest that the time is opportune for raising equity capital. The immediate outlook for the industry and its various product segments appears favourable but beyond this the usual uncertainties remain. The new tax environment will cause most companies in the industry to have to rethink their dividend and capital structure policies. Most shareholders will now be concerned to maximize dividend receipts and minimise exposure to capital gains tax. Companies in the industry that have relied fairly strongly on earnings retention to help finance growth in the past will- need to look to increased equity raisings in the Future.

Jan 1, 1986

The subject of heat sources in deep hard rock mines, the limitation of forced ventilation to cope with these heat loads and the sizing of refrigeration plants to boost the cooling effect of the ventilation air are discussed. The development of plant selection criteria and operating experience at North Broken Hill Limited is outlined. Future options for North Broken Hill Limited and like deep mines are summarised.

Jan 1, 1982

This paper explains why the valuation of mining assets is often a very different exercise from the valuation of the shares in the mining company which owns those assets. The fundamental reason for this is that mining assets, and the shares of the company which owns those assets have different risks. In order to properly value mining securities it is essential to: ò ensure all the different risks and other factors which impact on the value of the mining assets and the value of the shares are taken into account; and determine the extent to which the different risks and other factors are addressed in the value of the mining assets and the value of the shares so as to avoid double counting or not counting at all. If the alternative, but far from consensus, view is accepted that the correct valuation methodology to apply to shares in mining companies should be based on option pricing theory then conventional valuation practice of both mining assets and shares in mining companies will need to be fundamentally reassessed.

Jan 1, 1994

By Muge F, Pereira H

In the early stages of the planning of a new exploitation, the error in ore reserve estimation is an important factor that must not be disregarded. As this error can be computed by geostatistical methods, the risk of the venture can be calculated for different recognition patterns in a certain assumption of economical conditions. A case story is described for an open pit phosphate deposit in which grade/tonnage curves and their confidence intervals are related to an economic function for three drilling patterns and decisions are taken on the basis of cost and value of supplementary information.

Jan 1, 1977

A good deal of criticism has been levelled at Mines Division over the slowness of processing mining privilege applications, some of which is justified and some which is not. There are many reasons for delays in the processing of applications and not the least of these delays are caused by the applicants themselves.

Jan 1, 1982

Iron and steelmaking slags have been utilised for a century. All dumps are now exhausted. Because of constraints in establishing new stock yards, all slags have to be utilised immediately. At present, this is being achieved. Only in a situation where there is an increase in pig iron and crude steel production, together with the impact of new residual materials competing from other industries can marketing problems be anticipated.

Jan 1, 1979

By W van der Westhuizen

Mining professionals recognise the need and application for reconciliation and value tracking. It is necessary however to examine our current reality, and evaluate the following. Do our reconciliations really balance correctly, and are we able to track value effectively throughout processes? If we are honest, in most operations the answer is a resounding no. This means that we are surrounded by fluctuation and deviations that we do not account for and do not understand. This is astounding, because given our level of scientific knowledge and the technological tools at our disposal we should have a good understanding of our environments and be able to manage them effectively. How do we manage effectively if we are surrounded by so much uncertainty? The purpose of this paper is to describe, at high level, the principles of reconciliation and value tracking, to highlight some areas where deviations are introduced into the mining process, and to propose a different approach to the apparent reconciliation and value tracking conundrum. The paper also poses several questions that need to be critically addressed at most operations. Instead of making the same mistakes each month in reconciliations, mining professionals need to acknowledge two facts. Firstly there will be uncertainty that we need to accept, since all our estimates are based on sampling, an orebody is not homogeneous and peopleÆs behaviour will influence the process, etc. Variability will always exist and lead to uncertainty. What is the current approach in the reconciliation process when a deviation occurs and how do we use reconciliation and value tracking to manage and improve our business? The second fact is that we need to stop using reconciliation and value tracking to only measure and report. We need to adopt a new approach to manage mining throughput, where reconciliation and value tracking are enablers to the success of the business. In most mining operations, significant effort goes into planning and measurement for the purposes of reconciliation and value tracking. The importance of accurate and effective reconciliation and value tracking should be to ensure the maximum utilisation of the resource, maximising throughput and enabling the business to deliver a product to its client, of the correct quality and in a timely manner.

Jan 1, 2002

In contrast with mining in areas close to the main centres, mining in remote areas is characterised by comparatively high initial investment and relatively high running cost for the life of the mine. This is because of:the real cost of establishing and running the operation at a location distant from the necessary infrastructure; and the perceived risks priced into their costs by the multitude of suppliers involved in the project. Optimal co-operation between the mine and the supplier in developing the right rela tionship and the correct technical solution permit both cost elements to be reduced. This re duction may well mean the difference between success and failure. This paper examines the possibilities for optimising the contribution of the equipment supplier to the overall success of the process. Issues covered include the necessity to provide more than merely equipment fit for the purpose , but also the need to maximise the benefits of equipment ownership over the life of the mine. A simple method of determining the optimum timing for equipment replacement or rebuilding is proposed . Furthermore the maintenance contract (or performance agreement) is suggested as a means of leveraging the supplierÆs commitment to the mining operation. The specific examples are based on experience with mobile equipment but the methodology has relevance to other equipment and supplies.

Jan 1, 1998

The mine planning and operational aspects of applying Continuous Surface Miner (CSM) technology to Australian coal strip and open cut mines is investigated for both existing and planned deposits. CSM produc- tivity as a function of geomechanical properties, formation thickness, mechanical availability and in-pit physical constraints, are considered. Productivity and operational costs are derived from current production machines and from first principles.

Jan 1, 1989

During the past decade geopolymer technology has emerged as a possible solution for the effective stabilisation and solidification of waste materials. Amorphous to semi-crystalline geopolymers form by the co-polymerisation of individual alumino and silicate species, which originate from the dissolution of silicon and aluminium containing source materials at a high pH in the presence of soluble alkali metal silicates. It has been shown previously that geopolymerisation can transform a wide range of waste alumino-silicate materials such as fly ash and blast furnace slag into building and mining products with excellent chemical and physical properties, including high compressive strength as well as fire and acid resistance. These chemical and physical properties suggest that geopolymeric matrices derived from waste materials are well suited for environmental and other applications such as the encapsulation of mine tails, the immobilisation of heavy metals and also the fabrication of structural products. The current challenge is to demonstrate that a wide variety of natural Al-Si minerals could serve as potential source materials for the synthesis of geopolymers. Moreover, it should be shown on a large commercial scale that it is possible to encapsulate waste materials into the geopolymeric structure without compromising the chemical and physical properties of the final product for the desired application.

Jan 1, 2000

Detailed cash flow forecasts have always been almost essential as a basis for judging the viability of proposed new mining projects. In recent years attempts have been made explicitly to take account, in such forecasts, of the uncertainties surrounding the assumptions upon which they are based. With the risk analysis approach, Monte Carlo simulation of the cash flows indicates in probability terms the combined effect of these uncertain basic assumptions. While the use of risk analysis has been widely discussed, few specific applications to real projects have been reported. The application of such an analysis in the feasibility study of the large new Deelkraal gold mine presently being established on the Far West Witwatersrand gold fields by the Gold Fields Group in South Africa is described in the paper. The paper also indicates how one of the major sources of uncertainty, namely the gold content of the ore, can be`quantified in objective probability terms. This feature distinguishes the application fran other published accounts in which only subjective probability assessments have been utilised.

Jan 1, 1977