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By N H. S Oliver

Five major veining events have been identified within the area surrounding the Mount Whaleback microplaty hematite deposit. These veining events can be directly correlated to the established deformation history of the Hamersley Province (Brown et al, in press). Vein formation temperatures of 203 to 231¦C have been obtained from primary fluid inclusions within veins which formed around the postulated time of ore formation. Preliminary proton induced x-ray emition (PIXE) analysis of these inclusions indicates KCl is the dominant salt species with varying levels of Ca, Fe, Ti, Mn present. It is suggested that some of these veins may have formed from feeder or effluent fluids from microplaty hematite ore formation.

Jan 1, 2002

By B Rosemberg, F Lemos, A J. B Dutra

The chemistry of cyanide solutions is complex, this complexity being responsible for the ability to act as complex-forming agents in metal dissolution processes, among them gold and silver. Such ionic species are used in hydrometallurgical processes, in particular in gold extraction and electro-plating. Due to the high toxicity of cyanide, the discard of effluent from processes and/or industries demands rigorous treatment so as to minimise its concentration. Among the conventional chemical treatment of such effluents one can mention SO2/air; biological degradation; oxidation by using hydrogen peroxide; oxidation by sodium hypochlorite, etc. However, the electrolytic recycling process is also promising for cyanide recovery and offers the possibility of recycling it to the aforementioned industrial processes. Such a process does not use additional chemicals but enables direct re-utilisation to the main process aiming at adjusting the cyanide concentration.

Jan 1, 2002

By A M. Sardo, D E. Sinnett

This study uses the Q Method to examine how those living in former metal mining landscapes value this heritage and their preferences for the long-term management of mine waste. Such sites are often perceived as derelict or degraded, and of very little value. It is therefore assumed that their reuse, for example for development or recovery of metals, is likely to be beneficial. There are around 5,000 former metal mines in England and Wales, many of which are protected for their ecological, geological or cultural value. The Q Method is particularly suitable for issues where there is no consensus of opinion. We asked 38 residents of six mining areas in England and Wales to ‘sort’ a series of statements based on their resonance with the resident’s perspective; this is the Q sort. The statements covered a range of opinions of the mining legacy, its value and options for its management with a particular focus on the potential for metal recovery from the wastes. Analysis of the Q sorts revealed five perspectives on the mining heritage. All placed a high value on the cultural and ecological value of this heritage, however, they differed in their priorities for long-term management. For example, emphasis was placed on either nature conservation, cultural heritage, water quality or the opportunity for job creation through reworking the mines. Cutting across these themes there were also differing perspectives on the role of experts and local people in shaping the future management of the wastes. This research suggests that the views of local people are nuanced; they value their mining heritage but opinion is split on the most effective way to manage these sites especially where there is an impact on water quality.CITATION:Sinnett, D E and Sardo, A M, 2018. Former metal mining areas in England and Wales – local residents’ preferences for the management of wastes, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 126–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By S Sandover, D Glenister

Alcoa World Alumina Australia is committed to sustainability principles as a basis of business success into the future. In March 2001, Alcoa Inc chairman Alain Belda announced a set of far-reaching environmental goals for the corporation, with the challenge that they should be achieved in ways that enhance economic and social performance, while substantially reducing environmental impact. Application of Cleaner Production methods is seen as the key to achieving these joint objectives. In Australia Alcoa has launched a co-ordinated effort to accelerate our application of Cleaner Production principles to delivering cost-effective in-process solutions to environmental issues. Our Western Australian Operations are a signatory to the WA Cleaner Production Statement, through which we provide a Cleaner Production Plan to the State Government on a voluntary basis. This paper describes in general terms AlcoaÆs goals, achievements and directions in applying Cleaner Production to enhance business performance in the economic, environmental and social dimensions. Quantification of the benefits and tracking of progress in quantitative terms is a key challenge for the future

