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In the last two decades, equipment used in the coal mining operations has become much more sophisticated. The way that work is organised and performed in the industry has also changed significantly. Changes in equipment specification or procedures inevitably means that the risk associated with that equipment or procedure also changes. In an attempt to address this the Joint Coal Board Occupational Health and Safety Trust (JCB) commissioned the University of New South Wales Mining Research Centre and Mine Site Technologies to perform a feasibility study into the development and deployment of Virtual Reality (VR) based training simulators in the New South Wales coal industry. The main aims of the study were to identify, the key providers of VR Technology, the VR options available to the JCB and the information that would need to be included in any simulator. It was anticipated that a critical assessment of these components would produce a format for a cost effective, state of the art simulator that could be readily accessed by all mines. The expectations of the feasibility study were that VR should offer three-dimensional (3D) simulations that are interactive, high-resolution models of real environments based on best practice Safety Management Plans. It was anticipated that the simulations would allow trainees to experience the consequences of poor decision-making and allow them to learn from their mistakes in a safe and forgiving environment. It was envisaged that such simulators would become an addition to the existing training methods used in the industry.

Jan 1, 2003

By C A Heinrich, Jaques A. L, L A I Wyborn

Most orebodies have cross-sections of less than I km2 and hence do not offer a particularly large target for exploration. Fortunately, although in the geological record ore deposits are small and rare and result from the exceptional coincidence of certain geological processes, these processes are mappable on a much larger, district to regional scale and constitute a mineral system in which the ore deposit is the central feature. A mineral system can therefore be defmed as 'all geological factors that control the generation and preservation of mineral deposits, and stress the processes that are involved in mobilising ore components from a source, transporting and accumulating them in more concentrated form and then preserving them throughout the subsequent geological history'. The mineral system concept emphasises that for many ore deposit types, although economically viable mineralisation may only occur on a scale of say, hundreds of metres, the total system offluid-rock interactions that led to ore formation can extend over a distance of tens to hundreds of kilometres around the deposit. When mapped out, the total mineral system provides a far larger exploration target than the actual ore deposit itself. Important geological factors defining the characteristics of any mineralising system include: I. sources ofthe mineralising fluids and transporting ligands; 2. sources ofthe metals and other ore components; 3. migration pathway; 4. thermal gradient; 5. energy source; 6. a mechanical and structural focusing mechanism at the trap site; 7. chemical and/or physical traps for ore precipitation. Many of these factors individually are common through

Jan 1, 1994

By M I. Pownceby, A Torpy, C Johnson, N C. Wilson

To extract uranium from low-grade, calcrete-hosted uranium (CHU) ore is challenging owing to the presence of carbonate and swelling clay gangue minerals that require an alkaline lixiviant to be used. Western Australia possesses ~75 000 U3O8 t in CHU resources. Improvements to alkaline leach extraction practices would improve the economic potential of these deposits.A column leach study of CHU ore was run for 105 days using an alkaline carbonate-bicarbonate lixiviant. The uranium content of the liquor plateaued after 75 days at ~275 mg U/L; the calculated maximum solution capacity was 800 mg U/L. Spiked peaks and troughs were seen in the data set beyond the 60th day, where concentrations ranged from 220 - 290 mg U/L, indicating possible cyclic uptake and loss of uranium from the solution.Pristine and leached ore samples were geochemically analysed and mineralogically characterised at high resolution using a field emission gun-electron probe micro-analyser (FEG-EPMA). Results showed that leached ore samples from the top of the column contained less carnotite than pristine ore. In contrast, leached ore samples from the column base contained regions with more carnotite than pristine ore, indicating precipitation. Three carnotite grain micro-structures were identified in the leached ore; fan-spherulite, granular and core-shell cubes, with evidence for multiple growth phases.Evidence of carnotite precipitation was seen at the edge of and in pore spaces within montmorillonite and dolomite grains. The point of zero charge of both minerals is lower than the pH of the lixiviant (pH 10.8), thus the mineral surfaces are negatively charged and would not attract UO2(CO3)34- ions out of solution. Similarly, the decrease in the uranium content of the lixiviant is not attributed to super-saturation, as this was unlikely to have been achieved. Work is ongoing to understand the reason for carnotite precipitation and the fluctuations in the lixiviant uranium concentration that are seen.CITATION:Johnson, C, Pownceby, M I, Wilson, N C and Torpy, A, 2013. Microscale characterisation of pristine and processed ore - implications for leaching calcrete-hosted uranium ore, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 303-316 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Jaques A. L, Heinrich C. A

