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By Corbett GJ

The Bulolo Graben represents an intra-arc rift formed by activa- tion of transfer structures in an extensional setting formed be- tween the eastern and western sectors of the New Guinea Origin. Crustal thinning has facilitated the emplacement of dacitic Edie porphyry intrusions, locally as flow dome complexes, phreatomagmatic (diatreme) breccias and the Bulolo ignimbrite/ agglomerate as an extrusive equivalent of the Edie Porphyry. Gold mineralization is localized along intra-graben structures, com- monly at the intersection with cross structures and occurs in sub- sidiary dilational fractures and not the localizing major structures. Gradations are apparent in the styles of mineralization according to the degree of erosion of the hydrothermal system. Hamata occurs as the deepest mineralization of the quartz-sul- phide style Wau, Hidden Valley, and Edie Creek are dominated by carbonate-base metal styles. Kerimenge grades from quartz sulphide through carbonate-base metal to epithermal mineraliza- tion, the latter style also being present in the periphery of Edie Creek. Here, pre-existing fractures of the Edie Creek Structural Corridor have been reactivated by movement on NS structures to form the ore-hosting dilatant lodes. Fluid flow may have been from the vicinity of the Nauti diatreme margin and along the vein System.

Jan 1, 1997

By A C. Robertson

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authorsÆ personal observations and experience.

Jan 1, 1998

As mines become deeper, the problems of heat in the workplacebecome more acute. An important response from the industry hasbeen the widespread adoption of microclimate cooling such asair-conditioned cabins. However, not all work in mines can becompleted from inside an air-conditioned cabin, and in any event,it is still important to keep the ambient air in the mine outside ofany microclimate to a safe temperature. An important method forbringing workplace temperatures under control is the appropriateuse of refrigeration. The application of refrigeration inmechanised mines has been recently described (Brake, 2001;Brake and Fulker, 2000). This paper provides an overview ofsome of the important engineering considerations in thespecification and selection of mine refrigeration plants. Thepurpose is to provide a basic understanding of refrigerationprinciples, practices, terminology, hazards and opportunities formining engineers or other personnel who may need to beinvolved in the introduction of refrigeration onto a mine site.

Jan 1, 2001

Whilst decisions to commit projects have traditionally been heavily influenced by hurdle rates for d.c.f. analysis, it is suggested that evaluation of competitors' costs may be a desirable additional tool.The MICAS system developed over the past four years is described. This computer system uses standard costs modified by District and Mine factors to allow estimation of individual mine costs. The data base contains more than 15,000 items of data and more than 6000 costs are calculated.Recent applications include use for competitive analysis, predictive analysis, statistical analysis, and comparative assessments with scopes ranging from a few mines to the whole Australian export industry. Some areas where care is necessary are outlined and potential further uses are discussed.

Jan 1, 1985

I stand here as a financial advisor who has been particularly close to the whole concept of reporting, independence and all the issues that are brought together in Release 149. However, I was asked to introduce this session by dealing with matters of Prospectuses, Part B's, 3J3's, 12G's and other requirements to report. Now I find it very interesting that one of the keynote issues is whether or not one should have a panel from which one chooses the so-called expert, and this is to deal with the question of independence.

Jan 1, 1989

MIM Holdings Limited (MIM) committed to a long-term future in copper in the Carpentaria Mineral Province in 1996 with the development of the Enterprise and Ernest Henry mines, and an upgrade of MIMsÆ copper smelter in Mount Isa, and copper refinery in Townsville. The upgrade of the copper smelter will enable the smelter to produce 250 000 tpa of copper with a single primary smelting unit, the copper Isasmelt furnace installed in 1992. The copper Isasmelt furnace currently smelts concentrate containing 145 000 tpa copper. To reduce the risk associated with the copper smelter upgrade, and shorten the ramp up time of the upgraded smelter, two high-rate trials were undertaken in 1997 to demonstrate that the copper Isasmelt furnace could, with an additional 525 tpd of tonnage oxygen, treat concentrates containing 250 000 tpa copper. During the trials the concentrate feed rate to the Isasmelt furnace was increased from its average rate of 100 tph of concentrate to 150 tph of concentrate. The increase in the capacity of the furnace was achieved by: supplementing the installed tonnage oxygen capacity of 595 tpd with an additional 300 tpd supply; reducing variability in the furnace feed rate from ¦25 per cent to less than ¦5 per cent; and reducing tramp air. The Isasmelt furnace smelted concentrate at a rate of 140 to 150 tph for four hours 25 minutes during Trial 1, and at a rate of 150 tph of concentrate for five hours and 30 minutes during Trial 2. The oxygen utilisation was 100 per cent during the trials with the process remaining under control. As a result of the development work for the trials the average treatment rate of the furnace under normal conditions increased by ten per cent.

