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A vital ingredient in ensuring that metals exploration companies, working in the developing countries of thePacific Rim, support the development of national geologists is making such a learning program cost-effective. There is a wide spectrum of learning needed in the development of these explorationists: the technical and conceptual skills to carry out exploration efficiently, the professional and managerial skills to apply the exploration in the work situation, the personal attributes required to manage their exploration effectively, and a company organisation that allows them to learn and use these skills and attributes.

Jan 1, 1995

For the purposes of this discussion it is assumed that contributors should express the thoughts that arise from their personal experience. So wide is the range of mineral deposits, and so varied the methods employed in their discovery and development, that no two geologists are likely to have been impressed with the same applications of their science. The author's own personal experience has been, during recent years at least, very largely concerned with the broader aspects of the employment of scientific method and geological knowledge to the problems of exploration and exploitation, for the guidance of the general public and governmental authority rather than of mine executives and directors. The view-point thus reached is likely to differ in many respects from that of men who are much more intimately concerned with the mining problems of a single metal or a single mining field, and for this reason a statement may perhaps supplement those from others whose experience has been markedly different.It may well happen that, at some not distant date in the future, when systematic and comprehensive instruction in economic geology is embodied in the courses- prescribed for mining engineers during their years of training, the author's comments will be quitesuperfluous; but at the present time they appear to him to call for expression.The Need for Training of Mining Men in Economic Geology.Contact over a period of many years with mining men who have had different kinds of training and experience has been convincing that there is a general reluctance to acquire a full rational understanding of the geological factors involved in exploratory and developmental problems. The correction of this attitude is regarded as vital to the industry and it is necessary to insist that the outstanding requirement of the present day is the utilization of all branches of geological, investigation in the field and the laboratoryby men who have had systematic and specialized training in these matters. The science of geology is many-sided, but is, nevertheless, whole and essentially indivisible. No one can afford to disregard any fraction of its content 'or any of its methods of investigation.The greatest advances have been made in the understarnding of the occurrence of mineral deposits by those whose knowledge Qfbasal principles, has been soundest, whose endeavour has been to ascertain all their relationships in space and time, whose attention to detail of all kinds has been keenest, and at the same time, whose capability to distinguish between major and minor features has been most marked.With the passage of the years and the accumulation of data from many lands, it has been possible to build up a great body of information regarding the primary deposition and secondary alteration of mineral occurrences, which is of the utmost value in guiding thesearch for new deposits to take the place of those that become exhausted. This heritage is due not only to the efforts of gifted in...

Jan 1, 1950

Tougher physical mining and processing conditions as well as economic circumstances are causing many mining companies to re-evaluate the effectiveness of their mine planning. The recent wave of inexpensive computing power provides the engineer an opportunity to go beyond the simple one-off manual mine design and production schedule. The basis of a good mine plan is a good reserves model. Concepts of mine model development are explored. The only advanced computer methods that have found consistent success in optimising mine planning functions are economic pit limits determination and material scheduling. Three pit 'optimisation' methods are examined; the moving cone, the Lerchs-Grossman 3-D graph algorithm, and the new network flow algorithm. A comparison between the methods in terms of total profits generated and computer time involved are made. The results show that both algorithms produced a higher profitability than the simple moving cone, but at much higher execution times. However, the profit increase never exceeded much more than 1 % of the base moving cone case. Finally, a method for the development of long range material production schedules with forward waste planning is presented.

Jan 1, 1989

By Lancucki C. J, Nickson N. M

X-ray diffraction and differential thermal methods were used to determine the mineralogy of some clays used by the heavy clay industry in the Adelaide area. A detailed analysis was made of the mineralogy and particle size distribution of eighteen samples from beds in two pits in the Recent sediments in the Adelaide plains, of six white clays developed from the weathering of the Adelaide series of sediments, and of four Recent alluvial clays from a pit in the Mount Lofty ranges south of Adelaide. Structural clay products in the Adelaide area are manufactured from mixtures of these clays, so the mineralogy and particle size distribution was determined of eighteen clay mixtures used to make red bricks, cream bricks, facing bricks, pipes and tiles.Knowledge of this mineralogy is important in understanding the ceramic behaviour of the clays.INTRODUCTIONIn this investigation an account is given of the clay mineralogy and particle size distribution of some ceramic clays from the Adelaide area. The clays are used in the manufacture of structura,l clay products and the results to 'be described are part of an overall 'plan of study covering the heavy industrial clays and shales of Australia. Previous work has been published (Cole and Carthew, 1953; Ferguson, 1954; Ferguson and Hosking, 1955; Cole and Nielsen, 1958/59).In this work no attempt has been made to examine clays from all pits engaged in supplying materials for the structural clay industry. However, in 1954 the senior author collected detailed samples from two pits working in Recent alluvial clays in the Allenby·Gardens and Beverley areas near...

