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By J Balzary, A Mohais

Dynamic market and operating conditions, coupled with an environment in which multiple objectives and trade-offs are common, pose major challenges for planners and schedulers working in any mining entity. Many mining companies recognise the need to shift from a siloed mining-focused push model to an integrated value chain, demand-driven approach, but there are still fundamental barriers in business process and the supporting technology preventing a consideration of end-to-end optimality.This paper presents some elements of experiences working with companies to adopt such advanced approaches. In addition to algorithmic elements, an approach to phased and gradual deployment of progressively more sophisticated optimisation models is described. From a practical software adoption perspective, it is believed that this last concern is also of primary importance. Next generation approaches to the optimisation of complex bulk commodity demand chains, namely iron ore and coal are presented, with case studies in the world’s largest integrated operations in Western Australia and Queensland from the raw material mined through to market. Utilising accurate simulation models supported by metaheuristic optimisation techniques, a range of ways to engineer a dynamic decision support framework that can adapt and change with the inevitable changes in commodity markets is explored. Objectives such as total revenue, margin, cost, NPV, throughput, asset utilisation, contractual penalties and bonuses, and energy consumption can be managed simultaneously across the mine, plant, logistics network, port operation, shipping and sales domains.CITATION:Balzary, J and Mohais, A, 2014. Consideration for multiobjective metaheuristic optimisation of large iron ore and coal supply chains, from resource to market, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 213–222 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By S Harris, A Bossilkov

The Kwinana (Western Australia) and Gladstone (Queensland) industrial areas are among the few dozens of heavy industrial areas globally that demonstrate significant levels of regional resource synergies. Such synergies are also referred to as æindustrial ecologyÆ or æindustrial symbiosisÆ. Fundamentally they involve the exchange of by-products or sharing of utilities between companies in close geographic proximity to achieve competitive advantage and environmental benefit. A concerted research effort is currently underway to foster greater realisation of regional resource synergies in minerals processing intensive regions, in Australia and internationally. This paper summarises current insights from the foundation research into engineering tools and technologies and enabling mechanisms for regional resource synergy developments. Regional resource synergy developments were reviewed for 16 international and two Australian regions. It was found that Kwinana and Gladstone compare favourably with the well-regarded international examples of regional synergy development. Given the fairly strong evidence that self-organisation is critical for regional synergy developments, an implementation model has been proposed that captures entry points for synergy developments at the level of platform (industry collaboration), process (developing synergy opportunities) and project (assessing and implementing specific synergies). It was also found that regional synergies have so far developed in the absence of specific methods for identification and screening of synergy opportunities. Moreover, very limited attention has been paid to the associated technological and engineering challenges. The current technical research effort therefore targets: the development of a toolset for the identification and development of potential synergy opportunities; and assessment of technology needs and opportunities for regional synergies involving water, energy and materials recovery and reuse.

Jan 1, 2006

By B Tadesse, L G. Dyer, B Albijanic, M Jung

The presence of high concentrations of dissolved ions in groundwater, sea water or recycled water may alter the water structure, particle surface wettability and colloidal interactions between bubbles and particles and can have a significant effect on mineral flotation. While the impact of water quality on the flotation of precious and base metal minerals is well established, no relevant published study exists currently regarding the effect of water salinity on the flotation of rare earth bearing minerals. This paper attempts to quantify the effect of water quality variation on flotation recovery and grade of rare earth minerals and gain an understanding on which ions existing in saline water affect flotation behaviour. Specifically, it is aimed at investigating the effects of water quality on the flotation of monazite in the presence of cations such as Ca2+, Mg2+, K+, and Na+. Flotation tests, zeta potential measurements, and adsorption tests were performed to explain the flotation behaviour. It was found that monovalent ions such as Na+ and K+ have negative impact on rare earth minerals recovery and grade. The result of single mineral flotation tests showed that the floatability of monazite was significantly depressed in the presence of Ca2+ and Mg2+. The result of single mineral flotation test showed varying depression levels in the presence ions in the order of Ca2+ > Mg2+ > Na ~ K.

