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By J Li, A McFarlane, J Yu, L L. Kuhar, R Meakin, N Chapman

"Column leach tests are used frequently to predict recoveries and reagent consumption for nickel laterite heap leaches. These column leaches often run for more than 100 days and therefore require long-term monitoring and data analysis to achieve the desired information. To minimise the cost and time required to obtain relevant information for nickel laterite heap leaching, we have developed a small-scale hydrogeometallurgical laboratory test to serve as a proxy to column, and by inference, heap leaching. In excess of 50 leach tests were conducted using four different small-scale proxy and column leach tests to compare predicted nickel recoveries, acid consumption and leach kinetics and to determine whether insight into potential scale-up effects can be obtained. The most promising proxy test was identified and we achieved a statistically significant recovery and acid consumption correlations between this test and the column leach tests. The accuracy of the small-scale tests was confirmed by column tests run on new laterite ores. This geometallurgical proxy could be of use for the population of block models and process selection during the mine planning phase or for optimisation and control during processing.CITATION:Li, J, Kuhar, L L, Meakin, R, Chapman, N, McFarlane, A and Yu, J, 2016. A Geometallurgical Proxy for Nickel Laterite Heap Leaching, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 335–340 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By R N. Humphries

The aim of this paper is to question the need to develop bespoke monitoring and assessment methodologies and criteria, thereby ‘reinventing the wheel’, when designing and assessing the success of important natural habitat and ecosystem restoration schemes at mine sites in the UK and Australia. It draws attention to the existence and applicability of the Phase I Habitat, National Vegetation Classification (NVC) and Condition Monitoring methods in the UK and similar approaches used in Australia. These are long accepted established methodologies and have published accounts for describing, assessing and managing natural vegetation communities, habitats and ecosystems. They are often used at the environmental impact stage, but seemingly rarely, if at all, in restoration design and management at mine closure. Their application to mine restoration and closure is illustrated and discussed by reference to a surface coalmine in South Wales, UK.It is concluded that the application of a combination of the Phase I Habitat, NVC and Condition Monitoring methods is highly relevant to the expectations of the Convention on Biological Diversity (CBD) and its implementation in the UK, and probably in Australia too. The methodology and criteria described could be incorporated into the guidance and specified in the mining permits so that there is clarity as to the expectations and requirements for monitoring and assessment for bond release. Their use could be of wider application where there is a requirement to assess the success of restored CBD assets and ecosystems.CITATION:Humphries, R N, 2014. Why reinvent the wheel when there are established methodologies to aid the design and assessment of restored natural ecosystems on mined land?, in Proceedings Life-of-Mine 2014 , pp 675–692 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

Subsurface information from the "Upper Coal Measures" of the Sydney Basin is interpreted by means of structure contour maps, isopach maps and geological cross- sections. Particular reference is made to recent coal drilling operations by the New South Wales Department of Mines. The study is restricted to the onshore portion of the Sydney Basin.

Jan 1, 1972

By Moylan T, Stewart D

A case study examining the procedures and financial benefits of introducing dump leaching to augment the Mt Gibson Gold Project CIP operations is discussed. Metallurgical testwork, followed by pilot dump leach operations, confirmed that gold recoveries of greater than 60 per cent could be achieved by dump leaching Mt Gibson laterite ore. Capital and operating costs were determined. Pit optimisation using the Whittle FOUR-D optimisation program calculated an optimum cutover grade between CIP and dump leaching for one orebody. The resultant recalculation of reserves based on CIP and dump leach operating costs showed that reserves for that orebody could be increased from 329 000 tonnes at 1.9 g/t An, to 1 488 000 tonnes at 1.2 gh An. NPV for the CIP only option of $1.4 m, was increased to $4.0 m for the combined CIP/dump leach option. This technique can be applied to existing gold projects and to new Developments.

Jan 1, 1992

THE plant is one of the usual type of Mond plants, and contains no new features worthy of comment. A brief description of the process, however, with a few remarks on the working of the plant, may prove of interest.Producer gas is made by passing a mixture of air and steam through incandescent carbon contained in a furnace called a producer, which, in the Mond type, is a cylindrical casing of steel plate, lined with firebrick, and fitted at the lower end with sloping fire-bars'. Coal crushed to an even size (about 2-in. gauge) is elevated to bunkers over the producers, from which it is fed into a measuring hopper on each producer.The hopper is a cast-iron cylinder fitted with a swing cover at the top and a bell valve at the bottom, worked by a lever and balance weight. When a charge of coal is run from the bunker into the hopper, the cover is closed, and the bell valve is lowered, allowing the coal contents to drop into the producer. Thus no gas can escape from, or air be admitted to, the producer during the process of charging. The hopper discharges its coal through a steel pipe-shaped container called the bell, which projects about 9 in. through the roof of the producer. The function of the bell is to spread the coal evenly over the fire, and supply coal to any portion of the fire as it settles.

