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By Phillips RN

Semi-confined, trachy-andesite sills which overlie the German Creek Seam, within the critical tensile strain zone, form major groundwater hazards to longwall mining at the German Creek underground mines. The water contained in these aquifers is normally neutral, but highly saline. Techniques used to detect aquifers include routine air-lift pumping in exploratory drill holes, downhole geophysical and geological logging and upstage packer testing. Hydraulic constants are calculated from pump-out and pump-in test results. Hydraulic parameters for the calculation of mine inflow rates are determined from pump-out test results because these tests appear to be more representative of aquifer drainage during goat dewatering than pump- in testing. During mining of the first longwall block at Central Colliery, caving fractures intersected overlying aquifers after the longwall had retreated 40m, and mine water inflow rate rapidly increased from less than one litre/sec to 25 litres/sec. The amount of water pumped out of the mine during first panel extraction was 140 megalitres with drawdown occurring over an area of 168 hectares. In the Southern Colliery area approximately 324 megalitres of highly saline water which is actively stored in the Aquila Sill area will be pre-drained from six well points prior to longwall mining. With effective pre-drainage from surface drill holes, maximum inflow rate into the mine during initial goafing can be reduced from 165 litres/sec to about 45 litres/sec.

Jan 1, 1988

By Lewis J. W

The mineral sand orebodies of the east coast of Australia occupy approximately three per cent of the dune-heath-wetland coastal environment. They are associated with coastal plant communities ranging from Holocene high dunes carrying mature Eucalypt forests to low- lying heaths on Pleistocene deposits. Commonly, 0.25 to 1.5 per cent of the sand volume mined is removed from the site. Therefore, the volume change is insignificant. The equipment and techniques in use are flexible and the land can be returned in a manner suited to its subsequent use for grazing, subdivision or recreation. Landforms similar to the pre-existing are created in two case studies given. Sophisticated revegetation techniques are practised and are discussed in two case studies. Pre-mining vegetation surveys and post-mining monitoring are used to guide the management of the ecosystem.

Jan 1, 1976

The introduction of on-stream analysis in flotation circuits has raised the possibility of automatic control of flotation performance by digital computers. The development of control strategies for an industrial zinc cir- cuit is discussed with reference to identifi- cation of the major disturbances, investigation into the performance of the circuit, the design of the control algorithms, the testing of their performance and their implementation in a production environment.

Jan 1, 1983

'Industrial Minerals - their mining and use in New Zealand' is the theme of the 1978 Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy. This paper describes the use of phosphate rock, sulphur and potassium chloride (potash) - three industrial minerals which have enabled the farmers of New Zealand to increase production to current levels. The growth of imports of these raw materials for the New Zealand fertiliser industry is well documented in NZ Fertiliser Statistics 1977. This is the most recent of the Ministry of Agriculture and Fisheries annual publications on this Subject prepared from the detailed returns of fertiliser manufacture and sales from each fertiliser works. There are now 12 of these works in New Zealand one of the most recently established being in Whangarie where this conference is being held. Its capacity to manufacture superphosphate will shortly be 300 000 tonnes twice that when it opened late in 1964. New grinding and manufacturing equipment comes on stream early in 1979. This paper illustrates the interdependence of two primary industries, agriculture and mining. New Zealand's economy in the foreseeable future will be based on agriculture so that our standard of living is dependent on the overseas prices and freight costs of the bulk raw materials from which our fertilisers are made. For the year ended 31 March 1978 New Zealand's total exports were $3395 million, of this total $2413 million (71%) came from the products of pastoral agriculture (wheat, wool, dairy and other animal products), $291 million from forest products and $501 (15%) from manufactured exports. Approximately half of the pastoral receipts can be attributed to the fertilisers applied at a total cost of about $200 million including subsidy.

