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The Mammoth Mine is located some five kilometres from the town of Gunpowder which is approximately 120 km north-west of Mount Isa in Queensland.

Jan 1, 1993

By Barber S

The Golden Cross Mine is located within the Waitekauri Valley near the southern end of the Coromandel Ranges, eight kilometres north-west of Waihi, North Island, New Zealand. The mine is owned and operated in a joint venture by Coeur Gold NZ Ltd (80 per cent) and Viking Mining Ltd (20 per cent). The underground mine produces gold and silver from low sulphidation epithermal quartz veins which developed in the shallow parts of a meteoric water dominated system during the Upper Miocene (7.36 - 6.67 Ma). The Empire Vein System is hosted within a dilational structural environment which developed at the lithological contact between acid intrusives, rhyolitic-dacitic tuffs and reworked pyroclastics, and undifferentiated andesites. The formation of the Empire Vein System was controlled by the rheological properties of the host rocks and variable displacement along a series of normal, right lateral, easterly-dipping faults. These faults represent sub-parallel zones of master shearing within a Riedel shear model. Underground mining extracts ore from the steeply dipping hangingwall and the complex footwall veins of the Empire Vein System. Initially sills are driven along the hangingwall vein on ten to fifteen metre sublevel intervals. In the footwall zones where significant mineralisation adjacent to the hangingwall sill drives has been identified, a series of cross-cuts and footwall drives (sub-parallel to the hangingwall sill) are also developed. Where continuity of mineralisation and ground conditions permit a combination of post pillar flatbacking and AVOCA longhole benching methods are used. Detailed underground mapping of lithology, quartz veining and major structures provides the information for designing ground support and footwall pillars, planning mine development and ore extraction sequencing. Sectional interpretation displays the vertical extent of faults, fractures and the vein system. The mining methods used underground at the mine have evolved through a thorough understanding of the structural complexity and the systematic geological mapping of the Empire Vein System.

Jan 1, 1997

By J Skousen, C E. Zipper

"Prior to the 1950s in the USA, surface coalmines were generally left without any reclamation. As government regulations advanced, mine operators were required to backfill the area and plant grasses or trees. After the federal Surface Mining Control and Reclamation Act (SMCRA) was passed in 1977 in the USA, mine operators were required to conduct pre-mining analyses of the site and to designate a land use that could be achieved after the mining. Common post-mining land uses in the USA are: agricultural uses such as prime farmland reclamation with crops, hayland and pasture, and biofuel crops forestry wildlife habitat building site development.Provisions and regulations for each post-mining land use were developed and practices to achieve successful and sustainable land uses were established. Post-mining conditions should provide ecosystem services and produce lands capable of supporting societal needs in the future.CITATION:Skousen, J and Zipper, C?E,?2014. Post-mining land use options in the Appalachian coal mining region of the USA, in Proceedings Life-of-Mine 2014, pp 153–164 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

After extensive testing and a period of plant trials to establish the benefits of Caro's acid (H2S05) as an alternative oxidant, Queensland Mines Limited (QML) decided to replace pyrolusite with Caro's acid in its acid leach uranium treatment plant at Nabarlek. The decision was based on the reagent savings and environmental gains associated with the removal of manganese from the process liquors, as well as the labour savings and improved oxidation reduction potential control possible in leaching using the Caro's acid system. The permanent Caro's acid generating plant was designed by Interox Chemicals Pty Ltd of Australia (IC) to suit QML's require- ments and differed from the unit used during the plant trials. Commissioning of the plant was completed in April 1983 and it has been continuously used since that date.

Jan 1, 1984

Joint ventures exist as a means of sharing risks and obeying regulations. An unincorporated joint venture allows a company to take a share only of a project yet allows that company to treat such share as though it were an integral part of the company. The nature of the risks inherent in many ventures is described and comparisons made with alternative corporate vehicles. Different procedures for managing joint ventures are also reviewed and the types of problem encountered in establishing and operating joint ventures are discussed. The basic characteristics of successful joint ventures, in Australia, are listed and a conclusion reached that, despite its difficulties, the joint venture will continue to proliferate as a corporate vehicle for project development.

