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One of the more recent developments within the mining industry has been the adoption of formal continuous improvement programs. A continuous improvement (CI) program was launched across Kalgoorlie Consolidated Gold Mines (KCGM) in early-2002. The purpose of this program was to identify further operating improvements within departments. The focus of the continuous improvement program was not only on the areas of the operation which were performing below expectations but also on areas of the operation which were performing well but could still be further improved.The effectiveness of a continuous improvement program depends on the stability of the processes in place and the participation of many employees from all levels of the business.Continuous improvement has had some successes and failures at KCGM and this paper will discuss both within the open pits department. Further improvements that could be made to the process will also be discussed. Kalgoorlie Consolidated Gold Mines Fimiston operation is located in the Kalgoorlie Goldfields and it the largest gold mine in Australia producing over 800 000 ounces of gold per annum.

Jan 1, 2004

THE Great Fitzroy Mines Limited, comprising an area of 183 acres, and held under lease, are situated at Mt. Chalmers, within the Cawarral goldfield, 18 miles from the city of Rockhampton, Queensland, on the Rockhampton-Yeppoon railway.The nearest railway station i; Mt. Ohalmers, distant about half a mile from the mine, with which it is connected by a fairly good road. The outcrop of the ore-body consists almost entirely of ironstained quartzite, no sign of copper being visible. The outcrop and its immediate vicinity have been worked intermittently for gold during the past :fifty years, the ore being amenable to battery treatment.About twenty years ago a company was formed to prospect this outcrop, and work was commenced by driving an adit, but the results proved disappointing, and work ceased. Later a party of prospectors sunk a winze from the adit level, which has sincedeveloped into wh~t is now known as the North shaft. The property was afterwards prospected by Messrs. Oharley and Osborne, who continued sinking the winze, meeting with sulphides at a depth of about 120 ft.The Mt. Chalmers Copper Mining Company was formed to work the property, and smelting operations started on a small scale. These, however, met with ip.different success, and the property was again abandoned.

Jan 1, 1911

Mining and metallurgy are more capital intensive than all other industry in Australia. Capital demands are met by domestic and foreign sources of finance for whom the major constraints are the supply of funds and factors of risk and uncertainty. in both mineral development and institutional financing policies, specific options are available to administrators which would allow mining to benefit from a more reliable supply of capital. The strength of major partners involved and overseas participation are important aspects of financing mineral developments. Future changes in financing for the mineral industry are considered most likely in variable interest rate funding, in the leasing of major plant items, and in the development of flexible techniques to ease the burden of infrastructure costs. In a consultancy sense, financiers are available to mining to assist with and to advise on optimal develop- ment of mineral industry projects.

Jan 1, 1975

The gold industry has been revolutionized in the last decade by market forces and technological changes. The latter are discussed in this paper, with particular emphasis on carbon-in-pulp (CIP) and heap leaching. The nature and scope of the process development aspects of a gold project are considered, and factors which determine process decisions are outlined, including the choice of CIP versus carbon-in-leach (CIL), agitated leaching versus heap leaching and treatment of ores containing copper and silver. Likely directions for development of gold processing in general are discussed, and metallurgical process options for treatment of ores of platinum group metals (PGM) are outlined.Metallurgical process development for gold and platinum group metals proceeds through a number of well defined stages, with input from various disciplines and information sources. The orientation phase will include preparation of a general project overview; careful consideration of the issue of sampling and sample preparation; characterisation of the resource in terms of ore types, mineralogy, chemical composition; development of appropriate methodology; and development of an understanding of the potential metallurgical unit operations.The process definition phase will be-'directed to development and definition of a notional process flowsheet, and will include identification and appraisal of process options; development of, notional process flowsheets; testing of flowsheets against ore types; ranking of flowsheets; initial engineering, including preliminary mass balances, equipment selection and plant layout; and broad-brush economic appraisal.

Jan 1, 1986

Passive systems for the treatment of acid mine drainage (AMD) are typically more economic in the long term than active systems. Various flow charts for treatment selection have been prepared by scientists in the USA, however, they have typically not included a variable important at New Zealand AMD sites on the West Coast: topography and available land area. Very steep topography, dense and often protected vegetation (and animals such as snails), and a high-rainfall climate result in AMD with very high flow rates in locations with very limited space for remediation. Flow charts specific to New Zealand have been prepared which accommodate topography and available land area. Parameters necessary to use the flow charts are iron and aluminium concentrations, pH, ferrous to ferric iron ratio, dissolved oxygen concentration, topography and available land area. Prior to full scale construction, is it recommended that flow rates be quantified, small-scale trials be conducted, and cost, effectiveness, limitations, and risk of failure be reviewed for various options. One full-scale remediation system has been installed in New Zealand based on this methodology and another is planned. The performance of these systems, as well as future systems to be installed, will be used to validate these treatment system flow charts.

