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By J Ralston, G B. N Kaggwa, L Huynh

Three polymers of varying chemistries and molecular weights have been used to depress talc in a model sulfide ore consisting of talc, pentlandite, and chalcopyrite. Flotation testing revealed a distinct hierarchy of effectiveness of the polymers in the depression of talc (HP Starch > Polymer-H > Dextrin WY) but a different order of effectiveness for depression selectivity (Dextrin WY > Polymer-H > HP Starch). Adsorption isotherm determinations for the gangue and valuable mineral phases indicate that the differences in selectivity are partially due to adsorbed amount variations, with Dextrin WY adsorbing marginally less on the sulfides than Polymer-H. Contact angle measurements on packed particle beds have revealed that the polymers have differing abilities to reduce the contact angle of talc and the sulfide minerals. An explanation of the observed trends is given in terms of the binding mechanisms of the polymers on the talc and the sulfide mineral phases. Order of addition effects between collector and depressant were also investigated using adsorption isotherm determinations for the polymers in the presence of a pre-adsorbed layer of collector and vice versa. Adsorption of the polymers was not affected by the presence of the collector. Similar results were obtained for the adsorption of collector in the presence of pre-adsorbed layers of polymer.

Jan 1, 2005

By Brouwer G, Shaw J

As South African gold mines go deeper, and improved and more uniform working condi- tions are required, ever larger amounts of refrigeration are needed. At the same time new and more suitable cooling equipment is becoming available for use with new mining layouts as well as on existing shaft systems. The advent of the large diameter rotor screw compressor has meant that there is now a machine available with great flexibility in performance and construction for efficient underground use. The first installation using this type of machine is described.

Jan 1, 1988

By Chung S

The problems associated with equating calculated and measured properties of explosives with blast results are examined. The results from six full-scale test blasts in a limestone quarry are described. The purpose of the full-scale trial was two-fold, i) assess the role of varying aluminum levels (10% maximum) in a given explosive in terms of blasting performance, and, ii) find correlation between calculated, as well as measured properties of explosives and the resulting blasting performance. Each blast consisted of 36 holes, initiated with short period detonators in a staggered 3-row 2.4 m x 2.7 m (burden x spacing) pattern. Each 75 mm diameter borehole with no subgrade contained on the average 22 kg of 65 mm diameter cartridged explosive. The bench height was 6.3 m, with an average collpr of 1.2 m. The calculated and mgasured properties of explosive included, strength, detonation and explosion pressure, VOD, plate-dent depth, underwater bubble and shock energy, and the total energy efficiency. Each blast was instrumented to measure detonation velocity, initiation sequence, muck pile motion by means of high-speed photography and blasting vibrations. The post-blast measurements included photogrammetric survey of muck pile for size distribution on surface, muck pile profile, as well as the extent of backbreak. The results showed that the overall blasting performance of the explosive in question was nearly commensurate with the level of aluminum in the explosive, and there was excellent correlation between the underwater test properties and the blast results. The study also exemplified the need for more extensive post-blast analysis than is usual practice, for quantitative assessment of blasting performance of explosives and providing the necessary data-base for calibration of blasting models.