Jan 1, 1978

By R Lau

In recently completed road tunnel projects in Queensland, such as the Airport Link and the Clem7 tunnels, there is a smoke duct running along the roof of the carriageways to extract smoke in case of fire. In New South Wales, no road tunnels have a smoke duct. In the Melbourne City Link tunnels, there is a small smoke duct running along the roof. All of the tunnels are safe as claimed by the designers and authorities. However, there is significant cost associated with providing a full size smoke duct compared with no smoke duct. This paper is going to present a comparison of the road tunnel safety with a smoke duct and those without one from a risk perspective. It further discusses the cost-effectiveness of such provisions and whether similar levels of safety could be achieved without a smoke duct.CITATION:Lau, R, 2014. Smoke duct or no smoke duct for road tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 83–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Nolan D. P, Balales M

Over the last two years work has been undertaken within the Pasminco Metals - BHAS Zinc Plant to improve the efficiency and maintain the production capacity of the operation. The work has centred upon the installation of suitable process instrumentation to improve process control and the development of new unit operations to maintain control of the circuit water and sulphate balance. A key aspect of the new process instrumentation has been the development of an on-line analyser to monitor the total antimony concentration during zinc dust purification. As a result of changes made to the Zinc Plant in order to contain all effluent within the circuit, a problem developed with control of both the water and sulphate balance of the circuit. A new neutralisation plant to treat all cell house waste water so that it can be contained within the circuit has been developed and installed. In addition changes have been made to the existing circuit to control deliberately the circuit sulphate concentration by precipitation of sodium and potassium jarosite.

Jan 1, 1993

By Pinn N

Geosynthetics is an all encompassing word to describe a number of man-made products usually from hydrocarbons which are used in conjunction with the soil. The specific products are:Geotextiles Geomembranes GeonetsGeogrids GeocompositesIn mine establishment and associated construction work, Geosynthetics have proven to be successful in a wide range of applications. For example, geotextiles are now used to assist with the establishment of access roads, site preparation, haul roads and in connection with the construction of embankments for storage ponds and dams as well as for general hydraulic and foundation engineering problems.

Jan 1, 1990

By C OÆKeefe, A Thomas

Boom time in the mining industry has presented mill operators with several unique challenges including the need for increased throughput while being constrained by a shortage of skilled labour and aging capital equipment. New instrumentation technology that provides reduced installation costs; no process down time for installation; and reduced maintenance costs and labour requirements; has been introduced to address the labour situation while maintaining production. This new tech- nology also enabled more accurate and reliable process measurements thus providing the capability for operators to maximise throughput with their existing capital equipment. This passive SONAR based technology can accurately measure the volumetric flow rate of single phase and multiphase fluids as well as the amount of air entrained within slurries. This is accomplished in a non-invasive manner. This paper will describe the principle of operation as well as the application of the technology to critical minerals processing applications. Included will be operational examples comparing the SONAR measurement performance to traditional measurement techniques. These examples will include hydrocylone feed flow, flotation concentrate flow, and slurry streams containing magnetic ores. Actual plant data will be presented as well as a discussion on the operational advantages such a measurement capability.Also described will be the power of the technology platform to provide novel process monitoring and control capabilities such as pipeline sand-out prevention and pipeline acoustic monitoring.

Jan 1, 2009

The Auscoke project has reached-a stage where a pilot plant nominally able to produce 100 t.p.d. of coked briquettes is being brought on stream during Nov. 1971 . The targets for this stage of the project are to establish the technological and economic value of Auscoke for the iron blast furnace, and to verify the commercial feasibility of large scale plants. The project originated at the B.H.P. Central Research Laboratories (C.R.L.) and work to date has shown that using a two stage contin- uous process, strong large coke can be produced at good productivities from medium or low volatile poorly caking coals. General features of the pilot plant and processing are discussed.

Jan 1, 1972

This paper reviews the various processes successfully in operation to treat refractory gold ores and describes in detail the alkaline pressure oxidation circuit operating at the Barrick Mercur Mine, Utah, U.S.A., on car- bonaceous/sulphide refractory ore and the acidic pressure oxidation circuit operating at the Barrick Goldstrike Mine, near Carlin, Nevada, U.S.A., on sulphide refractory ore. The autoclave process is important to Barrick for the extraction of gold. The Company has operated successfully a 750 ton per day unit at its Mercur property for the past two years and more recently has commissioned a 1500 ton per day unit at Goldstrike. The paper presents data relative to operating costs, materials of construc- tion for autoclaves and peripheral equipment, reagent requirements, and changes required during commissioning for both autoclave systems.