Jan 1, 1963

By P Taskinen, D Lindberg

The increase in metals demand in the electrifying globe means significant growth in the smelting of copper, nickel, zinc, and lead, produced from primary sulfide sources or using sulfide mattes as the intermediates of the process chains. This means that leaner and complex mineral deposits will be evaluated as ores and are in the future traded in the commodity market for smelting and refining to pure metals. An important issue in the trend is the technology metals, like antimony, tellurium, and gallium, which exist as trace elements in sulfide ores and form no ores of their own. Their recovery becomes important in the coming decades as will be the case with growing slag amounts without use in other industries. The key is to produce environmentally acceptable slags in the smelting operations. It sets new boundary conditions to the treatment of flue dusts. This means that all material streams of smelting and refining must be re-evaluated for the deportments of the main and minority metals. In copper smelting, the recoveries of precious metals are today important for the feasibility of the custom smelters but due to low prices of many minority metals they are discarded in slag landfills. It is one of the emerging issues also in the secondary copper smelting today and once the demand grows, the same question will be faced also in the mining-beneficiation-smelting-refining chain of the primary production of nickel, zinc, and lead. The distributions of many technology metals in the copper and nickel smelting have been recently studied using methods where the chemically bound trace elements in the slag and its phases at the smelting conditions have been studied. Thus, the key data about options for process modifications and additional processing steps are piling up. Short processing routes in the metals smelting and refining are attractive due to their simplicity. At the same time, complexity of many raw materials challenges the fluxing at high oxygen partial pressures in low silica slags with high metal concentrations. The compromise between high primary recovery and safe operation is a demanding task in conditions where slag foaming outside the processing window is evident. The increase in the demand of pure nickel is challenging the raw material basis where low-grade sulfide ores are soon smelted along with nickel laterites to matte. It is a demanding task at high MgO concentrations. The low solubility of MgO in iron silicate slags requires new fluxing strategies and new smelting end points for the operation at reasonable temperatures; the direct nickel matte smelting in one-matte mode may be an option.

Aug 21, 2024

By J Hunt

A critical aspect of geometallurgy is quantifying mineralogical and textural relationships that affect mineral processing (eg, liberation and recovery). However, to date, this has been an expensive and time consuming venture and only minimal amounts of this type of data are typically available to be included in the mine planning process. Our research is focused on developing methods that will produce the required mineralogical and textural data rapidly and inexpensively. New methods of characterising liberation potential from image analysis of coarse particulate material and direct small-scale flotation measurement are compared with measurement of liberation at final grind size (ie conventional tests on MLA). The new tests are designed to rank the liberation potential of samples in order to classify an ore deposit into domains of low, medium and high liberation potential. This parameter can then be used to adjust the cutoff used to differentiate ore from waste. Results to date show that all tests provide the same ranking for the samples. The measurement based on coarse particulate material compares favourably to the results from MLA analyses on the same samples. Further work is being carried out to determine which of the tests will be the most effective in terms of time, effort and cost

