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By Golding D

The Charters Towers goldfield is located in the centre of a Lower to Mid-Palaeozoic igneous complex where schistose, amphibolite-grade metamorphic rocks were intruded by multiple phases of medium grained granodioritic rocks. Several generations of mafic and felsic dykes also occur. Two distinct mylonites cut all but the youngest granitoids. Gold mineralisation occurs in quartz veins located in brittley reactivated mylonite and in sympathetic fissures in the undeformed granitoids. The gold-quartz veins occur in complex, gouge-filled, 2.5m thick zones, with minor sulfides, surrounded by zoned phyllic and propylitic alteration assemblages. Four main vein systems are each restricted to separate granitoids or contain oreshoots near granitoid contacts. No genetic relationship between the granitoids and the vein systems can be documented. The early mylonitic fabrics and the granitoid contacts played an important role in ground preparation and in the localization of oreshoots. Non mylonitized granitoids also served as favourable hosts for many of the lodes. Whole rock values of 180 of the granitoids range between 6.5 and 7.9 per mil. Hydrothermal vein quartzes have 180 values between 12.2 and 15.7 per mil. Mylonite quartzes have values of 8.4 per mil. Variation in 180 values of quartzes is in part related to granitoid host rock type.

Jan 1, 1987

By Lawson F

Chrome chemicals are commercially produced by the alkali roasting of the chrome-bearing ore chromite with sodium carbonate. In order to ascertain the influence on the extent of reaction of the replacement of Mg(II) for Fe(II) in the chromite spinel structure and the presence of acidic oxides in the gangue material, a series of roasting experiments was conducted using chromite materials from a number of different locations. The roast feeds and products were chemically analysed and the major compounds identified using X-ray diffraction and scanning electron microscope techniques.Mg(II) replacement for Fe(II) in the chromite structure does not appear to restrict the amount of "available" chromium for reaction.Under the test conditions, namely an atmosphere of pure oxygen, finely ground chrome-bearing material, a roast temperature of 950°C and the stoichiometric amount of sodium carbonate to react with the chromite, the yield of water-soluble sodium chromate was able to be expressed as %yield = 104.5 -1.58 × %AI2O3 - 2.23 × %SiO2 for chromite samples containing alumina in the range 7.8 to 27.8 per cent and silica in the range 2.9 to 7.4 per cent.

Jan 1, 1984

By N Kojola, A Vickerfält, J Huss

The possibility of using an acidic autogenous hydrogen direct reduced iron (H-DRI) slag as a basis for vanadium extraction is investigated. For a raw material to be suitable for producing high-quality FeV, the vanadium oxide content should be sufficiently high and the phosphorus oxide content in a tolerable range. Therefore, the feasibility for vanadium extraction relies on fulfilling two demands: the predominate partitioning of phosphorus to the metal and vanadium to the slag. Correspondingly, the behaviours of phosphorus and vanadium in the Al2O3-SiO2-FeOx-VyOz-P2O5-Fe system were studied experimentally. Slag, 10 g, was put in contact with liquid iron, 30 g, for different durations (2–24 hrs) in closed alumina crucibles at 1873 K. The slag composition was varied between 33.1– 49.3 wt per cent Al2O3, 27.1–46.7 wt per cent SiO2, 16.6–30.1 wt per cent FeOx, and 2.5– 8.8 wt per cent V2O3. The equilibrium phosphorus distribution was 0.42, while the vanadium distribution ranged from 7.6 to 43.4, increasing with the Al2O3- and the FeOx-content.

Jun 19, 2024

By M Darby, B Burdett, F Lovell

The results of the process control improvement project aimed at improving the quality of Australian Bulk MineralsÆ (ABM) iron ore pellets produced by four vertical shaft furnaces are very positive. These results are achieved through process stabilisation and optimisation, improvement in process monitoring and taking early corrective actions when operating variables were outside the target ranges. A number of benefits are obtained from this project. These benefits include: More consistent and improved pellet quality. The average cold compression strength (CCS) value of pellets produced during the eight-month trial is 260 kg/pellet, which is 16 kg/pellet higher than that produced during the 12 months prior to the trial (244 kg/pellet). Reduction in the heat input by eight per cent, from 727 MJ/tonne to 668 MJ/tonne. Reduction in bentonite rate by six per cent, from 7.1 kg/tonne to 6.7 kg/tonne. Increase in the furnace throughput rate by four per cent and additional production of 10 000 tonnes per annum through process stabilisation. Better understanding of the process behaviour. This knowledge is valuable not only for setting the target operating conditions but also for developing the ABM expert system to control the process.