Jan 1, 1918

By H Jones

Closure cost estimates may be generated at any stage of a mining operationÆs life; commencing with the initial prefeasibility studies and continuing through to the final decommissioning cost estimates. However, not all mine closure cost estimates are necessarily the same. Cost estimates will vary depending on the purpose for which they are prepared, the organisations requiring or undertaking the estimate and the stage of the mining operation. Different organisations can legitimately arrive at disparate cost estimates for closing the same mine because the organisations have different reasons for requiring the estimates. Another, equally valid, reason for potentially wide variations in cost estimates by different organisations on the same mine site is the different definitions of æclosure costsÆ used by different estimators. This paper considers the different approaches by different organisations including operating companies, government authorities and financial organisations and uses a hypothetical example based on practical experience to illustrate some of these differences in estimation methods.The paper suggest that a more consistent approach to closure cost estimating in the Australian mining industry would assist mining companies, governments, the accounting industry and the broader community to better understand this complex component of mine planning. One possible approach to closure cost estimating is briefly outlined.CITATION:Jones, H, 2012. Closure cost estimation - All things to all men?, in Proceedings International Mine Management 2012, pp 115-124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By KenGemar P, Perembo R. C B, Winn R. D

The New Guinea orogen comprises terranes that have accreted to the northern margin of the Australian craton. The history of the accretion of terranes begins earlier (in the Late Cretaceous) and is more complex than has been suggested previously. There was a collision in the central highlands in the Late Paleocene or Early Eocene, and a Finisterre collision that precedes and is distinct from the later (Pliocene) Bismarck volcanic arc collision.

Jan 1, 1997

By A Horn

Mineral processing is characterised by a constant adaptation to changing raw materials and market conditions. It is the link between the mined raw material and a marketable product. As a lot of high-grade reserves are exploited, a steady deterioration of raw material quality can be observed. At the same time, the customer’s requirement for product purity and consistent quality increases.Over recent years beneficiation techniques for iron ore fines have become more important in order to achieve a maximised utilisation of ore resources and to produce competitive products according to international standards.Many high capacity iron ore beneficiation plants that target the production of fines focus on gravity separation processes using fluidised bed classifiers and spirals or wet high intensity magnetic separators as an alternative. This paper demonstrates the suitability of utilising the allflux® two-stage fluidised bed classifiers to treat iron ore particles up to 2 mm in size as well as showing how the high capacity gaustec® wet high intensity magnetic separation (WHIMS) technology offers several advantages compared to other WHIMS technology.The combination of the allflux® and gaustec® technologies offer the following benefits:The two-stage fluidised bed classification extracts a significant amount of concentrate from the feed. This in turn reduces the feed capacity required for the gaustec® WHIMS located downstream.The second classification stage produces a -0.5 + 0.1 mm product and a -0.1 mm product. The efficiency of the magnetic separation on these classifi ed products is high due to optimised settings for each size fraction.

Jul 11, 2011

By B Poborowski, A Chen

"For some time, the Australian and Chinese underground coal mining industries have evolvedindependently with minimal infl uence on each other. Despite the fact that in recent years severaltechnologies and solutions have become common to both industries, this trend has seeminglycontinued to the point that there are still many important diff erences in legislation and hazardmanagement systems in both countries. Austar Coal Mine as an Australian based and Chineseowned enterprise has a unique opportunity to benefi t from the technology and knowledge ofboth nations. This paper compares the Australian and Chinese approach towards spontaneouscombustion hazard management in order to exchange experience, identify possible improvements and learn from each other."

