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By G Capes, L Morizzi, N Mitkas, E Jones, D Grant

This paper describes the mining setting for the sub-level open stoping (SLOS) mining method used at Olympic Dam (OD), and investigates the range of stope performance conditions encountered over 30 years of production, using a qualitative description of the factors influencing performance. Utilising a continuous improvement tool, the Plan-Do-Check-Act (PDCA) process, and a forward-looking rock mechanics program, the intent is to identify the key factors driving productivity and performance to create a stable and achievable long term mine plan.

Mar 15, 2021

The extraction of world-class mineral deposits using massive underground mining techniques is not an entirely new theme to world mining companies and experts. Previous MassMin conferences have helped to gather and disseminate the valuable experience and knowledge so important for the proliferation of safe and efficient mining of large underground deposits. With the passing years since the first MassMin conference in Denver in 1981, a number of factors have contributed to an increase in massive underground mining around the world, including environmental pressures, gradual exhaustion of shallower deposits and the enabling effects of improving technology in disciplines related to underground mining. Massive underground mining is heading deeper, embracing challenges which include working with elevated temperatures, increasing in situ and mining induced stress levels and longer ore transport routes. Improvements in mineral processing technology will tend to lead operators to contemplate the extraction of lower grade orebodies in the event that the ore can be efficiently transported to the surface and hence the plant. No doubt this tendency, and its associated challenges is encouraging a rich growth in innovative engineering in such fields as mine planning and materials handling as well as geomechanical issues such as support design and the simulation of extraction sequence effects on stress re-distribution. MassMin 2000, we are sure, will showcase a wide variety of new contributions in thought and actions in these fields. There is a definite place for academic institutions and mining related suppliers in the process of developing new technologies and practices in support of present and future endeavour in this field. Dyno Nobel has its own part to play, certainly as an enthusiastic and proud major sponsor of MassMin 2000, but also by means of identifying common cause between our Vision and Values and the needs, present and future, of the underground massive mining industry. The critical success factors, which Dyno Nobel pursues are:health, safety and environment, customer relationships and market development, cost optimisation (while maintaining quality), technology and innovation, organisational development, and leveraging capabilities globally. Through the present paper we would like to share some of these values and offer some practical insights as to how their realisation will contribute to the achievement of MassMin goals and needs.

Jan 1, 2000

By A B. Christie, R L. Brathwaite, A Swain

This study provides quantitative data on vein distributions within seven selected epithermal systems, four deposits hosted predominantly in rhyolitic rocks: Ohui, Wharekirauponga, Neavesville and Komata, and three major deposits mainly hosted in andesite: Martha Hill, Golden Cross and Karangahake. The technique of fractal analysis was used to help quantify vein distribution patterns. The fractal dimensions (D) obtained are related to the number of veins per metre, the degree of vein clustering, and vein thickness. An increase in any of these tends to increase the fractal dimension.   It is the relative relationship of these parameters that is important for the characterisation of vein distributions, and the comparison of different deposits. Within the same systems, the rhyolites are characterised by lower vein thickness and vein density, but have a higher degree of vein clustering compared to the andesites. Sections that are deeper and more centrally located within the epithermal system and/or close to major structures tend to have a greater degree of vein clustering, higher average vein thickness and density, and higher thickness to density ratios. This depth control is most pronounced in epithermal gold-silver systems because they have formed at shallow crustal levels where physico-chemical conditions change drastically both vertically and laterally. In addition to lithological and structural control at vein scale, deposit scale structure is of great importance in the deposition of economic mineralisation. Large open vein structures capable of sustaining high fluxes of hydrothermal fluid, favourable for the formation of large, high-grade gold deposits, are best developed in andesite sequences.

Jan 1, 1995

The theme of this conference is æRediscover OtagoÆ. In order to ensure the development and exploitation of mineral discoveries in New Zealand, considerable capital will be required, particularly from overseas. This paper briefly reviews the Government's foreign investment policies and procedures and highlights some trends.

Jan 1, 1992

The International Symposium-cum-Workshop on Management andControl of High Gas Emissions and Outbursts in Underground CoalMines was held in Wollongong in March 1995. Coverage of high gasemissions was virtually confined to instantaneous outburst implications, essentially seam gas pre-drainage. Globally, instantaneous outbursts have been known for 150 years, andthe first Australian outburst occurred in 1895 and Australian occurrences and mines affected have increased since. Few significant coal producing countries are unaffected. The coals affected range in rank from lignites to anthracites. Geological disturbances are the most likely environments for occurrences. The most likely mining geometry is of virgin headings, with some occurrences on longwalls and in other situations. Widespread research into many aspects of the problem has yet to produce a generally accepted explanation. Explosive inducement is a well-known control. Apparently high advance rates increase face gassiness and create higher stress abutments, increasing proneness. The most popular preventive measure, pre-drainage of virgin coal ahead of faces has produced highly successful very long hole drilling performances but without the precision necessary for accurate geometric hole patterns, despite quite sophisticated drilling equipment and hole surveying instruments. For the future, more precise degasification is sought, even from the surface, together with rapid face coal gassiness assessments to confirm lowering below threshold values, as well as other proneness lowering measures, perhaps related to new heading and longwall geometries and to new equipment to provide them. But above all, safe management plans are required for each operation, to safeguard the miners and their working environments, and thus to protect underground coal mining from this mounting threatening problem.