Mt Todd lies towards the south end of the Pine Creek Geosyncline, sandwiched between the Cullen Batholith and the Edith Falls Basin, in an area of regionally metamorphosed sandstones, siltstones and shales. The Batman deposit, some 3 km west of Mt Todd is a sheeted quartz vein system hosted within greywackes of the Palaeoproterozoic Burrell Creek Formation (Finniss River Group). The gold-bearing quartz veins, trending 010¦-020¦ and dipping 60¦-70¦E, are commonly 0.5 to 5 cm wide and occur at intervals which are from 10 cm to 1 m apart. Gold tends to be restricted to the quartz veinlets and immediately adjacent country rock. Grade Control utilises two 4 m 'collar' samples which are collected from each 8 m production blasthole. The irregular distribution of the quartz veins and erratic gold mineralisation has resulted in a disseminated 'salt and pepper' type of gold occurrence, with only a poorly defined footwall. Delineation of ore and waste blocks for mining uses an approach which combines the smoothing effect of kriging with a pragmatic view of the raw data. Large ore blocks with simple geometry help to minimise mining dilution, reduce block variance and give good reconciliations to interpreted ore tonnes and grade. Daily mine face advance is reported against truck counts and provides continual comparison with budgeted production. All data processing uses Gemcom software, together with Lotus spreadsheets.

Jan 1, 1994

The weathering of different types of base metal deposits in the semi-arid environment of the Lachlan Fold Belt of western New South Wales affects the geochemistry of outcropping ironstones (gossans) and derived soils. W eathering of the pyrite- and pyrrhotite-rich mineralisation at the Elura Zn-Pb-Ag deposit leads to highly acidic conditions and strong depletion of Cd and Zn throughout the profile. There are local attainments of high concentrations of Ag, As, Ba, Cu, Hg, Pb, Sb and Sn in the profile and As, Ba, Pb and Sb are still highly anomalous in surficial material (ironstone and soil). However, at Parkers Hill, in the Mineral Hill Field, the primary Zn-Pb mineralisation is pyrite-poor and so weathering is not as acidic as at Elura. Thus, although Ag, As, Cd, Cu, Sb and Zn may be concentrated at various levels in the Parkers Hill weathering profile, Cu and Zn (as well as As, Pb and Sb) are retained in surficial ironstones in essentially the same abundances as in primary mineralisation. Thus, variations in the suite of geochemical indicators present in ironstones and residual soils are likely to reflect differences in the original mineralogy and the degree of acidity produced during the weathering of base metal mineralisation. Hence, an understanding of weathering processes is necessary to fully interpret exploration geochemical data.