Jun 1, 2012

By Y Cao, J C. Tien

Occupational health and safety is essential in modern mining workplaces and in China it is often not given enough emphasis due to a lack of knowledge and/or appreciation. Although many health and safety regulations have been passed over the years, serious and relevant laws and regulations on mine health and safety are of recent history (since 2002), the level of stringent enforcement is still inconsistent and accurate field data are scant and not readily available. As of year-end 2006 there were 676 562 recorded cases of occupational diseases in China, of which 616 442 or 91 per cent were miners’ pneumoconiosis. Of these, 146 195 (23 per cent) have died, and an average of 10 000 new cases were added every year between 1991 and 2006. Another report shows that 93.18 per cent of miners have never had a contract with their companies, which means their cases were not even part of China’s official statistics. This study attempts to examine the prevalence of occupational diseases in the Chinese mining industry during 2000–2013, compiled from government annual reports and academic studies. The research will review the correlational analysis among occupational diseases, ventilation practices, protection devices and legislation.CITATION:Cao, Y and Tien, J C, 2015. Occupational diseases in China, with the emphasis on its occurrence in Chinese mine workers, in Proceedings The Australian Mine Ventilation Conference, pp 155–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Huleatt M, Perkin D, McLeod I, Mock C, Pratt R, Gourlay A, Timoney E, Knight N, Ward J

Generally speaking, Australia's reserves of its more important minerals (in terms of export earnings) are adequate to sustain forecast rates of production to the year 2000. The rate of forecast production increases of these commodities (aluminium - whether as bauxite, alumina or metal, black coal, iron ore and ferro-alloy minerals, base metals, tin, uranium, and mineral sands) reflects a well- ordered and sustained growth phase of Australia's mineral industry.

Jan 1, 1981

By King D, Dickinson S. B, Matheson R. S

Commencing in 1956, Rio TInto Australian Exploration Pty Limited in association with Electrolytic Zinc Co of Australasia, Limited, has been carrying out a mineral prospecting program in North-West Tasmania over an area of about 4000 square miles.The program has comprised extensive airborne geophysical surveys, detailed geological mapping, ground geophysical and geochemical investigations. Out of the wealth of new data, and the examination of previous records, has emerged a new structural concept of regional ore control and distribution in North-West Tasmania. This roncept stems from the discovery of an ancient 'fossil' rift valley (graben), named the Owen Rift Valley, along which are located the major mines of the area and numerous well-known prospects. The known mines and prospects from north to south include Mt Bischoff (tin); the Pinnacles (zinc, lead, ropper); the Chester (pyrites); Rosebery-Hercules (lead, zinc, ropper, silver, gold); Mt Tyndall (lead, ropper, zinc); Comstock and Tasman (copper, lead, zinc); Mt Lyell (copper, pyrites, gold); Mt Jukes and Mt Darwin (ropper). The identification of the West Coast (Owen Conglomerate) Range as a fossil rift valley is due to Or B Campana, who carried out extensive geological mapping and interpretation work, and who, with S B Dickinson, are the senior authors of this paper.S B Dickinson, who introduced B Campana to the geological problems of West Tasmania, had previously investigated the Mt Lyell and Rosebery mining fIeld, to which reference is made in this work.D King assisted in the regional mapping and in providing numerous data on the mineral distribution of the area.R S Matheson rontributed to the fmdings on ore emplacement and rontrol in the discussions held on this subject. They are accordingly included as joint authors of this paper.Credit is also due to E McCarthy, who interpreted the geophysical results, and to J H Rattigan, who compiled the preliminary geological maps from published documents and by photo-geological methods.G Hall and V H Cottle, of the Electrolytic Zinc Co in Rosebery, provided invaluable geological data and suggestions in the course of the survey, and made a constructive criticism of the manuscript of this work. The airborne geophysical survey carried out by the Adastra-Hunting Geophysics Ltd company, furnished useful data which substantiated many of the fIndings on the stratigraphic and structural relationship. The Mines Department of Tasmania and S W Carey, Professor of Geology at the University of Tasmania, were instrumental in initiating the regional survey and provided the published and unpublished geological literature on the area.The authors also wish to acknowledge the invaluable assistance received from the Mt Lyell Mining and Railway Co in Queenstown, which made available the more recent geological and mining documents rompiled by M L Wade and M Solomon.

Jan 1, 1994

The Australian coal industry has undergone sevenfold growth over the last 30 years and since 1985 has been the world's largest coal exporter. Three quarters of Australia's coal production is exported so its future is dependent on it remaining internationally competitive with other energy sources and other coal exporting countries. Coal is likely to increase its share of the energy market during the nine- ties as oil prices increase, new coal-fired capacity is commissioned and some form of nuclear energy is developed which is of acceptable safety standards to the community for use in the 21st century. Gas may take a part of coal's anticipated market share by the Year 2000. While coal exports will increase from China, Colombia, Indonesia and Venezuela and satisfy some of this additional coal demand Australia will also expand its export production, due to its existing advantages. The United States, Canada, South Africa, Poland and USSR seem unlikely to enjoy the same degrees of expansion and some, particularly Poland and USSR, will decline. Australia will always find it difficult to compete in the more distant markets due to levels of ocean freight, although its high quality coals will tend to partly offset such disadvantage.