Jan 1, 1998

By P Cavieres, R Dunlop, S Gaete

El Teniente Mine started the exploitation of the primary rock in the beginning of the 1980s decade, using caving methods. Since the beginning the mining activities have induced seismicity including some occasional rockbursts. Owing to the relevant damages, the mining operations were stopped in some production sectors. This paper describes the concepts that have been used in order to control the induced seismicity based on the strategies for controlling the rockmass breaking process, which depend on mining parameters. It also presents the main concepts applied in the Teniente Sub6 sector design and the experience collected during its sector exploitation.

Jan 1, 2000

By L Scheunis, A Van den Bulck, E Jak, K Verbeken, M Shevchenko, R Starykh, I Bellemans, P-J Boeykens

As a result of the globally increasing consumer use of electronic devices, it is expected that pressure will increase on the supply chain of precious metals. Hence, recycling of these electronics becomes increasingly important, as well as optimising the current processes. One major issue in metallurgical processes is the amount of metal that is lost into the slag. This metal loss is inherent to the production process and therefore, additional processing steps such as slag cleaning may be required. Slag cleaning can be done in electrical resistance furnaces where heat is produced using the Joule effect, making the slag’s electrical conductivity an important operating parameter. Since slags are ionic liquids, the electrical conduction happens via the movement of ions which is called ionic conductivity. However, within the presence of transition metal oxides, a second mechanism of conductivity occurs as electrons are able to hop from one transition state to another, which is known as electronic conductivity. As ‘FeO’ is a common slag component in the non-ferrous pyrometallurgical industry, both mechanisms are present, but their proportions vary with the respective amounts of the two forms of the multi-valent ions and hence, with the oxygen partial pressure. The goal of the present study is to develop an experimental set-up and methodology for measuring the electrical conductivity of synthetic SiO2 – CaO – AlO1.5 – ‘FeO’ slags at various oxygen partial pressures.

Jun 19, 2024

The considerations which led to the decision to_ install discs at the Dampier Pellet Plant of Hamer ley Iron Pty. Ltd. are described. Initial testwork showed that the ore could be ground dry in open circuit to a Blaine index of 2500 cm2/g and that it pelletized readily. The various design criteria including diameter, slope, speed, motor size, depth of sidewall, feed point and water spray location were then determined. Plant performance after commissioning is described including the various problems encountered and the modifications since carried out to overcome them. The main problem was quickly identified as disc feed rate control. Various bin and bin feeder modifications were tried to overcome the effects of the fluidising characteristics of the dry ground ore. Other factors found to affect disc operation are ore size distribution, additives and operator competence.

Jan 1, 1974

By V A. Diemar

The Chatree Gold Project represents a greenfields discovery of metallurgically clean shallow gold mineralisation in a logistically simple terrain. Total Measured, Indicated and Inferred Resources are currently 31 tonnes of gold and 160 tonnes of silver. Gold occurs in an adularia-sericite epithermal system within quartz-calcite-adularia veins, breccias and stockworks. Host rocks are volcanic arc porphyritic latite-trachyte flows, their pyroclastic equivalents and volcaniclastics of upper Permian to upper Triassic age. The mineralisation was deposited in dilated zones during repeated reactivation of pre-existing structures. To-date five mineralised prospects have been defined by drilling with three reaching JORC Code Mineral Resources status. The project is in its definitive feasibility stage and is anticipated to be in construction during 2000.