Jan 1, 2004

By A Yame, P J. Pollard, E Atase, J Garu, M Tangwari, D R. Hastings, R W. Smillie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Townsville prospect is situated approximately 4 km north of the Ok Tedi copper-gold mine in Western Province, Papua New Guinea. Drilling in the 1990s delineated a resource of >1 Moz of gold within shallow, skarn breccia-hosted mineralisation associated with quartz-carbonate infill, together with pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, tennantite-tetrahedrite, arsenopyrite, marcasite, and a variety of Au-, Ag- and Bi-telluride minerals. The deepest of these historical holes (TVL034) also intersected copper-gold-silver mineralisation more than 100 m below the gold-rich zone that is associated with calc-silicate skarn breccia. Although copper-gold-silver mineralisation in DDHTVL034 is associated with clinopyroxene-rich skarn, it was also noted that garnet in the skarn breccia became progressively darker in colour with depth, ranging from green at shallow levels to dark red-brown at depth. This indicated that the skarn breccia is zoned, with more proximal garnet skarn at depth possibly indicating an association with porphyry-style copper-gold mineralisation.Based on this skarn zonation model, recent drilling at the Titan prospect, located approximately 500 m south of TVL034, was targeted at potential copper-gold silver mineralisation beneath shallow skarn breccia-hosted gold mineralisation. DDHTVL 081 intersected 46 m at 6.36 g/t Au from 68 m and 80.7 m and 1.67 per cent Cu, 1.27 g/t Au and 20.32 g/t Ag from 184 m. Exploration is now attempting to define the extent of copper-gold-silver mineralisation by defining structural controls on the skarn breccia together with paragenetic and mineral zoning data.CITATION:Smillie, R W, Pollard, P J, Hastings, D R, Yame, A, Tangwari, M, Garu, J and Atase, E, 2015. Exploration of the Townsville Cu-Au-Ag skarn, western province, Papua New Guinea – preliminary observations of paragenesis and zoning, in Proceedings PACRIM 2015 Congress, pp 593–600 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Agglomeration pre-treatment is a new process now being used here and overseas whereby problems arising with the heap leaching of gold and silver from materials containing critical amounts of fines or clay can be simply and cheaply overcome. The technique involves mixing the material with a suitable binder, commonly Portland Cement, and tumbling the moistened material to agglomerate the fines. These agglomerates are placed on the leach pad and cured prior to leaching. Test results, plant and operating cost data are presented. INTRODUCTION Heap leaching is a low capital and operating cost alternative to conven tional processing techniques for gold and silver extraction. A number of commercial-scale operations have recently started in the United States and the method is being considered for further deposits there and elsewhere.

Jan 1, 1982

To secure a sustainable competitive advantage some smelters may need strategies based on flexibility in feed and product ranges depending on immediate future projections of profitability. This paper explores the technical requirements for strategic diversity in smelting, leaving procurement, marketing and contractual considerations aside. The days when a smelting operation is tied specifically to say only processing zinc concentrates are perhaps drawing to a close. While internationally traded mineral concentrates are available, attractive business opportunities must exist for fully diversified custom smelters. Certain new and emerging technologies have inherent characteristics that are evaluated in this context. The paper identifies the basic building blocks that will permit such a scenario and assesses the technical feasibility. The ability to respond flexibly to environmental pressures is highlighted as being of paramount importance.

Jan 1, 1996

Over the last five years Du Pont (Australia) Ltd has developed a commercial range of new generation emulsion based explosives concurrently with the development of new explosives-placement systems. The paper outlines Du Pont's emulsion technology and history of product development from the initial emulsions (Tovex E & EL) to emulsion/ANFO blends (Tovex BE) through to the most recent development of Du Pont's SOL emulsion component. The paper also outlines the development of materials handling systems on site to load waterproof bulk explosives from the original pumper trucks through to the multipurpose agitator bowl blending and pumping units at the heart of Du Pont's SOL emulsion system currently available within Australia. The last section deals with some of the more important features of enhanced agitator bowl truck designs and outlines examples of the complete SOL emulsion system and methods of operations currently practiced at specific mines within the Bowen Basin coalfields.

Jan 1, 1986

By R Lastra

Applied mineralogy involves conducting investigations on ores, minerals and materials to solve problems encountered in mining, metallurgy, processing, industrial minerals, environment, health and other fields. The investigations are performed to determine the mineral behaviours during processing by using every mineral and ore characterisation technique and appropriate instruments. As the field is young, new techniques and instruments are still being developed. This paper attempts to convey the scope of the field by:describing the capabilities of the respective research instruments for determining mineral characteristics, summarising investigations of gold as an example of applied mineralogy studies of precious metals, andpresenting a case history where applied mineralogists worked closely with mineral processing engineers on a base metal ore and mill products to help the engineers optimise their processes for maximum recoveries.