Jan 1, 1997

Following extensive trials on a 100 000 tpa Research and Development facility at Kwinana, Western Australia, Hismelt Corporation (wholly owned by Rio Tinto) are confident of the future commercial success of this technology. The Hlsmelt process uses iron ore fines and non-coking coals to produce molten pig iron suitable for feeding to BOF and EAF steelmaking vessels. The unique process configuration combines direct injection of raw materials into the molten iron bath, high rates of metal and slag mixing, and effective post-combustion of the bath gases to achieve efficient coal utilisation. This is the key to the strong economic performance of the process.

Jan 1, 1999

Economic Sustainable Power for Mineral Processing

Sep 13, 2010

Innovative Technology for Optimised Thickening Sedimentation

Sep 13, 2010

By B Maybee, L Fava, D Millar

In the context of a case study for an underground gold mine, the value generated by a schedule optimisation tool (SOT) is assessed. SOT is a software tool for underground mine planning that maximises the net present value (NPV) of a development and production schedule. A baseline study measures the NPV of a schedule generated by SOT from a sequence prepared by the site mine planners. Operational resource constraints and precedence constraints are adhered to by the schedule and NPV is evaluated with a financial model including revenues, costs and discount rate, as specified by the mine planner.The case study has several facets in addition to the baselining component. Scenarios were conducted that examined the degree of constraint on operational resources, the projected gold price and unit costs. Life-of-mine schedules subject to optimisation using SOT allowed for equitable comparisons.Haulage was identified as a dominant constraint for the mine. It was one of six operational resources that were used to constrain the optimisation of the mine schedule, with alternative levels for some of these constraints being identified so that their effects on the NPV could be studied. Alternative price projections for gold and different cost projections were identified and their effects on the optimised schedule examined. Price and cost scenarios that brought additional economic material into the schedule at various times in the mine life were considered in comparison to a scenario that assumed no additional economic material would become available.This case study illustrated that the use of a schedule optimisation tool to optimise mine schedules provides mine planners with an ability to perform a wide variety of analyses in a relatively short period of time. Such tools thereby support strategic decision-making that can add significant value to an orebody.The case study demonstrates that by fixing the set of development and production activities to be carried out before optimising the life-of-mine schedule, the mine planners can inadvertently set up a situation where the NPV would be progressively eroded in the last several years of the mine life. This clearly illustrates the need for schedule optimisation to be integrated with life-of-mine planning.CITATION:Fava, L, Maybee, B and Millar, D, 2012. Decision support for an underground gold mining operation - A case study using the schedule optimisation tool, in Proceedings Project Evaluation 2012 , pp 41-48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By D Jensen, L Riffo, S Yu, F Traczyk, D Meadows

With the steady increase of molybdenum demand worldwide and the favorable molybdenum market, many technological innovations on both process and equipment have been developed and applied in many modern molybdenum plants around the world. This paper introduces the most commonly used molybdenum flotation flowsheet, together with the introduction of the flotation chemistry. Many different types of flotation cells are used in modern moly plants, and each type of flotation cell has its own unique advantages suited for particular ore and process conditions. This paper tries to provide some insight and guidelines in flowsheet development and flotation cell selection in the molybdenum plants.CITATION:Meadows, D, Jensen, D, Traczyk, F, Yu, S and Riffo, L, 2013. Molybdenum flotation circuit and flotation cells, in Proceedings MetPlant 2013 , pp 387-398 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By G R. Hancock, D Verdon-Kidd, M J. Saynor, J B. C Lowry, T J. Coulthard