Sep 5, 2011

By A Maldonado, A Robert, K G. Mercer

The Hamersley Group in the Pilbara, Western Australia, consist of interlayered banded iron formation (BIF) and shale host rock formations within which a large number of open pit iron ore mines have been established. The slope stability of most of the mining excavations developed within these formations is controlled by the relatively low shear strength of the shale groups and shale bands, which are the weakest rock types. Shale formations range from fresh to highly weathered and are generally highly fissile when fresh, and clayey when weathered. An accurate understanding of the shear strength of these materials across the entire weathering continuum is therefore a key importance for assessing the slope stability of these mines.Historically defect laboratory testing results for the Pilbara mines have been analysed mechanically using direct shear testing (DST) to measure a number of geotechnical characteristics of the rock bedding and defects. This paper sets out the current practice in the industry in terms of the laboratory testing and presents a possible application of hyperspectral data to empirically correlate the shear strength of shale bedding with the relative mineralogy abundance on the bedding surface. This was achieved by creating both hyperspectral and geotechnical data sets for the same samples.In the study the shale samples were separated into three distinct assemblages: iron oxide + kaolinite, iron oxide + white mica + kaolinite, white mica + kaolinite, which had 40, nine and two samples respectively. Analysing these assemblages alongside DST data showed that samples with white mica had reduced non-variable shear strength, whereas samples with iron oxide + kaolinite had an overall higher shear strength but with a greater variance. It is inferred that the reduced shear strength in the white mica samples is due to the sheet (or plate) like structure of the mineral, giving it a weak stress plane. Confidence in the trends observed can be reinforced by expanding the data set in future works. The investigation also includes a discussion on weathering grade and addresses the question as to whether mineralogy abundances influence these characteristics in Hamersley shales.CITATION:Maldonado, A, Mercer, K G and Robert, A, 2017. The relationship between mineralogy and shear strength of Pilbara Hamersley Group shales across the weathering spectrum, in Proceedings Iron Ore 2017, pp 423–430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By M Baker

Biodiversity offsets are conservation actions intended to compensate for the residual, unavoidable harm to biodiversity caused by development projects. The use of biodiversity offsets in the context of mining has significant potential for enabling mining to take place in areas with biodiversity values, where it would not otherwise be possible to meet the relevant legal tests under the Resource Management Act 1991, and potentially the Conservation Act 1987. This paper looks at the concept of biodiversity offsets (and environmental compensation generally) both in New Zealand and internationally, and considers how lessons learned overseas may be adapted for this country. In New Zealand the practice of biodiversity offsets and environmental compensation is ad hoc and variable. The challenge with biodiversity offsets is to establish a transparent and coherent means of identifying the overall priorities and objectives of adopting such an approach, as well as how the relevant values are measured and protected. Establishing a methodology for quantifying biodiversity value, and the need for clear policy guidelines on biodiversity offsets are identified as key areas in need of wider discussion.

Jan 1, 2007

Wire rope, when used for hoisting on a mine is one of the most vulnerable units in the most expensive group of installations on the mine. With the introduction of hoisting on the Koepe sheave, a new technique was established. This innovation brought with it certain advantages which long had been recognized and which are being developed further.A need exists for the development of an infallible non-destructive testing device for wire ropes and it is axiomatic that the development and application of such a device should be coupled with the physical examination of mine hoisting systems. Therefore an integrated type of research programme is necessary in order to correlate the effect of shock loading with rope damage, which may be detected ultimately bynon-destructive means. This paper reviews certain historical aspects of investigations on this topic and it outlines a policy for research which can cope with a.c. or d.c. methods of excitation of the rope.INTRODUCTIONThe importance of wire rope in mining operations is often not fully recognized. A wire rope when used for hoisting in a mine shaft should be regarded as a "machine" forming part of a system of machines, and consequently it should be specified as such when it is purchased, it should be maintained as such during its working life, and it should be discarded only when it has done its duty and has been rendered either unsafe or uneconomic for further use.Every mine shaft, vertical or inclined, has in it one or more wire ropes which are used to transport men, material, and ore. Considering the long history of wire rope haulage and the large number of rope applications, it is a tribute to wire rope makers and to mine maintenance engineers, throughout the world, that not many serious accidents have occurred because of failure of wire rope. However, when a...

Jan 1, 1965

As the chief field of the gold dredging industry in Otago is the district traversed by the Molyneux River (called above Cromwell the Clutha) and its tributaries, a brief reference to the geology of that region and the origin of its alluvial gold will not be out of place. The prevailing rocks are metamorphic schists, chiefly mica and quartz schists, pr.obably of Silurian age. Though these rocks do not contain many payable quartz reefs, gold appears to be distributed in small quantities all through them,chiefly associated with the quartz lamime and lenses. The river drift, however, contains numerous pebbles of quartzite, quartzoze conglomerate, and fme-grained slate. Seeing that these rocks are hardly known to occur in situ within the watershedof the Molyneux River, though Devonian and carboniferous rocks of similar character occur to the north-east and south-west, it seems probable that the schists were at one time overlaid by carboniferous and Devonian rocks, and that these have been removed by denuding agencies. Be this as it may, it is certain that the schists themselves have been greatly eroded by the action both of water and of ice, and that the resulting drifts have themselves, in many cases, been sorted and re-assorted by the same agents.Consequently the drifts are very varied in character and often developed on a grand scale. In geological age they vary from Early Tertiary (though some may be older) to Recent.

