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By Eupene GS, Cheong GE

Operations at the Mount Bonnie gold/silver project are described. The project is based on the gossan of a stratiform and stratabound polymetallic sulphide deposit. The gossan contains approx- imately 100 000 tonne of ore grading 8g/tonne Au and 230g/tonne Ag. This is mined in an open cut, and transported to a stockpile area lkm away, from which it is fed to the treat- ment plant. The ore is crushed through two stages and fed to a fine ore storage shed, from which it is reclaimed, milled and cyanide leached in draft tube agitators. The pulp is filtered using a horizontal belt filter to recover a pregnant solution. Silver sulphide is precipitated using sodium sulphide solution, and collected as a mixed sulphide/precoat concentrate on a drum filter. The solution is then passed through carbon columns where the gold is adsorbed and is subsequently recovered by methanol desorption using a process developed by Micron Research, and electrowinning. Modifications to the treatment plant circuit based on operational experience are Described.

Jan 1, 1984

Recent developments in engine, transmission and control technology, likely to give rise to improved performance and efficiency of underground mobile equipment, are reviewed. Turbocharging and the electronic control of fuel pumps and injectors can improve diesel engine performance whilst minimizing exhaust emissions. Ceramic materials promise further improvements in engine efficiency. Nevertheless, electrically powered machines, equipped with trailing cables or 'travelling plugs' are expected to find increasing application where there is less need for flexibility and where the cost of ventilation and heating or cooling makes diesel engines unattractive. Voltage to frequency converters and induction motors appear to have a future in mains powered machines. Vehicles employing energy storage in the form of batteries or flywheels will find increasing application, but it is expected that they will remain a minority until there is a significant break-through in battery technology. Hydrostatic transmissions having high power density and efficiency are likely to be used more widely. Electronic control systems are likely to be used to simplify jobs and to improve performance and productivity. Enhancement of remote control systems is to be expected for work in unsafe areas, but true robot operation is considered unlikely for the moment. Attention to ergonomic factors should produce significant productivity gains.

Jan 1, 1985

By Koppe J. C

This paper describes the methodology developed to establish a sequentia mining plan applied to a coal mine, using computers. Firstly, isocontou. maps were generated from the drill holes and outcrop description information, representing the thickness and depth of the rock formation: present in the mine site. The procedure relies on the repeated application of the cross validation techniques, until the standard deviation of thi estimation is reduced to a minimum.From this map the coal reserves of the two coal seams, the overburdet (separated in hard and soft material) and the interburden were calculated After that, the maps were transferred in digital files to AutoCAI software, where different mining plan simulations were performed. 7b ore evaluation in each case was done automatically, including tonnages volumes and stripping relations. The final mine configuration consider the economic aspects of the operation.

Jan 1, 1993

By Willis GM

The matte-metal-equilibria in the system Pb-Cu-S have been studied at temperatures between 720 and 920¦C by direct sampling and D.T.A. methods. These results are compared with those of other workers. The applications of such data to a continuous copper drossing process, and to a number of other metallurgical processes are discussed.

Jan 1, 1975

By Skaviniak M

Some better perspectives applying to the exploitation and dressing of polymetallic ores in the Banskfa. gtiavnica-Hod- rusea Ore District are supposed to be achieved after a suc- cessful investigation and proving there the existence of deep-seated mineralization as well as due to increasing de- mand for non-ferrous metals and consequently to higher mar- ket prices of those recently noticed. With respect to the present situation in mining and to the further technical development as well, a several times higher exploitation may be in this region expected, especially in the deeper .eated parts of the deposit. When solving the tasks of a complex economic exploitation over the whole region, consi- derable attention is paid to regional relations and impact studies (due to expected exploitation and ore dressing but also to very difficult problems of dewatering (drainage pro- blems-). It will be first of all necessary to find there an equilibrium between the consequences resulting from the re- naissance of mining industry and environmental requests un- dispensable for the city of Banska 9tiavnica and the other neighbouring towns in the vicinity of mining plants.