Jan 1, 1983

By C W. Lu, Y F. Chen, M J. Lian, W W. Guo

This paper proposes a set of new approaches for the optimisation of planning and designs in mines by means of evolutionary algorithms, which include the determination of ore grade, layout of development system, selection of mining methods and production scheduling in underground mines. The applications indicate that evolutionary algorithms are particularly suitable to the complex and complicated problems in mines.

Jan 1, 2003

The knowledge in the field has been reviewed by literature studies, and using experience from personal research in sublevel caving. There is a lot of material regarding gravity flow of fine grained materials in bins, but the theory of flow for these materials are normally not applicable for coarse blasted rock. This study was therefore concentrated towards coarse rock fragments created after blasting in orebodies. The goal for this study was to make a report of known knowledge, and identify what we have to learn more about. The Bergmark-Roos theory, which was a paradigm shift in the science of gravity flow, is today the best mathematical theory for calculation of the drawbody for a homogenous material or when we wish to simulate the mean drawbody for a large number of draws. The Bergmark-Roos theory must however be improved, so it can take into account the flow pipe effect. When this is done it will be possible to construct a 3D computer model for calculation of ore extraction versus amount of loaded ore and waste. It is also necessary to find the 3D shape of the flow cone to be able to calculate the 3D ore rest that normally develops on footwalls. Calculations should be done for the draw on several sublevels including determination of the ore losses and temporary ore rests. First when this computer model is developed optimisation of ore recovery and waste rock dilution can start for a given orebody. The author points out the importance for international co-operation and standardisation of methods for determination of material properties. More field tests and model blasting tests should also be done. When enough knowledge is gathered, a handbook of the optimisation of sublevel and block caving should be written.

Jan 1, 2000

The undeniable fact of life in the next 25 years will be the increasing difficulty of the physical conditions of Australian orebodies facing future miners. We are all familiar with names such as the 3000 orebody at Mt Isa, Hilton, Century, Macarthur River, Cannington, and Ernest Henry. These projects represent a significant. proportion of the planned underground mine development in Australia. Moreover, many of these new orebodies are an order of magnitude more difficult to mine and process than their predecessors. Extraction will be from deeper and potentially more hazardous working environments. Occupational health and safety considerations will place unprecedented demands upon mine operators and technology providers of the future.

Jan 1, 1994

By P A. Jenkins, I W. O Jones

WMC has mined the Perseverance disseminated orebody exclusively by SLC (sublevel cave) methods. Deteriorating ground conditions in the vicinity of an orebody inflection forced a re-evaluation of future mining at Perseverance and a strategy to drop down below the inflection zone and recommence the cave was implemented. This strategy has led to increased production at higher grades, resulting in lower costs and better mill recoveries. This paper describes the evolution of mine planning, development, support and production strategies through the successful process of implementing the ædrop-downÆ and re-establishing the SLC.

Jan 1, 2000

By Forssberg KSE

The behaviour of cationic and anionic collector mixtures in the feldspar-quartz flotation system has been investigated througl conductivity, surface tension, zeta-potential and flotation studies. Tht results show the formation of molecular complexes between oppositel; charged collector ions through charge neutralisation. The molecular complexes are found to have a higher surface activity than the individua components. The mole ratio of the mixed composition is found to have, significant effect on flotation. Mole ratio less than unit} (anionic/cationic) of collector mixtures increases the flotation recoveries If the mole fraction of the anionic collector is greater than the moh fraction of cationic collector in a mixed composition, flotation ceases The flotation selectivity principally depends on the inherent differences it the surface charges of feldspar and quartz at the flotation pH values of

Jan 1, 1993

By Reeves T. J, Hansen J. Y

Dense medium cyclone theory, supported by extensive experimental and plant-scale evidence, demonstrates that medium rheology (stability and viscosity) substantially affects cyclone performance in mineral applications.Two instruments have therefore been developed to allow medium stability and viscosity to be-monitored in the plant environment. The instruments are described, and examples are given of their application in full-scale plants.