Jan 1, 1999

By R Pie, J Crusius, P Whittle, J J. McNee

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of an ongoing three-year government- and industry-funded research program. In order to assess the feasibility of various bio-remediation strategies, field-scale manipulations were conducted using enclosed mesocosms (limnocorrals). Two manipulation strategies were tested: addition of algal nutrients (phosphate and nitrate) to Main Zone Pit surface waters; and addition of algal nutrients (surface waters) and dissolved organic carbon (deep waters) to the Waterline Pit. Nutrient addition was conducted in order to stimulate algal production and enhance metal scavenging by biogenic particles, while dissolved organic carbon (ethanol) was added to increase oxygen demand and foster the development of sulfate reduction in pit bottom waters. Fertilisation resulted in rapid growth of natural phytoplankton populations in the surface waters of both pits. In the Main Zone Pit, the stimulation of algal growth resulted in the pronounced removal of both dissolved and total metals (Zn and Cu) from surface waters, with higher rates of metal removal being observed at higher nutrient additions. Metal removal could be attributed to the scavenging of dissolved metals by biogenic particles and subsequent particle settling. A similar pattern of removal from surface waters was observed in Waterline Pit (Zn and Cd). The addition of ethanol to deep waters in Waterline Pit was effective in promoting sulfate reduction in the lower layer. The development of reducing conditions resulted in near-quantitative removal of dissolved Zn and Cd, presumably as secondary metal sulfides. Iron, As and Ni profiles in Waterline Pit exhibited no evidence of removal from either surface waters or bottom waters. Collectively, the results demonstrate that the passive forms of bioremediation tested in these pit lakes may be effective for whole pit-lake remediation.

Jan 1, 2003

Blast furnace slags which fall into the quaternary system SiO2 - A1203 - MgO - CaO have latent hydraulic properties which depend on the degree of vitrification. When the oxides com- bine to form Calcium Silicate Hydrates and other products of hydration the bonds between elements are at a lower energy level than those which exist in the glassy state. Transition from the glassy state to the crystalline state is thermo- dynamically favoured and, in the context of this paper, such slags possess internal energy. Manufacture of Portland cement is respon- sible for about 3.6 per cent of total industrial energy consumption in Canada. Pyroprocessing accounts for about 83 per cent of this figure or 3 per cent of the total. The processing of blast furnace slag to a condition in which it can be used as a partial substitute for Portland cement requires no pyroprocessing and, on average, only about 11 per cent of the energy needed for Portland cement. In North America the benefits of slag as a cementitious materials have been obscured by other considerations, the most important being commercial strategy. This situation has under- gone radical change as a result of the rising cost of energy, and government pressures to conserve energy.

Jan 1, 1979

Seven papers have been reviewed and in this session. Broadly they can be grouped into three categories as follows: A Chemical Characterisation of Mine Waters Miller & Murray - Prediction of Time Dependent Factors in Acid Mine Drainage Jeffrey et. al. - Sulphide Oxidation in Pyritic Overburden; A Controlled Leach Column Study Sheridan et. al. - The Effect of Ore Type, Depth, and Leach Time on Cyanide Species in Column Tests using NaCN Leach Solutions B Mine Water Treatment Management Gilchrist & Hunt - The Recovery of Water from a Colloidally Stable Kimberlite Suspension Chapman, et. al. - Treatment and Utilisation of Hilton Mine Water

