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By D A. McCallum

With depth, many gold ores become sulfidic with minerals such as pyrite, pyrrhotite and arsenopyrite becoming prevalent. In addition, many underground gold mines use tailings backfill to bind and store the waste. In these cases, acid mine drainage (AMD) can become an issue. One approach to the control of AMD is desulfurisation whereby the sulfide minerals are removed prior to disposal. Four sulfide tailings samples, representing different ore types and gold and base metal operations, were selected for assessment and testing using simple physical beneficiation techniques. The aim was to determine the extent to which mineral processing methods were suitable for separating sulfides from non-sulfides and for extracting potentially marketable by-products from the tailings. In order to streamline the testing procedure a simple diagnostic separation technique was developed to enable quick screening of bulk sulfide tailings for suitability for reprocessing. The testing procedure involved detailed characterisation and a sequential set of testing regimes based on simple unit processes including water washing, classification, gravity concentration, magnetic separation and bulk flotation. The preliminary test results indicate each unit process can play an important part in producing effective sulfide/non-sulfide separations and in generating useful by-products from the tailings. Potential valuable products identified include coarse, benign silica sands, bulk iron sulfide products rich in pyrite and/or pyrrhotite, high-grade iron products (magnetite) low in silica, low-volume bulk sulfide concentrates and low-grade molybdenite and talc products. The work presented shows how sulfide tailings can be viewed as a resource rather than a waste stream, and identifies a pathway for developing a more sustainable approach to the environmental management of sulfide tailings for the future.

Jan 1, 2007

By H Han, W Wang, E Zhou, D Duan

"In this study, physical, chemical and microscopic characteristics of high phosphorus oolitic hematite were studied firstly. Based on which, the new methods of high phosphorus hematite used in the æsolid state reduction by rotary hearth furnace - magnetic separationÆ and iron nugget by rotary hearth furnace direct reduction processes were discussed. The results showed that high temperature, low basicity and high carbon content is conducive for the apatite in iron ore to reduce into molten iron, but not conducive to the removal of phosphorus. Through optimisation of process parameters, dephosphorisation rate of high phosphorus hematite is more than 60 per cent by æsolid state reduction roasting-magnetic separationÆ process while that is up to 80 per cent by iron nugget process. This study can provide theoretical and technical basis on economical and rational use of high phosphorus oolitic hematite.CITATION:Han, H, Duan, D, Zhou, E and Wang, W, 2013. New methods for high phosphorus oolitic hematite dephosphorisation by direct reduction process, in Proceedings Iron Ore 2013, pp 391-396 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

General recognition of the potential benefits of utilizing advanced technology has focussed public attention on the organisation of tertiary education. This has produced a situation where opportunities exist for significant changes to be implemented. The challenges to Mining education in this environment of change are analysed with respect to the setting of education objectives, the role of centres of education, course structures and student access to courses. The scope of the analysis includes formal courses for professional education and technical training, and programmes for continuing education and postgraduate research. Previous significant advances in mining technology illustrate the importance of encouraging the establishment of an extensive involvement with mining education. Education cannot be the sole responsibility of professional academic organizations; significant industry participation is essential. Methods of achieving this interaction are discussed. Major changes in techniques available for disseminating information provide a significant incentive to assess the relevance of existing course structures and restrictions on student access to courses. Establishment of a less rigidly progressive system of education is discussed with respect to the development of the full potential of computer based learning. This will expand the availability of mining education to include remote locations. The practical feasibility of such changes and recognition of the value of education as a commercial resource could also increase overseas involvement in Australian mining education. Benefits of such changes and problems that may develop if accreditation systems are not also changed to take account of new technology are outlined.

Jan 1, 1989

By R P. Langford, T A. Moore

Indonesia over the last 15 years has experienced a surge in coal exploration, which has led to the development of a major export industry. This coal exploration has improved the understanding of the geology of the Indonesian coal deposits. The main economic coal deposits are of Eocene and Miocene to Pliocene age, which mainly occur in Kalimantan and Sumatra and were formed from peat deposits in an equatorial paleoclimate similar to that prevailing today. Some of these peats were domed peats, which grew above the normal water tables, under a climate of year-round rainfall; these peats grew above the level at which waterborne mineral matter can enter the system, resulting in low ash and sulphur, and locally very thick coal. It is believed that such peats have formed the unusually thick, low ash, and low sulphur Miocene coals of Indonesia. Coal deposits of Eocene age are typically characterised by thinner seams, with relatively higher contents of ash and sulphur. The Miocene coals and Eocene coals both appear to have formed in lacustrine, coastal plain or deltaic depositional environments, similar to the modern peat-forming environments of eastern Sumatra and parts of Kalimantan. The Eocene coals formed mainly in extensional tectonic settings. Miocene - Pliocene coal deposits formed in a range of tectonic settings; the most significant, for large economic coal deposits, are the foreland basin setting of the large Neogene coal deposits of South Sumatra.

