Search Documents

The bureaucracy in Victoria has worked against exploration and mining development. There is no doubt that the new Mineral Resources development Act has simplified matters on the mining side of the system. However, WMC's Bendigo and Deep Lead experiences demonstrate that other parts of the bureaucracy can cause serious delays. The mining industry continues to view the approval process causal of excessive costs and delays compared with other States (and countries) and prohibitive to investment in Victoria.

Jan 1, 1992

Mount Isa Mines Limited has been mining silver-lead-zinc ore at Isa Mine for 60 years. Mining methods have evolved continuously, and current production rates of 4.7 Mt/yr are obtained from a combination of sublevel open stopping, cut and fill, and benching methods. In the near future, orebodies mineable by open stoping will be gradually depleted, and the relatively new benching method will be further refmed to replace cut and fill methods wherever possible.

Jan 1, 1993

By G Lane, S La Brooy

A century ago, new mines were often accompanied by smelters. In Australia, smelters were built at the Daydream mine near Broken Hill, at Kuridala and Mount Elliott near Mount Isa, Broken Hill, Mount Lyell, Mount Morgan, Mount Isa, and more recently at Tennant Creek, Kalgoorlie and Olympic Dam. Now the big miners eschew site-based processing in favour of shipping concentrate to smelters in Europe and Asia. As Chip Goodyear was in the process of vacating his leadership role at BHP Billiton, he was quoted as saying that BHP should concentrate on mining ore and leave æto others the skill set of processing that materialÆ. Yet there are times when on-site processing clearly makes sense. Few companies ship gold ore or concentrate to China for gold extraction. New smelters are being built in Zambia. Solvent-extraction and electrowinning plants frequently produce copper from oxide ores and concentrates while pressure leaching is increasingly being considered for copper sulfide ores. Some argue that on-site processing is best because the waste products can be returned to the ground from whence they came, avoiding potentially large disposal costs in more-populated areas. Copper treatment and refining charges will not remain at $45 per tonne and 4.5 cents per pound forever. This paper examines when it makes sense to use on-site pyro- or hydrometallurgical processes in todayÆs environment and comments on how current trends might alter the balance in future.

Jan 1, 2008

By O Ostrovski

Iron ore reduction and iron cementation by CH4-H2-Ar gas was investigated in a laboratory isothermal fixed bed reactor. Iron ore was first reduced to metallic iron by hydrogen, then carburised to cementite by methane. Increasing temperature and hydrogen content accelerated the reduction process. Methane had almost no effect on the reduction process. Meanwhile, higher temperatures increased the rate of cementation and also the rate of free carbon deposition. The optimal temperature for cementite formation was found to be 750¦C. At this temperature, reduction of iron ore to cementite by gas containing 55 vol per cent hydrogen, 35 vol per cent methane and 10 vol per cent argon was completed in about 15 minutes. Addition of sulphur into the reducing/carburising gas strongly retarded the process of cementite formation and free carbon deposition. Cementite is an unstable phase which decomposes to iron and carbon. The rate of cementite decomposition increased with temperature up to 600¦C and above 750¦C . In the temperature range from 600¦C to 750¦C the rate of cementite decomposition decreased with temperature. Cementite was the most stable at 750¦C and least stable at 600¦C. The two-interface grain model was used to describe the process of iron ore reduction and the volume reaction model was employed to model the iron cementation process. The simulated results for both reduction and cementation are consistent with the experimental data.

Jan 1, 2000

By A D. Bugarski, B R. Conard, G H. Sc

The objective, of the Diesel Emissions Evaluation Program (DEEP)-sponsored project at IncoÆs Stobie mine, was to conduct a long-term field evaluation of selected diesel particulate filter (DPF) systems, available to the underground mining industry. Nine state-of-the-art DPF systems were retrofitted to heavy-duty and light-duty vehicles and were subjected to extensive long-term in-mine evaluation. Periodic efficiency tests were conducted at various stages of the study (in 2001, 2002 and 2004) to establish in-use efficiencies and durabilities of the tested DPF systems. During efficiency tests, the vehicles/engines were operated over several steady-state operating conditions. Various instruments were used to measure particulate and gaseous emissions upstream and downstream of the filter systems. The results were used to assess the effects of the filter systems on the concentrations of diesel particulate matter (DPM), nitric oxide, nitrogen dioxide and carbon monoxide in the vehicle exhaust. Experience with the operational issues related to deployment of the filter systems on underground mining vehicles, coupled with the assessment of the filtration efficiencies, were the primary objectives of the study. The variety of filtration systems and regeneration concepts used in this study offered the opportunity to investigate the advantages and disadvantages of the various types. Some of the major issues studied were criteria for selecting the filter media, means of regeneration, the long-term operational reliability, and the occurrence of unwanted secondary emissions.