Jan 1, 1988

By G A Brown

Environmental legislation is changing rapidly throughout Australia at the present time, and with that change comes additional responsibilities for the mining and petroleum industries. Among the many changes that are being made are increased penalties for both criminal and accidental environmental impairment. The defences for criminal offences are limited and for other offences the laws may impose strict liability - in effect the offender is guilty until proven innocent. Mines may be included under contaminated land legislation, creating additional liabilities for clean-up, rehabilitation and long-term management. It is not unknown in Australia for the value of a mortgaged property to be less than the amount of the environmental liability acquired by a mortgagor in possession due to contamination of the site. An essential part of the management program for resource projects is now the regular conduct of an environmental audit, the results of which assist in the management of the legal and financial liabilities facing company directors and managers. The audit can also assist with negotiations with government agencies, staff, unions, insurers, Aboriginal and other community groups. An environmental audit may also help to ensure that companies are claiming the maximum allowable deductions for environmental works under the tax laws, and provide evidence in support of such claims. Environmental legislation affecting resource industries Environmental legislation in Australia is changing rapidly and can impose massive constraints, substantial administrative costs, and considerable liability on directors, managers and the corporation. Pollution control legislation Every State and Territory of Australia has a range of pollution control legislation contained in either individual acts relating to air, water, noise and land, or embodied in a single environment protection act. Pollution control legislation provides a critical management baseline for resource industries throughout Australia, often requiring the full-time attention of an environmental manager or an environmental department. In general, it is an offence to discharge effluents into water, or emit gases into the atmosphere above prescribed limits, cause noise above a regulated level, or contaminate land without a licence. A licence determines how much of a substance can be discharged, the location, the receiving environment, the quality, and the time at which discharges can be made or noise can be caused. Planning legislation Planning legislation controls where a project is located, how it will be constructed and operated, how large it is allowed to be, and what will happen once the project is completed. Development consents or approvals will generally contain a range of conditions controlling the preparation of the site, the construction of the facility and the way it is operated throughout its expected life time. Resource projects may be regarded under legislation as scheduled or designated developments requiring special treatment during the decision-making process. Under planning legislation, it is usual for resource projects to be subject to an environmental impact assessment process. Resource legislation Resource legislation specifically covering mining and petroleum in Australia, also contains requirements regarding protection of the environment during exploration for and extraction of minerals and oil. A mining or petroleum production lease usually contains numerous conditions regarding protection of the environment and rehabilitation of the site during and after the life of the extractive process.

Jan 1, 1994

By R Lloyd

Coal Services (Health and Safety Trust) funded ARRB Transport Research Ltd to investigate fatigue and performance of truck drivers over consecutive shifts. The main questions were to assess: What is the most important contributor to acute fatigue in mining? Is it length of shift (eg eight hours versus 12 hours) or is it time of day (eg circadian effects)? What is the limit of successive day or night shifts before chronic fatigue affects operator performance in open cut mines? The project methodology included utilising ARRB Fatigue Monitoring Devices (forced-choice stimulus reaction) in eight haul trucks, testing 24 subjects over several weeks. Each subject filled in a Fatigue Risk Questionnaire on lifestyle and health. Operators worked a 14-night, one day off, 13-day roster of 12-hour shifts in a fly-in/fly-out operation with excellent opportunities for restorative sleep between shifts. A total of 3500 hours of real-time data was collected, representing the first set of objective, real-time driver performance data for Australian mining. The data showed that for a single night of driving haul trucks, there appears to be no effect on operator fatigue from the amount of time on task (for the 12 hours). In fact performance was worse through the first eight hours than the last four. The circadian influence had a stronger affect than working more than eight hours. Of the 14 nights worked at the site, nights 13, 14, seven and two respectively, were the worst. This presents a conundrum for policy makers who may like to place caps on working hours or rosters in the hope that it will alleviate the fatigue issue. It will not. The major finding within this study is the combined influence of circadian rhythms (human body clock) and individual variability on performance. The lifestyle habits and the health of individuals have a profound effect on operator performance as shown by the strong positive correlation between high fatigue risk scores from the Fatigue Risk Questionnaire and poor performance. An individualistic approach would appear to have the best chance of reducing high potential incidents due to fatigue through successive nightshifts.

Jan 1, 2005

By T Wambeke, J Benndorf

A risk-robust development of a heavy mineral resource requires an assessment of the geological uncertainty and spatial variability of the key factors impacting the mining and processing operation. Attributes of interest are the total heavy mineral grade, the slime content and the amount of oversized particles. The modelling of a mineral sand deposit presents two main challenges. Firstly, the exact location of the geological boundaries are obscure due to the complex interaction of the deposit formation processes. Secondly, the properties of interest exhibit a rather complex transitional behaviour across the so-called soft boundaries. Traditionally, the modelling exercise is restricted to a consecutive stochastic simulation of distinct geological facies and orebody properties. This results in different zones separated by hard boundaries, ignoring the typical transitional behaviour.This contribution presents an alternative approach which models the entire sand body as a single domain while accounting for the complex trends present. Error curves are used to infer covariance model parameters without the need of a prior removal of the trend. The principle is based on minimising the differences between empirical and theoretical errors resulting from two methods of prediction calculated for different rings of influence. The added value results from the unambiguous decomposition of the spatial variation into a deterministic trend and a stochastic residual. The trend model neither overfits nor underfits the data. The calculated residuals are thus unbiased and the uncertainty can be correctly assessed.The effort results in a characterisation of the resource uncertainty which provides a more realistic image of the spatial variability of the key properties in and across the geological domains of an existing heavy mineral sand deposit.CITATION:Wambeke, T and Benndorf, J, 2014. Optimal inference of modelling parameters to simulate complex trends across soft boundaries – a case study in heavy mineral sands, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 73–84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By A Galley, M Plouffe, T Hynes

