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By M Ogle

"Booster fans are relatively rare in Australian coal mines. However, as mines become progressivelydeeper it is likely that such fans will be increasingly adopted as a method to sustain or improve the ventilation of underground workings. The reasons why booster fans may be an att ractive alternative include: increased cost of sinking additional ventilation shafts with greater seam depths; environmental objections to shaft sinking projects; and increasing urbanisation and surface constraints limiting availability of potential ventilation shaft sites. As Tahmoor Colliery movedinto its northern lease the ventilation constraints became the limiting factor on production. Thelimitations of the old workings meant that the existing ventilation system would be inadequateto sustain the required production. Extensive ventilation modelling was carried out to evaluatevarious potential solutions and the recommended option was the installation of a booster fanor fans, to gain underground access to an already approved shaft site in the northern lease.Proposals were sought from recognised fan manufacturers and various alternative arrangements were tendered. Ultimately the choice was between one large centrifugal fan and a set (three or four) of smaller æauxiliary-likeÆ fans in parallel. The successful tender was for a single centrifugal, an arrangement very similar to the booster fans that have been operating eff ectively at Westcliff Colliery for a number of years. This paper describes the current ventilation network, evaluation of the ventilation options, the fan selection process, and the project status to date."

Jun 1, 2012

The ERMS Process was developed during four years of testwork by Austpac Gold NL to overcome the severe metallurgical problems of the ilmenite atWestport, in the South Island. These deposits have been known for about one hundred years. They were originally mined for gold, and only later attracted attention as a possible source of titanium minerals.   The resource is of world scale and may exceed 20 million tonnes of contained ilmenite. Similar deposits occur at Barrytown further south and together these areas would constitute an important opportunity for export-oriented mineral development, if a viable beneficiation technology were available. Further processing is essential, as the composition of the ilmenite is well below market specifications.

Jan 1, 1993

The minerals industry focus over much of the past twenty years has been on cost reduction and production growth supported, but not driven, by technology improvements. Mergers and acquisitions, and the demands of financial markets, have been high priority items whereas research and development and technology based innovation have received less attention and have been cut back in many companies. Technology improvements will be critical if the industry is to make progress on the stated aims of improving energy efficiency, reducing water usage and maximising recovery from deposits. They will also be important for improving capital efficiency and in treating difficult deposits. However the role technology based innovation will play both in the overall industry, and within individual companies, during the next decade is quite uncertain. There are major challenges in progressing technology based innovation in an industry with limited technical resources which is dominated by long life high capital operations. Specific opportunities for energy and productivity improvements exist but face significant technical and structural barriers that need to be overcome if the industry is to significantly improve performance. Current evidence suggests that changes in approach will be needed for these improvements to be realised. Recent studies in the United States and Canada have highlighted the wide range of energy performance across the industry and the scope for marked improvement from both incremental improvements and increased research and development. Comminution, material transportation and underground mine ventilation were identified as high priority areas. Opportunities within these areas are discussed both in respect of specific technologies and in how they may change performance. The role of open innovation as a source of new technology is also discussed. This is an abstract only. No full paper was prepared for this presentation.

Sep 13, 2010

A great range of contacting equipment is used in solvent extraction. However, a tower filled with a regular packing offers many advantages in the direct extraction from slurries. A study was made of the flow of a dense slurry through a packed tower in which the continuous phase was kerosene. The grid type packing, which was preferentially wetted by the slurry, had slats inclined at an angle of 30¦, to the horizontal. On the sur- face of the slats there were uniformly spaced longitudinal indentat- ions. These were of a height slightly less than the film thickness and divided the slurry discharging from the bottom of the slats into a number of uniform streams. When slurry entered the tower it was distributed by means of a troughs and weirs type of distributor. Because of the relatively high slurry velocities that occur at the entry region, it was necess- ary to have the distributor and the first two grids above the solvent level. The interface at the bottom of the tower was located at the mid-point of the bottom grid, so that the slurry entered the interface as a continuous film across the full width of the slats. Using the above system, stable flow with low entrainment was achieved at slurry flow rates of 3.4 mis/cm/sec. This would be equivalent to a flow rate of 177 gallons per minute through a tower of cross-section 4 ft 4 in. by 4 ft 10 in., or 1200 tons per day of solids of specific gravity 2.6 when the pulp density was 65 per cent. Previous tests indicated that a total tower height of about 30 ft would be required for a recovery of better than 99 per cent.