Jan 1, 1990

The Kyaukpahto gold deposit is located at latitude 23¦ 47Æ 55" N and longitude 95¦ 56Æ 35" E in the Kawlin-Wuntho district, Sagaing Division, Myanmar. Gold mineralisation is hosted in sandstone of the Male Formation (Eocene) and occurs as stockworks and disseminations. The high-grade gold mineralisation is locally concentrated in a breccia zone. The gold deposit is closely associated with a NNE-SSW trending fracture system that forms tensional open fractures. These tensional zones are thought to be directly related to the Sagiang transfer fault system that experienced several hundred kilometres of northward dextral movement during the post-Upper Miocene. Major sulfide minerals are pyrite and arsenopyrite with minor galena, chalcopyrite and sphalerite. Gold mineralisation is associated with intense silicification, sericitisation and argillic alteration. Primary Type I fluid inclusions in the quartz from the mineralised zone are 5 to 15 ¦m across and yield homogenisation temperatures of 239¦ - 310¦C and salinities of 1.2 - 10.9 wt per cent NaCl equivalent. Laser Raman spectroscopic analysis indicates the presence of CO2 and CH4 in Type II fluid inclusions. Sulfur isotope analysis of disseminated pyrite in the ore zone by the laser ablation method indicates d34S values from -5.48ë to +5.53ë. The geology, alteration, ore mineralogy, fluid inclusion microthermometry and sulfur isotope data of the Kyaukpahto deposit are consistent with an epithermal ore deposit model for the deposit. However, the presence of CO2-liquid bearing fluids and the detectable CH4 in the gaseous phase of the fluid inclusions conflict with a typical epithermal origin for the Kyaukpahto deposit. The host siltstone and mudstone sequence, trace element geochemistry, and the disseminated nature of sulfide and gold mineralisation are also common characteristics of a sedimentary rock-hosted gold deposit, and these features may indicate a Carlin-like affinity. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By H Zahiri

Utilisation of the InSAR technique for monitoring of subsidence in mining areas, employing open pit and underground mining methods, has large potential due to sensitivity and safety issues associated with usage of the classical surveying techniques. InSAR can also be very competitive concerning the cost of provided results. However, there are a few issues that may significantly limit InSAR applicability for subsidence monitoring in mining areas. The altered terrain topography, involving steep slopes and deep pits, may lead to the layover of radar signal for specific satellite and pit geometry. Also, the highly dynamic character of subsidence induced by mining, especially using mass mining methods, may lead to issues such as apparent heave and ambiguous results. In this paper the authors analyse the above-mentioned issues and demonstrate how InSAR technology was applied, as a supporting system, to monitor large scale and highly dynamic subsidence for a real case study in Western Australia.

Jan 1, 2008

By M J. Kelleher

CREAM is an acronym for coal recovery, evaluation, analysis and management and is a business improvement project at BMAÆs Goonyella Riverside mine that is focussed on maximising coal recovered. In August 2003, Goonyella Riverside was set a challenge to quantify coal loss and dilution and their relationship to cost, revenue and ultimately profit. While the mine was confident in its site forecasts of recovery (and loss), it was clear that the traditional measurement and analysis systems were inadequate to firstly, identify key loss areas and mechanisms and secondly, successfully quantify the benefit of various coal recovery initiatives. The path that BMA Goonyella Riverside has travelled to maximise coal recovered can be divided into four key steps: Mapping the process û This step involved the development of a coal flow process map for Goonyella Riverside that stepped through each component of the process from the coal reserve to the customer and identified key measurement points for the purposes of reconciliation. Understanding coal loss and identifying opportunities û This step involved conducting two detailed Reserve to Customer projects at the mine site to track a block of coal from the reserve to the customer and to gain a greater understanding of the relationship of dilution, coal loss mechanisms, revenue and costs associated with recovering additional coal. Coal data systems development û Two important coal data systems have been developed and implemented at Goonyella Riverside in the past twelve months, namely SnowdenÆs Coal Reconcilor and SeamFix. These systems enable coal losses and dilution to be quantified and reconciled back to the initial coal reserve. Implementation of loss reduction initiatives û This step involved the formation of a business improvement project referred to as æCREAMÆ in August 2004, for the purposes of improving pit coal recovery and maximising business value. To date a series of coal recovery trials have been run in a number of pits at Goonyella Riverside that have yielded significant improvements in business value. The key to the success of this project has been the discipline to follow a defined process map, management commitment through resourcing and shared key performance indicators, a successful acceptance strategy resulting in holistic ownership and the implementation of sustainable reconciliation systems. Coal loss and dilution are now quantifiable and their relationship to cost, revenue and ultimately profit is well understood. This paper discusses the process that Goonyella Riverside has adopted to maximise coal recovered.