Jan 1, 1999

The discussion which followed the publication of my paper by the formert has, I think, enhanced its value. It may therefore be of interest to members of our Australasian Institute, who are not members of the Institution of Mining and Metallurgy, if I give a synopsis of the discussion.My attention was drawn to the fact that my paper did not make clear the extent of the improvement in furnace operations, which followed the use of coke of high quality; this comment applied more particularly to the lead content of slag. My failure to supply comparative figures in regard to the lead content of slag was governed by a condition which, I think, is of interest to metallurgists. As a result of industrial...

Jan 1, 1932

By Lyman G. J

Magnetic separator operation in the recovery of magnetite in heavy medium circuits was studied by conducting a series of tests on a full size wet drum magnetic separator.The significant operational variables were found to be feed pan clearance, squeeze pan clearance, dry magnetite feed rate and separator drum speed. With feed and squeeze pan clearances optimized for typical primary separator operation, magnetite loss and concentrate specific gravity were found to be related in a regular manner to dry magnetite feed rate at any drum speed.A two component model of magnetite loss is proposed, relating total magnetite loss to losses in the feed pan and squeeze pan zones. The experimental curves relating magnetite loss to dry magnetite feed rate at the various drum speeds are interpreted in terms of the two component model.The magnetite particle size distribution in the separator was also examined. The tailings magnetite was found to be finer than the feed magnetite only when the dry magnetite feed rate was low, or immediately following the introduction of a new charge of magnetite when the separator was fed at an intermediate dry magnetite feed rate.

Jan 1, 1983

By D Kent, D Eisner

A lot of talk has been generated about the so called ‘Internet of Things’ (IoT) and its potential to transform the way we interact with our homes and devices. But the true potential and value of IoT is not going to be realised by the general consumer but by businesses.This paper outlines the application of IoT in mining and how it is a natural extension to the base networks becoming commonplace in both surface and underground mines. The potential for ubiquitous monitoring throughout a mining operation at low capital and support costs will transform the ability to monitor, analyse, report and manage all of the key processes involved in a mining operation.Importantly, the paper will discuss the practical applications that the IoT offers mining and explain how this really is transformative technology, not just the latest buzz words from the information technology (IT) world. If leveraged correctly the impact on mining, its cost base and efficiencies, is enormous.CITATION:Kent, D and Eisner, D, 2015. What the internet of things means to mining, in Proceedings Third International Future Mining Conference, pp 65–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

Soon after the Rosebery concentrator commenced operations in 1936, an investigation was begun in an attempt to discover a substitute for cyanide in lead flotation. Cyanide is an excellent depressant for zinc and iron, but it also powerfully depresses the copper, silver and gold bearing minerals present in Rosebery ore, thus allowing them to pass through to the zinc concentrate or final residue where they are of little or no value.The investigation was not entirely successful, but it did indicate that sodium bisulphite or sodium sulphite could be used as a depressant for zinc without depressing the copper, silver and gold bearing minerals. The sulphites were, however, much inferior to cyanide as apyrite depressant.At about this time, I. W. Wark, using the captive bubble technique, had shown that, at the concentrations normally used, sodium aerofloat is not a promoter for pyrite or galena in alkaline solutions (see his book "Principles of Flotation", p. 188). Some preliminary tests on the production of a copper concentrate from Rosebery ore were therefore carried out using sodium sulphite as depressant and sodium aerofloat as promoter.The results of this work were promising but, since Rosebery ore usually carries only about 0·5% copper, there did not seem to be much incentive to carry the work further. With the outbreak of war, however, Australia became desperately short of copper and the relatively small amount in the ore. became of sufficient importance to...