Jan 1, 1969

By N Anderson

The world-class Golden Mile gold deposit in the Eastern Goldfields of Western Australia is part of the Kalgoorlie Consolidated Gold Mines (KCGM) operation, which is wholly owned by Northern Star Resources Limited. Current mining operations across the Golden Mile is dominated by the large Fimiston Open Pit, which is over 4 km long, 1 km wide and 600 m deep. It is part of a larger mineralised system that stretches over 8 km and includes the Mt Charlotte Underground Mine, which is also operated by KCGM, as well as numerous historical open pit and underground mines. This mineralised system has been continuously mined for over 125 years and is set to continue well into the future. The Golden Mile deposit is in the Norseman Wiluna Greenstone Belt which is made up of a series of mafic volcanic and sedimentary rocks that have been structurally deformed and intruded by granitic rocks. There are two main styles of mineralisation across the Golden Mile. Firstly, the Fimiston style, which consists of shear hosted Golden Mile lodes with abundant sulfides and tellurides and secondly, the Charlotte style that comprises younger stockwork veins. Fimiston style mineralisation is the primary style of mineralisation within the Fimiston Open Pit. Historically, in excess of 3500 m of underground development and over 755 stopes were mined prior to the consolidation of the area and the commencement of Fimiston Open Pit operation. Old underground workings, known as voids, are either empty or backfilled and extend to more than 1.2 km below surface. Although they are a routine part of mining operations at KCGM, voids pose a significant challenge for the geology team in terms of planning and executing exploration and grade control drilling, geological modelling, grade and tonnage estimation, drill and blast design and execution, marking up ore block designs, mining, and reconciliation. This paper will discuss the various challenges faced by the geology team due to the presence of voids, solutions used to overcome some of these challenges and the results of these activities.

Mar 22, 2022

By M Foster

The new environmental legislation of 1986 was left incomplete and to date remains so. The 'missing' process by which environmental consideration should be applied was never embodied in law and has predisposition to a wide interpretation. The Resource Statutes which govern land use and development place demands on the environmental process without that definition. The Resource Statutes are themselves under review by Government. There is a new Government Department of Conservation. It is still in its early days and facing a challenge to compose its role as a steward over large tracts of land holding significant marketable resources, animal, vegetable, mineral, and abstract. It has also taken over numerous consent and advocacy roles in legislation beyond its own empowering Act. Enter the mining company, anxious if not able to get an easy passage for consents to prospect and mine, then at least to have a clear path to tread to get there, within a fixed time period. Whichever options appear available to process environmental approvals, public participation is that being favoured most by the regulatory bodies. Where a public notification of consent applications is mandatory, public participation should lead to the fastest track available.

Jan 1, 1988

By R Wedmaier

Henty Gold Mine is an underground operation producing 100 000 ounces of gold per annum. The original mining method used was flatbacking with paste fill. However, a non-entry method û uphole benching û was introduced in 1998 to recover the deteriorating crown pillars. Initial challenges were encountered, including poor drilling accuracy, difficulty in charging holes and poor rise performance. These challenges were overcome by a Continuous Improvement Team, consisting of mining engineers, supervisors and miners. Following this, the Team implemented further changes aimed at reducing ore loss and dilution. A second area addressed by the Team was development blasting, where innovative detonator technology known as the ExelTM DevelDetTM was introduced and rapidly accepted by the operators. Continued use of the ExelTM DevelDetTM resulted in a number of benefits, such as easier bogging, less perimeter damage, faster charging and hook-up and decreased wastage. Finally, improvements were made in the area of explosive handling, where competency-based training of operators was conducted and manual handling of ANFO has been significantly reduced by the introduction of the MiniMoverTM into the underground magazine.