Jan 1, 1903

By S L. Nicol, B J. Hogg, O J. Mendoza, S Nikolic, A Burrows

The top submerged lance (TSL) technology, developed in the 1970s, is now widely used for the processing of a range of materials. The key advantage the ISASMELT™ TSL technology provided was the ability to process feed materials in a highly turbulent bath, reaching close to equilibrium conditions, uniquely allowing for operation below the liquidus of the molten slag phase. The details on what happened below the liquidus line in the phase diagram became critical for the successful operation of the technology. During the development of the ISASMELT™ technology this led to a collaboration between the Process Technology group of Mount Isa Mines, now part of Glencore Technology, and the Pyrometallurgy Research Centre (PYROSEARCH) at The University of Queensland. The fusion of the phase equilibria research into the technology development allowed for understanding of the behaviour of molten splash, reliable tapping of the furnace, and the ability to operate the furnace with a refractory lining and achieve a year campaign life in excess of four years. The outcome has allowed for the highly successful adaption of the ISASMELT™ technology to recycling of complex feed streams necessary to drive circularity in our modern global economy.

Aug 21, 2024

The Raub Gold Mines are situated approximately in the centre of the Malayan Peninsula in the State of Penang. Part of the area, now known as "Raubhole," was opencut some 800 years ago by the Mon Khmers, a Cambodian people, whose vestiges mark numerous outcrops in South Eastern Asia. With their decline and extinction the work was abondoned, leaving a large pond in a dense thicket of Beluka (secondary growth).From the year 1885 onwards the history of Raubhole and the water therein records a chain sale starting from an enterprising local "Rajah," who had "assumed" authority, to an equally wakeful Singapore Arab; thence through the agency of a "down-and-out" beachcomber to a hopeful Australian company in the "goldbrick" days. Subsequent catastrophe on a depleted stringer was followed by reconstruction; the deserved reward of a long mining life, and an output of nearly 800,000 ounces of gold. Owing to the loss of notes and data stored in Singapore, this paper is not as complete as it should be, especially in respect to its metallurgical phases. Apologies are therefore tendered in advance for any deficiencies which may be noted.The necessary regional geological data have been taken largely from the admirable investigation of the Raub area by J. A. Richardson, A.R.C.S., B.Sc., F.G.S., of the Malayan Geological Survey*, and, throughout the paper, months represent lunar periods of 28 days and money is expressed in sterling.MINING SECTIONSAs shown hereunder the reef system has been divided by nature into seven isolated sections, which have been of necessity worked as seven separate small mines. From north to south these are:-(a) Sungei Agas consisting of very shallow workings to the south of, and adjacent to, a granite-porphyry mass known as Bukit (hill) Kajang. This area has not been worked for many years.(b) Bukit Malaka which is also shallow.(c) Bukit Jalis.(d) Bukit Koman which, with (c) and (e), consitutes the main workings and which has possibly been determined in depth.(e) Anderson Section.(I) Raubhole Section.(g) The workings under Raub Village.

Jan 1, 1945

IN concentrating mills, where several millerals are recovered for realisation in more than one product, various systems are used to express the relative economic value of the work done, and, in the hope that it may prove of use to other operators, the writer will describe a system which, in his opinion, is more complete than any other that he has seen published.The controlling factor in all mill work must be based on the economic result represented by the greatest margin possible between the realizable value of the products and the cost of obtaining same.From a mill-man's point of view these are affected by the following factors:1. Metal contents of ore.2. Grade of products.3. Recoveries.4. Working costs.The grade of ore milled is usually outside the mill-man's control, but this may exercise a considerable influence on the grade of his products, metal recoveries, and revenue per ton of ore. Higher grades or recoveries may be obtained by using a more expensive process, or by additional grinding or reagents, and the economic comparison can only be arrived at by obtaining an analysis showing the monetary value of each variation within the possible limits.In the system to be described, the value of unit variations of metal contents of the ore, grade of products and recoveries are calculated in terms of a monetary unit per ton of ore with the returning charges ruling, and any suitable metal prices. To do this it is necessary to assume what, for convenience, is termed a "standard" set of results from the mill, preferably representing about average conditions, and having calculated the effect of unit...