Jan 1, 2002

The International Symposium-cum-Workshop on Management andControl of High Gas Emissions and Outbursts in Underground CoalMines was held in Wollongong in March 1995. Coverage of high gasemissions was virtually confined to instantaneous outburst implications, essentially seam gas pre-drainage. Globally, instantaneous outbursts have been known for 150 years, andthe first Australian outburst occurred in 1895 and Australian occurrences and mines affected have increased since. Few significant coal producing countries are unaffected. The coals affected range in rank from lignites to anthracites. Geological disturbances are the most likely environments for occurrences. The most likely mining geometry is of virgin headings, with some occurrences on longwalls and in other situations. Widespread research into many aspects of the problem has yet to produce a generally accepted explanation. Explosive inducement is a well-known control. Apparently high advance rates increase face gassiness and create higher stress abutments, increasing proneness. The most popular preventive measure, pre-drainage of virgin coal ahead of faces has produced highly successful very long hole drilling performances but without the precision necessary for accurate geometric hole patterns, despite quite sophisticated drilling equipment and hole surveying instruments. For the future, more precise degasification is sought, even from the surface, together with rapid face coal gassiness assessments to confirm lowering below threshold values, as well as other proneness lowering measures, perhaps related to new heading and longwall geometries and to new equipment to provide them. But above all, safe management plans are required for each operation, to safeguard the miners and their working environments, and thus to protect underground coal mining from this mounting threatening problem.

Jan 1, 1997

Retreating Cu-Mo Rougher Tailing by Flotation for Concentration of Copper and Molybdenum

Sep 13, 2010

By F H. S dosSantos, R L. C Santos

The main objective of this work was to develop, at a laboratory scale, a process for treating residues from the settling stage of water treatment so as to remove and recover the aluminium as sulphate. The chemical analysis of residues from different water treatment plants indicated that the aluminium content varied from 15 to 20 per cent w/w. By using the appropriate experimental conditions, it was found to be possible to leach most of the aluminium content. The pH value of the recovered water was suitable for it to be recycled to the water treatment process and the residue appears to be suitable as raw material for bricks. The process developed contributes to the sustainability of the water treatment process.

Jan 1, 2002

By E N. Sajin

The final arsenic bearing waste products at the majority of metallurgical and chemical enterprises are cakes in which arsenic is present in the form of calcium arsenate. Burial of cakes demands construction of special burial sites and does not guarantee reliable protection from arsenic penetration into the ground and surface waters. Under laboratory conditions we developed technology for processing calcium arsenate cakes with obtaining low toxic products suitable for long-term storage, meeting environmental requirements. The investigations have shown that thermal processing of briquetted mixtures of cakes containing 15 - 20 per cent weight of pyrite under the temperature of 873 - 923¦K during 45 - 60 minutes gives briquettes sufficiently hard for transportation and long-term storage. Arsenic, under high sulphidisation temperature is bonded into low solubility non-volatile iron sulphide bearing compounds having chemical properties similar to the natural arsenic compounds. Solubility of the obtained products in neutral, acid and alkaline media was investigated during long period of time (three to 12 months). It was determined that arsenic content in the solutions did not exceed the norms for cultural and welfare basins and fish-ponds.

Jan 1, 2002

By P W. Wypych

The iron ore industry faces significant challenges in the control of dust to meet emissions regulations and goals, as well as ensuring sustainable operations. This paper describes some of the different techniques and innovative technologies that are being developed and implemented to improve the suppression of airborne dust, specifically through the use of high energy micromist sprays. The utilisation of computational fluid dynamics (CFD) modelling and simulation is identified and described as a key enabling technology for an improvement in dust suppression solutions both from a level of understanding the source and flow of dust emissions, and for the development of new systems that can be used in the iron ore industry. CFD modelling is shown to be effective for modelling both spray dispersion and cross-wind effects, allowing designers to develop high-efficiency dust suppression systems with a greatly improved level of confidence when compared to traditional techniques. New high energy micromist technology is also outlined as a key element in developing high-efficiency dust suppression systems. Experimental results and industry applications are presented to demonstrate the significant improvements that can be achieved in suppressing or reducing airborne dust emissions.CITATION:Roberts, J M and Wypych, P W, 2017. Research into improving the efficiency of water spraying airborne dust control techniques in the iron ore industry, in Proceedings Iron Ore 2017, pp 359–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Bratt G. C