Jan 1, 2005

The great philosopher, Marshall McLuhan, is said to have stated that the use of forecasting as a means of guiding future actions is akin to driving an automobile through observations made in the rear-view mirror! In effect, in forecasting it is assumed that there will be an orderly progression from the past into the future, and that the model will be sufficiently unvarying for use to gauge both the directions and the rates of change. The concepts of forecasting have served man well in disciplines in which the relationship between causes and effects can be clearly demonstrated; such as between rainfall and crop yield, for example. These are of no value, however, when conditions change rapidly and unpredictably, or when there is no model at all. Even worse, under such circumstances our preconceived notions may cause us to make some horrendous errors in judgement. Such are the risks at present in attempting to make an assessment of the educational needs of the minerals industry for the coming century! The model, and the conceptions that we have had of the linkages between cause and effect are in disarray. Minerals markets are chaotic, and there is almost no ability to forecast trends in metal values. Linkages between supply and demand seem tenuous. Internationally, producers are struggling for survival. Mine closures, temporary shutdowns, and reopenings are frequent occurrences. Decision-making under uncertainty is probably one of the most certain things about the world mining industry Today!

Jan 1, 1986

By T Raynlyn, J J. Campbell, J M. Young

In order to correctly predict the performance of beneficiation processes, such as hydrocycloning or ultrasonic treatment of iron ore fines, it is important to understand possible changes in size distribution, mineral composition and textural peculiarities. During beneficiation processes, iron ore can be subjected to various physical actions which may result in changes in size distribution. In the case of soft or friable ores, attritioning and/or deagglomeration may have a significant effect on both separation performance and product stream specifications. Optical image analysis tools, which give statistical information on a particle by particle basis, can help in better understanding the response of the ores to these processes. An experimental study has been conducted to investigate the response of a haematitic-goethitic iron ore to a combination of stirring and ultrasonic treatment. The effect of stirring and ultrasonic treatment on the size and mineral distribution has been quantified using image analysis and automatic ore texture classification. This approach has been applied to several size coarse fractions of the initial feed and product. The results show that, following treatment, the mass proportion of ore texture classes which contained higher amounts of ochreous goethite and kaolinite had significantly decreased compared with that in the feed, while the proportion of texture classes where haematite was the major mineral had increased. Liberation analysis also showed a significant increase in the proportion of particles with more than 95 per cent haematite and vitreous goethite.

Jan 1, 2007

By C Smith, D Lilly

The Lafarge Marblehead Plant in Marblehead, Ohio, USA produces 4.2 million tonnes of sized aggregate yearly. In 1997, a program was instituted to maximise primary crusher productivity through the optimisation of blasting variables and procedures. A proprietary blasting shot report database and the Lafarge production database was statistically analysed to provide guidance in the program. Blasting powder factor (kg/m3) was the main control variable utilised to increase crusher throughput. In 2005, the program was refined to increase the production of certain high margin aggregate sizes and the reduction of fines. The principal blasting component affecting the percentage of high margin size production appears to be pattern area (burden and spacing area). This can be coupled with powder factor to optimise the production rate of high margin aggregate sizes. The size optimisation program incorporates the blasting shot report database, Lafarge production database, statistical analysis and aggregate sampling. A preliminary indication is that the production of high margin sizes (12.7 mm X 4.8 mm, 24.4 mm X 12.7 mm, and 50 mm X 25.4 mm) has been increased seven to 12 per cent utilising these techniques. As an added benefit, blasting costs have been reduced linearly as burden û spacing pattern areas have increased and powder factors have decreased. The program is ongoing and will investigate other blasting procedures and variables including electronic blasting caps to further increase the production of high margin products. The statistical methods involved in the analysis are described in this article for use in other mines and situations. The methods described can be used to optimise crusher throughput, digging rates and product size.

Jan 1, 2007

By G M. T, M Zh Bitimbayev, F K. Shadiyev

In the paper a complex problem was formulated for studying and establishing an effective and safe technology of selective underground leaching of useful components from polymetallic ores. Solving this problem will allow increasing technical and economic efficiency, technological and ecological safety of mining of useful minerals of polymetallic deposits.

Jan 1, 2003

Mining engineering, metallurgy and minerals-related geology have proud traditions and are essential professions to support a safe and sustainable minerals industry. However, the future of these professions is under threat. The courses that produce such graduates are disappearing worldwide and the number of graduates available to enter the industry has been falling in English speaking countries for at least a decade. It is unlikely that this problem will be remedied by æsupply and demandÆ. Instead, some active intervention is required.

Jan 1, 2004

The purpose of this paper is to review recent approaches by regulators, employers and employees and their associations to the introduction of flexible employment practices and the management of fatigue related risk. More importantly, it will focus on developments in our law either through legislative change and cases which have dictated trends. The paper particularly considers the limitations imposed by occupational health and safety legislation to resist or limit the move to flexible workplace practices on the basis that such practices are unsafe.