Jan 1, 1989

By C R. Fountain, W R. Cannings

The zinc-lead-silver mineral resource at Lady Loretta ranks amongst the worldÆs richest when measured in terms of in situ metal grades. However, the project remains undeveloped 28 years after its discovery in 1969. The primary obstacle to development has been the fine and complex grain structure of its ores, which make flotation concentration inefficient even with fine grinding. The size and remote location of the deposit have also hindered exploitation. BUKA planned to directly fume the volatile target metals from the ore when it acquired the project. Intensive, post-acquisition modeling showed the innovative processing route to be uneconomic, notwithstanding high metals recovery and low waste content in fume product. Progressive modifications and supplements to the underlying fuming process enhanced economics and resulted in a new mine-to-metal processing route for zinc-lead-silver ores. The proprietary, three-stage BUKA Zinc Process offers technical, economic and environmental advantages. It is expected to find widespread application in the treatment of ores and residues. However, neither continued R&D nor application to Lady LorettaÆs currently delineated resource can be justified under prevailing market conditions. The objectives and results of each step in the process development sequence are outlined with reference to their impact on the commercial viability of the Lady Loretta project.

Jan 1, 1998

By Weller KR

A study of high pressure rolls grinding of a number of Australian ores and minerals has been carried out using a pilot-scale machine with rolls 300 mm diameter and 70 mm wide. The results from this study have been used in conjunction with plant survey data to construct computer simulation models of various comminution circuits and these have been used to investigate options for incorporating high pressure grinding rolls into these comminution circuits. Possible rolls options for three of these circuits are presented, and likely energy savings over the existing circuits are discussed together with potential improvements in plant throughput and/or product sizing. A scale-up procedure for predicting full-scale machine performance from small-scale testing is described, and the effects of rolls operating conditions are also discussed.

Jan 1, 1991

The ore deposits of the Oobar mining field are confined to sediments of the Early Devonian Cobar Supergroup. The mineralisation is discordant to bedding and parallel to cleavage. The structural association is variable with the deposits near the eastern margin of the Cobar Basin formed in zones of deformation and faulting. The Elura deposit located further to the west is in less deformed sediments within the core of a small anticline. There are wide variations in ore type fran lad sulphide chalcopyrite - pyrrhotite - pyrite to high sulphide sphalerite - galena - pyrrhotite - pyrite assemblages. The deposits ccnmonly contain an inner zone of quartz - sulphide - chlorite veining grading outwards into a chlorite halo containing quartz - carbonate veining. The Elura deposit differs in having an inner massive sulphide zone surrounded by a zone of big-Fe carbonate formation. The mineralisation probably formed during regional metamorphism and deformation in the Early Carboniferous. A possible genetic model involves the injection of metal bearing hydrothermal fluids formed in the upper mantle or lower crust up basement structures into the overlying Cobar Supergroup sediments. An alternate model proposes the leaching of metals from the sediments by brines formed during metamorphism and subsequent emplacement in favourable structural zones.

Jan 1, 1983

By B, R E. Browner, H R. Watling

A number of hydrometallurgical treatment methods are being developed to extract copper from chalcopyrite flotation concentrate including microbial leaching and ferric sulfate leaching. However, chalcopyrite is difficult to process efficiently by hydrometallurgical methods as it exhibits slow reaction kinetics. Comparative leaching tests do not always satisfactorily explain or predict observed copper recovery, acid consumption, or differential leaching of minerals. This is especially true when reactive gangue constituents are present. The aim of this study was to determine how the leaching regime (microbial versus ferric sulfate) affects both the extraction of copper and residue mineralogy. Chalcopyrite flotation concentrate was leached at 30¦C and 65¦C using a pure culture of Acidithiobacillus ferrooxidans and a mixed consortium of thermophiles, respectively. In addition, the concentrate was leached at the same temperatures using 0.1 M ferric sulfate. Microbial leaching of chalcopyrite extracted more copper than ferric sulfate oxidation of chalcopyrite at 30¦C, demonstrating that the microbes promoted the solubilisation of copper at this temperature. This result was confirmed by leach solution analyses and residue analysis using quantitative X-ray diffraction (QXRD). More chalcopyrite was oxidized with ferric sulfate at 65¦C than at 30¦C (as expected). QXRD confirmed that pyrite reacted during ferric sulfate leaching at 65¦C but was relatively unreactive during lower temperature leaching. The high ferric ion concentration in the ferric sulfate leach at 65¦C led to significant precipitation of jarosite. This phase was only detected in small amounts at 30¦C in both the microbial and ferric leached residues. Sulfur also precipitated in the ferric leaching at 65¦C whereas no sulfur was detected in the microbial leached residue. Quartz was a relatively unreactive mineral phase regardless of the leaching medium and temperature. QXRD analysis indicated the residue mineralogy differed with different leaching regime.

