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By C Bellia, A Maldonado, S Strong, H Baxter

This paper discusses the technical and cost benefits of alternative data collection techniques used to collect lithological information, obtain laboratory testing samples and perform in situ testing. A comparison between diamond coring and sonic coring techniques is made using data from a recent geotechnical investigation for a final pit slope cut-back. The impacts of the coring method on laboratory strength testing results, material character testing and, ultimately, the mass strength parameters and subsequent slope design adopted are compared. The sonic coring method was chosen out of necessity and enabled the collection of tube samples of a clay unit of interest as well as bulk samples for material character and geochemical testing. The sonic coring generated unexpected degradation of clastic units, while cohesive clay-dominated units were recovered well. The likelihood that disturbance due to the coring method would result in lower than expected triaxial strength results was recognised ahead of time, with surplus samples collected and single-stage triaxial strength testing undertaken. This testing compared favourably with historic three-stage testing, where sample degradation occurred during the later stages. Material character testing of fine-grained, clay-dominated units was comparable with historic diamond core testing, while grain size estimates for more clastic units tended to be finer than previous results. The use of sonic coring over non-cored methods enabled the collection of material texture data, geotechnical properties and a full suite of geochemical analyses. This provided a comprehensive understanding of the lithological and geotechnical character of the rock and soil mass. A high-confidence geotechnical model was developed. The end result was the development of a slope design that was more aggressive than was previously designed (5° steeper inter-ramp angle), which has proven to be appropriate to the conditions following excavation. Overall, sonic coring was a cost-effective means of obtaining additional geotechnical data for the site.CITATION:Baxter, H, Bellia, C, Maldonado, A and Strong, S, 2015. Case study assessing alternative data collection techniques and analysis methods to assist with geotechnical slope design, in Proceedings Iron Ore 2015, pp 419–428 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By A Scott, S Kanchibotla, J Segui

The æMine to MillÆ concept is not new. In fact, it is the underlying objective of every mine. Unfortunately, in many operations the management structure and reporting systems have created independent æbusinessesÆ within the overall mining enterprise. This has created incentives to optimise the performance of each component of the operation rather than the enterprise as a whole. The Mine to Mill Conference organised by The AusIMM in October 1998 documented a number of case studies where run of mine ore was not presented to the mill in the best possible form for subsequent stages of comminution and processing. A number of examples were quoted where modest expenditure in the mine had a very significant impact on downstream process efficiency and hence costs. Examples included:the minimisation of fines in the mining and handling of iron ore; the management of fines in blasting and crushing for a copper heap leach operation; the control of blast damage, mining recovery and dilution in open cut coal operations; and the optimisation of mine fragmentation to increase mill throughput in gold and copper operations. The latter topic has been trialed at a number of mines and is referred to as æMine to MillÆ fragmentation. A number of æMine to MillÆ type investigations have been reported in the literature including Pease et al, Simkus and Dance, Nielsen, Scott et al, Kojovic et al, Kanchibotla et al, Bulow et al and Hawkes from the 1998 Mine to Mill Conference. In addition, a number of studies are in progress or the results have yet to be published. These studies have demonstrated the feasibility of obtaining the data required to characterise the breakage behaviour of ores and to model the impact of changes to blasting practices on process efficiency. Characterising the breakage behaviour of ores is a vital step in the management of fragmentation and comminution in mines. The characteristics of importance to fragmentation fall outside the parameters conventionally required to describe the economic geology of a deposit. æMine to MillÆ optimisation of fragmentation means that the mining engineer needs information from the geologist in order to be able to help the metallurgist. Providing this information requires close interaction between these groups.

Jan 1, 2000

By R F. Sandenbergh

Due to environmental considerations, mineral processing plants are increasingly recycling water to decrease the impacts of wastewater on environment and the depletion of fresh water resources. Industrial experience has shown that increasing recycling water in flotation typically negatively impacts the recovery and selectivity, especially in the selective flotation of minerals from complex sulfide ores. The major reason for the reduced selectivity is typically the inadvertent activation of sphalerite or pyrite by the heavy metal ions (HMI) in solution. These HMI are often produced during milling and flotation and absorbed by other minerals. In the normal flotation pH value range (8 - 10), these HMI are often in the form of precipitates or complex ions that may re-appear in solution or become active should conditions favour this. In this paper, microflotation, batch flotation and XPS surface measurement were used to investigate the use of HMI absorbents additions to the pulp to improve flotation selectivity of a complex sulfide ore. It has been demonstrated that HMI removal does improve flotation selectivity by facilitating more effective depression of the sphalerite. Microflotation and XPS surface measurements have shown that HMI absorbents compete with sphalerite to absorb HMI, and thus reduce the surface concentration of HMI on those sulfides. The practical use of HMI absorbents in complex sulfide ore flotation is also discussed.