Jan 1, 2005

By R B. Evans, M G. Townsend

In Northland, New Zealand, localised large deposits of halloysite clay have been produced by in-situ alteration of rhyolite volcanics of Pliocene or Pleistocene age, which were erupted through pre-Pliocene sedimentary strata and locally through Pleistocene basalt; and which were subsequently onlapped by further basalt flows. Alteration to clay has been a result of both hydrothermal and of meteoric processes, and decreases in intensity of alteration with increasing depth. The raw material is crushed and fractionated to produce a product of less than two micron particle size, which is of exceptional whiteness and brightness. The unique properties of the clays render them highly desirable for specialised ceramic purposes.

Jan 1, 1990

THE Australian States and New Zealand have for many years provided instruction in mining, metallurgy, geology, and their allied subjects through their Universities and Schools of Mines. Though such education has been provided at considerable expenditure, there is no legal recognition whatever given to the holders of degrees, diplomas, or certificates granted by the authorities controlling these educational institutions. Certain of the, Australian States and New Zealand require, however, that mine managers and other officials employed by the mining industry shall 'hold' certificates granted by their respective Mines Departments.The position at present is that each educational institution is practically a law unto itself, and therefore in many ways there is a want of uniformity amongst institutions all aiming at the same result the training of mining men. The object of this paper is, in the first place, to point out certain aspects of this want of uniformity, and thereby how disabilities accrue. Some points in connection with the granting of State certificates will also be...

Jan 1, 1915

By P Williams, S Flynn, R Birchfield, R Simcock, R Toft, P Comeskey

Direct transfer, or community translocation, comprises salvage and replacement of intact æsodsÆ of vegetation together with underlying soil. It has been applied to New Zealand mine sites restoration of native grasslands, wetlands, scrub lands, and forest. It is an equivalent technique to æinstant lawn or tree gardenÆ, commonly used in urban landscaping. Two to six m2 scoops of vegetation, with up to 0.7 m of soil attached, and including root plates of trees and shrubs, are relocated from stripped areas ahead of mining to sites prepared for restoration. Direct transfer uses hydraulic excavators or face shovels and dump trucks, possibly with the aid of bulldozers and other earthmoving machinery. The main advantages of direct transfer, compared with sowing or planting systems for mine site restoration, are the recycling of plant and soil materials which were often wasted by burying under overburden materials, a significantly faster revegetation process, and restoration of the whole ecosystem (plants, animals, birds, invertebrates, and microbes). The main disadvantages are higher costs of stripping and dumping, a greater degree of machine operator skill required, and scheduling becomes critically important. To illustrate the key principles, this paper gives examples of successes and failures of the technique for a variety of New Zealand mining situations. Direct transfer has been successful for a range of communities, from fern wetland and sub-alpine tussock grasslands to 5 m-tall beech forest under storey and seral shrub land, and from temperate to sub-alpine climates. Successful examples show both rapid recovery of indigenous vegetative cover and conservation of habitat for birds and invertebrates. Failures have resulted from excessive death of plants because of inadequate soil salvage depths, acidic leachates, inappropriate handling of stripped sods by inexperienced machinery operators, or prolonged drought conditions immediately following relocation. Change in plant species composition has occurred where clumps of vegetation are too far apart, or shifted plants were too small - in both cases invasive weeds have smothered the original vegetation. Changes in hydrology can also have significant impacts. Our experience indicates that the advantages of direct transfer far outweigh the disadvantages and is now used as the preferred restoration method, where practicable, at mines where it has been trialled.