Jan 1, 2004

By A Sinuhaji, H Kalangi, T B. Setyoko

Ore fragmentation at the DOZ block cave mine is highly variable, both as a function of rock type and column height of draw. Initially, the mine was constructed and equipped with limited capability to handle drawpoint oversize material. Significant issues with drawpoint availability and achieving overall mine production targets resulted. A suite of secondary sizing tools was added to the mine equipment fleet over a one-year time frame. Although significant oversize continues to be experienced, use of the correct secondary breakage tool for each particular oversize or hang-up occurrence has resulted in increased drawpoint availability, production rate, draw compliance, and operator safety. Currently, a range of secondary breakage techniques is being utilised to size material for delivery to the primary crusher. Run-of-mine material (3) is directly mucked to ore passes fitted with grizzlys that have one-metre square openings. Ore containing small boulders (>1 m3, 3) is loader-trammed to ore passes fitted with rockbreakers. Medium-sized boulders (>2 m3) accessible from the drawpoint are drilled with Sandvik Tamrock Commando drills. Boulders hung-up within the drawbell are drilled and charged with a Sandvik Tamrock Secondary Breakage Unit. Compacted, fine-grained muck is blasted utilising 55 mm cartridge powder concussion bombs.

Jan 1, 2005

By R R. Lovel

In this paper, life cycle assessment methodology has been used to assess the variations in water use associated with different metal production and processing routes and provide insights into the value derived from water usage in the minerals sector. Using water consumption data derived from the literature it has been shown that the æcradle-to-gateÆ water consumption (or embodied water) for production of the various metals considered in the study ranged from 2.9 m3/t for steel up to 252 087 m3/t for gold. The results largely reflect the grade of the initial ore used to produce each metal, and can be approximated by the following equation: W = 167.7 G - 0.9039 where: W = embodied water (m3/t refined metal) G = grade of ore used to produce metal (per cent metal) The study showed that indirect water consumption in the metal production life cycle, in particular that due to electricity generation, can make a significant contribution to the embodied water value, eg aluminium production. When expressed in terms of m3/t ore, the results for all metals considered indicated that the embodied water is roughly, on average, three times the water consumption of the mining and concentration stage. It was also shown that the economic value per m3 of water consumed for the minerals industry exceeds that for the agricultural and industrial sectors, supporting the view that allocating water resources to the minerals industry has a strong underlying economic basis. Water reforms currently taking place in Australia aim to address issues such as competition for water access, reduced security of supply and increase in cost. Consequently the minerals industry, along with others, can be expected to come under increasing pressure to reduce fresh or raw water use and to integrate water use across sectors. While water recycling is an obvious candidate to help reduce water consumption in the minerals industry, issues such as water quality, among others, will influence the extent to which this can be achieved. In addition, wastewater volumes can be minimised using techniques such as pinch analysis to establish and use the minimum water requirement for the process. The use of dry or near-dry processing technologies, for which the demand for water is small or zero, may be a more radical solution to the water consumption problem; however, it is possible that the introduction of dry processing would bring with it a new set of problems, including dust.