Jan 1, 1988

By Tapp B. A

The minerals industry in Australia is currently regarded as the country's economic saviour; the bastion of economic security. As Fitzgerald (1974) stated, 'Australia's natural endowments in minerals are the envy of most countries of the world'. As a result the proposed new mineral developments are on a scale that hitherto in the sixties would have been completely unenvisaged. It is reported that Australia is poised on the verge'of a sixteen billion dollar mining-based investment boom: a boom that will see Australia dominate the energy export field, the mineral processing field, and create the 'coal dollar'. This growth scenario has many inherent dangers, and it is the authors' contention that these should be carefully considered before further development proceeds. Two of the major problems related to the mineral industry growth scenario are the predictability of the future metal market, and the energy cost of mining. The latter problem is the one discussed here. The mining-mineral processing industries in Australia currently use about 36% of Australia's primary energy

Jan 1, 1980

By A S. Venkatesh, A Das

The Precambrian iron ore of Singhbhum-North Orissa region of eastern India occurs as part of the horseshoe-shaped broad synclinorium known as the Iron Ore Group (IOG) of rocks, which hosts the most important iron ore deposits in India. The Jilling-Langalota iron ore deposits are part of the IOG. Detailed mineralogical characterisation of different ore types has been carried out using transmitted and reflected light microscopy. Scanning electron microscope-energy dispersive spectroscopy (SEM- EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) have also been used with a view to test the amenability of these ore types for beneficiation requirements. It has been observed that haematite, martite and goethite are the main iron-bearing minerals. Kaolinite and quartz are the major gangue mineral phases. Considerable mineralogical, textural and compositional variations have been observed among the different ore types. Characterisation data reveals that the massive and hard-laminated ores are of higher grade with very few interlocking textures having haematite and martite as major mineral constitutents. The soft-laminated lateritic and friable ores are relatively low-grade varieties containing various proportions of impurities with complex interlocking textures. The soft-laminated and lateritic ores are porous in nature and contain friable oxide and hydroxides of iron along with kaolinite, gibbsite and quartz. The occurrence of kaolinite, gibbsite and hydrated oxides along the cavities and weaker mineral planes of haematite and martite has been observed. The friable nature and high alumina content of these ores are attributed to these secondary phases. The nature of these ores is responsible for producing large amounts of alumina-rich slime during mining and handling operations. Suitable beneficiation schemes have been recommended for each type based on detailed characterisation investigations on these ores.

Jan 1, 2007

A major high grade zinc deposit, Dugald River has fine-grained and complex mineral associations which provide considerable metallurgical challenges for both mineral dressers and downstream processors. A long history of metallurgical testing focusing on mineralogy and flotation concentrate production has shown that while separate lead and zinc concentrates can be produced at saleable grades, high levels of iron, and particularly manganese, are likely to place constraints on the marketing of zinc concentrate produced from deeper zones where coincidentally lode development is at its maximum. Testwork has focused on characterising the flotation response of ore types ranging from banded and stringer sulphides to brecciated ores in a variety of sulphide matrices. A high level of variability with lower than expected metal recoveries has been indicated across some of the higher grade brecciated ores. However, the dominant slatey breccia has generally provided the best results. Heavy media preconcentration testwork has been moderately encouraging and at this stage, although value adding downstream of concentrate production on-site is not seen as an economic option processing developments are being monitored on a broad front. Providing satisfactory means can be developed for handling manganese during downstream processing of the concentrate, it is not difficult to see a world-class operation emerging from the resource in the medium-term Future.

Jan 1, 1993

By P J. Harper

Maximising shareholder value is a widely stated strategic goal of many mining companies. Mining projects can be capital intensive and achieving good returns is essential to encourage future investment in the industry. Despite the widely accepted importance of shareholder value, the minerals industry is often accused of providing relatively poor returns when compared to other industries. There are many recent and well publicised examples of minerals companies that have failed to deliver value to their shareholders. There are numerous business improvement initiatives employed within the mining industry to assist mine operators improve performance. Some are more effective at creating value than others. Benchmarking is one technique that is commonly used to identify performance gaps and target and prioritise opportunities for improvement. However to be effective, Benchmarking must be used appropriately and result in actions that lead to measurable operational improvement. When conducting a Benchmarking project it is important to remember that the aim should be to improve value. For this to be achieved, the strategic goals must be incorporated into the process. This paper details a structured and comprehensive approach to conducting a successful Benchmarking project. Focusing on Benchmarking as a technique for measuring and improving operational performance in underground mines, the underlying drivers of best practice in underground mining are identified.