Jan 1, 2000

Exploring long-term future possibilities for your business and methods for achieving them are critical functions of leadership. More than ever, strategic initiatives today have to be planned and delivered in an environment of disruptive change û driven by shifting business or regulatory imperatives, new technologies and global economic change, and diverse stakeholder interests. The notion of The Future as a single inevitable outcome is obsolete. There are many possible futures. This paper explains an innovative process û known as scenario planning û to help executives in the construction and testing of longer-term strategies to deal with uncertainty.

Jan 1, 2006

By J A. Wells, K G. Thomas, R F. Dewhirst

"One of the contributing factors to the extreme cost escalation in the first decade of the 21st century was the increase in the amount and cost of engineering work that went into studies and projects. Various reasons for this were identified, including unsatisfactory productivity due to a shortage of experienced/qualified engineers, the increased complexity and infrastructure requirements of many projects due to location, metallurgy that is more challenging and increasing environmental and social requirements. These conditions often led to unsatisfactory project results in terms of cost and schedule blowouts and created a loss of confidence – both internally and externally – in the industry’s ability to complete projects on time and on budget.Technical fundamentals aside, the experience and effectiveness of project teams has had, and continues to have, a major impact on project cost, schedule and ramp-up to nameplate capacity and operating parameters. There are unfortunately too many examples of where project teams have not been as effective as they could or should have been, all to the ultimate detriment of the project.Using the authors’ extensive experience on both owner’s and engineer’s teams, this paper discusses some of the main reasons for suboptimal team, and hence project, performance and offers thoughts on how best to build and maintain project teams. The analysis and conclusions drawn are built around the Tuckman model of group development known as ‘forming-storming-norming-performing’, which was first proposed some 50 years ago. Given the importance of good teamwork to project success, understanding how project teams grow and become efficient and productive is an essential part of good project management that should receive more attention.CITATION:Dewhirst, R F, Thomas, K G and Wells, J A, 2016. Building and maintaining effective project teams, in Proceedings Project Evaluation 2016, pp 38–48 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By S Lloyd, J Chow, S Fitzpatrick, D Greenup

The Tropicana deposit was discovered in 2005 after AngloGold Ashanti followed up an unexplained gold-in-soil anomaly. Discovered in a remote, barely-explored area of Western Australia not previously thought prospective for gold, Tropicana is the most significant gold find in Australia for more than a decade. The new, large scale open pit gold mining operation will produce an annual production of around 330 000 to 400 000 oz over a ten year mine life mining around 60 Mt/a.Process plant construction started in early 2012 and is due to finish in the December 2013 quarter. The mining contract was awarded to Macmahon Holdings (Macmahon) and mining commenced in July 2012 using conventional drill and blast, truck and excavator open cut methods.As a construction and start-up project in a greenfields location, the establishment of mining activities at Tropicana Gold Mine (TGM) involves the implementation of technical and operational systems, including the mining contract. Some of these systems and likely challenges were identified during earlier studies, while others were not foreseen until they were encountered. Alternatively, the time frames around implementation change depending on the changing knowledge of the project and industry environment. These systems include those common to the industry and those specific to the operation and location.This paper examines the implementation and development of a number of the systems specific to the establishment of mining operations, including the history, process and some outcomes. Although expected to be discrete systems to implement, they become interdependent. This linkage between systems further offers challenges and opportunities for the continuous progress of each system and for TGM as a whole.CITATION:Chow, J, Fitzpatrick, S, Greenup, D and Lloyd, S, 2013. Tropicana Gold Mine - mitigating the challenges of a mining start-up, in Proceedings World Gold 2013 , pp 51-60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

Valuable Components Recovery from Lead-Zinc Metallurgical Slag

Sep 13, 2010

A numerical method for discriminating between replacement and sedimentary processes is applied to a folded stratiform sulphide occurrence. It is shown that numerical treatment of chemical analyses from a single diamond drill hole allowed a rapid assignment of the ore to the syngenetic sedimentary class and thereby enabled a revision of the evaluation program concerned with consequent reduction in costs.