Canadian mining research has recently been reinvigorated through a pan-Canadian research strategy driven by the industry, the research community and government departments. These organisations have come together to form the Canada Mining Innovation Council, whose role is to focus and increase mining research in the country. One of the major themes of the organisation is environment; including major research initiatives on energy, tailings and environmental stewardship. Other major initiatives on exploration, mineral extraction and mineral processing will also consider environmental benefits in the research projects they undertake. All the initiatives have their priorities determined principally by the mining and exploration companies, whose first obligation is to determine the long-term research priorities of the industry as a whole, rather than for their individual companies. Only after industry consensus on priorities does the research community become engaged in the implementation of specific projects to address those identified priorities. A goal of the program is to effectively create a virtual mining research laboratory, by engaging all the major research centres in the country. Membership to date includes most of the major mining companies operating in Canada and almost all of the mining-related universities. Other members include federal, provincial and territorial governments, consulting and service companies and manufacturers.CITATION:Hynes, T, Plouffe, M and Galley, A, 2012. A new approach to mining research in Canada, in Proceedings Life-of-Mine 2012 , pp 333-338 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

The rapid industrialisation of the world was driven by an improved ability to utilise chemical energy. Unfortunately harnessing explosive energy did not come cheaply given the hundreds of lost lives. However, the modem explosives industry has made significant technological achievements, for explosives are now considered to be both safe and extremely effective. Upon closer inspection, it would appear the key to this achievement has been the development of initiation systems. While the focus may have been originally on safety, modem developments have concentrated upon harnessing the benefits of initiation control. Before attempting to gaze into the future, it is worth reviewing some of the significant advances that have occurred.

Jan 1, 1990

By N Wharmby

In recent years in New Zealand there have been a number of tunnelling and deep directionally drilled pipelines projects that have required access shafts. Often these shafts are in urban environmentswhere vibration and high noise levels are not tolerable. There are a number of methodologies that can be adopted dependent upon the shaft plan area, depth and geology.This paper will describe some different methodologies that can be adopted that use piling methods such as large diameter piles, and secant piles. The paper will use case studies to highlight:· construction methodology,· specific methodology issues and constraints,· lessons learnt, and· recommended specifications.The development of piling technologies in New Zealand has enabled the development of cost effective solutions for the construction of deep shafts in sensitive urban environments.

Mar 8, 2011

By R van Berkel, J Lay, D van Beers

The development of regional resource synergies in intensive areas with concentrations of minerals processing industries provides a significant avenue towards sustainable resource processing. Gladstone (Queensland) and Kwinana (Western Australia) are two of AustraliaÆs major heavy industrial areas. There are a number of successful regional synergies in both areas. In addition to the existing regional synergies in both areas, more potential synergy opportunities appear to exist which, upon implementation, could benefit industry, the environment and the community. To further enhance the development of such potential regional synergies, the Centre for Sustainable Resource Processing (http://www.csrp.com.au) commissioned research projects to facilitate the identification of potential synergies and assist with their implementation in both regions. This paper presents a selection of specific examples from both regions to illustrate the sustainability benefits from regional synergy developments. Although the composition of industries in the Gladstone and Kwinana regions is different both in terms of geography and industry diversity, similarities in synergy developments for both regions are apparent. Consequently, the examples discussed in this paper are organised around the key themes of water, energy and inorganic by-products. Comparison on a theme basis highlights success factors of successful synergies and demonstrates the range of benefits resulting from their implementation.

Jan 1, 2006