Jan 1, 2008

Boring of a 7.5Km long tunnel under the city of Stockholm commenced in January, 1987. The 3.5m diameter tunnel will pass under the buildings and as no ground settlement is allowed, the regulation for water leakage into the tunnel is very strict. Probe drilling will be carried out continuously ahead of the boring and when water is encountered the rock has to be grouted before passing with the TBM. The tunnelling system enables probe drilling to be carried out during boring with the TBM. This has earlier been a capacity reducing factor as the whole operation has been stopped during probe drilling. The project is using a new generation TBM especially developed for hard rock formations which require higher thrust per cutter to get a high penetration rate.

Jan 1, 1987

Many of the large refrigeration plants used in, the cooling systems on deep South African gold mines are situated on surface where they are exposed to seasonally and diurnally varying climatic conditions, and to a diurnally varying demand for cooling made by the mine. It has been traditional to accommodate the seasonal variation in climate by manual control applied to the plants at appropriate times of the year, and the plants have normally been specified to conform passively to the diurnal variations. This paper introduces new strategies for the active automatic control of the plants on a diurnal cycle, and shows that attractive benefits in energy and chilled water resource management can be accrued through the use of these strategies. The results have been derived through the modelling and simulation of a representative refrigeration plant.

Jan 1, 1985

By Gregg PEH, Horne D, Bolan N, Stewart RB

The Tui mine site is situated on the NW flank of Mt. Te Aroha, at approximately 400 m altitude. During underground mining operations two lead-copper-zinc ore bodies were exploited and processed on site. The legacy of the mining operation is a barren dam containing over 100,000 m3 of sulphide-rich tailings. The Tui mine site is arguably the worst case of environmental degradation resulting from past mining activity in New Zealand. Although the impacted area (approximately 4 ha) is extremely small by international standards, acid mine drainage (AMD) emanating from the abandoned tailings dam and mine adits has severely contaminated local streams and prevented natural plant recolonisation of the site for more than 20 years.

Jan 1, 1995

By Wyborn L, Giddings J. W, Plumb K. A

The McArthur, Balma (new name) and Habgood Groups are thick (up to 4.5 km) correlative sequences of shallow water evaporitic carbonates, mudstones and sandstones that are exposed largely within the Batten, and southern and northern Walker Fault Zones (Batten and Walker Troughs) of the McArthur Basin respectively. Recent re-mapping of the Walker Fault Zone has provided data for refined stratigraphic correlations between these groups. Two significant hiatuses are now recognised within the Balma Group (base of Vaughton Siltstone and base of Yarrawirrie Formation) and these may represent tectonically-generated sequence boundaries which may correlate with similar local hiatuses within the McArthur Group such as at the base of the Teena Dolomite and Lynott Formation respectively.

Jan 1, 1994

Large scale open pit mining at Ok Tedi and Misima are described in this paper. The paper also presents the socio-political problems encountered in the construction, operation and waste disposal of high technology, high output gold and copper mines in very remote and rugged terrains. Despite these handicaps, mining companies from all over the world have established top class mining facilities including huge open pits, underground mines and mineral processing plants to extract rich mineral deposits of gold, silver and copper.Papua New Guinea is the sixth largest gold and copper producer in the world. New projects likely to come on stream before the end of this century would make it the world's third largest gold producer. The mining industry is the largest organised industry in the country employing over 10 000 persons and investing over US $1000 million on these mega projects per year.

Jan 1, 1992

The process of establishing the design criteria is the key step in commencing a new project.. The method for establishing design criteria and translating them to a workable plant design is described. INTRODUCTION The use of activated charcoal to recover gold from alkaline cyanide leach liquors is the most rapidly expanding technology in hydrometallurgy today. The process, known as carbon-in-pulp (CIP), has replaced countercurrent decantation as the method for recovering gold by cyanidation. Carbon-in-pulp entails mixing activated charcoal with a ground ore-water slurry containing gold cyanide, allowing the charcoal to adsorb the gold, and then mechanically removing the gold loaded charcoal from the pulp. The pulp is sent to tailing disposal and the loaded charcoal is sent for gold bullion production. Activated charcoal's affinity for gold has been docu- mented for over one hundred years. In the first cyanide plants, one of the preferred methods of stealing gold was to place a piece