Aug 24, 2022

ecent work on decoppering lead is reviewed; CuS is formed rapidly even from dilute solutions of copper in lead. he mechanism of decoppering is discussed, and an explanation for the retention of metals such as silver in lead is dvanced. As decoppering tin appears to be an analogous process, the Cu-Sn-S system is studied at 300¦C. CuS, hich is not, an equilibrium product, is found in decoppering drosses. In the removal of nickel from lead, Ni3pb2S2 formed; preliminary measurements show the equilibrium nickel content to be greater than that obtained by tirring in sulphur. Decoppering bismuth is thermodynamically favoured, but is complicated by the occurrence of uBiS2. The Cu-Pb-S system is the only one of the four studied where the equilibrium can be calculated simply, as ' resence of ternary sulphide or other phases invalidates calculations based on binary data.

Jan 1, 1970

By H von Blottnitz, J L. Broadhurst

Eco-efficiency has been proposed by the World Business Council on Sustainable Development as an environmental performance indicator framework that contributes to sustainability by assisting corporate decision makers improve the environmental performance of their operations and processes, while also extracting additional economic value. Given that the recent engagement of the minerals industry with sustainability has highlighted the need for requisite tools and methodologies, it is therefore of interest to assess whether eco-efficiency indicators can drive sustainability performance improvement during process design within the minerals industry. Previous work indicates that the choice of sustainability performance indicators to be used for decision making needs to be governed by the decision context; ie the performance indicators need to be fit-for-purpose. Here, the strengths and weaknesses of eco-efficiency indicators are analysed using case studies. First, a more rigorous definition of eco-efficiency indicators for the minerals industry is proposed based on indicators currently offered in the literature. Two case studies are then selected to reflect typical decision situations encountered within minerals process design. For each case study, eco-efficiency indicators are computed and are compared to more traditional graphical representations of the economic and environmental performance of process design alternatives considered. The sensitivity of these indicators to various process design parameters is also investigated. Results confirm that the meaningful application of eco-efficiency indicators is strongly dependent on the decision context in which the process data is generated. Results also show that eco-efficiency indicators can be related to technical process design parameters to allow for richer communication of performance information for various decision trade-offs; however, in some cases, graphical approaches that provide more insights into the environmental-financial trade-offs should be preferred. The research thus contributes to guiding the selection of the appropriate tools for more environmentally sustainable design of minerals beneficiation processes.

Jan 1, 2009

By Bulters J, Sheppard I

Two blasthole density logging programmes have been conducted on the Mt Whaleback iron ore mine to evaluate the use of this type of logging as an aid to blast pattern design. The first programme also involved the setting up of a Density Test facility with which to calibrate the density probe. The programmes indicated that about 22-23 blastholes can be consistently logged per day at a cost of $1.30 per metre. Even though this is only half the rate required to log the average number of blastholes drilled daily on Mt Whaleback, testwork indicated that no significant loss of accuracy results if only half the holes in a pattern are logged. The major results of the programmes were: 1. The density range for black pyritic Shale is 2.2-2,9 g/cc. 2. The density range for soft to medium hard BIF is 2.1-3.0 g/cc. 3. The density range for hard BIF is 3.0-3.6 g/cc. 4. The front row blastholes show consistently lower densities than the main body holes due to blast damage. 5. A low density zone extending to a maximum depth of 6 m occurs at the top of most blastholes and results from blast damage from the bench above. These density results have been used to implement savings in drilling and blasting via pattern expansion and charge optimisation of blastholes. Eight ore