When zinc is electrowon from concentrates or residues of high manganese content, the zinc sulphate electrolyte may contain high levels of manganese. The manganese level is usually controlled by removal of manganese at the anode as the dioxide during the zinc electrodeposition stage.By increasing the temperature of an electrolyte containing 8 gll manganese from 35°C to 90°C, decreasing the acidity from 100 gll to 30 gll, reducing the current density from 432.A.m-2 t6 286 A.m-2 and using new lead anodes containing over 0·75 per cent silver, the current efficiency for manganese dioxide removal was .increased from less than 1 per cent to over 20 per cent.At the same time the current efficiency for zinc deposition was maintained above 90 per cent by additions of high molecular weight cationic polyacrylamides to the cell. By utilization of these conditions in a small number of cells, the manganese level in the circuit could be economically concrolled to any desired level.With these conditions the formation of the dioxide changes from an indirect route, via Mn04-, to a direct oxidation of Mn2+ to Mn02.The incorporation of impurities such as Pb, K, NH4, Cu, Ni, or Fe makes the deposit unsatisfactory for direct use in Zn - Mn02 dry cells. The deposit structure changes from cryptomelane at low temperature to y3-Mn02 at high temperature.

Jan 1, 1975

Prediction of fragmentation by blasting is most commonly based on theassumption that a single distribution of pre-existing discontinuities is present within a blasted rock volume and that the underlying mechanism of failure is tensile failure. It is assumed that the tensile stress field created by a blast initiates and extends radial cracks around the blastholes. Interaction between radial cracks from different blastholes and the free surface creates rock fragments. In reality, fragmentation of the rock occurs due to two mechanisms.One is related to the compressive-shear failure of the rock (mainly rock matrix) close to the blastholes, while the second mechanism is the previously mentioned tensile failure of the rock mass. The secondmechanism of failure occurs in the form of extension of the larger cracks in the region beyond the crushed rock, and this type of fragmentation occurs after the crushing phase. In the case of hard rock or blasting where the extent of crushing is minimal, the currently used prediction methods give a reasonably good result. However, there are many blasting conditions where the amount of rock crushing is significant. In the case where fragmentation of the given rock volume occurs dueto two different mechanisms, modeling of the rock fragmentation with a single distribution function is not appropriate. To model the fragment size distribution generated by two different mechanisms, it is necessary to use a two-component fragment size distribution function and a scaling parameter that will determine the proportion of the fragmented volume created by each mechanism. The purpose of this paper is to present results of blast fragmentation modeling based on two mechanisms of failure. The two-component model (TCM) utilises experimentally determined parameters from small scale blasting and parameters of the Kuz-Ram model, for more accurate prediction of the complete rock fragment size distribution curve. The methodology is such that it is possible to predict complete fragment size distribution, including fines, of ROM product for a future mine, at the feasibility phase of mine design.

Jan 1, 1999

Recovery of Vanadium from Stone Coal Through an Environmentally Friendly Acid Leaching Technology