Jan 1, 1952

By P K. Smith, R J. Ryan, W R. H Ramsay, D C. Arne, F P. Bierlein

Turbidite-hosted, mesothermal lode gold deposits in Paleozoic metasedimentary rocks of the Buller Terrane, western South Island have a similar geological history and genesis to the Paleozoic lode gold deposits ofVictoria, Australia and Nova Scotia, Canada. In all three regions the gold deposits are hosted by interbedded meta-sandstone and meta-argillite that have been folded and regionally metamorphosed to greenschist facies, and locally in Nova Scotia to amphibolite facies. The gold deposits are typically narrow, structurally controlled quartz veins associated with dilatant zones in reverse faults or fold-related fractures. The principal vein types include: bedding parallel or concordant veins, discordant veins, saddle reefs, and stockwork veins. En-echelon and "ac" type veins are sometimes also gold-bearing in Nova Scotia. The contrasting competency of the host meta-argillite and meta-sandstone beds is an important factor in vein formation, particularly for the bedding parallel veins, which are typically developed within meta-argillite beds or along the contacts between meta-argillite and meta-sandstone. Veins found within meta-sandstone units are generally discordant. The deposits in Victoria are well known for their bedding-parallel veins, saddle reefs ( Bendigo ) and leather jacket reefs (Ballarat). Bedding-parallel veins are also common in Nova Scotia , along with a few examples of saddle reefs. In contrast, vein formation probably occurred later in the deformation history of the Reefton and Lyell goldfields, with most veins being bedding discordant and more typically aligned with the axial plane cleavage of the folds rather than bedding planes. The quartz lodes in one deposit, Globe-Progress, strike approximately perpendicular to the bedding and fold axes. No saddle reefs have been recorded from the Buller Terrane. Mesothermal vein morphology reflects the amount of fmite strain, the strain rate, competency contrasts, lithotypes, and the confirming pressures to which the system was exposed. On the basis of comparable depositional depths and rheologies of the host rocks, a controlling factor influencing the development of different vein styles (and timing) might be finite strain, as exemplified by the tightness of folding in the host rocks. Folding appears to be tighter in the Victorian rocks than in either the Buller Terrane or Nova Scotian rocks.

Jan 1, 1999

The mineralogy of the rocks now observed in the Nairne pyrite deposit developed under conditions of internally-controlled sulphur activity during amphibolite facies metamorphism. In the sulphide-deficient metasediments the activity of sulphur was low, and pyrrhotite developed with iron-bearing silicate minerals. At higher sulphur activity, in the sulphide-rich meta-sediments, pyrite formed in addition to pyrrhotite, and the associated silicate minerals are iron-deficient.

Jan 1, 1969

DESCRIPTION OF OREThe ore consists, in general, of a very finely grained mixture of sphalerite, galena, and pyrite, with a gangue of quartz and schistose material, and contains about one ounce of silver to the unit of lead.Minor minerals are chalcopyrite, tetrahedrite, and ruby silver. The amount of gangue within the ore-bodies themselves is usually less than 20% of the weight of the whole. The ore is banded in a way that corresponds to the structure of the original schists, and is by no means uniform in composition-at one point, for example, blende may predominate, and a few feet farther on the body may become highly pyritic.Owing to the intimate association of the mineral constituents of the ore, it is very difficult to separate them from one another.Although this remark applies to ore from all parts of the field, the difficulty is particularly noticeable with Rosebery ore, the minerals of which are more intimately mixed, and are of smaller grain size than are the minerals of the Hercules ore.To effect a reasonably clean separation, it is necessary to grind the ore so that 90% passes a 200-mesh I.M.M. screen. Microscopic examination of the crushed product shows that 85% of the minus 200-mesh material is less than 30 microns in diameter, or, in terms of screen sizing, is minus 400 mesh. Particles under 30 microns are found to consist, of one mineral only, but in particles over this size separation has not always been effected. For instance, it is known that part of the galena and of the pyrite in the zinc concentrate is associated with sphalerite, and that part of the galena in the mill residue is associated with pyrite. There is only slight association between the minerals in the lead concentrate.

Jan 1, 1927

This paper reviews the manpower requirements of the Australian mining industry. It has been necessary to provide general background information in order to support the view that university education in mining and mineral process engineering should be strengthened rapidly in Australia to provide graduates for the industry.