Jan 1, 1986

By W J. Botha

The Palaeoproterozoic Transvaal Supergroup in the northern Cape Province of South Africa hosts high grade (>60 per cent Fe) hematitic and specularitic iron and manganese mineralisation. The mineralisation is primarily exposed along the western margin or in the central part of a major interference fold structure known as the Maremane dome. The bulk of South AfricaÆs iron ore production is currently provided by two active mines, Kumba Resources megaton Sishen iron ore mine on the northern end of the dome, and the smaller Assmang Beeshoek mine on the southern closure. The undeveloped Sishen South deposit, which contains ~400 Mt of high-grade hematite ore, is located approximately 9 km towards the southwest of Postmasburg. It forms a linear extension of the Beeshoek mine and as such contains comparable laminated, breccia and conglomeratic iron mineralisation. The Transvaal Supergroup sediments were deposited in two distinct fault-controlled basins on the Archean Kaapvaal craton. Basement rocks in the western Griqualand West basin are formed by a carbonate platform sequence (Campbellrand Subgroup), which is overlain by a thick sequence of banded iron formation of the Asbesheuwels Subgroup. A major unconformity separates these rocks from the red-bed Gamagara Formation, which is correlated with the base of the Olifantshoek Supergroup. Diamictites and lavas of the Postmasburg Group have been thrust over these units from the west. The mineralisation process is related to regional scale supergene iron enrichment of Kuruman banded iron formations along the unconformity. During regional tectonism associated with the Kheis orogeny (2400 - 1700 Ma) the Maremane dome was uplifted, and the basal dolomite units thus exposed to erosion and karstification. The overlying banded iron formations collapsed into karst sinkhole structures where leaching of silica and enrichment of hematite occurred. Although the exact mechanism of the mineralising process remains unclear, karstification preserved components of the original concordant laminated and massive ores. These ores were subsequently eroded and deposited as conglomeratic and gritty ores down-dip of the Maremane dome in alluvial fan systems. A thin veneer of recent calcrete or Tertiary Kalahari clay beds masks the subsurface geology and most of the orebodies, thus ground geophysical gravity surveys proved excellent exploration tools to penetrate the surficial cover. These surveys were used extensively for delineation drilling and to deduce the subsurface geology and structural development of the area. Finally Sishen South orebodies were modelled with ModelVision software in an attempt to obtain an exploration template for the surrounding area.

Jan 1, 2005

Sampling protocols and metallurgical flow sheets should be designed to suit the style of mineralisation in question. In support, the a priori need for evaluation programs is the characterisation of the mineralisation type(s) and domain definition. The proportion and size of gold particles has a direct impact on the effectiveness of sampling protocols and metallurgical processes employed. Within the coarse- to-fi ne gold spectrum, the samplability of a deposit ranges from relatively simple for fine-grained disseminated particles, through to difficult for coarse gold mineralisation. Conversely, metallurgical processing may be relatively simple for coarse gold ore and more difficult for very fi ne gold ores. Most deposits contain a proportion of both particle size types. The nature of mineralisation, mineralogy and associated gold particle sizing can only be determined by preliminary sampling to facilitate testing. Mineralogical studies, focussing on ore mineralogy and gold particle deportment, size and distribution are required as part of wider paragenetic and geometallurgical investigations. This paper discusses key issues and presents a methodology for the determination of gold particle size in coarse gravity-gold ores to support sampling optimisation and which also contributes to metallurgical characterisation.

Aug 1, 2010

In considering the organization of research, it is necessary to know just what research is, what objects are in mind when setting out to conduct research, and what are the functional units which are required to enable a coordinated effort in research to proceed.The dictionary defines research in the following terms: Laborious and patient search, as for truth, diligent inquiry or examination in seeking facts or principles; inquiry, scrutiny; to search or examine with continued care; to seek diligently; to search again; to examine anew.This is, of course, simply a formal definition, but the reference to "labour", "patience" and "diligence" should be noted.The following quotation from an answer to the question "What is Research?", published recently in a technical journal, puts some life into the formal definition:- Essentially, it (Research) is nothing but a state of mind a friendly, welcoming attitude toward change. Going out to look for a change instead of waiting for it to come. Research, for practical men, is an effort to do things better... The research state of mind can apply to anything: personal affairs or any kind of business, big or little. It is the problem-solving mind as contrasted with the let-well-enough-alone mind . . . It is the "to-morrow" mind instead of the "yesterday" mind. Note the statements that: Essentially, it (Research) is nothing but a state of mind, and the research state of mind can apply to anything.