Jan 1, 2007

By Gutsche O, Kapur PC

Experimental data on the production of fines as a function of specific grinding energy consumption show that in general the energy utilisation in a choke fed high-pressure roll mill is higher than in a ball mill, but lower than in the single-particle mode of comminution under slow compressive loading. There is some evidence to suggest that the presence of water in feeds improves the energy efficiency of pressurised roll milling somewhat. Within a wide range of energy input, the size distributions of the ground product are self-similar, the logarithmic median size decreases linearly with the amount of fines produced and the inverse of the median size increases linearly with the energy spent. The production of fines as a function of energy expended follows essentially the same pattern as the one frequently encountered in media mills. The kinetics of grinding in the high-pressure roll mill can be simulated satisfactorily by modifying the standard particle population balance equation in order to account for energy dissipation in the tightly compressed bed. Common characteristics and important differences in grinding by the media mill and the high-pressure roll mill are highlighted.

Jan 1, 1993

With the proclamation of the Environmental Protection Act, 1971-80, the Environmental Protection Authority and Department of Conser- vation and Environment were established to enhance the quality of the environment. Proposed gold developments of all scales can be referred to the Authority in the form of a Notice of Intent. Environmentally significant projects might then require preparation of an Environmental Review and Management Programme. Current environmental issues include the'effects of clearing by prospectors,, mine dewatering and tailings disposal. INTRODUCTION In the past, the environmental aspects of gold industry related activities have received little attention. However, with the proclamation of the Environmental Protection Act, 1971-80, mechanisms were instituted which allowed both for referral of projects to the Environmental Protection Authority (EPA) and establishment of the Department of Conservation and Environment. As well as providing assistance to the EPA on referred projects, the Department is concerned about a number of environmental issues associated with the gold mining industry.

Jan 1, 1982

In this paper is given a general description of the Black Star copper orebody, its relation to the lead orebodies and the controlling factors in the mineralisation.Copper ore, in the form of chalcopyrite, was first noted at Mount Isa in 1930 during the surface drilling campaign to prove the downward continuation of the silver-Iead-zinc orebodies.Details of the occurrence are set out in table 1.Other sub-commercial widths were also disclosed and examination of these occurrences showed that commercial mineralisation could not be expected within 800 ft. of the surface. It was therefore decided that further exploration was not warranted until underground workings had advanced to this horizon.Detailed surface mapping showed two small outcrops of the host rock of the copper orebody. One occurrence, 50 ft. x 75 ft., was of quartz, with leaching suggesting former dolomite. Another outcrop, further north and west of silicified shale, with low grade oxidised copper, has recently been found. Both occurrences were above the hangingwall of the main copper orebody.When the workings in the silver-Iead-zinc orebody reached No. 7 level (875 ft. below the surface) further...

Jan 1, 1953

By Thomas R

The successful `marriage' between a company seeking to raise funds to develop a project and their financiers calls for a strong mutual understanding of each other's needs. For a company attempting to raise funding, the alternative methods are ever expanding. The optimum method will vary depending on the financial position, risk/reward outlook of the company and the strength of the project for which development capital is being sought. It is likely that small mining companies will need to raise equity funds for advancing projects to the development stage. At that time, they will probably still require a reasonable level of shareholder equity to meet the requirements of banks and other parties to cover potential cost over-runs on the project and feasibility costs. Larger companies, however, are likely to find it much easier and cheaper to raise debt from banks. When evaluating companies and projects for funding, banks will pay particular attention to the quality and experience of management in developing similar projects and it may be necessary for some companies to retain the services of outside consultants. Before a project needs funding, companies should meet with potential financiers to develop relationships to select and ensure a smooth transaction to funding in the future.

Jan 1, 1997

By O Ostrovski

Direct iron smelting reduction has been examined using a modified 50 kg induction furnace. The furnace was equipped with continuous raw material feeding, a top oxygen lance, argon bottom bubbling, and sensors for measurement of gas and bath temperatures, gas composition and other parameters. In the base case, iron ore was charged at the rate of 1.5 kg/h, coke flowrate was adjusted to maintain a char fraction in the slag at 30 wt per cent, the oxygen flowrate was 100 Nl/min and the post-combustion ratio (PCR) was 60 per cent. The PCR was varied from 45 to 75 per cent by changing the lance height relative to the bath surface. Smelting reduction of Whaleback iron ore was investigated at different post-combustion ratios and iron ore feedrates using coke and coals with different volatile matter. The rate of iron oxide reduction increased with increasing iron oxide concentration in the slag, with a slight deviation from a linear function. The post-combustion ratio affected iron ore reduction and partitioning of elements between phases in the smelting reduction furnace. The high volatile coal investigated was found to be unsuitable for iron smelting reduction in the laboratory furnace.