Jan 1, 2003

The Institute of Geological and Nuclear Sciences (GNS) is commencing a project to develop a National Minerals Information System (NMIS) for New Zealand . Initially, the NMIS project will focus on providing public access via a web site to existing minerals related databases maintained by GNS and some other organisations. Core components are geological maps, GERM (Geological Resource Map), REGCHEM (Regional Exploration Geochemistry), PETLAB (rock catalogue), GEOCHRON (radiometric ages), mineral deposit models, mineral deposit profiles and 3D mineral deposit GIS databases. In addition to developing the web site, the project will include upgrades of some of the databases and the production of derivative products such as mineral resource and prospectivity assessments, and mineral inventories.

Jan 1, 2004

By George CW

Western Mining Corporation (W.M.C.)operate a 30 000 tpa nickel refinery at Kwinana, W.A. using the Sherritt Gordon Process. Following ammonia/air leaching of sulphideminerals and subsequent copper removal, nickel metal is produced as powder by hydrogen red-uction of the ammonium sulphate-rich solution. Batchwise reduction in pressure autoclaves is preceded by an oxidation/hydrolysis step to ensure nickel powder quality.The reduction process is energy intensive, requiring high temperatures and pressures. Present energy requirement is 24 GJ per tonne of nickel reduced. Of this, 95% represents steam and hydrogen consumption and 5% electric power. The design and operation of the red-uction circuit is reviewed, outlining the main areas of steam and hydrogen usage.

Jan 1, 1985

By Setterfield TN, Jones GFP, Tua P, Davis B, Antonio M

The Emperor gold deposit occurs on the western margin of a 5 Ma caldera in a large, mafic shoshonitic shield volcano on the island of Viti Levu, Fiji. Products from two major pulses of post-caldera intermediate volcanism filled the caldera. Caldera collapse-related steep and flat faults and zones of shattered rock provided per- meable conduits for vertical and lateral fluid migration and favourable sites for ore deposition. One large hydrothermal system, operating concurr- ently with extrusion of the second pulse of resurgent volcanism, may have produced porphyry- style alteration within the caldera, epithermal mineralization at Vatukoula, and weakly minera- lized, siliceous veins and breccias in an outflow zone northeast of Vatukoula.

Jan 1, 1987

It is argued, that plate convergence, i.e. subduction, at other than right angles under a continental margin may lead to compensa-tional transcurrent faulting in the sialic environment. In this pro-cess the introduction of ultrabasic slivers, derived from the down-going oceanic crusial plate, along this fault may occur. This regi-me, both compressive overall and tensional along the transcurrent fault, will contain numerous indications for ongoing igneous and tectonic processes (such as volcanism, hot springs and frequent earthquakes).Examples for this scenario are California, the hinge between the Alpine- and Appennine orogens and the island of Sumatra.Igneous manifestations of subduction will be present both as inter-mediate intrusions and/or andesitic piles. The intermediate volca-nics may be intensely altered (chloritic, propylitic, argillic). Silice-ous breccias and banded chalcedonic sinters may be commonly found. This entire scenario is indicative for epithermal gold mine-ralisation.

Jan 1, 1990

By Shiels O. J

The paper reviews developments in general galvanising in Australia, including a brief history of the industry and its technology. The changes in galvanising process technology are covered, as well as developments in galvanising bath design, materials handling and pre-treatment. Developments in zinc management through the use of aluminium and nickel alloys are discussed. The paper addresses the cost components of general galvanising and relates this to the competitive position of general galvanising against other coatings used for protecting steel. The environmental aspects of the general galvanising industry in Australia are outlined with respect to the utilisation of process chemicals, problems associated with their disposal and developments in filtering and regeneration of process solutions. The current status of the industry is assessed in terms of zinc usage and usage trends. Likely changes in technology which may impact on the general galvanising industry in the future are reviewed.

Jan 1, 1993

The Australian mining industry can expect to be working internationally competitive high quality coal mines during the twenty-first century. Cost efficient mining methods such as high productivity longwall units with heavy reliance on remote control will be standard and worked by well paid and intensively trained operators. Major changes in mine ventilation engineering can be expected in the use of computers and mine telemetry, the understanding of the mine environment and the frequency of mine disasters, the utilization of mine air contaminants for profitable purposes and the provision of a pleasant and comfortable work environment. New approaches to mine ventilation such as air recirculation will have been considered. There will be an increased need for highly trained ventilation engineers. With the present pace of technological change, quite revolutionary new approaches to mining and ventilation can be expected by the end of the twenty-first century.