Jan 1, 1950

By G M. Tranell, M Tangstad

The CO2 footprints in the production of Mn-ferroalloys and silicon/ferrosilicon are correlated with the fossil carbon consumption. The CO2 emissions may be reduced in the Mn-ferroalloy process by increasing the degree of prereduction and reduction of carbonate materials, while the silicon/ferrosilicon process is optimised based on silicon yield. By changing the fossil reductant into biogenic reductants, the global warming potential will be decreased even more. Even if the reductants are biogenic reductants, there will still be a global warming potential (GWP) in eg the electrode consumption and the CH4 emissions in the charcoal production. To reduce the use of fossil reductants there are also more disruptive technologies like the use of H2 that at least for the silicon production is on a very low technology readiness level (TRL). Using metallothermic processes will reduce the use of carbon but requires carbon neutral metal reductants. Electrowinning can have low CO2 emissions, and the electrowinning of pure Mn is a technology of high TRL. Salt and oxide electrolysis is under investigation for both Mn and Si production however the research is still on a low TRL. The use of CCS/CCU (carbon capture storage/utilisation) is a part of obtaining carbon neutral processes. Last, the energy mix used for these energy demanding processes is discussed.

Aug 21, 2024

The effects of changes in sintering bed height, coke fuel, suction and basicity on sinter productivity, physical strength and mineralogy were determined. It was found that, for a given iron ore, there is a narrow -coke range which maximises sinter strength, irrespective of bed height (in the range 300 to 500 mm) or basicity (in the range 1.2 to 2.2). Increases in bed height, at a constant coke level, improved the physical strength of the sinter. Productivity increases were obtained by increasing the sintering suction but, at coke levels other than the optimum, these *ere somewhat offset by the decrease in sinter physical strength. At basicities higher than 1.2 (i.e. 1.6, 1.8 and 2.2) there was a narrowing of'the size range of product sinter, with a decrease in the percentage of top size material, and a decrease in the amount of fines produced. Changes in coke, bed height and basicity exert major effects on sinter mineralogy, while the Nagoya index was mainly influenced by cote and bed height Changes.