Sep 13, 2010

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 P Meehan, R McAree, Z Guan

Equipment maintenance is 30 - 50 per cent of the operating costs for a typical mining company. While this is substantial, its importance is beyond its significance as a cost heading. Modern mining requires large amounts of investment in capital infrastructure and equipment to produce a product sold at a low unit cost. To stay competitive, such a business has to focus on full realisation of its capital investment, ie sustained production at high levels. Maintenance plays an essential role in achieving this goal. Mining companies typically use a mix of breakdown or corrective maintenance, planned maintenance, and some condition-based maintenance. The share of breakdown maintenance has been coming down through more effective planned maintenance and better condition monitoring tools. Planned or preventive maintenance (PM) is playing an increasingly important role in todayÆs mining maintenance. This is the suite of inspection and repair/replacement actions performed at scheduled time intervals as part of a preplanned activity. The activities are scheduled well in advance and, usually, the current wear-state of the machine is irrelevant. For example, the replacement of a major gear may have been planned 18 months in advance; replacement is carried out when the time comes regardless of the actual condition of the gear. The PM costs are significant and include direct cost of parts and labour as well as the opportunity cost of lost production while the machine is under maintenance. It is important to identify the optimum PM effort because over-maintenance should be avoided as much as under-maintenance. A new concept called severity-based maintenance is introduced in this paper. We have seen that measuring equipment ageing in mining merely by counting the engine hours is a very imprecise way of planning and scheduling maintenance because the damage accumulated in one hour varies enormously from operator to operator and with changing pit conditions. We recommend continuous monitoring of duty on all major equipment. This is feasible without having to fit out the machine with an army of sensors because most of the physical sensors required by dutymeters are already installed and maintained as part of the existing performance monitors. While the investment is modest, the potential benefits are huge and can be grouped under three headings:Immediate benefits will come from providing operators with direct feedback on the effect of their behaviour on machine health and training them to use this feedback to correct their operating style. The equipment can operate closer to the limits of capacity, producing more without unduly sacrificing the availability by monitoring and controlling the severity of the operation, ie the duty on the machine. Longer term benefits accrue from establishing correlations between actual time to failure data and measured equipment duty and using these correlations to optimise maintenance effort as well as planning new equipment purchases and warranty conditions.

Jan 1, 2002

This paper is a collection of thoughts and frameworks. It addresses a simple question: æIf we are to believe the large number of people and institutions indicating that humans are destroying the Earth and that the end is nigh, why do we bother trying to be sustainable?Æ The paper lays out evidence for the existence of multiple hazards to global society. The existence of a hazard alone is insufficient to make an assessment of risk. Risk estimates are required to support decision-making. An approach to assessing risk is provided and some limited data are presented. A new ædefinitionÆ or statement of what sustainability (in a broad sense) might have become is then given. A decision framework for guiding decision- making about the risks is developed. This framework includes a definition of leadership with inherent implications for what determines whether a leadership position by title is actually leading. The paper concludes by offering a view of minerals industry sustainability and considerations around maturity in the current economic situation. It is hoped that by placing this collection of frameworks around sustainability, a supporting structure emerges that will facilitate action. It is proposed that action taken in this way will be more effective than reaction to regulation or even social license to operate imperatives because it is driven by a more holistic view of the challenges and the potential roles of individuals û all of whom are potential leaders at some scale of action.

Jan 1, 2009

By Y Xiao, C Lei, C Shu, W Wang, K Wang, J Deng

To investigate the effect on coal spontaneous combustion with high geo-temperature, an experimental apparatus was developed to measure characteristic parameters of two kinds of coal samples at different temperatures: one was 40°C (G coal sample) and the other was a rising temperature from room temperature (C coal sample). Based on the relationship between CO concentration and the temperature variation, a calculation model of the apparent activation energy of coal was established. The results indicated that the oxygen consumption rate, the generation rate of CO and CO2, and heat release intensity of G coal sample were higher than C coal sample. This trend was more and more obvious as the temperature increased. Furthermore, the apparent activation energy of G coal sample was lower than C coal sample, especially at low temperature stage, which demonstrated that the more the oxidation and exothermic reaction of G coal sample was enhanced, the less energy was required to break the barrier of oxidation reaction. Under the same condition, the speed of oxidation reaction was faster for the coal in the high geo-temperature environment, which was more liable to spontaneous combustion.CITATION:Lei, C, Deng, J, Xiao, Y, Shu, C, Wang, K and Wang, W, 2017. The effect of high geo-temperature environment on spontaneous combustion – an experimental study, in Proceedings Australian Mine Vent Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Beneficiation of Iron Ore - Washing with Surface-Active Agent The stability of the dispersed phase in 10 wt per cent slurry of iron ore slime and fines was studied at pH 5 and different concentrations of surface-active agents. The behaviour of the dispersed phase of iron ore slime and fines is different for different surface-active agents. The improvement of iron value of slime and fines in the presence of surface-active agent is best realized at pH 8, where the Al2O3/Fe and Al2O3/SiO2 ratios in the concentrates are appreciably reduced. The polar functional group like -COO- interacts with hematite surfaces and forms outer- and inner-sphere surface complexes depending on the suspension pH and adsorbate.