Jan 1, 1988

The paper describes the design of the dilute medium and medium recovery circuits installed at the coal preparation plants at the Cornwall Coal Company's Fingal Mine, and the BP Coal Australia's Howick Mine. These circuits maximize the use of clarified water for rinsing to improve the mass transfer of adhering medium from the coal surface into the carrying liquid, and have been combined with the use of a two stage magnetic separator. The separator utilizes a conventional concurrent first stage and a counter-rotation second stage. This combination results in high medium recoveries during both normal operation, and start up and shut down phases when large quantities of medium can be lost from a conventional circuit. Overall losses using this circuit have been estimated to be, 200g/t, over a twelve month period. Further advantages in plant operation are also obtained, especially steady operating conditions in the centre-tube pump tank, lower slimes contamination of the product, and lower quantities of non magnetics trapped in the separator concentrates. The techniques are particularly suited to incorporation in circuits treating coals containing high percentages of sticky and difficult clays, as are found in the Walloon coal measures.

Jan 1, 1987

By Fowke NC, Williams RJ, Hungerford F

In-seam, directional drilling has been implemented at Huntly West Mine, New Zealand as the most cost effective means of obtaining geological information at a level of detail and accuracy required for planning of longwall ("flexiwall") panels. No geological or geophysical technique tried at the mine prior to 1989 has been able to reduce geological risk to an acceptable level. Surface and in-seam seismic methods have not had adequate resolution. Obtaining the required knowledge via surface drilling would be prohibitively costly, and still not precisely locate or orient faults or the axes of seam "ridges and valleys".A total of 3543 m was drilled at an average of 67m/shift including setting up time. Unplanned delays totalled only 9.6 percent. Major re-interpretation of seam structure resulted from the drilling. Lateral and longitudinal panel grades have been defined. which should be negotiable with the Coalcorp longwall equipment.

Jan 1, 1991

By R Pinksen

The Iron Ore Company (IOC) of Canada Mining and Operations Departments expressed an interest in reducing the amount of oversize material (>1 m × 1 m × 1 m) being produced and its subsequent downstream effects including in-pit sorting and reduction, damage to mobile equipment, and significant delays in the loading pockets and the primary crushers. To achieve this goal an oversize reduction project was undertaken by the mine and to date has significantly improved upon baseline measures.One key approach used to reduce the amount of oversize was the implementation of thicker emulsion. The introduction of a thicker emulsion into the blastholes provided more resistance to the forces created by dynamic water and reduced the infi ltration of the emulsion into the cracks and fissures of the rock mass. Blast results showed reduced amounts of oversize and more consistent fragmentation throughout the muck piles. Additionally, a significant reduction in nitrates leached into the mine water discharge has been realised.To determine the effectiveness of the oversize reduction project, IOC used shovel based camera technology to assess fragmentation presented to the shovel at the digging face. A digital vision system (DVS) was installed on one of the shovels to capture images that were stamped with global positioning system (GPS) locations. A large population of digital images was analysed to produce a robust fragmentation distribution baseline that was used as one of the mine key performance indicators (KPI). Changes to blasting practice were subsequently measured against the baseline KPI to assess effectiveness.

Jul 11, 2011

By Batterham R. J

Some developments in copper, lead and zinc extractive metallurgy which have gone in to production or seem to be close to production scale are described with emphasis on why these innovations have been adopted.Mineral processing operations are now using: automated quantitative mineralogy,high capacity fine crushing equipment, ò fine grinding equipment, andcolumn cell flotation.Extractive metallurgy plants are using:ò bath smelting of concentrate at various scales, and ò flash converting of copper.Hydrometallurgical process developments are slower to make a commercial impact. Concerns about ability to handle impurities in the feed and production of saleable by-products are often major hurdles.An expression for the probability of implementing the first example of a new development is presented.