Jan 1, 2005

By M Lak, R Amiri, A Haratian, M Asghari, S Haji

In recent years, due to advances in designing of various magnet assemblies, a wide range of magnetic materials with different properties can be concentrated. Jalal Abad iron ore beneficiation plant, which is located in Iran, Kerman province, is currently producing iron ore concentrate with the capacity of 0.8 Mt/a by having medium intensity magnetic separators (MIMS) with rougher and cleaner stages that finally leads to the production of an iron concentrate with the Fe grade of about 65 per cent. In this plant, the rougher tailings directly goes to the thickener as the final tailings and cleaner tailings feeds to the ball mill for regrinding. Since some hematite particles with weak magnetic properties cannot be recovered from only these two stages of magnetic separation, the obtained tailings from this concentration plant has approximately an iron grade of 25 per cent to 27 per cent. Accordingly, laboratory processing tests were conducted on the obtained representative sample of the final tailings. Based on the experimental results performed on final tailings, a new magnetic drum separator with a specific magnetic assembly was designed that could finally lead to product with iron grade range of 58 per cent to 60 per cent with relative and total weight per cent of 8.6 per cent and 3.86 per cent. Finally, it could be concluded that feeding of magnetite particles to the existing drum separators, due to their high magnetic field intensity, cannot efficiently lead to improvement of the grade of concentrate. Therefore, pilot magnetic separation tests were done on the final concentrate for evaluation of product upgrading probability. Consequently, by increasing another stage of cleaning and by decreasing the magnetic field intensity, the final product grade could be enhanced from 65 per cent to 67 per cent.

Nov 8, 2021

By i, A Shirbazo, S Saydam, S Ata, H L. Ram, B Li

The integration of internet technology into industrial sectors has significantly accelerated the adoption of Internet of Things (IoT) devices, transforming communication, data aggregation, and information distribution. The mining industry has embraced this evolution by deploying IoT devices and advanced technologies like autonomous robots and sensors to enhance operational safety. These sensors enable real-time data transmission and continuous monitoring of key parameters, providing decision-makers with timely insights. However, the interconnected nature of these devices has introduced complexities, resulting in inconsistencies across operations. Addressing these challenges, this research explores the application of modern digital principles to the mining industry through the Reference Architecture Model Industry 4.0 (RAMI 4.0). RAMI 4.0 offers a robust framework that integrates digital and physical systems, promoting data transparency, interoperability, and decentralised decision-making. This study aims to briefly introduced framework designed for the unique challenges of mining operations, leveraging the latest digital technologies. The lack of standardisation in the mining sector highlights the need for a comprehensive approach to tackle issues such as interoperability, scalability, security, safety, and repeatability. Establishing standard procedures can ensure smooth interaction between connected devices, ultimately enhancing operational efficiency in the growing IoT ecosystem within the mining industry. Introducing a well-defined reference architecture like RAMI 4.0 can streamline management processes and improve operational efficiency in mining. By adopting this framework, the mining industry can effectively navigate the challenges of digital transformation, leading to a more connected and resilient future. The study concludes that RAMI 4.0, with its structured approach, can significantly enhance the efficiency and productivity of mineral processing operations, fostering sustainable growth in a digitally driven industrial landscape.

Sep 1, 2024

Carbon sequestration in planted forests provides an immediately available, low cost option to address the greenhouse impacts of coal mining and coal utilisation in a carbon constrained world. In addition, planted forests also offer the opportunity to address other environmental issues, particularly salinity and loss of biodiversity. Given salinity is characteristically associated with agriculture in the 500 to 700 mm rainfall belt, then where such forests can also produce commercial timber products, they offer the additional opportunity to establish new, diversified rural employment in both timber growing and processing. In the majority of Australian catchments affected by salinity, where rainfall is generally less than the 700 mm limit to conventional forestry, and where groundwater reserves are often saline, the objective of achieving economically viable forestry production presents a significant challenge. In 1996, Saltgrow commenced a collaborative breeding program to combine the salt and stress tolerance of E camaldulensis, with the growth rate, stem form and wood properties of the commercial species, E grandis and E globules. This program aimed to produce trees with the potential for commercial rehabilitation of saline landscapes. Results covering a range of site conditions from SaltgrowÆs network of over 100 trials around Australia are presented. The opportunity for commercial plantations integrated with agriculture in low to medium rainfall areas to address salinity and sustainability will be discussed. In addition, the significant potential for partnerships between land-rich, cash-poor farmers, catchment management authorities seeking to invest in public good projects that enhance environmental sustainability, and major carbon producing industries with either mandated or voluntary requirements to curtail net emissions will also be discussed.