Jan 1, 1991

By P Jago

KCGMÆs Fimiston Open Pit, located in the centre of the historic Golden Mile, is situated above some 3000 kilometres of old underground workings. These workings, both level and vertical, present significant safety and operational problems in the pit. One of these challenges is in safely drilling void areas so that they can be charged and blasted effectively. Current drilling practices in these areas require machines that can only drill 115 mm holes on a smaller pattern than the standard blast pattern. This results in more time and cost to both drill and charge these areas. Any other method currently available to drill out these areas involves putting operators in a potentially hazardous situation by being too close to the void area being drilled. Not effectively drilling and blasting these areas leads to hazardous situations further in the mining cycle including oversize, large toe and uncollapsed voids. Ineffective blasting also causes reductions in mining productivity and mine to mill performance. In response to these issues, KCGM has commissioned the implementation of a fully remote controlled DM45 blast hole drill rig to drill out selected void areas. The remote system, installed in conjunction with Ausdrill Ltd and GM Mining Electrics, is designed to operate similarly to a tele-remote bogging system with the operator controlling the drill rig from a separate control cabin via radio signals and video feed. This allows KCGM to drill in areas of higher risk without exposing the operators to voids. The drill rig will also be able to drill standard patterns through some specially selected void areas, reducing costs and extra time associated with drilling and charging void affected areas. The remote rig is expected to provide a number of benefits, both in the drilling process and in further downstream operations. Costs of drilling in void areas are expected to decrease with standard patterns instead of smaller patterns being drilled. Safety and operator comfort are also expected to increase through removing the operator from the pit floor. Blasting is also expected to see significant improvements through increased ease of charging void areas (because of larger holes and standard patterns), more consistent patterns resulting in less secondary blasting and toe and an overall improvement in the speed and cost of charge-up practices. This more consistent blasting will also improve shovel productivity, crusher performance and overall mine-to-mill efficiency. This paper presents an overview of the development of the remote controlled system, including modifications that have occurred since commissioning. It explains some of the problems encountered and how these have been solved. Key issues for operational success will be identified and explained with a view to making future implementations easier. Factors used to assess the performance of the remote controlled rig will also be explained in further detail and used in a preliminary assessment of the rigÆs feasibility.

Jan 1, 2003

By R Engle, R P. McMahan, D A. Bowman, S Schafrik, W Thabet

Preventing injuries and fatalities related to conveyor system use in the mining industry is important and increases uptime while decreasing lost time. The research presented here is funded by the National Institute for Occupational Safety and Health (NIOSH), and intended to accomplish this prevention by the use virtual environments (VEs) to improve training and help miners better understand the hazards of working around conveyor systems. Two conveyor system VEs designed to teach miners about hazards and to safely complete tasks around conveyor systems were developed for this project. The first conveyor system VE, called the instructional tour, gives the miner a semi-automated tour of a conveyor system and teaches the miner about possible hazards (eg, missing guarding) and how to safely fix conveyor problems (eg, a stuck idler) using lock-out, tag-out procedures. The second, called the virtual shift, allows the miner to freely navigate around a conveyor system to detect and avoid hazards. The miner is presented with equipment failures that need to be safely repaired during the virtual shift. If the miner fails to identify and avoid a hazard or fix a failure in a safe manner, an animation of the consequences is shown to the miner, who must start the virtual shift over. The models for the conveyor system VEs were created using 3DS Max. Desktop versions of the VEs were then created using Deep CreatorÖ, an authoring application for creating interactive 3D environments. Later, more realistic versions of the VEs were created for CAVEÖ, a room-sized visualisation system, using DIVERSE, an application programming interface. In initial evaluations of the conveyor system VEs, mining colleagues have indicated great interest in such training tools. According to their feedback, these and similar VEs would provide excellent alternatives to normal classroom training and serve as positive precursors to hands-on experience. These VEs provide new miners a chance to experience hazards associated with working around conveyor systems without being in possible danger.