Jan 1, 2001

By M Brady

"It has long been recognised that the barometer infl uences areas of underground coal mines that havebeen sealed off from the current, or active, mine workings but it appears litt le formal research hasbeen done on how the barometer aff ects the goafstream sample point. Based on statistical analysis of samples from a number of mines from Queensland and New South Wales it can be concluded that there is a direct correlation between the barometer and oxygen concentration at a goafstream sample point. To help mitigate some of the high consequence hazards within the underground coal industry and protect the health and safety of the persons within that environment, many monitoring tools are utilised. A control recognised in management plans prescribed under New South Wales and Queensland legislation is the need to conduct monitoring to identify the early warning signs of spontaneous combustion. One of the monitoring tools utilised involves a bagsample being collected from a goafstream sample point then returned to the surface for analysis.When the sample is incorrectly collected, the resultant analysis from a gas chromatograph provides litt le value to the persons charged with the obligation of operating the coal mine at an acceptable level of risk. This, therefore, increases the probability of spontaneous combustion leading to a loss of equipment, mine and in the worst case, life. When the sample is collected correctly, the analysis presents early warning signs of low level oxidation allowing corrective action to be taken, to prevent the oxidation accelerating to spontaneous combustion. The eff ect the barometer has on this sample point should be recognised and the knowledge imparted to persons who conduct sampling to remove a variable in the bag sample collection process. This will ensure the persons operating the mine have a bett er understanding of what is happening within their longwall goaf."

Jun 1, 2012

A research and testing facility has been developed at Simtars to allow the spontaneous combustion testing of coal on a large scale. In this adiabatic reactor, the coal particle sizing is closer to that which could be found in the goaf and therefore the reaction is more likely to simulate the underground situation. This allows aspects of the spontaneous combustion process and methods for detecting a heating to be investigated which cannot be done in an operational mine. Up to 18 tonnes of run of mine or crushed coal is loaded into the reactor and allowed to self-heat while the temperature and gas profiles within the coal pile are monitored. The gases evolved from the coal are analysed using a fixed gas monitor system and gas chromatography to determine which of the common mine fire indicators and ratios can be used to predict the onset and progress of coal heatings. Benchmarking of the inherent propensity of a coal to spontaneously combust at both the large- and laboratory-scale is also possible by comparing the sample against previously tested samples. It has been found that the coal particle size affects both the time it takes for the coal to react and the location of the developing heating. The heatings generate approximately one metre from the inlet but in the crushed coal case do not progress to an advanced heating stage until the æhot spotÆ migrates towards the coal surface where there is an increased oxygen supply. Physical properties such as the compressive strength of the coal also affect the heating size and the time it takes for a heating to develop. Higher strength coals appear to oxidise more slowly and therefore take longer to self-heat as oxidation of the coal is the heat-generating step in the spontaneous combustion process. The best indicators of the state of the heating were found to be CO make and GrahamÆs ratio which are independent of air flow. Investigation of a potential spontaneous combustion should begin as soon as the CO make or GrahamÆs ratio exceed the background levels. The results from the tests undertaken on a number of Queensland and NSW coals are reported here together with the implications for the mining industry.

Jan 1, 2005

Miners and explorers in New Zealand are expected to consult with stakeholders, keep out of core conservation areas, and operate a high standard of environmental management and rehabilitation. These requirements are not difficult to meet, but many of the industry's own actions have brought it to a low level of general public esteem in New Zealand. Reasons for this are discussed, drawing examples from the Maruia Society's experiences with the industry since the mid-1980s. The boundary between core conservation areas and other land is not easily drawn, and the Maruia Society has sought to work with the mining industry to promote legislation for net conservation benefit trade-offs. However this initiative was not successful. Today the industry, unlike most other major industry sectors in New Zealand, has no accord with the country's conservation movement.

Jan 1, 1997

CSA mine, which is a deep level copper operation, located 12 km north of Cobar, NSW, currently uses a top down stoping method, utilising cemented hydraulic backfill (CHF) to fill and stabilise the stoping void thus assisting the extraction sequence. The stope sequence then requires development back through the CHF stope so that the necessary infrastructure for the subsequent stoping, such as raise bore pads can be sited. The primary and secondary support installed in the CHF consisted of 100 mm thick fibrecrete from floor to floor with 7 + 2.4 m long resin support tendons installed at 1.5 m ring spacing. This support system relied on the resin achieving a quality bond with the CHF, and also the fibrecrete developing early structural strength due to the use of an accelerator. In addition to the delays in the excavation turn around time, it was felt that a superior support system could be designed. Such a system was designed; risk assessed, tested underground, and trialled in selective CHF digouts, and eventually signed off as the chosen support method in CHF digouts. This paper discusses the change from a passive support system used in CHF digouts to an active support system using Swellex bolts and weld mesh, which has provided an active support system, that is superior, faster to install, reduced the excavation turn around time and is overall a cheaper support system.