Jan 1, 2005

By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of the Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper, in which he presents his own A factor.Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blasthole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, eg in conjunction with image-based fragmentation measurements or crusher modelling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function, such as in the KCO model.The mean to median issue is investigated in some detail and it is found that using x50 instead of the mean:has a sounder theoretical backgroundis less prone to errorsis not contradicted by the original Soviet data.It is finally suggested that future work on fragmentation prediction equations focus on the use of distribution independent quantities like percentiles, eg x50, x20 and x80. Some previous work in this direction is briefly analysed and one consequence is that the n-value of the Kuz-Ram model should depend on specific charge.CITATION:Ouchterlony, F, 2015. The median versus the mean fragment size and other issues with the Kuz-Ram model, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 109–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Berry, F MacCorquodale

The ownership, management and employment structures operating in the Australian minerals industry have dynamically evolved during the last 30 years. One of the most dramatic changes, from an exploration and mining geology perspective, is the reduction of in-house geological expertise and an ever increasing reliance on contract and consulting services.For all companies - big and small - two key issues resulting from these changes are the management of core geological intellectual property (IP) and competitive advantage. This is because there are less experienced geologists at exploration and mine sites, there are fewer head-office technical service teams to support mine sites, exploration teams are smaller with less specialists employed, and there is an ever-greater dependence on contract and consulting services.This paper reviews and explores these issues with an industry-wide geological context, then provides a case study of how Newcrest Mining Limited (Newcrest) has dealt with these issues in exploration. Newcrest has grown from a one-mine company with an Australian exploration focus, to a large global company with multiple operations and an extensive international exploration portfolio. NewcrestÆs management of its geological IP and competitive advantage has evolved as the company has grown and responded to market conditions, including its internal restructuring in mid-2013.CITATION:Berry, M and MacCorquodale, F, 2013. Managing geological intellectual property and competitive advantage - Newcrest Mining LimitedÆs experience, in Proceedings World Gold 2013 , pp 37-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By H Barrie, L Ameglio

"Current methods for acid rock drainage (ARD) mitigation revolve around insulation of the waste from oxygen in the atmosphere with water and dry (soils and liners) covers. Both are of limited effectiveness and present significant drawbacks. Furthermore, while they reduce oxygen influx, they reduce but do not prevent ARD.The inert gas mixture (IGM) technology has been designed to overcome the deficiencies of gas transfer into tailings and waste rock materials across the surface and instead block oxidation by controlling the transfer of oxygen from the atmosphere. Inert gas is injected into the mine waste at low flow rates and the positive but low flow purges the oxygen that tends to diffuse into the sulfide waste across the surface. The positive flow of IGM compensates for inward oxygen diffusion and creates a pressure drop across the cover layer preventing inward diffusion of oxygen and, hence, acid generation.The IGM processes are evaluated in this paper: theoretically, with a review of the theory of ARD and the current state of knowledge about the performance of notably dry covers as atmospheric oxygen barriers via models to predict the performance of the IGM technique practically, with a bench-scaled experiment.The results demonstrate the effectiveness of IGM to prevent oxidation of sulfide minerals and ARD in waste rock. The laboratory experiments further identified key variables to be used to monitor performance and control efficiency of IGM, which is now awaiting field-scale application.The IGM technology is a patented process by Terraquest Technologies Ltd (Canada) in USA, Canada and Australia. The IGM technology can be cost-effectively manufactured on-site with commercially available compressors and gas filtration membranes. It is predicted that low-cost covers can then be utilised with IGM, which in turn lowers the overall capital costs of ARD mitigation.CITATION:Ameglio, L and Barrie, H, 2015. Acid rock drainage prevention using inert gas mixture technology, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