Sep 13, 2010

By V Cullinan, D Buchanan

The Brunswick plant is located in Costerfield, approximately 40km east of Bendigo in central Victoria. Crushing, grinding, gravity gold concentration and flotation methods are used to produce a saleable gold concentrate and an antimony-gold flotation concentrate. This paper discusses the improvements made within the processing plant which have resulted in a 99% increase in throughput over nameplate capacity of 6 250 average tonnes per month to 12 445 average tonnes per month and increases of 12% gold (from 2007 average of 78% to 2014 average of 90%) and 16% antimony recovery (from 2007 average of 79% to 2015 average of 95%). This combined effort has resulted in an increase of equivalent gold ounces (AuEq oz) produced from 2010-2014 of 15 872 to 82 574 – a 66 702 increase.AuEq oz= Au oz +Sb t × Sb (US$/t)Au (US$/oz)CITATION:Buchanan, D and Cullinan, V, 2015. Improvements in bi-metal production at the Brunswick Plant, Costerfield, in Proceedings MetPlant 2015, pp 267–272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

This paper talks about the experiences of groups we have worked with over the last few years in the Asia-Pacific region (Australia, Canada, New Zealand and Papua New Guinea) and the ways that they have worked to bridge the divide between traditional and introduced structures, governance at a regional level and the introduction of traditional values into monitoring and evaluation practices. In doing this these groups have created structures and processes which have helped them engage both more effectively with external stakeholders while maintaining the legitimacy of their own operations with their own constituents. These are important ideas for those involved in the mining industry that could provide a number of very tangible benefits to mining firms and their engagement with these kinds of groups.

Jan 1, 2009

Any hypothesis for the origin of the Otago gold-quartz lodes must account for the following observations. 1. Southeast of Glenorchy, where the schists hosting the lodes are comparatively unaffected by Neogene Alpine Fault deformation, the dominant strike of the vein systems is NW-SE, parallel to the axis of greatest post-metamorphic uplift in the Otago Schist belt (Paterson, 1986). 2. The lodes are fault-hosted, with some developed along steep, low-displacement normal faults (eg Barewood, Bendigo, Nenthorn), implying NE-SW extension, and some developed along low-angle thrusts (eg Macraes) implying, in apparent contradiction, NE-SW contraction (Teagle et al, 1990). 3. The mineralising fluid was of metamorphic origin (McKeag and Craw, 1989), but while some of the lodes developed in a mesothermal environment at considerable depth (eg ~10 km for Macraes), others appear to have formed at very shallow depth (eg <1 km for Nenthorn) (Craw and Norris, 1988). 4. The timing of the mineralisation is generally poorly constrained but postdates the main Rangitata schist metamorphism. It probably initiated during early Cretaceous exhumation and unroofing of the schist belt (140 - 120 Ma?) and may have continued well into the Tertiary (Craw, 1989). Estimates for the relative ages of the different lodes are largely speculative but, based on pressure estimates from fluid inclusion studies, Macraes likely represents the deepest and oldest lode system while Nenthorn (just 12 km to the southwest) is perhaps the shallowest and youngest (Craw and Norris, 1988).

Jan 1, 1992