Jan 1, 1969

By J W. Hedenquist

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Epithermal deposits (Au or Ag dominant, ± base metals) form within ~1 km of the surface in volcanic belts, both arcs and rifts, with the different tectonic settings reflected in distinctly different characteristics. Within arcs, deposits are typically intrusion centred and commonly associated with hypogene advanced argillic alteration, both in lithocaps and as halos to shallow or proximal portions of some veins; such alteration is coupled with processes that form porphyry Cu-Au deposits at depths of ~1–3 km. Introduction of metals is related to the subsequent phyllic-stage overprint; if this fluid rises to the level of the lithocap or into epithermal veins, Au mineralisation with Cu or Ag may occur, associated with sulfate minerals or muscovite. By contrast, Au-rich (both low Ag:Au ratio and bonanza grade) colloform quartz veins form at shallow depths in volcanic rifts, typically within a few hundred metres of the surface, with clay halos and topped by silica sinter if the palaeosurface is preserved. The geologic variability in volcanic belts, including host rocks, structures and hydraulic gradients, means that many epithermal deposits vary from the end-member features of the principal styles. Effective exploration requires familiarity with end-member styles as well as potential variations, plus the mineralogical indicators of palaeotemperature (eg evidence for erosion depth, fluid flow channels). This knowledge helps the geologist in the field to imagine what might be buried and where, and how to best test the target with drilling.CITATION:Hedenquist, J W, 2015. Recent developments in understanding of and exploration for epithermal deposits in volcanic arcs , in Proceedings PACRIM 2015 Congress, pp 11–16 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By K H. Esbensen, K Engström

The conclusion from the debate over the last decade in the mining sector is that, for grade control, reverse circulation (RC) drill sampling gives more reliable results due to less sampling problems than blasthole samples. However, by conducting the latter with well-controlled procedures there still exist fair possibilities to counteract the major blasthole sampling problems and achieve fit-for-purpose representativeness, especially if based on minimal loss of fines. In the present PhD study, extensive replicate experiments and variographic characterisations are conducted to evaluate the performance of manual blasthole (BH) sampling and sectorial segment sampling. The experiments were performed in Luossavaara-Kiirunavaara AB (LKAB)’s Leveäniemi open pit mine in the north of Sweden. The experimental area is an apatite-magnetite iron ore deposit of the Kiruna type, with the demand to exhibit a maximum of local heterogeneity to allow the experiment the largest possible conclusion powers. Gathering and splitting the complete BH drill cutting cones (fines cone, coarse cone) served as an authoritative reference on which to assess the representativity of the two BH sampling methods.Results show that manual BH drill sampling is able to produce samples with an acceptable accuracy and precision if performed properly and with insight. Based on variographic comparison, segment sampling shows similar precision for chemical grades as the manual sampling, while the particle size distributions were more deviating for segment sampling than for manual sampling at the high and low size ranges. Possible reasons for these partly surprising results are discussed.For further investigation of the performance of BH versus RC drill sampling, a second experiment has been planned on a parallel profile. This will result in an unprecedented opportunity for a full variographic comparison between RC and BH sampling, aimed at designing specific, fit-for-purpose sampling procedures as a function of ore quality, cut-off grades and important contaminant levels.CITATION:Engström, K and Esbensen, K H, 2017. Blasthole sampling (replicate and variographic experiments) in LKAB open pit iron ore mines – fit-for-purpose representativity?, Australia, in Proceedings Eighth World Conference on Sampling and Blending , pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The Precambrian Eastern Creek Volcanics comprises spilitic basalts with interbedded sediments and tuffs which were extruded and deposited during Middle Proterozoic time. The rocks have undergone low-grade regional metamorphism.The Eastern Creek Volcanics are approximately 17,000 ft thick and have been divided into four units.The rocks were laid down in a geosynclinal basin elongate to the north. The main structural features are the northerly trending Mount Isa and Gorge Creek-Quilalar fault systems.Major east-west faults cause repetition of the sequence.Copper and uranium mineralization is known within the formation. Copper mineralization is confined to quartz-filled shears anp basalts. Nothing of economic importance has been found in the area though ore deposits have been found elsewhere in this type of environment.