Jan 1, 2005

Iron and steelmaking slags have been utilised for a century. All dumps are now exhausted. Because of constraints in establishing new stock yards, all slags have to be utilised immediately. At present, this is being achieved. Only in a situation where there is an increase in pig iron and crude steel production, together with the impact of new residual materials competing from other industries can marketing problems be anticipated.

Jan 1, 1979

By Brennan D. J

The trend worldwide is for increasingly stringent control of sulphur dioxide emissions to the environment. It is therefore likely that Australian industry will be placed under increased pressure to restrict such emissions, and this will have implications for Australian smelters of mineral sulphide ores. Traditional outlets for sulphur dioxide emissions have been in sulphuric acid manufacture, but Australian demand for sulphuric acid has declined markedly in recent years. This paper examines the balance of supply and demand for sulphur and related products in Australia, the shifts occurring in that balance and the underlying causes of those trends.

Jan 1, 1994

By Schmidt LC

The method of supporting excavated roofs in underground coal mines by conventional roof bolting systems is challenged due to its shortcomings of being time-consuming and leading to possible unsafe installation. Though a few alternatives have been considered, the ultimate and most efficient bolting method has often been conceived as one using a self-drilling roof bolt, or a Rapid Face Bolting System (RFBS). The on-going Rapid Face Bolting Project undertaken by the University of Wollongong includes a special tubular bolt design.The tubular bolt designed for the RFBS is a "single-pass" bolt equipped with cutting tips used to drill a bolthole to accommodate the bolt. Different from that of the coring bit employed in geological site investigations, the principal design consideration for the tubular bolt is low cost associated with a small working life for the cutting tip.

Jan 1, 1991

By Mirabediny H, Whitchurch K

A computerised simulation model has been developed to select the most suitable digging method of a dragline operation for a given geological condition. The developed procedure uses a geological ore body model as the basis for the geologic database. The simulation selects the most cost effective dragline digging method from a database of various dragline digging methods The database consists of common and innovative dragline methods currently used in Australian open cut mines. A generalised computer package, DSLX, was extensively used to simulate various dragline digging methods. The DSLX software uses predefined functions to build strip geometry, working benches, blast profiles and spoil piles. The outputs from DSLX in form of volumetric, swing angles and hoist distances data are then aggregated with dragline specifications and site time study data to compare productivity of selected digging methods. The result of a case study showed that this procedure lends itself to the 'optimum' selection a dragline digging method for a given coal deposit.

Jan 1, 1995

The first stage in process design for coal preparation is a study of the coal seam and its associated features followed by an examination of the mining method to.be employed and the coal market requirements. Normally benefication is based upon the differences in relative densities of the coal constituents and asso- ciated ash forming components. Since initial liberation is obtained at a relatively large particle size, the size to which coal is crushed is more subject to the market requirements than to liberation studies. It is possible to estimate energy requirements for comminution and recoveries and product grades can be cal- culated following the interpretation of standard laboratory tests. Numerous units are available for the separation and concentration of the components of run of mine coal in- cluding jigging, dense media separators, and for the finer particle size fractions, flowing film separators, dense media cyclones and froth flotation.