Jan 1, 1975

By B, G Strobos, J P. Maree, N Smit

In mining and processing operations where minerals, high in pyrite and low in calcite/dolomite are processed, acid is generated, which needs to be neutralised. Ticor at Empangeni in South Africa (SA) produces rutile (TiO2), leucoxene (TiO2 plus iron compounds), titanium (Ti), zircon (Zi) and ilmenite (TiO2 plus iron compounds). Neutralisation is required in the processing plant where acid is leached into the wash water. This water needs to be treated to a quality suitable for re-use in the metallurgical process or to a higher quality to make it suitable for discharge into the Empangeni sewage system (SA). For re-use the water needs to be neutral and under-saturated with respect to gypsum while for discharge into the sewage system the sulfate concentration needs to be reduced to less than 500 mg/L (as SO4). Acid mine water is generally neutralised with lime. Disadvantages associated with lime are the costs and maintenance of the slaking equipment as well as hazards, associated with handling of the alkali. The cost of powdered limestone (CaCO3) in South Africa, a by-product, is 50 - 60 per cent cheaper than lime. A technology has been developed where limestone is used for neutralisation of acid mine water instead of lime. This development includes: Limestone handling and dosing system. A novel, robust system has been developed where waste CaCO3 from the paper industry is slurried to a constant density. A full-scale plant was constructed to evaluate its performance (Figure 4). The dosing system consists of an inclined slab onto which the limestone is stored and from where it is slurried into a make-up tank. The density of the slurry in the make-up tank is controlled via a loadcell that measures the weight of the tank (operated at constant volume) and activates/deactivates the spray of the recycle slurry onto the slab. Integrated limestone neutralisation/lime treatment process. In this process powdered CaCO3 is used for neutralisation and partial sulfate removal of acid leached from the coal washing plant. The sulfate concentration can be further reduced to below the saturation level of gypsum (ie 1200 mg/L) through gypsum crystallisation by means of lime treatment, resulting in metal precipitation (eg Fe3+ and Al3+). CO2- treatment for CaCO3 precipitation. The pH of the lime treated water can be adjusted to pH levels of 8.5 and lower using CO2. The CO2, generated during limestone neutralisation (Equation 2), can be captured and used in this stage of the process. The first two stages (limestone- and lime neutralisation) of this technology have been implemented on full-scale at Ticor to treat the effluent of the process. The constructed plant is 80 m3/hr and differs from coal processing plants by way of not containing Fe(II) and Fe(III) in the water. The CO2-treatment stage (Stage 3) will soon be implemented at IHM as part of a program to optimise the technology for maximum benefits.

Jan 1, 2003

The State of Western Australia has a land area of 2 525 000 km2, and is well endowed with minerals and petroleum products. In 1989 - 90 these products were valued at nearly A$10 500 million.

Jan 1, 1992

Some attempt to minimise the importance of the greenhouse phenomenon. They do so by observing that global temperatures are still within the range of recent variations and that it is still not possible to predict with any certainty what the precise consequences of greenhouse will be. Both observations are true though the conclusion is dangerous. Ice core samples from the Antarctic and Greenland have established the composition of the atmosphere and global temperature over almost the last 200,000 years. The profile of these twin variables shows that they have moved together; when the concentration of CO2 has been up, the temperature has been up and when the former has been down the temperature has also been down. Over almost 200,000 years the CO2 content has ranged between lows of 190 ppm and highs of 270ppm. In just 200 years of industrialisation the CO2 content of the atmosphere has increased to 350 ppm, 50% higher that the mean of the last 200,000 years and 30% higher than at the start of the industrial age. Carbon dioxide is now increasing at 0.5% p.a. Methane, about twenty times more effective than CO2 as a greenhouse gas has doubled in concentration in the last two centuries and is now increasing at about 1.1% p.a. Methane, nitrous oxide, chlorofluorocarbons together with a number of lesser gases will double the greenhouse effect due to in creased CO2 over the next 40-50 years.

Jan 1, 1989

In the Renison Bell area of western Tas mania, a series of Lower Cambrian quartzites, shales, carbonate beds ("dolomites"), cong- lomerates, tuffs and argillites have been folded into a broad monocline whose general strike is NW-SE, plunging slightly north and dipping NE. The downwarped eastern side of the monocline is disrupted by a steep (50-800) east dipping normal fault, known as the Bassett Structure, whose throw is in excess of 500 m. A series of flat north dipping normal faults, each with a throw of approximately 50 m, further disrupts the sequence. All major faulting was pre-mineralization. A cassiterite- bearing Devonian quartz porphyry body intrudes this Cambrian sequence 2 km south of the currently operating mine. Of economic importance is the presence of three carbonate beds in the sequence. These carbonates consist of a mixture of calcite, dolomite and siderite. The No. 1 (youngest) and No. 2 carbonate beds are each approximately 15 m thick and are separated by 20 m of hematitic conglomerates and tuffs. The No. 3 (oldest) carbonate bed is approximately 5 m thick and is separated from the No. 2 horizon by 50 m of dark grey, finely laminated shales and quart- zites. Whilst the carbonates are remarkably persistent over at least 30 km2, facies changes are common and as a result of these changes, the carbonates vary considerably in