Jan 1, 2005

AustraliaÆs record-breaking drought, efforts towards environmental best practice and the current commodities boom is demanding water use and reuse as never before. Mining practices, processing, the remote communities and support industries require vast amounts of specific quality water. Sustainability of water use has been a key factor in mine development, expansion of existing operations and increasing profitability of processes involving water. Developments in water treatment technology have enabled the use of a range of processes to produce this water reliably at ever decreasing costs. This increasing acceptance of new technologies has seen seawater desalination, recycling of plant wastewater streams, municipal wastewater reuse and others to become commonplace. Processes including seawater and groundwater reverse osmosis (RO), low pH RO, thermal desalination, high rate clarification, brine water treatment, ion exchange and other advanced treatment technologies are now used as part of mining operations. This paper surveys the trends in water treatment for the mining industry both in Australia and internationally with a review of technologies and case studies of operating plants. The key technologies are explained with an emphasis on the specific requirements for mining operations û unusual raw water, process and operations limitations, environmental concerns, as well as harsh climate. Case study information from several mining operations is included.

Jan 1, 2006

By Ritchie I

Copper minerals are often associated with gold ores. These create processing problems since cyanide solutions are not selective for gold alone. Copper minerals are also leached by cyanide, and typically each one per cent of `reactive' copper in the ore consumes about 30 kg t 1 cyanide. Once in solution, copper cyanide species create further processing problems as they adsorb onto carbon along with the dicyanoaurate ion. These problems make conventional cyanidation of gold ore uneconomic if the ore contains too much copper. As a result, methods of economically processing gold-copper ores are becoming of increasing importance.One of the more promising methods of treating these ores is by selective leaching of the gold by an ammoniacal cyanide solution, a method first described by Hunt in 1901. This method is already in commercial use in Mauritania, treating copper/gold tailings. In general terms, the addition of I - 2 g U1 ammonia to a standard cyanide leach solution causes a significant increase in gold extraction and decrease in copper extraction. However, early testwork on this system has concluded that the optimal leach conditions are critically dependent on ore composition, and the mechanism is not well understood, making predictions of best conditions impossible.

Jan 1, 1997

Over the past 15 years many world-class gold discoveries have been made in the region. Some deposits, such as Lihir and Porgera in P.N.G., have a contained gold resource that places them among the top dozen deposits ever found on a worldwide basis. Can we see any pattern to these discoveries, or are they the result of good luck or chance by geologists and prospectors who struck it rich? Whilst such discoveries were a feature of the gold rushes of the 1850s and the 1900s, the present boom is now scientifically based. This paper develops an argument that long-tent, multi-disciplinary exploration by experienced geoscience teams underlie the successes achieved. Dis- coveries nearly always reflect a combination of skills, drawn from the areas of geology, geochemistry, geophysics and remote sensing, and a team approach. They do not represent the chance finds of a prospector's pick or such as the Norseman discovery where the gold reef was first noted by the prospector when his horse fell over the outcrop. The following deposits provide major examples of exploration successes within the Australian-Pacific region, it is not an exhaustive list and I have noted other significant producers at the end of this paper. For the Australian mines listed and based on our estimates for 1990 gold production, they represent about 20 per cent of the Australian production total.

Jan 1, 1991

The pyroclastic-filled Voorspoed kimberlite pipe has a low grade due to significant internal dilution which translates to a marginal business case. The site, with excavations, tailings dumps and buildings remnant of mining from 1906 to 1912 is to become De BeersÆ benchmark mine in South Africa. In a climate of skills shortages and lean structures, a geological service to optimise exploitation of this complex resource was established. As historical mining removed the higher-grade centre of the pipe, initial production was in the weathered upper benches along brecciated pipe margins. Trenching and blasthole logging before blasts helped to mitigate the effects of the drastic contact deviations that occur when working with an inferred geological model. However, identification of unfamiliar weathered kimberlite and delineation of unmodelled internal waste posed challenges. Efficient grade control by demarcation and allocation of individual truck loads will be vital to continue profitable mining at Voorspoed. Further challenges arose across disciplines. The first yearÆs planned production of mostly weathered kimberlite was processed through a plant designed for VoorspoedÆs unusually competent ore. The high clay content of the weathered material led to clogged chutes and overloaded fines disposal, hampering efforts to commission the plant. Resolving this problem involved mining æout of planÆ to provide a blend of fresh and weathered kimberlite. The calculation of an accurate mine call factor was hindered by a lack of haul truck monitoring, process stoppages and stockpiling in the plant during commissioning. Updating of the geological model to incorporate the contact changes observed in the pit was slowed by the need to first understand how 40 years of exploration data was integrated to create the model. A plan, involving focused mine geology practices, is in place to upgrade a portion of the resource from Inferred to Indicated level of confidence. These challenges are not limited to new mines but will be ongoing as new information is constantly gained at Voorspoed and many mining operations.