Jan 1, 1988

By Walter GW

Rock mass classification systems for stable excavation design have been studied. The parameters which are important in such a classification system and those which should be included in a classification system formulated to predict explosive fragmentation behaviour are briefly reviewed and compared. There is significant overlap in the data requirements for excavation design and explosive blast de- sign. Recently there has been a trend to ob- tain some of the data required for excavation design by the use of both field and laboratory seismic investigations. The theory of seismic techniques is summarised and the results of seismic investigations carried out for excava- tion design are reviewed. On this basis it is considered that seismic techniques have the potential to be used for data collection prior to blast design. A programme designed to de- velop such techniques and which includes both field and laboratory experimentation is Presented.

Jan 1, 1978

By A Jha, R Merz

The substantial growth in world demand for Queensland coking coal has seen a number of new coal mine developments in the Bowen Basin in recent times. The Bowen-Broken Water Supply Scheme (BBWSS) is presently based on water supplied from Eungella Dam and storages at Collinsville to two major pipelines. In early 2004, three successive years of well-below average rainfall had left Eungella Dam at critical levels, threatening the regionÆs mines, which rely on it for their essential water supply. SunWater noted that without significant inflows into Eungella Dam, or the development of a new water supply to the region, existing mines would be severely restricted in water supply, and downstream economic impacts to the region would follow. SunWater investigated the opportunities for additional supply capabilities, including combinations of off-stream storages, additional pipelines, and raising Eungella Dam. An off-stream storage (OSS) was selected as being the preferred option to improve the reliability of the system and head off impending falls in announced allocation for the system. The integrated quantity quality model (IQQM) is the Queensland GovernmentÆs preferred model to define and assess total catchment performance against water security and environmental objectives. Modelling of the performance of the water supply system, with and without the proposed OSS, was required to provide justification to the customers of the system that the OSS was in fact required, and also to optimise the configuration of the OSS within time and budgetary constraints. In the case of the BBWSS, no environmental base flows are dictated by the Department of Natural Resources, Mines and Water (NRM&W) at present and the primary reason for applying IQQM was therefore to investigate the trade-offs between supply options and reliability. SunWater produced IQQM outputs for a range of scenarios for the proposed off-stream storage, and these IQQM outputs were then used as input to a decision-support tool based on the GoldSim modelling package. The GoldSim model was then applied to investigate the water supply reliability for high priority users resulting from various existing and/or proposed water supply infrastructure configurations coupled to the hydrologic system. The GoldSim model included the ability to assess the long-term water supply reliability impacts for each of the water supply end-users for a wide range of user-defined scenarios. Non-technical model users were able to change the size of the off-stream storage, pipeline capacities and assumed climatic conditions and test for themselves the relative benefits (in terms of water supply reliability) of different infrastructure configurations under consideration. The decision tool was of significant benefit in assisting the decision process to SunWaterÆs mining customers. These customers needed to decide if they felt that the increased reliability in their water supplies from the system that would be created warranted the estimated increased charges that would require to be levied to recover costs of the new infrastructure with appropriate profit margins. The conjunctive use of IQQM and GoldSim was successful in demonstrating the impact of both hydrological and non-hydrological issues on the future water supply reliability in the BBWSS and resulted in a decision to proceed with the construction of a new OSS.

Jan 1, 2006

By D Nourry

Optimising the blast is a major issue in the blasting business. It generally means acting on the blasting pattern (drilling, charging, detonating) in order to get a given æresultÆ. This result may either be related to economic reasons, such as the fragmentation influencing productivity, or technical reasons, for example vibrations and projections. Within the frame of the EEC funded Brite-Euram project entitled æBlast-ControlÆ, involving academic research and applied expertise, a general methodology was developed to approach such a problem and currently applied to the industrial partners of the project and final end-users of the generated results. These partners are the limestone ALZO quarry of the CALCINOR group in the north of Spain and the dolomite DMD (Dolomies-de-Marche-les-Dames) quarry of the LHOIST group in the east of Belgium. A first part of the project, over 18 months, was dedicated to establishing a clear relationship between productivity of operations from drilling to primary crushing and the fragmentation resulting from the blast. Extensive monitoring of blasting, production performance and fragmentation data was carried out and automatically collected into a database on both quarries. As expected, it appeared that excessive amounts of fines or boulders were substantially reducing productivity and thus profitability of the operation. Furthermore, an æoptimalÆ fragmentation was assessed for the quarries to run at the best (high throughput, low cost). The second and last part, for the remaining 18 months, was then dedicated to adapting the blasting practice in order to orientate the fragmentation towards a æbetterÆ one. A very common problem normally addressed by any consultant. Nevertheless, the target was not limited to solving the problem for these two quarries, but also to develop a generic method to address this blasting adaptation process and to implement it into a computerised tool. At this stage, it is then obvious that portability of the method and the system are major qualities to be looked for. This paper is aimed to present how this method was developed, how the system was implemented and how it was finally used.

Jan 1, 2001