The ability to simulate the stability of post-mining landscapes over time scales ranging from decades to millennia is a critical element in the assessment of closure designs for uranium mines. Landscape Evolution Modelling (LEM) technologies provide a means to simulate and assess the long-term geomorphic stability of a conceptual rehabilitated landform for periods of thousands of years. However, a major issue with simulations derived from long-term modelling are the limitations associated with the data inputs. Specifically, simulations which utilise historic rainfall data only represent the variability of rainfall events that have occurred over a relatively short period. Consequently, these simulations run the risk of not accounting for the full range of rainfall variability that might be expected over an extended period of up to 10 000 years. Therefore, for this study a probabilistic approach was adopted to generate a stochastic synthetic rainfall data set to produce a series of unique rainfall scenarios, each representing a simulated period of 100 years. Importantly, utilising such an approach allows uncertainty in predictions to be better accounted for and provides a range or probability of likely outcomes.In this study, the effect of ten individual rainfall scenarios are assessed in terms of their impact on the predicted erosion and denudations rates produced by the CAESAR-Lisflood LEM for a conceptual rehabilitated landform of the Ranger Uranium Mine (RUM) in the Northern Territory of Australia, focusing on the Corridor Creek catchment (Figure 1). While legislation requires this site to be erosionally stable for at least 10 000 years (Commonwealth of Australia, 1987), here the focus is on the first one hundred years of landscape evolution, as this is the period in which erosion is expected to be higher, with limited vegetation cover or pedogenic development in the initial decades after rehabilitation. It is also the period where the drainage pattern is set.CITATION:Lowry, J B C, Verdon-Kidd, D, Hancock, G R, Saynor, M J and Coulthard, T J, 2016. Application of synthetic rainfall data to long-term modelling of a rehabilitated landform, in Proceedings Life-of-Mine 2016 Conference , pp 75–79 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By B Murphy

Traditionally comminution optimisation has been focused on energy minimisation, whereas flotation optimisation has been focused on recovery improvement. One of the largest, if not the largest, operating cost over the life of a flotation circuit is electrical energy. With increasing pressure on operators to lower production costs and the cost of energy increasing, reducing the energy consumption of the flotation circuit can be beneficial to site economics. This paper reviews the use of energy by mechanically agitated flotation machines and discusses the measurement and benchmarking of energy consumption in modern flotation concentrators. Opportunities for improving flotation energy efficiency are also identified.CITATION:Murphy, B, 2013. Flotation energy consumption and opportunities for improvement, in Proceedings MetPlant 2013 , pp 399-412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The first mention of gold in Western Australia was in 1848 when some specimens of copper ore, which are believed to have come from the Murchison district, were sent to Adelaide for assay. Gold was present in these specimens, but no particular interest seemed to be attached to this fact as the search at that time was mainly concentrated on base metals and coal. Interest appeared to be shown in gold in 1852 when several parties moved out eastwards from York looking for goldbearing country. Though these parties inmany cases were very near to what is now known as the Yilgarn Goldfield, nothing was found.The next record of gold was reported in some specimens which were brought in from Cardup, some 25 miles from Fremantle. Though this area was investigated, it would appear that all the gold had been contained in the specimens and nothing further was found, though the report had been the cause of a small rush of people interested in gold.From time to time specimens had been brought in by various people from the district east of Northam, and in 1861 a reward emanating from private sources was offered for the finding of gold within a radius of 150 miles from Perth. The Government at this stage took an interest in exploration for gold and in the same year supplemented this privately offered reward on a £ for £ basis. The Government also, about this time, commissioned a practical miner, with prospecting experience in the Eastern States, to examine the country between Albany and Northam with a view to the possible existence of goldbearing veins in that area. His report, however, was entirely unfavourable and nothing further was done. In 1873 a quartz lode was discovered near Albany arid a company was formed to work...

Jan 1, 1956

By Xu Z, Hu C

An attempt has been made to investigate the performance of green pellet formation of the Daye magnetite concentrate from the weak-magnetic separation plant. The optimum conditions for the commercial production of green pellets was found through experimental research. The satisfactory size range for balling is 75 ¦ 3 per cent -200 mesh. The suitable moisture content is between 8.7 and 9.1 per cent and the optimum amount of bentonite added is between 1.5 and 2.5 per cent. The emphasis is on the size of the feed materials since the grinding fineness, which can be obtained at the plant, at most is 78 per cent -200 mesh. If the optimum fineness for the pellet formation is above this value, this means that the concentrate must be re-ground before balling. The results from experiments showed that a good quality green pellet can be attained by using materials below 78 per cent -200 mesh, which provides a strong foundation for the commercial production of green pellets.

Jan 1, 1999

Nowadays, technology has improved to extract dimensional stone blocks at quarry sites and also to process these at processing plants for making slabs and tiles. In the process of quarrying and processing, performance evaluation of machinery is very important to achieve optimum output at minimum cost with improved technology. Cost analysis of improved technology includes parameters such as manpower, energy consumption, tool consumption, depreciation, maintenance and also others. The chainsaw machine with long boom and rail in marble quarries and multi-diamond wire saw machine for slab making from granite blocks at processing plants have recently been introduced in India. Thus, a study was carried out under a research project on these machines to assess their suitability. In this paper, performance evaluation and cost analysis of chainsaw and multi-diamond wire saw have been carried out with existing machines on the basis of research findings.