Jan 1, 1973

By Y Yamaguchi, S Nomura, M Matsumura, C Kamijo

In order to increase productivity and decrease reducing agent rate (RAR) of blast furnaces, slag content of sinter ore must be decreased. However, gangue content in iron ore tends to increase because of resource depletion. Therefore, amount of high-grade concentrate in sinter ore feeds should be increased, but this situation causes a decrease in permeability of the sintering bed so that the productivity of sinter process decreases. In order to increase the amount of concentrate, NSSMS has developed the P-type separate granulation method, RF-MEBIOS and SPEx II technologies. These technologies have been introduced to actual sintering machines. In this report, a new technology using microparticles of iron ore is proposed to increase the amount of concentrate in sinter blends. Basic experiments simulating the sinter making process using microparticles of iron ore were undertaken. Crushed pisolite, containing >60 wt per cent -10 µm was prepared for binder. The pisolite microparticle binder was mixed with another Australian sinter feed ore in a high-speed agitating mixer. They were mixed for about one minute, and then granulated using a pan pelletiser. After that, they were added to another raw material mixed by a drum mixer, and then charged in a pot for a sinter pot test. As a result, when the amount of concentrate increased from 13 wt per cent to 20 wt per cent, productivity was almost kept constant using pisolite microparticle binder.CITATION:Kamijo, C, Yamaguchi, Y, Matsumura, M, Kawaguchi, T and Nomura, S, 2017. Development of an iron ore microparticle binder for increasing the concentrate content of sinter blends, in Proceedings Iron Ore 2017, pp 69–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Taking the third meridian as the eastern boundary of proved payable auriferous country, there is a stretch of country, nearly 600 miles in width, in which no appreciable amount of gold has yet been discovered. Many prospectors have attempted to .penetrate or traverse it, but comparatively few have thought it worth while proceeding with the examination.The desolate stretch of waterless desert-the very few and insignificant outcrops through the sand and the almost total absence of feed for horses have, combined, presented such a barrier as to preclude prospecting. The few who have traversed the country are eloquent in denunciation, yet their investigations, necessarily hurried, are not quite satisfactory. The absence of water utterly debars a thorough examination being made. Gold may exist in quantity, yet it would have to be extraordinarily plentiful to render its obtaining profitable. Too fantastic is the idea of its ever being a mining district; shifting sand to traverse, utter absence of wood and water render the notion absurd. Likely looking belts occur, but these in all "cases are small and remote from water. Gold has been obtained from likely look ing quartz reefs, but only by fire assay, and then but a few do to the ton. Without wishing to be pessimistic, I would unhesitatingly declare that east of the third meridian, and between the parallels 25 and 30 degrees in West Australia, there is no gold in payable quantities.

Jan 1, 1901

Permitting, engineering and evaluation, detailed design and construction aspects of the Golden Cross goldmining project in New Zealand are briefly reviewed. The extremely lengthy and complicated governmental approval process together with the delaying tactics of opponents of the project are outlined and comment is made on aspects of the draft legislation proposed as part of the overhaul of New Zealand's resource management laws.

Jan 1, 1990

Over the past few years, there has been an emerging relationship between business and civil society, especially NGOs. This relationship has the potential to bring about significant change, identifying common ground between commercial and societal interests. The mining industry has been a leader in acknowledging the need for community consultation and engagement. This paper argues that partnerships can make a very significant contribution to the industry as it comes to terms with the dilemma of an open economic system pushing against a closed ecological system.The paper will pose a number of questions: where is the locus for debate about sustainability in the mining sector?; how well embedded within companies are the new competencies that Leon Davis first identified in 1995 for the mining sector?; how has education for mining engineers or exploration geologists changed to prepare people for what are very different expectations within the working environment?; how well is the industry doing in managing its own environmental impact and what is its responsibility to an agenda for sustainability which extends beyond its own operations?;and how can NGO partnerships contribute to more sustainable outcomes? The paper does not aim to answer these questions, but to explore them in the hope that the issues and possibilities raised will contribute to advancing progress towards sustainability within the industry.