Jan 1, 2006

By R C. Cox

The Brukunga pyrite mine was operated from 1955 to 1972 to supply feedstock for sulfuric acid production in the South Australian fertilizer industry. Iron sulfide ore, mined by Nairne Pyrite Ltd, was finely crushed and concentrated onsite with the concentrates being sent by road and rail to Port Adelaide for roasting. Waste rock was dumped at two locations on the western side of Dawesley Creek and the tailings pumped to a valley-fill storage facility on the eastern side. Production of 1.5 Mt concentrate resulted in 3.5 Mt tailings and 8 Mt waste rock. The site has been administered by the South Australian Government since August 1977 and a lime treatment plant has been operated on the site since September 1980. Environmental issues arising from these operations included: diversion of Dawesley Creek to accommodate the waste rock dumps; dumping of low-grade sulfidic ore in waste rock dumps at the angle of repose immediately adjacent to Dawesley Creek; exposed fresh sulfide mineralisation in the quarry floor; tailings storage facility dam wall constructed by upstream up-lift using tailings and waste rock; an acid water pond sited on the tailings; and pollution of natural drainage. As a result, the minesite rapidly became a source of acid drainage and potential contaminants (sulfate, Al, Fe, Mn, Cd, Zn, and Ni). Various Government bodies have been responsible for considerable effort and expenditure in reducing the flow of acid seepage and contaminants into Dawesley Creek. Presently an estimated 60 per cent of seepage from the waste rock dumps, tailings storage facility and quarry is collected and neutralised prior to discharge into the creek. Tailings have been covered with waste rock, biosolids, neutralisation sludge and soil and planted with grasses, shrubs and trees to reduce rainfall infiltration. Monitoring of water flows, water quality and riparian ecosystems is on-going. Consultants have been engaged to develop cost-effective remediation techniques and a five-member Brukunga Mine Site Remediation Board was appointed to oversee remediation of the site and liaise with the community. Construction has commenced on the diversion of Dawesley Creek, and plans are being developed for the relocation of waste rock back to the quarry benches and upgrading of the neutralisation plant. The paper examines operations, environmental monitoring, remediation, research and community involvement with respect to current best practice.

Jan 1, 2003

QEMSCAN« technology is a widely accepted automated e-beam technique providing quantitative and statistically robust mineralogical data to the mining industry. It uses X-ray mapping combined with backscattered electron (BSE) brightness to identify minerals in almost any type of geological material (Gottlieb et al, 2000). Besides the modal mineralogy also the liberation, associations, average grain size and other textural information can be obtained. The aim of this study is to test reproducibility of this technique by setting up and running standard tests on different QEMSCAN« systems. Multiple sample blocks were prepared by our standard operating procedure as epoxy-mounted, carbon-coated, polished blocks. The replicates were measured under the same conditions and measurement parameter settings on different QEMSCAN« instruments. The relative standard deviation (RSD) for the set of measurements was calculated. Generally the reproducibility of the systems themselves was found to be excellent, ranging between 0.4 and 1.5 per cent RSD. The more significant change in the reproducibility was found to be caused potentially by the sample preparation and variation in the mineralogy of the replicates. The measurement parameter settings together with these variations can account for almost 15 per cent RSD for minerals of low abundance. For analysed samples good results for the main phases present in quantities higher than 2 - 5 wt per cent of the total mass of the sample were confirmed with RSD generally below six per cent. Following the experiments, the parameters having the biggest influence on the performance of the QEMSCAN« and its precision are discussed in detail. The importance of sample preparation procedures and measurement parameter settings is emphasised. It is shown that experience and excellence is necessary for getting the most from the automatic mineralogical methods like QEMSCAN«.

Jan 1, 2008

By Callinan AN

Broken Hill Proprietary Company Limited have recently commissioned a 14 Megawatt power station adjacent to its underground coal mining operation at Appin NSW. The power station is fuelled by methane gas extracted from the coal seams 500 metres below the surface. The methane is compressed and cooled prior to its injection into the combustor of a single shaft gas turbine. The turbine is coupled through a reduction gearbox to an alternator. There is sufficient power generated to cover colliery load, with any excess being exported to Prospect County Council, which is the supply authority for the south western region of Sydney.

Jan 1, 1987