Jan 1, 2009

By Gresham J. J

The rapid and successful development by Western Mining Corporation Limited (WMC) of a gold mining industry based on the deposits of the Kambalda-St Ives group, was the final chapter in a story that started some 85 years earlier. Although the exploration work that led to the development of the current mining operation took place in the 1970s and 1980s, the successes had their roots in the 1890s and it took three gold rushes, and separate uranium and nickel exploration booms to make the discoveries Possible.

Jan 1, 1991

By Jones KW, McClelland RA, Denholm WT, Taylor RN, OÆShea J

Associated Tin Smelters, Sydney, are developing tin smelting operations in a prototype commercial SIROSMELT plant comprising two furnaces of 5 to 8 tonnes capacity. Features of the plant and its operation are discussed and results of its application to tin slag reduction and high-grade tin concentrate smelting are presented. Development work is still in progress but experience indicates that the technology has potential for lowering the costs of tin smelting and relieving constraints on grade and iron content of concentrate imposed by conventional technology.

Jan 1, 1984

By Martin C. H, Met B

INDEX OF CONTENTS:1. Introduction, Explanatory; and Reasons for Coal Cleaning.2. Principles on which Coal Cleaning is based.3. Location of Broken Hill Proprietary Co. Ltd. Plant.4. Description of Processes Selected Barvoys Bath Process; Barvoys Medium Preparation and Treatment; Static Dry Cleaning Plant.5. Detailed Description of Plant.6. Typical Results of Cleaning Operations.INTRODUCTION, EXPLANATORY, AND REASONS FOR COALCLEANING:The Institute proceedings have not previously published any matter on coal cleaning and the reasons thereof; in consequence it has been deemed advisable to allot a part of this paper to explanatory matter, prior to entering into a detailed explanation and description of the Newcastle plant.At the outset it would be as well to consider briefly the kinds of materials from which coal has originated. All coals represent some stage in the decomposition and transformation of vegetable matter laid down in prehistoric times, the vegetable matter undergoing numerous geological changes, such as submergence, overlaying by sediment, with subsequent pressure and re-elevation; these processes may...

Jan 1, 1946

By Stevens P

The Isa Mine of Mount Isa Mines Limited currently produces 5.4 million tonnes of copper ore and 3.3 million tonnes of silver, lead and zinc ore annually. Of this, 5.1 million tonnes of copper ore and 2.2 million tonnes of silver-lead-zinc ore is produced by sublevel open stoping. This paper summarises the capabilities, operating practices and problems encountered with current production drilling practices used to drill sublevel open stopes at Mount Isa.

Jan 1, 1982

By B Wiggins, M Russell

Off-gas handling systems are a critical component of modern metallurgical furnaces and typically represent as much as 50 per cent of the total installed smelter capital cost. Inadequate off-gas system performance, due to insufficient exhaust flow or excess maintenance downtime, can present a serious process bottleneck and limit smelter production rate. Therefore, it is essential that the relevant performance issues are fully understood and considered in the design of these systems, particularly when combustibles produced within the furnace must be combusted or handled in the off-gas system. This paper examines the requirements, design issues, and conceptual design process for state-of-the-art postcombustion off-gas systems. The relevant design considerations of safety, environment, energy consumption, and maintenance are presented, and the relative importance of these key issues are compared and discussed. The benefits of using computational fluid dynamic (CFD) modeling in the design process at the conceptual design stage are also demonstrated. Finally, the design basis and performance of a recent Hatch-engineered system currently in operation is evaluated.

Jan 1, 2002

The Olympic Dam mineral discovery by Western Mining Corporation (WMC) in South Australia has been shown to contain one of the world's largest known deposits of copper and uranium; gold and silver are also present. Development of the deposit jointly by WMC and the BP Group is awaiting commitment, with planning based on initial production of gold in 1987 and copper and uranium in 1988.

Jan 1, 1985

By Gillies A. D S, Just G. D

Coal washability data can be used for assessing coal quality. However, the techniques of using these data to solve quality problems differ from one mine to another and certain problems may never really be investigated due to limitations of the available techniques. One promising way to overcome these limitations is by correct application of geostatistics.A geostatistical study on coal washability data was undertaken based on a data set of closely spaced in-pit bore cores. These bore cores were analysed consistently over a relatively simple geological area. The average distance between the drill holes was about lOOm. There were 78 drill holes available for the area after deleting the erroneous bore cores. During the study, nine extra closely spaced drill holes were drilled within a single mining block.A procedure to construct two coal quality models, a kriging or cokriging model and a simulation model, was proposed. The modelling results for the data above are discussed and results of a mine scheduling exercise based on the models developed are included.

Jan 1, 1992