Jan 1, 2008

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 Wyborn L. A I, Idnurm M, Hinman M. C

Comparison of the Proterozoic Apparent Polar Wander Path (APWP) for Australia with the corresponding geology of northern Australia suggests that a number of discrete interplate tectonic events, manifested on the APWP as bends or inflections, may have controlled sedimentary basin evolution, ore fluid production and the timing of mineralisation. Similar features in the Phanerozoic APWP for the North American plate appear to correlate with major orogenic events, basin deformation, movement and 'entrapment' of hydrocarbons and minerals. Interplate tectonic events cause intraplate deformation which in turn controls the subsidence/uplift and sedimentation histories of the basins. Interplate events are thus responsible for creating, deforming and destroying sedimentary basins and the associated petroleum and mineral systems. The basins of northern Australia show remarkable similarities in the successions of volcanic and sedimentary deposits. Unconforrnities of regional or sometimes only local extent have been mapped between the major sedimentary sequences and it is predicted that interplate tectonic events corresponding to bends or inflections on the APWP directly reflect the processes that have produced these widespread unconformities. These processes are also likely to have controlled the geometry and character of the fluid migration pathways and hence the mineralising events. Palaeomagnetic studies of Proterozoic rocks in sedimentary basins provide a tool for predicting the timing of regional mineralisation events, particularly for low-temperature mineral systems. The techniques, when coupled with systematic regional basin analysis, using petroleum exploration techniques, may identify a number of new mineral 'plays' in northern Australia. Prominent inflections in the APWP occur at approximately 1700, 1670, 1650, 1600, 1540, and 1480 Ma. Each of these may be related to a regional compressional deformation, important mineralising event, or significant change in style and type of sedimentation. Most appear to be associated with magnetic overprints. Some of the inflections between 1400 and 540 Ma may also mark significant events in the evolution of Meso- and Neoproterozoic basins. Further work is required to correlate inflections in the APWP with alteration events in order to understand their regional significance.

Jan 1, 1994

By S Chaudari, T Ren, T Harvey

Management of respirable dust on longwall face remains a challenging issue for mine operators, particularly for the new generation of thick seam longwalls. A fundamental understanding of the airflow behaviour around the shearer is critical for dealing with the dust control issue on longwall faces. Computational fluid dynamics (CFD) modelling techniques have been used in this study to conduct a detailed investigation of the air and respirable dust flow patterns around the longwall shearer. Three CFD models have been developed to represent different longwall cutting heights. The results of these modelling studies tallied well with field measured airflow data from different mines. The validated thick seam longwall face model was then used for detailed parametric studies to simulate the effect of various parameters and dust control concepts. The dust control options investigated include various spray configurations, shearer clearer, modified cutting sequences and shearer scrubbers of various capacities to minimise the respirable dust migration towards the walkway area of the longwall face. This paper presents a summary of the results of these CFD modelling investigations.

Jan 1, 2005

By R Lurf, C Weber

In the frame of this paper a holistic dynamic process model approach is presented in order to introduce operational and technical excellence in drilling and blasting. Both on a macro and micro level the single process parts of drilling and blasting are outlined and their interaction is explained. The use of this approach for closing the gap between process planning and process implementation is explained and an example of the value generated is given.

Jan 1, 2007

By Koppe J. C, Dimitrakopoulos R, Costa J. F

Grade control and the delineation of ore/waste in open pit operations is traditionally based on the comparison of estimated grades with an economic cut-off. This paper deals with an alternative approach to grade control based on estimating gra