Jan 1, 1973

By D Liang, L Zhang, X He

The sulfurisation-flotation process was unsuccessful when initially applied to the oxidised Pb-Zn ore in Lanping County of Yunnan Province China. A comprehensive mineralogical study indicates that the problem is caused by the soluble salt gypsum in the Lanping oxidised ore, which produces a large amount of Ca2+ cations. The Ca2+ cations react with S2- anions (from sodium sulfide) in preference to Zn2+ and Pb2+ forming calcium sulfide, and make it difficult to form zinc and lead sulfides on the surfaces of the respective oxidised Zn and Pb minerals. In addition, the calcium sulfide formation consumes a large quantity of the available sodium sulfide, further inhibiting the sulfurisation process. The efficiency of the sulfurisation of oxidised Zn and Pb minerals has been improved greatly by the pretreatment removal of gypsum, with the added benefit of the required dosage of sodium sulfide being substantially reduced.

Jan 1, 2008

By J H. Kyle

Cyanide is a significant cost in gold processing, as well as an environmentally sensitive issue. It has been suggested that precipitation of cyanide from leach liquors as copper-iron-cyanide compounds such as Cu2Fe(CN)6 may account for part of the total cyanide consumption. This may be especially true for ores that are rich in both copper and iron minerals. Ammonia addition has been shown to decrease the cyanide consumption by copper. Cu2Fe(CN)6.xNH3 precipitates have also been postulated to form during conventional cyanide detoxification processes, using oxidants such as SO2/air, with ammonia arising as a breakdown product from the oxidation of free cyanide. The present work has examined the conditions under which such precipitates may form, particularly in gold plant process and detoxification liquors. Ammonia and pH were found to have a large effect on the extent of precipitation. The compounds that were formed were found to comprise mainly Cu2Fe(CN)6.7H2O, as well as a range of NH3-bearing variants. The stabilities of the various precipitates are important from an environmental perspective. The long-term stability of copper ferrocyanide precipitates in tailings dams may be a problem under alkaline conditions and when some free cyanide is present, elevating the measured total cyanide in solution significantly. Case studies including data from actual plants are also considered, and the importance of these effects is reaffirmed from these results.

Jan 1, 2000

The mmmg operations carried out by North Broken Hill Limited, necessitate the use of four shafts for the haulage of ore, men, and supplies. These are:-1. Blackwood's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 800 feet level plat;2. Thompson's Shaft.-British Section, which has 100 feet intervals between levels to the bottom 1400 feet level plat;3. No. 1 Shaft.-With intervals between levels:(a) 100 feet to the 800 feet level,(b) 150 feet from 800 feet level to the 1700 feet level;4. No. {2 Shaft.-2770 feet from collar to bottom plat, with intervals between levels: (a) 100 feet to 800 feet level, (b) 150 feet from 800 feet level to the 2600 feet level. (c) 170 feet from 2600 feet level to the 2770 feet level.All shafts have two cage compartments, and the No. 2 Shaft a skip installation in addition.For the control of hoisting operations an electric signalling system is installed on each shaft, and is supplemented by a counterbalanced rope pull ("Knocker line") operating a surface gong. The latter system is shown diagrammatically in Fig. 1.Two sets of electrical equipment are used per shaft. The first, shown in Fig. 2, is that operated by the braceman or...

Jan 1, 1940

This paper shows how small calculators can be used for ball mill simulations. Two calculations are examined, the first to calculate the mill parameters and the second to predict the mill product. In the case of small programmable calculators the programs for two common models are given.

Jan 1, 1976

This paper examines the concepts of risk analysis and uncertainty in open pit mine design. It describes the relationship between risk analysis and uncertainty, describes methods that can be used to quantify uncertainty, and suggests ways of reducing the geological and geotechnical uncertainties that are inherent in open pit mining.

Jan 1, 1994