Nov 25, 2010

By V Gupta, Z Huang, S K. Biswal

G-Cell is a new design modification of the Imhoflot pneumatic flotation technology, which utilises a self-inducing aerator inside a downcomer, where bubble-particle attachment takes place. The present study has investigated the suitability of the G-Cell technology for cleaning fine coal using a 0.8 m diameter prototype unit at a coal preparation plant operating in the Midwestern United States. A slip-stream obtained from the overflow of raw coal cyclones operating in the plant, containing nominally minus 150 micron size particles and having ash content in the range of 40 per cent to 50 per cent and sulfur content in the range of 1.30 per cent to 1.50 per cent, has been used as the feed for the G-Cell. The performance data produced from the G-Cell tests are found to be very close to the ideal performance curves produced from release analysis. A statistically designed experimental program has been conducted to investigate the parametric effects on various key process responses, such as combustible recovery, product ash and sulfur rejection. The empirical models developed in this study have been utilised to identify a suitable experimental region for achieving a desired combination of response targets.

Jan 1, 2005

Large mining operations need equipment that consistently performs as expected. The most effective way of ensuring this is to have a defined life cycle with an optimised maintenance strategy. The determination of this life cycle is an economic decision, influenced by the construction and utilisation of the equipment. An effective life cycle costing (LCC) tool must be able to process the many variable factors involved.Many factors influence the costs that are associated with a machine over its life. The most variable of these are the costs of maintaining the equipment. Maintenance costs are dependant not only on the utilisation of the machine, but also on the strategy that has been developed to support the machine through its life. A combination of supplier support, component changes, regular servicing and unscheduled maintenance needs to be modelled, based on a variety of drivers. Traditionally spreadsheets have been used to model these factors, but the increasing complexity of the situation can make spreadsheets unwieldy and difficult to manage. A database solution that breaks each activity into its constituent components, links them to an associated mine plan driver and then aggregates the result is the ideal tool to provide a time based cost profile. The evaluation of a number of scenarios, representing different maintenance strategies/life cycles can be rapidly undertaken. Auditability through inbuilt tools is required to provide easy tracing of data. Use of the host company's account structure allows for reporting against the standard chart of accounts.

Dec 6, 2010

Mineral Processing Education in China

Sep 13, 2010

By C J. Unger, A M. Lechner, A Walton, V Glenn, M Edraki, D R. Mulligan

In Australia, responsibility for abandoned mines can be unclear. With a few exceptions, state and territory governments have become responsible for abandoned mines on Crown land and private landholders are responsible for abandoned mines on freehold land. Abandoned mines pose risks and opportunities across the full suite of sustainability themes (environmental, human health and safety, socio-economic and community development) after mining ceases.Across Australia, there are more than 50 000 abandoned mines recorded, ranging in size from individual shafts to large polluting open cut mines. Addressing the safety and environmental impacts of these sites, as well as the socio-economic development opportunities of significant rehabilitation projects, requires the implementation of effective policies and programs. Qualitatively defined graded scales or ‘rubrics’ have been used for many years in student assessment and increasingly in the performance assessment of other sectors (Davidson, 2005). While risk-based maturity models have been used for safety prioritisation (Westrum, 1993; Hudson, 2007; DRET, 2008; Hancock, 2010) and evaluation of organisational development (Esteves et al, 2010), this paper is the first to adapt maturity models for the evaluation of abandoned mine rehabilitation programs in Australia.In this paper, we used indicators based on the national policy for abandoned mines to assess the maturity of abandoned mine programs. Fourteen elements of maturity were identified (Unger et al, 2012) under the five chapters of the national policy for abandoned mines (MCMPR and MCA, 2010). Jurisdictions were then evaluated and ranked on their maturity on the basis of information that was web-accessible. Information transparency of abandoned mines policies and programs is in itself one element of the maturity chart. Each jurisdiction in Australia was compared with one another and with a Canadian jurisdiction; the British Columbia (BC) Crown Contaminated Sites Program (CCSP), which represents leading practice (Unger, 2009; Unger et al, 2012).Our research found that in some jurisdictions in Australia there is little or no information on abandoned mine programs or individual abandoned mine sites on government websites, while other jurisdictions provided very detailed program information on planning, funding and implementation. Each jurisdiction in Australia, for which web-based information was available, had some elements where they were more mature than other Australian jurisdictions. For some elements, maturity ranked equivalent to the BC CCSP, but most Australian jurisdictions were less mature. There was only one element where a single Australian jurisdiction ranked higher than the BC program in maturity. Legacy mine policies, programs, priorities and funding information via departmental websites are easier to find in some jurisdictions, indicating progression toward greater transparency and more mature programs. A systematic approach to monitoring and evaluating abandoned mines programs is essential for accountability as it can demonstrate liability reduction over time and continual improvement. The maturity model approach can provide both a measure of progress over time as well as a tool to support the implementation of the national policy for abandoned mines (MCMPR and MCA, 2010).CITATION:Unger, C J, Lechner, A M, Walton, A, Glenn, V, Edraki, M and Mulligan, D R, 2014. Maturity of jurisdictional abandoned mine programs in Australia based on web-accessible information, in Proceedings Life-of-Mine 2014 , pp 467–480 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