Jan 1, 1975

By T Huynh, V Matanitobua, J Zheng, B N. Noller, J C. Ng, H H. Harris

A risk assessment was undertaken of the aquatic ecosystem and bioaccumulation of metals and metalloids in fish at the Leichhardt River, Mount Isa, Queensland. Residual contamination of metals and metalloids in Leichhardt River sediment was assessed and arose from mine practices using river discharge in the 1940s. The ecological risk assessment of sediments involved comparison of the concentrations of heavy metals and arsenic with those of the ANZECC/ARMCANZ (2000) Interim Sediment Quality Guidelines (ISQG). Results indicated that all sites including the background site exceeded one or both the ISQG-high and ISQG-low trigger values based on total concentrations. A lesser number of sites exceeded the ISQG-low trigger values following the 1 M hydrochloric acid extract step, which was used as an indication of bioavailability. An additional risk from particulate matter in river sediment is that acute human toxicity from the consumption of fish contaminated with metals and metalloids is unlikely. The potential risk was assessed by comparing with the maximum levels set by FSANZ (2010) for fish consumption by children and adults. In general, the liver of the fish have higher heavy metal and metalloid concentrations compared to the muscle. Frequent or regular consumption of fish from the Leichhardt River that exceed maximum levels (ML) of heavy metals and metalloids is not recommended. Risk analysis showed that an adult can consume up to 5 kg of fish fillets every day from fish caught at the man-made Lake Moondarra downstream on Leichhardt River and still be within safe consumption levels whilst a child can eat up to 1 kg daily.CITATION:Noller, B N, Ng, J C, Matanitobua, V, Harris, H H, Zheng, J and Huynh, T, ?2014. Assessment of ecotoxicology and health risk from bioaccumulation in fish of heavy metals and metalloids from historical mine practices in the Leichhardt River, Queensland, Australia, in Proceedings Life-of-Mine 2014 , pp 337–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By H Rose, T J. Sheer, M Dumka

Whenever rock is tipped from above, severe eruptions of airborne dust occur into the airways connected to tipping stations of rock passes (ore and waste) on the lower levels of a gold mine in the North West Province of South Africa. An investigation was undertaken to understand the nature of the physical phenomenon, in order to propose possible solutions. Accordingly, measurements were taken underground, involving the simultaneous logging at two levels of the transient pressures produced in the orepass by tipping from various levels. Two portable data loggers with associated transducers were custom-built for this purpose. Measurements were taken during a tipping program in which rock quantities and levels were controlled. Pressure pulses that are generated by the falling rock drive the airborne-dust eruptions. When tipping from a specified level, recorded pressure pulse waveforms were found to be repeatable on any given level, irrespective of the amount of rock falling, but measurements were conspicuously different on different levels. It was recognised that a pressure pulse is generated as the falling rock passes through the constricted region û a relatively narrow neck û at each tipping station. In passing through the constricted areas the mass of falling rock acts as a æleaky piston in a cylinderÆ and compresses the length of the air column in the orepass below that level. Once the rock has passed through the constriction, the pressure is released and this behaviour causes a regular train of pressure pulses that are separated by the time taken for the rock to move from one level to the next. Based on this physical understanding of the dust eruptions, a computational model has been developed that can reproduce all the main features of the measured phenomena. The model has been verified adequately against the measurements and can now form the basis for simulating a range of possible engineering solutions.

Jan 1, 2005

By Neill T. J, Howarth D. F, Malcolm J. McPhersqn

For many years Isa Mine has seen the need for a continuous mining machine which will economically cut hard rock. Tunnel borers are unsuitable due to the size and inflexibility of the machine and the shape of excavation mined. The design of roadheader type machines will not permit the use of the necessary cutting technology. in 1983 a joint project was undertaken by The Robbins Company and Mount Isa Mines Limited to develop and to trial a machine suitable for cutting hard rock in an operating mine. The project was based on the proven technology of raiseboring applied to horizontal development. The Mobile Miner was fabricated and trialled in a disused quarry in the U.S.A. during early 1984. Following these trials, the machine was transported to Mount Isa and commenced mining in September that year. The initial duty was to continue the development of a decline commenced by conventional mining for a conveyor system to serve the deeper southern areas of the 1100 copper orebody. This system will permit direct tipping of copper ore to a new crusher complex and conveying of the - crushed ore approximately 2 kilometres to the central hoisting shaft facilities. The Robbins Mobile Miner MM120-3001 uses a vertical rotating cutting wheel mounted on a horizontal swinging boom to excavate a nominally rectangular shaped heading. The cuttings are collected on an apron and conveyed back through the machine. The resulting excavation is smooth-walled with no blasting damage to the surrounding rock. This provides a safer working environment than does conventional drill and blast development mining. Ground support requirements are considerably reduced.