Blasthole cone samples are used for grade control in most of the iron ore mines of the Pilbara of Western Australia. This method of sampling is straightforward when the target sampling interval matches the mining bench height but is problematic when the blasted bench is 'flitch' mined in two or more passes. Crucially, the sampler needs to decide which part of the blast cone represents the upper and lower flitches to be mined. This sampling selection decision is usually made by assuming a certain proportion represents the subdrill component of a sampling face in a blasthole cone and the two flitches are split equally from the remaining portion. In this study of a West Australian channel iron deposit, sampling experiments were carried out to determine the actual proportions of a sampling face in a blasthole cone by spray painting the blast cones at flitch and subdrill boundaries during the drilling process. Measurements were then taken to assess the differences between assumed sampling face proportions and actual proportions. A set of paired samples was also collected from a number of blastholes with one set using the assumed proportions of each flitch for each sample, while the other set sampled the actual proportions, which were identified from the cone painting process.

Mar 1, 2010

By A Parry, C Fitzmaurice

After conducting laboratory ore sorting testwork on samples of a low grade nickel ore stockpile at Western Areas’ Flying Fox nickel mine, a mobile crushing, screening and ore sorting plant was located adjacent to the stockpile. An initial two month trial of the ore sorter program proved successful and was extended to process the entire Flying Fox low grade stockpile in a further four month campaign. A total of 167 660 t of low grade ore was processed, providing highly upgraded feed trucked 26 km to the Cosmic Boy concentrator. A more than three-fold grade increase was achieved on ore sorter accepts. The moderately upgraded fines that by-passed the mobile ore sorter were also subsequently blended into plant feed. This paper describes the mineralogy of the Flying Fox low grade ore, the mobile ore sorting campaign and provides some commentary on the economic and environmental benefits achieved in the ore sorting campaign. The ore sorting campaign demonstrated the benefits of being able to utilise mobile ore sorting equipment temporarily located adjacent to sub-economic low grade stockpiles in order to effectively treat these stockpiles and produce viable plant feed.CITATION:Parry, A and Fitzmaurice, C, 2018. The upgrading of low-grade nickel ore stockpiles at Western Areas Ltd Forrestania operations, using a mobile ore sorting plant, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 541–550 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By C Mason, A Littleboy

This paper presents the results of a large scale survey of The Australasian Institute for Mining and Metallurgy (AusIMM) membership. This survey aimed to understand and define the key issues and drivers that AusIMM members perceived would shape the development of the Australian minerals industry over the next 20 - 30 years. Nine hundred and fifty-nine participants rated the importance of 11 issues and six drivers (generated from interviews with AusIMM members), and 236 of these participants also provided qualitative descriptions of the future. Issues were defined as problems or opportunities for the minerals industry that may be controlled or influenced by the industry, while drivers were defined as those factors that will influence the direction of the industry that are not within the control of the industry. The quantitative data revealed that the top four issues, in order of their perceived importance to the Australian minerals industry, were: investment in exploration, workforce, health and safety, and innovation. The top three drivers in order of their perceived importance, were: economics of mining, global context and Australian society. While the top four issues were largely consistent across professional groups examined, metallurgy and mineral processing professionals rated water inputs and energy inputs significantly higher than the other professional groups. For the list of drivers, there was strong agreement regarding their ranked order of importance across the professional groups examined. Within the qualitative data, however, a single issue (technology) and a single driver (economics of mining) dominated participantsÆ descriptions of the future. These findings provide important input into a broader program of scenario development for the Australian minerals industry being undertaken by CSIRO and its partners. The results of this study demonstrate the importance of using a mixed methodology in generating these inputs to understand more fully how important stakeholders view the future and the factors that will shape it. The results of this study are also discussed with respect to the role that CSIRO may play in facilitating the exploration of uncertainty around the future of the Australian minerals industry.