Computation is believed to be a powerful tool in scaling-up chemical processes and in designing materials, however, is being challenged by low predictability and limited scalability. This presentation will discuss the promising future of multi-scale computation in solving these two problems to realise the real-time simulation of industrial processes. Multi-scale structures are a common nature of most chemical systems and the meso-scale phenomena are believed to be the road blocks not only in improving the predictability of physical modeling but also in extending the scalability of computation. Focusing on the meso-scale phenomena, a series of research has been carried out at the Institute of Process Engineering, Chinese Academy of Sciences, for the past three decades. Starting with a simple idea of modeling the meso-scale clusters in gas-solid two phase flows, the so-called EMMS (Energy-Minimisation Multi-Scale) model was established. In verifying the stability condition of the model, the pseudo-particle approach was proposed to explore the micro-mechanisms in particle-fluid systems, and the strategy of the EMMS model was extended to other six different multi-phase systems, resulting in a unified conceptual formulation of multi-phase complex systems expressed by a multi-objective variational problem. In applying this model to different multi-phase systems and to industrial problems, it was recognised that the EMMS model defined a new paradigm of multi-scale computation by realising the structural similarity between software, hardware and the problems to be computed. This paradigm of computation was implemented on a multi-scale supercomputer with a capacity of 1.0 petaflops by integrating CPUs and GPUs (Graphic Processing Units), showing high efficiency and low cost. Running the EMMS model on this computer, the simulation of hydrodynamics of multi-phase systems can be speeded up very much, indicating a promising future of virtual reality of process engineering. The presentation will review this series of work, introduce successful applications in industries, and will be concluded by emphasising the critical importance of the meso-scale phenomena as the bridge between macro-dominants and micro-mechanisms. This is an ABSTRACT ONLY. No full paper was prepared for this presentation.

Sep 13, 2010

Permeability and fluid pathways in fracture-controlled hydrothermal systems are governed by a dynamic competition between permeability-creation processes and permeability-destruction processes. Permeability evolution is coupled with the evolution of fluid pressure and stress states. Key permeability-creation processes are micro-scale to macroscopic fracture growth, and the generation of damage zones during co-seismic slip on faults or aseismic creep on faults and shear zones. The competing permeability-destruction processes include crack-healing and sealing, compaction and pore cementation. High rates of permeability destruction in hydrothermal systems require ongoing permeability enhancement to sustain high fluid fluxes and ore genesis.   In aseismic regimes, competition between permeability-creation processes and permeability-destruction processes can lead to continuous flow in deep level hydrothermal systems. However, in seismogenic regimes, rapid co-seismic permeability-enhancement is followed by progressive permeability-destruction in the intervening interseismic periods, and leads to episodic flow. The results of high pressure experiments are used to illustrate how pore fluid factors and stress states are dynamically coupled with permeability evolution in hydrothermal regimes. Particularly in the seismogenic mid- to upper crust, large changes in permeability during the seismic cycle govern relative rates of change of fluid pressure around active faults and shear zones. Rapid, post-seismic recovery of pore fluid pressures, relative to rates of shear stress recovery, leads to growth of hydrofracture networks prior to successive fault rupture events.   Pre-rupture hydrofracture networks do not develop where post-rupture fluid pressure recovery is modest relative shear stress recovery. At elevated temperatures, low rates of pore fluid pressure recovery relative to shear stress recovery promote ductile shear failure and grain-scale permeability enhancement within shear zones prior to rupture events.   The influence of pore fluid pressure cycling, shear stress cycling, and deformation processes in controlling the evolution of permeability, flow localisation, and flow anisotropy at the deposit scale are illustrated for mesothermal and epithermal lode gold systems.