Jan 1, 1968

Being a geologist I intend describing the renaissance of the gold industry in Australia within its geologic framework; there is a geological pattern to the numerous gold projects which have been brought on stream over the past decade. We are now about midway through our third and largest gold boom which, at a peak of 7.5 million ounces is about twice the production peaks achieved in the preceding booms. From discovery in 1851 through 1870 we saw the first boom largely based on alluvial production in NSW and in Victoria at the great Ballarat and Bendigo Goldfields. The discovery of the Golden Mile in Kalgoorlie, Western Australia, underpinned the second gold boom in the period 1895 - 1915. On that basis the present boom should last through the next decade.   It has been a golden decade for Australian gold production. From less than ten mines in 1980 with production over 10 000 ounces and the largest, Telfer, with output of about 130 000 ounces we now find over 130 deposits being worked around the country today that produce over 10 000 ounces with the largest, Boddington, having an output of over 400 000 ounces. In total these mines produced an estimated 210 tonnes of gold in 1989 and we expect this year, 1990, that a new record production of between 240 and 250 tonnes will be set. This positions Australia in third place in the Western World behind South Africa #1 and the USA #2 and fourth in the world with the Russians holding second place overall behind the South Africans.

Jan 1, 1990

By X Zhang, B McFadzean, P E. Ngoepe, B Nemutudi, P P. Mkhonto, S Pikinini

There is still a huge challenge in efficiently recovering the arsenides minerals that are largely concentrated in the Platreef Bushveld Complex which constitutes about 21 per cent of the platinum group minerals (PGMs). Therefore new collectors are required to improve the recovery separation of hard to float minerals, in particular sperrylite. The triazine modifications are promising reagents for mineral flotation and have not been given much attention in minerals processing. The adsorption of sodium 2,6-dithio-4-butylamino-1,3,5-triazine (SDTBAT), sodium 2,6- ditrithiocarbonate-4-butylamino-1,3,5-triazine (SDTTCBAT) and sodium normal butyl xanthate (SNBX) on sperrylite (100) surface were performed to identify a well performing collector molecule. We observed that the triazine collectors preferred to bridge on surface As and Pt atoms through the S atoms. We found that the adsorption energies were in the order: SDTTCBAT > SDTBAT > SNBX, indicating that the SDTTCBAT had strong exothermic adsorption on sperrylite and pyrite. These results showed that the ditrithiocarbamate had a great influence in the adsorption strength on the sperrylite surface. Importantly it was found that the triazine collector had stronger adsorption than the xanthate, which portrayed a promising replacement of xanthate collector. These results paved a way for design of novel collector for sperrylite and other chalcogenide minerals to improve their recovery.

Aug 24, 2022

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 Larkin F, Farrer E, McGhie R. R

The Electrolytic Zinc Company of Australasia Limited commenced productive operations during February, 1936, at the- Rosebery and Hercules mines, which are situated near Rosebery, Tasmania. At this time it was decided that before re-organizing the steel sharpening shop a test should be made of the relative merits of conventional drill-steel and detachable bits. For this purpose Ingersoll-Rand type"I" thread centre hole.jackbits were selected and seventy-two of these were tested against conventional steel. Results indicated that, under the conditions pertaining at these mines, j ackbits should prove more economical than conventional drill-steel bits, and that a large-scale test, under working conditions, should be made. This was done by gradually replacing conventional drill-steel with jackbits at the Rosebery mine. Results were satisfactory and by the end of 1936 both mines were using only the jackbits.

Jan 1, 1939

Recently published extensions to the mill-dump cutoff grade theory for joint open pit-concentrator operations lead to equations that must be simultaneously satisfied as a necessary condition for an optimal operating policy. These equations are parametrically dependent upon ore quality parameters, other than grade, relating to the ease of recovery of the disseminated mineral in the concentrator. Since it is not possible to treat quantities of ore corresponding to the size of selective mining units separately in the concentrator some mixing is inevitable and often deemed desirable in the interest of homogeneity of mill feed. This renders the calculation of cutoff grades for individual mining units futile; mining units must be grouped to form larger parcels that can be dealt with separately. In doing so an opportunity cost may be incurred; the loss of potential benefit that would result from such separate treatment. This matter is considered from a theoretical, qualitative, point of view. A numerical example then shows that a significant variability in the quality parameters can be tolerated without incurring such opportunity cost, provided sufficient knowledge is available concerning the distribution and effect of these variables to enable the use of effective mean values of these parameters in the cutoff grade calculation. Lack of such knowledge can have major consequences for the economics of the operation.

Jan 1, 1981