Dec 6, 2010

Small scale' table concentration tests have many critics. Many metallurgists consider that such tests are of problematical value because of the difficulties involved in conducting and interpreting them.Many kinds of small-scale ore dressing tests are difficult to conduct, and there is, perhaps, good reason for thinking that table concentration tests are amongst the most difficuIt.Interpretation of results from small-scale tests is the responsibility of the metallurgists and engineers in charge, and it is often held that small-scale table concentration tests are particularly difficmlt to interpret.TESTING FOR TABLE CONCENTRATIONOn analysis it appears that the difficulties encountered in conducting small-scale table concentration tests are of three fairly distinct kinds. Firstly, there are difficulties due inherently to the smallscale nature of the operations; for example the smaller width of all mineral bands on the table and the less complete separation due to the shorter length of travel between the feed and discharge points.Secondly, there are the effects of batch operation owing to the fact that the mineral particles behave differently during the initial period when the sample is just beginning to spread over the table, the middle period when feed and discharge are even and continuous, and the final stage, when the last of the sample has been added and the table is beginning to empty itself.

Jan 1, 1954

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By I Doye

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals responsible for highly acidic, sulfate and metals-rich drainage. Several methods of mine waste management have been developed that reduce liabilities on environment. Layered co-mingling of waste rock with compacted tailings, covers with capillary barriers effect, and co-disposal of waste rock and tailings are these new methods which are used to reduce the formation of acid mine drainage. These methods shield waste rock dumps from oxygen. These techniques could prevent oxidation reaction. In this study, alkaline industrial wastes are used with acid generating tailings to inhibit acid mine drainage. The alkaline wastes selected are cement kiln dust (CKD) and red mud bauxite (RMB). These alkaline materials are used to keep neutral conditions in the fine material layer and to inhibit the metabolic activity of Thiobacillus ferroxidans which catalyses the oxidation of sulfide minerals. A series of timed static leaching tests were performed by reacting samples of mine tailings with two, five and ten per cent alkaline material in order to characterise geochemical balance between liquid and solid phases. Column tests have been set up with oxidised tailings, waste rock, CKD, and RMB. Column tests have been carried out to simulate layered co-mingling, covers, liners, and co-disposal of waste rock and tailings. Column leach tests were conducted in order to investigate the long-term neutralisation potential of alkaline materials and the drainage water quality. Bacteria counting were performed on each sample after testing. The results obtained show that the addition of alkaline materials permit the retention of near neutral conditions in the fine material layer, thus increasing water quality and preventing bacteria development. In fact, the pH results show that the use of five per cent, ten per cent CKD or ten per cent of a mixture of CKD and RMB permit the retention of neutral pH conditions in the reactive layer. At these percent rates, the concentrations of Al, Fe, Cu, Zn, and SO4 in solution are significantly reduced compared to those obtained with the tailings only. In presence of waste rock, the relative position of the fine material layer is important. When the fine material layer overlaying reactive waste rock is composted of reactive tailings with ten per cent CKD and ten per cent (CKD:RMB), a delay was observed before achievement of near neutral pH. The neutral pH conditions remain stable over time. The mixture of CKD and RMB provides a better short-term neutralisation than the use of CKD alone. The use of alkaline materials is beneficial in order to reduce the concentrations of Fe and other metals such as Cu and Zn as well as the number of viable bacteria. The use of ten per cent RMB alone does not involve the neutralisation of reactive tailings. In the cases where the fine-grained layer are below or mixed with the waste rocks, the near neutral pH values are directly reached with ten per cent CKD. However, the pH values decrease rapidly and the number of viable bacteria increases.

Jan 1, 2003

By Liu Q, Siefken T. C, Misra V. N

The bubble size was measured in a laboratory flotation column. The effect of variables such as air flowrate, frother dosage and type, pulp density, particle size and water column height on the bubble size was investigated. The results show that an increase in either air flowrate or pulp density cause the bubble size to increase, while increases in water column height, frother dosage, surface tension or solid particle size cause the bubble size to reduce. Among the frother types tested, MIBC was found to be the most effective in reducing the bubble size.

Jan 1, 1992

The smelting of the Broken Hill lead concentrates at the Broken Hill Asso,ciated Smelters produced, among other products, approximately 4,900 ounces of gold and 8,800,000 ounces of silver during the year ending June 30th, 1938. The following table shows the actual amounts of gold per ton of lead concentrate produced during this period at the important mines. The total gold in the period is calculated from the number of tons of lead concentrates produced, and by comparison with the production' of silver, shows thatthere is no constant relation between the amounts of gold and silver.The fact that no gold is seen during milling, even when gravity concentrating tables are employed, signifies that the gold does not occur as occasional coarse particles.Further, as the values increase considerably in the flotation slime, it can be inferred that the gold occurs as minute inclusions in one or more of the minerals in the lead concentrates.The four most abundant minerals in the lead concentrate are galena, zinc blende, chalcopyrite, and...

Jan 1, 1940