Jan 1, 1931

By P Moser, R Ivanova, F Ouchterlony

This paper describes model-scale bench blasts on mortar blocks with distorted drill hole patterns, done in 2013–2014 at the Montanuniversitaet Leoben. The main aim of the project is to see if the fragmentation from and the crack development behind blasts with and without drill hole deviations differ significantly.The dimensions of the test blocks were 660 × 280 × 210 mm (L × W × H). They were mounted inside a yoke that allows the blast waves to escape (see Figure 1). Three rows in each block were shot row by row with a nominal pattern of B × S = 70 × 95 mm. The same nominal delay 73 µs (ie 1 ms per m burden) between holes was used throughout. Blocks with holes of stochastic collar position errors (variations in burden or in burden and spacing but constant row volume) and systematically shifted collar positions (blasts with staggered pattern) were shot. The results were compared to reference blocks without collar deviations.Apart from the sieving analysis, the remaining bench faces were measured with a stereo-photogrammetric method and horizontal roughness profiles for each row were constructed. Sawing slabs from block remains after the third row and use of dye penetrant allowed the study of internal blast damage.The analysis showed that none of the changes in borehole collaring had a significant effect on the sieving curve (median). The sieving results confirm earlier findings though that the fragmentation gets finer with the number of rows shot, implying that blast damage from earlier rows has an influence on the blasting results. The tests demonstrated that the nequiv (equivalent n-value) has increased ten per cent by shooting staggered pattern and decreased by seven per cent by pattern with burden and spacing errors. For the rest of the patterns, the nequiv was roughly the same.The surface roughness investigation showed that a smooth surface was achieved by the staggered pattern. The other deviations patterns did not show a clear trend.The internal blast damage, which was measured in the remaining part of blocks, showed that out of eleven, four crack families seemed to be most affected by blasting. The comparison of the reference and distorted patterns showed that less cracks were apparent for the staggered pattern, ie less damage was introduced.CITATION:Ivanova, R, Ouchterlony, F and Moser, P, 2015. Influence of distorted blasthole patterns on fragmentation as well as roughness of, and blast damage behind, remaining bench face in model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 693–706 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

In the last 30 years, human appropriation of global renewable resources has accelerated to the point where 35 per cent of the earthÆs land surface is now in managed agro-ecosystems, consumptive water use consumes between 50 per cent and 85 per cent of freshwater supply and 60 per cent of ecosystem services are utilised in an unsustainable manner. There are virtually no landscapes in which renewable resources are not already fully allocated among different economic and environmental uses. Furthermore, it is increasingly recognised that water availability issues do not exist in isolation but are linked with the related environmental issues of biodiversity preservation, the carbon cycle, soil degradation, and energy use and supply. It is against this background that the sustainable management of water in mining is increasingly developing a strategic viewpoint where water is viewed as a resource within an interconnected landscape, having economic, environmental and social value and providing a range of environmental services in the provision of public and private goods. This paper explores the issues associated with sustainable management of water in mining from a strategic viewpoint. The cumulative impacts of multiple water users, both within and outside the mining sector, is increasingly threatening the security of supply for all users. To quantitatively assess the ætrueÆ value of water it is necessary to: Better understand the science of ecosystem functioning and how human actions impact on environmental processes. Develop appropriate policy, finance and governance structures to support innovative programs that preserve ecosystem function and services (including market based instruments). Apply knowledge as interventions across landscapes in ways that maximise benefits and minimise unintended consequences taking into account differences in the value of water among sectors. A strategic viewpoint of water management relies on knowledge to guide decision making that has been acquired at a range of scales from mine site to mining region. This knowledge must be based on rigorous science, sound data and syntheses of different types of information. Strategic management of water resources will better position the industry in terms of understanding the risks posed by complex, interlinked environmental issues that are increasingly impacting on future access to land and renewable resources, including water, thereby ensuring miningÆs future social licence to operate.

Jan 1, 2009

By Blanchard R

In stopes of the 2000- and 2150-ft. levels in the North mine section of North Broken Hill Limited, whence a substantial proportion of the company's production is being drawn, and especially in stopes which involve the portion known as the Northern orebody, occurs it light-coloured friable porous material which represents average grade ore from which the lead and zinc minerals, and certain gangue constituents, have been largely or wholly removed by leaching. The 2000- and 2150-ft. levels lie, respectively, 1550 and 1700 ft. below extreme base of the pre-mine oxidized zone. Composition of the cellular product shows it to be supergene. The oxidation and leaching, therefore, must be assumed to have taken place since drainage of the affected areas was accomplished by mining operations.The matter is of more than passing interest, because the post-mine...