Jan 1, 1982

By M Titley, M NoppT

A study on the feasibility of mining the recently discovered Wallaby gold deposit is due for completion by mid-2000. Open pit mining is the favoured method. Determination of the impact of mining bench height on the recovery of ore, including the estimation of dilution and ore loss, is critical to the economics of the operation. Conditional simulation was used to derive a number of gold estimation scenarios within a typical volume of the deposit. These scenarios were interrogated for a selection of mining bench heights and ore block dimensions. The results were reported as a range of grade tonnage relationships and compared to the kriged resource model. This allowed the resource model to be calibrated to a specific mining bench height and ore block size. Once calibrated, more realistic dilution and ore loss values for a number of mining bench heights were calculated from the resource model. These values were then used to determine the economic sensitivity of particular mining methods. The spread of results from the simulations also provided an indication of the confidence in the kriged grade estimates for the different zones of mineralisation within the deposit and highlighted areas of any significant uncertainty.

Jan 1, 2000

Subsidence prediction methods can be divided into two basic types: empirical and analytical. Empirical methods are based largely on a combination of experience, intuition and observations from a large number of observed subsidence data. They are simple in their application, but they are not based on any principle of mechanics. Analytical methods are based on equivalent material modelling principles, where the ground surrounding the extraction is mathematically represented by idealised materials that deform according to the principles of continuum mechanics. Wide applicability and improved understanding are the principal advantages claimed for this approach. In NSW, significant progress has been achieved in the area of subsidence prediction during the last ten years. Empirical prediction curves are available in NSW for predicting the ground movement in the Southern and Newcastle Coalfields. A' comparison of subsidence values predicted from these curves with the actual monitored values indicates that the curves are adequate for use in conjunction with the existing damage assessment methods. Future research for improving the existing empirical prediction curves can only be justified if it is cost effective. There are several numerical models currently in use in NSW for predicting subsidence. The models do not appear to be superior in their ability to predict subsidence when compared with the empirical curves. the performance of these models will no doubt improve along with advances in defining strata properties and failure mechanisms.

Jan 1, 1991

By J Liu

In situ coal gasification is a method of extracting a high proportion of the energy value from coal without the need for mining. In situ conversion of coal to combustible gases is achieved by drilling wells into the seam, injecting gasification agents and initiating combustion. The product gases are then extracted to surface using production wells. These gases are clean energy sources for power generation, heating or synthetic fuel production. In situ coal gasification is of particular interest with respect to its lower environmental impact, potential application to otherwise inaccessible energy resources (ie offshore, deep deposits or beneath protected lands) and low capital intensity. Practical application of this clean technology is restricted primarily by lack of satisfactory quantitative descriptions of the processes involved, in particular the hydromechanical processes.In this study, three characteristic physical zones of an in situ gasifier are identified as the rubble zone, combustion front and virgin coal zone. Coupled mechanical processes of coal consumption and overburden collapse are used to describe the permeability profile in the rubble zone. Additionally, the redistribution of overburden load associated with coal consumption is accounted for with the formulation of a stress (compressive) dependent permeability profile, which is applied to the virgin coal zone. The model was implemented into and solved by FEMLAB, an advanced computer simulation tool. The flow process, according to DarcyÆs Law, is subsequently described in terms of permeability dependent injectivity. Injectivity is an indicator of flow velocity, which has been identified as a crucial factor in determining the commercial value of product gases from in situ coal gasification. The stress alteration to coal permeability was found to have a dominating influence on the flow process. This finding implies that a greater understanding of the in situ coal burning induced deformation of surrounding rocks would be of significant value in assessing the economic viability of applying this clean technology to potential sites.

Jan 1, 2004

The New Zealand experience has shown that the trend in technologi- cal change in gold extraction can be characterised by a systems approach which grows progressively broader with advances in understanding and allowing for an increasing number of factors. The Australian experience has demonstrated that the elements of developing an exportable process include allowing projects to prolifer- ate where substantial entrepreneural involvement is likely to occur. In both countries useful technological breakthroughs were invariably discarded when first tried at operations not well established and under great pressure of achieving and maintaining production. It required the efforts of persistent individuals at operations which had become bedded in and profitable, to follow the initial work up and commercialise it.

Jan 1, 1988