Jan 1, 1986

By J Chen

Research conducted into backfill drainage at Mount Isa Mines since 1992 is described. Piping in draining backfilled stopes has been the primary cause of bulkhead failures and emphasis is placed on research into the piping mechanism. Laboratory and in situ tests aimed at understanding the piping mechanism have been conducted and the results are presented. A case history of piping in a draining bench stope fill mass is described and a technique for reducing the potential for bulkhead failures in bench stopes is presented. Hydraulic fill is produced by standard cycloning of tailings and the overflow (reject material) is sent to thickeners prior to placement in the tailings dams. Research into the partial introduction of thickener underflow into the backfill system and its influence on backfill drainage is also described.

Jan 1, 1998

By M P. Sandy, J B. Simpson

The empirical stope design techniques developed by Mathews et al (1981) and refined by Potvin (1988) and others, have gained rapid acceptance in Australia in the 1990s as a simple, æfirst-passÆ means of designing primary stopes. However, it is recognised that these æstability graphÆ methods can only provide broad design guidelines. Recently published stability graphs (Hutchinson and Diederichs, 1996) encompass a wide range of geological environments, which are not discussed, and the influence of time and blasting practices cannot be easily reviewed. The æscatterÆ in the graphs must reflect, to some degree, different operating practices as well as subtle but important differences in the pre-mining conditions that are not adequately accounted for in the æmodified stability numberÆ. Development of a ælocalÆ, site-specific stability graph may overcome some of these problems. At NormandyÆs Golden Grove Operations, Western Australia, detailed reviews of stope stability performance, including Cavity Monitoring System (CMS) surveys, are undertaken for every stope, with the objective of developing a series of local stability graphs, customised to site conditions and calibrated in terms of æAverage Falloff ThicknessÆ (AFT). Cablebolting of stope hangingwalls is used to develop reinforced æbeamsÆ on each sublevel, effectively dividing the full span into smaller, more stable æsubspansÆ. By analysing stope stability performance in terms of fall-off, cost-benefit studies can be undertaken of the effect of cablebolting and other options for modifying stope spans. The approach used to develop the local stability graphs, and their integration into routine stope design procedures at Golden Grove, is described. The experience gained during stope extraction in the Scuddles orebodies has been successfully applied to the Gossan Hill æC-PanelÆ orebody. This methodology should be applicable to other underground mining operations.

Jan 1, 2000

Exploration requires substantial capital, and is an extremely risky business (only 1 in 100 prospects ever becomes a mine). The average lead time, that is the time between discovery and production, varies from around two years for a gold mine, to 15 years for a lead/zinc mine. Since it takes years to find, prove and develop most ore bodies, exploration must be carried out years ahead of the depletion of existing deposits. Investors in exploration are exposed to risk for long periods before knowing whether they will receive a return on the funds invested. The risk, high-cost, uncertainty and long lead times involved in exploration make it an aspect of commerce that most managers and investors find difficult to rationalise or understand. Nevertheless, it is a given that the long-term survival of the mining sector depends on discovery of new mineral deposits, however the immediacy of the need to find or acquire new mineral deposits in order to compete and prosper in the industry is less well understood. This paper examines the commercial realities which underlie exploration for new mineral deposits. The first and foremost reason for exploration is to maintain or increase depleting ore reserves which are the asset base of mining, but there are other compelling commercial reasons for exploring, and these are: to maintain return on investment, to achieve growth or create wealth through discoveries which lead tonew mining ventures, to remain competitive in the industry, to diversify, and to control raw material source for mineral processing and/ormarketing ventures. Exploration is necessary for survival of the industry, and also for survival of organisations competing in the industry. The organisations which discover the best orebodies are in the best position to compete, and mining organisations which fail to find or acquire new mineral deposits rapidly become uncompetitive and unable to maintain return on shareholdersÆ investment.