Jan 1, 2009

By T Kojovic, S J. Windle, J Sullivan

"The Geometallurgical Mapping and Mine Modelling (GeM) comminution index (CI) was developed as part of the AMIRA P843 GeMIII project. Drill core geochemistry samples were passed through a Boyd Crusher with standardised settings and the resulting particle size distribution (PSD) was measured using sieves.Disadvantages of the original measurement were the relatively coarse crush size, requiring a second pass of crushing for geochemical sample preparation, and the limitation of throughput caused by the sieving step. At Antamina, the measurement has been modified to use a 2.2 mm crusher size setting, which permits a single pass. The PSD is measured using a Camsizer, an automated optical sizing instrument. The Camsizer sample is a +180 µm fraction, used to avoid passing too many fines through the instrument and slowing down the measurement. In the sieving step, the weights of the two fractions are recorded and subsequently used to normalise the distribution measured by the Camsizer. In this way, the throughput of the Camsizer can match that of the Boyd Crusher. The PSD data are therefore measured without penalising the throughput of the sample laboratory.The normalised PSD distributions are used to derive modified CI parameters, based on the slope and intercept of the breakage product size distribution, which are indirect measures of the material breakage hardness.Fifty samples were selected as a training set, each sample a composite of five or six individual assay intervals and each with its own measured CI. The average PSDs were calculated for the composites and used to calculate a composite CI. The intact half of the core, approximately 40 kg, was tested to measure the BWi, A*b and crushability. The results were used to develop predictive algorithms for these hardness parameters.A further 50 composites were chosen for lab testing, to serve as a blind test of the algorithms. The paper reports on the test results and the incorporation of the modified CI data and predicted hardness parameters into the Antamina block model.CITATION:Windle, S J, Kojovic, T and Sullivan, J, 2016. Use of a Modified Comminution Index to Predict Bond Work Index and SMC A*b at the Antamina Mine, Peru, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 153–160 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

Education for the Mineral Industry in Australia developed in an uncoordinated but effective fashion till the mid 1960's, with recognised quality in graduates, with output matching demand, and with industry needs being fulfilled. Then in the space of a further 20 years, as company structures expanded, as the number, complexity, and costs of mineral projects escalated, as educational facilities, costs and politics increased, as community perceptions and aspirations changed, as government control of minerals and education increased, and as mineral sales cycles and markets fluctuated widely, the very fabric of Australian Mineral Education fell in tatters. Extractive Metallurgy Education suffered most in this collapse, and no compre- hensive remedies have been initiated. We are all the losers. In the 1990's, the extraction of Australian minerals and metals will increase in international significance, and the education of Extractive Metallurgists must meet this need. After examining the current situation, a series of management strategies are proposed to enable Extractive Metallurgical Education to survive and prosper in the next two decades and beyond. These strategic proposals involve industry, the government, the educational bodies, and individuals, in a range of short and long term objectives, policies, and actions.

Jan 1, 1984

By R Lastra, Y Choi, C Hamilton, P Kondos

Hydroseparation (http://www.cnt-mc.com) was used to concentrate sized fractions (from <38 ¦m to 150 ¦m) of various ore products ahead of carbon-in-pulp (CIP)-treatment. The resulting size-by-size concentrates were mounted as monolayer polished sections and subjected to automated unattended precious metal searches by image analysis (see Lastra, Wilson and Cabri, 1999). Systematic variations in Au-deportment permit quantification of Au reporting as discrete grains from fresh-feed through to pressure oxidation (POX)- and CIP-feed. Application of hydroseparation, image analysis and assays to characterising tailings (from <10 ¦m to 106 ¦m) from four mine sites is also described. Results are encouraging enough to predict that the combination of hydroseparation (HS) and automated image analysis could become a standard methodology for study of precious metal ores and metallurgical products.

Jan 1, 2008

By J D. Tolley

The shift towards clean energy technologies is having a significant impact on the mining industry, with the demand for minerals such as copper, nickel, cobalt, lithium, manganese, and graphite increasing exponentially. To meet the goals of the Paris Agreement, mineral requirements for clean energy technologies would need to quadruple by 2040, and to achieve net-zero globally by 2050, mineral inputs in 2040 would need to be six times more than today. The most significant driver of mineral demand is electric vehicles (EVs) and battery storage, with lithium seeing the fastest growth, and copper demand doubling over the same period due to the expansion of electricity networks globally. The demand for these minerals is expected to rise significantly as investments in clean energy technologies continue to grow in the future. As the world moves towards a decarbonised economy, the minerals industry is under increasing pressure to reduce its environmental and social impacts and meet the increased demand for minerals. Mining companies are facing additional challenges due to the depletion of near-surface mineral deposits globally, with more mines transitioning from open pits to underground. The transition to underground mining requires the right strategy to economically access deeper mineable inventories and to keep up with future clean energy technology demands to achieve net-zero globally by 2050. One key way to achieve this is through decarbonisation using ‘green’ mining technologies such as replacing current primary diesel mining fleets with battery electric vehicles (BEVs). However, these measures through electrification overlook the bigger opportunity to maximise the socio-economic returns from the mine while also reducing the overall carbon footprint. Corporate cut-off grade policy is one of the most significant influencers on the total environmental and social impacts of the mining industry. The purpose of a corporate cut-off grade policy is to implement strategies aligned with achieving all the mining companies’ corporate goals, with decarbonisation targets becoming a primary driver for mining companies. Table 1 shows the evolution of cut-off theory with the increasing number of dimensions and driving inputs per iteration.