Jan 1, 2002

By P L. McCarthy

To design and operate a successful mine the technical specialists must agree on what is ore, what is not ore, and how quickly the orebody is to be mined and processed. These seemingly simple questions defy easy analysis and can push mining engineers, geologists, metallurgists and others to the limit of their capabilities. The questions are rarely addressed adequately in feasibility studies or in operational planning. To optimise the mine and processing plant requires proper determination of cut-off grades or values, prediction of feed variability on an hourly, daily or longer basis, right-sizing the mining rate for optimum product quality, understanding the cost of capital and the expectations of investors, and many other considerations that involve geology, geotechnical engineering, mining, metallurgy, environmental effects and economics. This paper addresses the key matters that should be considered as inputs to the practical issues of metallurgical plant design and operation.CITATION:McCarthy, P L, 2015. Integrated mining and metallurgical planning and operation, in Proceedings MetPlant 2015, pp 35–45 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Rixon K. L

Hargraves (1983) has reviewed the phenomenon of instantaneous outbursts of coal and gas with special attention to Australian occurrences. The purpose of this discussion is to highlight some problems and omissions in his review that reflect particularly on the authors' structural geological investigations of outburst-prone coal seams.It is surprising to find that much of the authors' reported work has either been glossed over or the results distorted by Hargraves (1983) and it is, therefore, important to clarify the contribution that structural analysis of coal seams can make.For many years it has been known that faults provided preferred loci for gas outbursts (for example, Briggs 1920-21) but the roie that faults played in outburstprone seams was unclear. The present authors reviewed the association of faults and outbursts drawing upon local investigations and the world-wide literature (Shepherd et aI., 1981), and discussed some wideranging aspects that result from the high coincidence of faults and outburst sites. Without repeating large segments of this article the authors will discuss four aspects of coal seam faulting and fracturing.

Jan 1, 1983

By K Niyomjinda, B Etschmann

Chatree Gold Mine is currently the only modern day gold mine operating in Thailand, and is situated approximately equidistant from Chiang Mai in the north and Bangkok in the south. Environmental guidelines set by the Thai authorities require Chatree Gold Mine to achieve a Total Cyanide level of 20 ppm or less in the process plant discharge slurry stream prior to release into the tailings storage facility. This paper describes both the initial difficulties faced in achieving compliance on this limit utilising the conventional INCO SO2/Air cyanide destruction system and the subsequent process improvements initiated to both the leaching process and the standard INCO process to achieve the current compliance levels of approximately 99/100 shifts. Improvements were focussed on the dual aspects of reducing the formation of WAD cyanide and ferrocyanide species in the leaching circuit coupled with process changes to improve removal of the ferrocyanide species from solution during the cyanide reduction stage.

Jan 1, 2004

By B Hiebl, J Martens, L Petzold

A research team at the Iron and Steelmaking department at Primetals Technologies has established new upgrading measures for improving the efficiency of the beneficiation process in ironmaking plants, relying largely on pre-existing equipment. After the upgrade, the iron content in the final iron ore concentrate was shown to be significantly higher. Remarkably, the costs for employing the respective measures are surprisingly low.This case study is based on a Kazakh iron and steel producer, whose beneficiation process is currently generating a magnetite concentrate with a final iron content of 65.65 per cent. The study shows that the implementation of Primetals Technologies’ intelligent modification measures to the current beneficiation process, the realisation of more effective dewatering, and the utilisation of an innovative binder lead to an increased iron content in the resulting pellets, reaching a concentration of 69.17 per cent (iron ore concentrate) and 66.5 per cent (pellets).The current operation consists of three closed circuit grinding stages, four stages of low intensity magnetic separation, vacuum disc filters and straight-grate pelletising. By dividing the slurry after the second stage of grinding and the third stage of low intensity magnetic separation, it is possible to divert the more iron-rich fines before they would enter the third grinding stage and the fourth stage of magnetic separation. This then reduces the load on the existing third stage ball mill. Afterwards, the ground material is treated in an additional low intensity magnetic separator and mixed with the previously diverted fraction of the fines. An improved filtration procedure, combined with the application of a highly sophisticated binder, further reduces the amount of additives needed, so that a genuine direct reduced (DR)-grade iron concentrate is produced as a result.All laboratory, pilot and pelletising test work was executed at Primetals Technologies’ laboratories in Austria.CITATION:Martens, J, Petzold, L and Hiebl, B, 2017. Enabling iron ore concentrate for the production of direct reduced iron with pre-existing beneficiation lines, in Proceedings Iron Ore 2017, pp 227–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017