Jan 1, 2005

By K L. Brown

Sampling and analyses of deep waters from Wairakei and Rotokawa geothermal systems indicate a wide range of precious metal concentrations (<0.1 to 23 ppb Au; 6 to 2400 ppb Ag), suggesting that eastern ôandesiticö TVZ geothermal systems (eg Rotokawa) have higher aqueous gold and silver than western ôbasalticö geothermal systems (eg Wairakei); this interpretation is consistent with known occurrences of high grade precipitates in wells from eastern systems. The fact that the deep waters are undersaturated in gold further suggests that the aqueous gold concentrations of deep waters are limited by metal availability. The flux of gold for the two systems ranges from ~1 to 50 kg Au/yr, and the flux of silver ranges from 65 to 6900 kg Ag/yr. At Rotokawa, it only takes ~600 years to flux one million oz of Au and >100 million oz of Ag. The supply of hydrothermal gold and silver is obviously important during genesis of an epithermal deposit, but ore formation also depends on the existence of a suitable ôtrapö that efficiently extracts metal from solution in a small volume of rock. Such traps seem to have been poorly developed until geothermal drilling in the TVZ.

Jan 1, 2006

The offshore Maui gas/condensate field was discovered by Shell BP and Todd on Services Limited in 1969. Subsequent appraisal drilling and negotiations with the Government led to a development agreement, æThe Maui White Paper' being concluded in 1973. Part of this agreement provided for the Government to take a 50 per cent shareholding in the field. The field is comprised of a double domed anticlinal structure containing two gas reservoirs at depths ranging from 2700 - 3000 m. Water depth is 110 m. The development plan called for two standalone steel platforms to be installed sequentially over a period of some years depending on gas demand. The first platform (MPA) was put in place in 1976 but difficulties were experienced with piling and drilling of the 12 (later increased to 14) wells did not start until 1978. First gas was piped ashore late in 1979.

Jan 1, 1994

By C Caris, K Fowle, M Schmid, E van Wyk, D Schofield, A Squelch, M S. Kizil

This paper has been written collaboratively by members of the International Mining VR Group. It is the first of a series of papers. Mining in the 21st century is a high technology industry that strives to reduce risk and improve safety through the use of improved processes and procedures. This risk reduction process is aligned with the innovative use of technologies often developed for other industries. Computer-based visualisation systems and their content are such innovative technologies, in particular the use of virtual environment systems and mixed reality. A primary objective of developing virtual environment systems and the mixed reality content displayed in them for the mining industry is to allow mine workers and operators to practice mine processes and demonstrate competency in tasks that will be encountered in day-to-day mining operations at mine sites. It is anticipated that providing easy access to virtual environment systems will facilitate the avoidance of high-risk situations through improved knowledge, skills, understanding and decision making. Via virtual environment systems mine workers will also be able to practice infrequent or emergency events and maintain preparedness for such events. Day-to-day mining practices can also be evaluated. The rapid pace of technology innovation and the decreasing cost of simulation hardware and software present a plethora of technology to the uninitiated. This can be confusing. In this paper taxonomy is presented that classifies hardware, what it can display and also content that can be included or displayed on the various computer-based visualisation systems. The taxonomy provides insight into where technology can and may be implemented in the future as virtual environments are a dynamic and evolving technology. The taxonomy should also assist in the decision making process when scoping or selecting technology for a particular purpose.

Jan 1, 2008