Aug 2, 2023

By Chappell B

Backfill in the form of mine waste tailings has inherent problems associated with attaining adequate strengths upon placement. Fines are usually removed to ensure adequate drainage, which lowers the cohesive strength of the fill, leaving the fines to he placed in a tailings darn. Electro-drainage and electro-chemical grouting is examined to investigate its effects on densification and shear strength within a silty clay tailing having low permeability and shear strength. Two separate grouting mechanisms are observed for the iron and silica grouts used. Electro- osmosis is associated with iron grout that deposits within the tailing matrix under a converging pH gradient, and increases the permeability of the tailing. This process initiates cation exchange and causes cementing of the granular contact points between the clays. Electro-phoresis causes sodium silicate solution to deposit silica grout in the voids of the tailings. The resultant effect of these mechanisms results in an increase in cohesion, leaving the void ratio of the iron grouted tailings as it was but significantly reducing the void ratio of the silica grouted tailings.

Jan 1, 1998

By J L. Stacey

The diverse priorities, drivers and concerns of multiple stakeholders in the minerals industry complicate the integration of sustainable development considerations into mine design, as well as operational and strategic decisions. The ability of the industry to address all role-playersÆ needs, or indeed, to achieve consensus among all role players on the plethora of sustainable development issues seems a noble yet unattainable goal. One of the difficulties in assessing the relative importance of sustainable development issues across many stakeholders is the inevitable lack of impartiality in valuing these issues. Starting from a premise that transparency and fairness of the process are absolute prerequisites for progress, but that consensus is not, an approach has been developed in which all stakeholders are asked to assess the importance of all other stakeholdersÆ priorities, excluding their own. The approach recognises that stakeholders have different levels of contribution, understanding, vested interests, and perceptions of legitimacy and entitlement, across the diversity of sustainable development issues and decision criteria. Using Triangular Value Analysis, the relative weightings of each of the stakeholderÆs priorities are determined through a regression-like technique. The uniqueness of this approach is the manner in which self-assessment bias and overemphasis of stakeholdersÆ own priorities are avoided. The methodology can be used for both internal and external stakeholders, and in conjunction with other group decision making techniques, such as the nominal group or Delphi techniques. This paper will illustrate how Triangular Value Analysis may be applied in the minerals industry to determine priorities in various decisions relating to potentially conflicting sustainable development priorities within the industry.

Jan 1, 2009

By S E. Wallah, D Hardjito, B V. Ran

The manufacture of Ordinary Portland Cement (OPC) is not only energy-intensive but also releases a significant volume of carbon dioxide (CO2) to the atmosphere. In addition, OPC in concrete often causes premature deterioration that affects the durability of concrete structures. This paper explores an alternative to OPC concrete called geopolymer concrete.The present research utilises low calcium (class F) fly ash as the source material to produce geopolymer concrete. Several factors that affect the mix design process such as mix proportion, curing time, and curing temperature have been studied. In addition, the long-term properties such as drying shrinkage, creep, and exposure to sulfate attack are also being investigated.The test data presented in this paper reveal that geopolymer concrete possesses high compressive strength, undergoes very little drying shrinkage and moderately low creep, and shows excellent resistance to sulfate attack. The result is extremely promising and demonstrates the sustainability of geopolymer concrete as a construction material for a sustainable future.

Jan 1, 2004

This paper describes a detailed geostatistical study of producing copper orebodies at Mount Isa Mines Limited in Queensland, Australia. As a result of this work, kriging has been adopted for grade estimation for final stope design at Isa Mine. Extensive variogram and back analysis studies indicate that one relative variogram model can be used to give optimal kriged grade estimates from production sampling throughout the 100 million tonne copper orebody complex. The kriging method replaces a computer technique used at [sa Mine based on inverse distance weighting using parameters chosen from experience.Comparative stope designs based on 10 million tonnes of ore indicate a 16% increase in minable ore tonnage at a grade well above the cut-off, as a result of the geostatistical work.Although this paper is written as a practical description with simple explanations of geostatistical concepts, the theory and use of relative variograms has been expanded. A possible link is suggested between relative variograms and first order kinetics of natural mineral concentration processes.

Jan 1, 1982