Jan 1, 1998

The link between exploration success and new ideas from research and development (R&D), although often assumed, is rarely well explained or well illustrated. One issue is understanding the role of innovative ideas in the exploration process, and another is determining the relative contributing factors to an exploration success. A useful measure of gold exploration success over an extended time period and geographic area is discovery rate (θ): Discovery rate θ = gold discovered/exploration expenditure (usefully expressed as tonnes of gold per $1 million). The total gold discovered is strongly leveraged to discovery rate, as any increase in θ typically has a positive effect on exploration expenditure. Hence, improving the discovery rate is a key driver for a sustainable mineral industry, especially for gold. There are very few ways to influence θ beyond innovative R&D ideas and breakthroughs, and well-motivated and trained staff. The Australian gold industry has experienced exceptional exploration success with 9956 tonnes of gold discovered from 1979 to 2003, inclusive. This equates to: Discovery rate θ = 0.9 t/A$1 M Two-thirds of this gold has been found in the Yilgarn craton of Western Australia (6265 tonnes Au). Without this exploration success, there would have been no platform on which to build the current gold industry and to take advantage of elevated gold prices and advances in mining and processing. Several causes of the Western Australian gold success have been proposed, and more than one may be correct. Gold price, and mining and processing advances have all had influence; but exploration success and discovery of gold were essential to add to the miniscule resource base of 1979. A comparison of the exploration methods used to search for gold in the Yilgarn craton in 1979, and 1990, highlights a small number of breakthrough ideas introduced to the industry during the 1980s, and in most cases emanating directly from local R&D. By the 1990s, these ideas were being used in most gold exploration programs in the Yilgarn craton, and are still used today. These six breakthroughs are: epigenetic timing of gold deposit formation (ie after formation of rock sequence), chemical and mechanical role of host rocks, relevance of carbonate alteration haloes, gold dispersion in the regolith, optimal sampling media, and appreciation of landforms in exploration program design. Interestingly, gold exploration science in Western Australia entered the 1980s period without rigid paradigms in place regarding gold deposit formation; there was a balance between descriptive and genetic models, there was scope to research gold deposits from microscopic to global scales and there were highly effective industry research uptake processes in place: it is suggested here that these favourable conditions contributed to the exploration success and industry growth.

Jan 1, 2007

By S Bandopadhyay

The seasonal fluctuations of the dust content in Arctic mine environments and the environmental variables affecting the intensity of dust production are qualitatively well known, but quantitative models that allow simulation and prediction of dust generation and the effects of engineering control of thermal regime on the mine environment are still non-existent. In Arctic mines, the migration of moisture in the surrounding rock mass releases fine dust by freeing it from the ice matrix allowing it to escape into mine airway. The migration of moisture is the direct cause for the production of mine dust and heat is the primary driving force. This paper examins the heat and moisture exchange between the ventilation air and the surrounding rock mass in frozen ground, placer mines in the Arctic. Based on the simulated results of a coupled heat and mass transfer problem with phase change, methods of dust control have been identified for mines in the Arctic.

Jan 1, 2005

By A Datar, D Mulligan

The extractive phase of broad-scale mining can have major impacts on landscapes and associated ecosystems. Post-mining ecological rehabilitation typically starts with reconstructing topography. A fairly common industry practice has been to use landform elements such as plateaus, terraces, and gentle slopes for stabilisation purposes. However, this approach can lead to the generation of fairly uniform landforms that do not necessarily reflect natural ecosystems. Previous research in undisturbed and agricultural landscapes shows that ecological attributes and diversity in microclimates is positively correlated with landform heterogeneity. An objective of this study was to investigate if those findings are still valid in post-mining rehabilitating landscapes on North Stradbroke Island, Queensland, Australia. We investigated the relationship between landform heterogeneity and status of ecological recovery. The landform heterogeneity is measured through variance in three landform characteristics (relief, slope, aspect) using remote-sensing data and the status of ecological recovery is represented by ecological indicators measured through field surveys. The results indicate strong correlations between landform heterogeneity indices and native vegetation species richness with sensitivity to the spatial scale of investigation. It is recognised that climate, substrate and rehabilitation practices act as primary drivers of rehabilitation success. However, the results indicate that, in some examples, landform heterogeneity (heterogeneity in relief and slope angles) contributes up to 30 to 50?per?cent of the variance in native vegetation species richness. While the primary drivers of ecological recovery are difficult to control over extensive areas and extended time periods, landform heterogeneity provides a tool to indirectly control the micro-environmental parameters to improve ecological recovery. Reducing the uncertainties in the choice of ecological and landform indices and the degree of landform heterogeneity suitable for particular rehabilitating landscapes would be site specific. The introduction of desired landform heterogeneity may provide a very effective tool for significant improvement in ecological rehabilitation across broad-scale post-mine landscapes, an outcome of benefit to industry, government and local communities.CITATION:Datar, A and Mulligan,?D,?2014. Do we need to change the way we set up the stage?, in Proceedings Life-of-Mine 2014 , pp 29–46 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014