Jan 1, 2000

Australia's gold mining industry has seen a resurgence in the past seven years - a resurgence the likes of which has been seen in very few, if any of this nation's other mineral industries. Industry experts are predicting that Australia could become one of the world's largest gold producers as the future of the South African gold industry looks increasingly tenuous under the present political crisis in that country. Therefore, it is utterly ludicrous for the Federal Government to introduce a tax which will see the Australian gold industry "wither on the vine."The Queensland State Government is utterly opposed to a tax on gold. Anyone in their right mind, who has seen the statistics could only agree with our stance. In 1984/85, activity in the gold mining industry is estimated to have accounted for over $750 million in national income, over$1,200 million in national output, and tax revenue of at least $115 million as well as providing more than 16,000 jobs. Chartered accountants Coopers and Lybrand's survey on the gold industry last year showed an increase in exploration expenditure by gold producers and explorers by up to 36% in 1986 from 1985 levels. That level is expected to be maintained in real terms for most of the remainder of the decade under the present tax arrangements. This is in contrast with the mining sector as a whole, where a recent Australian Mining Industry Council survey forecasted a 14% FALL in production.

Jan 1, 1986

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 N Kusuma

Recoverable copper and gold estimates for resource models and ore control routing decisions at Batu Hijau were initially based on flotation testwork from several commercial laboratories. Due to the greater number of copper and gold assay grade available, regression relationships were developed between assay grades and flotation recoveries. Other recovery controlling variables such as oxidation and lithology were included to improve the regression models. With additional drilling, more flotation work was carried out and the regression models were revised to include the new flotation data, also alteration classification and in situ pH. The regression models were replaced in favour of spatially derived models for ore control and short range mine planning. To harness local variability in the block model, blast hole flotation testing is carried out in unison with routine grade assaying. Recovery data are processed (kriged) simultaneously with grade assay data prior to ore polygon delineation. Short range mine planning utilises this model in conjunction with a spatial recovery model derived from drill core flotation data. Long range mine planning utilises the æhybridÆ recovery model whereby the globally robust regression recovery models are overprinted by a spatial (kriged) recovery estimate where flotation data density is adequate (Phase II reserve).

Jan 1, 2002

The Golden Cross is the first large precious metals mine to be both commissioned and closed in the æmodernÆ era in New Zealand. This paper discusses the life cycle of the Golden Cross mine, with emphasis on the closure process and post closure management.   The closure process has generally been very well managed, and successful, but in spite of that some on-going issues remain unresolved. Nearly nine years after the end of mining the mine owners are still actively managing the site, with no immediate end to that in sight.   The site has been described as atypical, due to the identification of a deep seated landslide below the tailings and waste rock storage facilities. However that should not be given too much emphasis when addressing the overall closure and post-closure management issues, which could well apply to other existing and future mine sites in New Zealand.   The Golden Cross can provide valuable lessons for other miners, and the issues arising at this site should be watched closely by the industry as a whole.

Jan 1, 2006

When Australian voters elected a Labor Government in March 1983 the value of the Jabiluka uranium deposit as an asset of Pancontinental Mining Limited effectively evaporated overnight. The day before the election, Jabiluka was Pancon's principal asset, with the Company's 65% stake in the deposit having a market value of the order of $US1 billion. This value had been set by an agreement reached with a potential customer, who was prepared to pay $US150 million for 10% of Jabiluka. The months before the election had been the culmination of ten years of unremitting effort to bring what was then the world's largest reserve of high'grade uranium ore into production. These efforts had included two and a half years of negotiations with the local aborigines, as well as exhaustive environmental studies and conceptual mine planning. All domestic approvals required to develop the Jabiluka deposit had been given to Pancontinental and marketing efforts had successfully placed about 50% of the expected uranium production with overseas utilities. It appeared that Jabiluka was about to emerge as one of the world's great mining enterprises. The election of a government with an anti-uranium policy stopped Jabiluka dead in its tracks. Pancontinental's largest asset had effectively become worthless and the Company appeared to be facing a bleak future.