Jan 1, 1998

By R J. Nicholson, J M. F Clout

As part of an overall strategy to make significant new technological advances for the sustainability of the mineral processing and related process industries CSIRO Minerals has developed a new dry separation device. It represents a technology breakthrough and has the potential to radically change the way in which dry particle size classification is achieved in the minerals industry. Conventional dry separation techniques have limited applications and often suffer from low productivity, high operating costs, low separation efficiency, the need for dust control and a lack of flexibility. In the absence of efficient dry techniques, wet processing is often used. The use of wet processing either requires the introduction of water into a separation process, which causes environmental concerns through the need for water supply and tailings dams or the use of æunfriendlyÆ chemicals for dense media separations that have considerable impact on handling and disposal. Wet processing also increases operating costs due to plant instability, materials handling, thickening, filtration and product drying. The new CSIRO technology exploits a combination of natural and applied forces to achieve specific particle motions that produce size separation. In doing so, many of the traditional shortcomings of dry separation have been overcome. The CSIRO Dry Particle Size Separator is ideally suited for dry size separation applications within the size range 1 mm to 30 ¦mfor moderate moisture levels (2 per cent), have low unit throughput, produce a fixed cut size and are therefore impractical where very high unit capacity and low operating costs are required. This paper presents a review of dry separation devices together with details of the new Dry Particle Size Separator and typical results for a number of materials, including iron ore and quarry dust.

Jan 1, 2002

By B Morey, J Gordon, P Mackenzie

Mount Tom Price Mine is peerless amongst Rio Tinto iron ore resources around the world. It has provided Hamersley Iron with premium quality, high lump yield haematite ore over the last four decades. The Brockman type bedded ore, containing bands of haematite and shale of varying thicknesses has been traditionally bulk mined to either high-grade or low-grade based on alumina cut-off grades. As open pit mining has progressed deeper into the orebody approaching the keels of the megastructure, increased structural complexity, chemical and physical variations in the ore, unfavourable ore presentation and reduced blending options have become an issue for grade control and may have serious impacts on product stockpiles. The grade blocks and boundaries must be accurately defined according to geological contacts and where identified, selective mining may be applied. Therefore in-pit geological mapping is the definite and ultimate guide to achieve target grades and grade predictions. Under this scenario, it is absolutely vital that the mine geology team ensures this geological knowledge is passed onto the related departments including mining crews as well as to the short- and long-term planners.

Jan 1, 2002

A BRIEF account of the water-power potentialities of Tasmania is given, together with possible applications of the power commercially. A short history of the Waddamana development is then given, and the main works are described.WATER POWER POTENTIALITIESTasmania is an island of approximately 24,500 sq. miles area (exclusive of small islands). An area of 12,000 sq. miles is at an elevation of over 1000 ft. above sea-level, and of 2300 sq. miles at over 3000 ft. above sea-level. Average annual rainfall varies from' over 140 in. on West Coast to 20 in. on East Coast, and for the whole island averages 48.5 in. The total water-power available, based on conservative figures for run off and efficiency, is 6,000,000 b.h.p. Only a small percentage of this total will, under present conditions, and under likely conditions in the immediate future, be capable of being developed commercially.An extensive hydro-metric and water-power survey is at present being carried out in order to collect information concerning the most promising water-power schemes. Already 400,000 b.h.p. has been located in different proposals, and there is still a large area of very likely country along the West Coast which has not been investigated yet. Tasmania thus has very vast power potentialities, which, combined with good ports and communications and wonderful mineral and timber resources, should augur well for the establishment of the great key industries, particularly chemical and metallurgical.

Jan 1, 1923