Jan 1, 1942

By L Mottola

Three decades ago mining companies, principally in North America, aided by machine and explosive manufacturers, started significant attempts to develop and implement automated mining systems, mainly underground. These tended to be motivated by decreasing cost, increasing productivity, reducing labour requirements, and improving safety. These are important business drivers, however, little attention was given to the underlying goal of mining automation, namely to bring upstream processes in control and reducing variation, as seen in downstream mineral processing plants.This paper first reviews the nature of Lean Thinking and its application in the context of the growing commitments by industry to develop future automated mine production systems. The paper then makes reference to prior and current experiences in open pit blasthole drill and shovel performance monitoring, to demonstrate the principle that machine performance data offers as a means, not only to characterise the dynamic geological and working environment, but also to provide a foundation for automation. In this case, drill and shovel monitoring was originally motivated as a means to optimise blast fragmentation through more effective drill and blast designs that are based on an accurate determination of the bench geological and geotechnical characteristics, hence managing variation in the drilling and blasting process. This paper considers how automating and integrating such components of the mine production system would bring processes into a controlled state, creating value at the face, within a framework of Lean mining.

Nov 22, 2011

This paper describes a proposal to reopen the Sylvia gold mine for underground exploration and development for an initial production of 10 000 tpa. A combination of trackless mining equipment and railtrack would be utilised for development with ore extraction being carried out by undercut and fill methods. The use of the smallest LHD units for mucking, and rail track for the main haulage together with airleg drilling will form the basis for development and stoping. The proposal has been subjected to an environmental impact assessment report to evaluate the impacts of the proposal on the natural and social environment in the area.

Jan 1, 1987

By D Brooks, S Gunn, T Perkins, J Siliezar

Ernest Henry Mining (EHM) is a copper, gold and magnetite mining and processing operation located 38km north east of Cloncurry. The EHM ore body has an average grade of 0.9% copper (chalcopyrite), 0.5g/t gold and 22% magnetite.Open pit mining commenced in March 1998, but EHM transitioned to underground mining in December 2012, extending the life of operations beyond 2024. The underground mine currently produces up to 3Mt/year of ore, hauled up a decline by truck. This figure shall double in 2014 with the completion of a 1000m shaft. The EHM Concentrator has a nameplate capacity of 10Mt/year. In June 2011, Xstrata Copper acquired the Mount Margaret resource to supplement underground production and utilise the full capacity of the Concentrator. The Mount Margaret Mining (MMM) operation was established to develop the five deposits making up the resource by way of open pit mining.Copper concentrate is produced by the EHM Concentrator via grinding, flotation and dewatering circuits. The grinding circuit comprises a SAG and ball mill in a closed AB configuration. Flotation consists of a rougher train, regrind and three stages of cleaning, with the tail from the first stage reporting to the tailings thickener.The mineralogy of the MMM ores is complex, comprising fine textures of active pyrite, copper oxides, native copper, clay and secondary copper sulphides. This paper provides an overview of the metallurgical test work completed to forecast the performance of the MMM ores through the EHM Concentrator and identify flow sheet modifications for maximising copper recovery and producing a saleable concentrate. A discussion of the challenges experienced in the plant to date follows.CITATION:Gunn, S, Siliezar, J, Brooks, D and Perkins, T, 2013. Adapting the Ernest Henry Mining concentrator to process the Mount Margaret ores, in Proceedings MetPlant 2013 , pp 347-370 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Chalcopyrite concentrate was combusted in oxygen-nitrogen atmospheres, the composition of which ranged from 1-100 per cent oxygen. Factors studied included particle size, experimental temperature and oxygen concentration. The study was assisted by chemical and X-ray diffraction (XRD) analysis and temperature measurements of single particles. Size reduction occurring after melting was found to have a major effect on the overall reaction time. Thus time to attain ignition was largely determined by the original particle size, whereas combustion time was independent of this factor. For particles larger than 40 I'm in air the time to attain ignition predominated. The maximum temperatures measured for single particles were the result of pyrite present in the concentrate. Chalcopyrite did not attain thesame temperatures. Vaporization, either as CU(g) or CuO(g) lImited the temperature. Maximum temperatures measured for single particles of pyrite ranged from 1610°C in 14 per cent oxygen to 2360°C in 100 per cent oxygen (both at 700°C). Measured temperatures were compared with those calculated from a diffusion-based model.

Jan 1, 1983