Jan 1, 1987

By Sturgul J. R

A major electricity generating authority have a proposal to construct a Power Station. An understanding of the operation of the bunker system is of importance to the designers and a computer simulation model of the operation was constructed. The computer language used was GPSS/PC which is a recent form of the language designed for the per- sonal computer. The model simulated trains arriving at the power sta- tion and unloading onto conveyors which carry coal to the power station bunker. Coal was drawn from the bunker at a specified feed rate to the power station. Numerous restrictions were placed on the model, if the bunker level got too high dozers would pull coal out of the bunker onto the stockpile, and if the level got too low the dozers would push coal back into the bunker. The conveyors and dozers were unavailable due to breakdown'at various times and trains would arrive randomly about a mean interarrival time. The system was simulated for 30 years of oper- ation and the model used a basic time unit of 30 minutes so that the system was updated 525,600 times during the simulation. The results of the simu- lation gave the designers a greater understanding of the critical factors in the operation, which may now be engineered to minimise adverse Effects.

Jan 1, 1988

Cyanidation tests by bottle agitation were conducted on an oxidized lead-silver ore containing approximately 12% Pb and 500 g/t Ag. Over 60% of the silver was leached when the ore was ground to 100% passing 0.15mm, whereas 50-60% of the silver was leached when the ore was only ground to 100% passing 0.5mm. Slurry handling and dewatering at the fine grind size were very difficult due to the high clay content of the ore, however this problem was greatly reduced at the coar- ser grind size. The silver recovery at the fine grind size was very dependent on cyanide solution strength with stronger cyanide sol- utions (containing more than 0.1% NaCN) re- sulting in lower solution silver contents. This was thought to be due to the precipi- tation of leached silver by zinc, which was also leached from the ore by the higher cyanide levels. There was a critical zinc level in solution of approximately 1000ppm, above which the silver recovery fell markedly. Cyanide and lime consumptions for this ore were high (typically 5 kg/t and 40 kg/t respectively), hence the processing of this particular ore by cyanide leaching is un- economic at current silver prices.

Jan 1, 1987

By L C. Thompson

BioLix is the term for a new class of biologically-derived lixiviants for precious metals (gold and silver) recovery. BioLix can be used as an alternative to cyanide on virgin and spent ores. The BioLix process is based on inducing microbial enzymatic reactions that generate organo-lixiviant chemicals. The bioprocess involves a two-stage culture strategy. First, specialty microorganisms are cultured to generate a high biomass. Then, a food-grade quality amendment is introduced that forces the microorganisms to produce the organo-lixiviant. The second-stage culture is applied to the ore where the microbial/lixiviant system acts on mineral surfaces to extract precious metals. The process operates at ambient temperatures and near neutral pH. This paper will examine the BioLix process through an extensive laboratory development and demonstration project. Laboratory development consisted of identifying and isolating specialty microorganisms and inducing agents for the production of the organo-lixiviant solutions. A demonstration was performed on low-grade and high-grade oxidised ore from the Buffalo Valley mine in Nevada, USA. Results indicate that the BioLix process was comparable to cyanide in terms of gold recovery and operated at near neutral pH and ambient temperatures. Applications for the BioLix process will be discussed including spent-ore re-leaching, cyanide replacement for virgin ore, and in situ mining.

Jan 1, 2004

This short paper outlines the authorÆs views regarding the progress we have made as an industry in managing mining assets over the past 500 years. It represents a personal view û but one founded in fact-based observations of mining companies and of the mining industry in general. There is no doubt that AgricolaÆs views as expressed in De Re Metallica (1556) were visionary. There is also little doubt regarding another issue û that whilst a great deal has been learnt about the management of mines since AgricolaÆs time, 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 management, it is hoped that this short paper contributes a small step along the next 500-year-long learning curve. The paper concludes with a brief description of the progress and impact of continuous improvement initiatives at Kalgoorlie Consolidated Gold Mines (KCGM). Located in the Kalgoorlie Goldfields, KCGM is currently AustraliaÆs largest gold mine producing over 800 000 ounces of gold per annum. Improvement initiatives at KCGM look set to deliver some $100 million in value over life-of-mine.

Jan 1, 2004

Before any accident prevention and total safety programme can succeed, a safety concientiousness or attitude needs to be implanted in the employees' minds. Psycholog- ical and physiological conditions play a vital role in accident causation and prevention. Both need attention in a good safety programme, but working place conditions and environment are more easily corrected. However, the challenge is to change attitudes in the minds of men - psychological factors in accidents. To do this does not require a Safety Officer, but does require a Safety Adviser. At Blackwater mine a Safety Adviser is available to all sections of the organisation to guide and assist, to provide data and material to use at meetings, to help in accident investi- gations and to help organise training. To eventually achieve total commitment requires every member of the management team to be a salesman towards all around selling an attitude to safe working, a way of life. At Blackwater mine the workforce is young overall with most employees being under 40 years old. Psychologically this is a quite different problem to a balanced ages working group. A great deal of effort is needed to communicate with the younger, articulate, better educated employee who is also generally a skilled operator in the capital intensive

Jan 1, 1975