Jan 1, 1992

By A Tang, K Ringwood

"Water is increasingly being recognised as a material business risk that many companies are still not well-equipped to deal with. Despite a raft of water-risk focused initiatives, methodologies and guidelines, the challenge of managing the strong link between the technical and operational water issues, along with the growing external challenges and interests in water, remain a significant risk to a companyÆs ability to deliver value.This paper provides an overview of the key lessons learnt from ERMÆs experience of working with companies across a range of water sensitive industry sectors, in particular, the mining and oil and gas sectors, to develop and implement practical approaches to manage business critical water risk. These examples highlight the importance of managing water risk by linking technical and operational aspects of water management - with the longer term strategic and social license aspects. Four key ingredients were identified that are central to providing companies with a leading edge in the successful mitigation of water risk: understanding and evaluating water risk including the technical and operational aspects of water management, plus the longer term strategic and social aspects articulating a strong business case that prioritises water risks and their financial exposure to the organisation constructing a clear roadmap that practically links the water strategy objectives with on-the-ground implementation and action building capacity in the organisation to manage, engage and coordinate on water to mitigate risk.CITATION:Ringwood, K and Tang, A, 2013. Practical approaches to managing business critical water risk, in Proceedings Water in Mining 2013, pp 293-300 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By D R. Venkatesulu, N K. Nanda

Due to increased production of steel in India, the thrust is now on iron ore producers not only to enhance productivity from existing mines, but to look also into alternative resources, like lean grade iron ores such as banded haematite quartz (BHQ)/banded haematite jasper (BHJ), which are available in abundance but not yet utilised for want of suitable process technology. In this context, BHJ ore from the Bellary-Hospet sector was collected and subjected to detailed physical, chemical and mineralogical characterisation and beneficiation studies. The as-received sample was found to occur physically as alternating layers of haematite and jasper. The chemical analysis of the sample was 41.20 per cent Fe, 39.10 per cent SiO2 and 0.86 per cent Al2O3. Based on the mineralogical observation, haematite was found to be the lone ore mineral and jasper was the major gangue mineral. The microscopic observations revealed that the ore minerals liberate at a top size of 0.150 mm. Guided by the characterisation results, indicative tests were conducted using gravity and magnetic separation equipment, namely, Floatex«, gravity slime table and wet high intensity magnetic separator (WHIMS). The results indicate that it is possible to upgrade the sample by both gravity and magnetic separation techniques. However, the WHIMS results indicate that jasper grains report to the concentrate at higher gauss intensities. Therefore, based on the encouraging gravity separation results and the availability of new design spirals for treating fine particles, the applicability of gravity spirals for beneficiating BHJ in the liberation size range of -0.150 mm was studied. The sample was ground to a top size of 0.150 mm and was subjected to preconcentration using wash waterless spirals. Tests were conducted at different feed rates, pulp densities and splitter positions. The results indicate that it is possible to upgrade the sample from a feed grade of 41.20 per cent Fe to a preconcentrate ranging from 46 per cent to 62 per cent Fe with a yield ranging from 19 per cent to 55 per cent. The obtained preconcentrate was then subjected to a cleaning stage by using a combination of wash water and wash waterless spirals. The test results indicate that it is possible to obtain a final concentrate assaying 65.75 per cent Fe and 4.75 per cent SiO2 with a yield of 25.9 per cent and an iron recovery of 41.31 per cent. It was concluded that further test work is necessary to increase the recovery and improve the product specification.

Jan 1, 2009

By T E. Hayward, D H. English, S J. Smith

Gold mineralisation at Bendigo is exclusively associated with quartz reefs, commonly found within or near anticlinal fold hinges. The gold is typically coarse grained (0.5 mm to 5 mm), free milling and displays a complex, nuggetty distribution within the veins. This ore is highly amenable to gravity recovery processes. As the Bendigo operation is not permitted to treat whole ore by a cyanide leach/CIL circuit, the flow sheet is more complex than conventional gold recovery circuits. Primary gold recovery is from a gravity circuit closing the grinding circuit to a bulk gravity concentrate and from a flotation circuit treating cyclone overflow to a bulk float concentrate. The plant capacity is relatively low by current gold industry standards at 600 000 tpa. Re-establishing gold production at Bendigo has presented several challenging, and sometimes competing, issues in process design and operation. The mine, process plant, associated services and infrastructure are at Kangaroo Flat, a low density, semi-rural zone in the southern urbanisation of the Bendigo metropolitan area. One of the main processing challenges during the design was the competing comminution requirement to avoid over-grinding, which would flatten or smear the characteristic nugget gold and hinder effective gravity gold recovery, whilst also providing sufficiently well liberated particles that would respond well to flotation. Important, non-metallurgical challenges were to minimise impacts on the local community from noise, dust, air emissions, visual impact, water egress and off-site traffic.

Jan 1, 2007