Search Documents

Statistics on the imports of industrial minerals into the EECshow that the traded volume in 1987 is approximately 23 million tonnes.The following table documents the imported quantities on the most important industrial minerals.

Jan 1, 1989

Tin mineralization in both eastern and western Tasmania shows a spatial correlation with middle Palaeozoic biotite granites and adamellites. The range of composition of these granitic rocks is restricted with respect to Mg, K, and Na content. Because this compositional restriction is shown by granitic rocks from other tin provinces, the concept of a genetic relationship between these granites and the associated tin mineralization is reinforced, and similar concentration mechanisms may be involved.Gold mineralization is largely restricted to eastern Tasmania and in contrast to the tin mineralization is rarely spatially associated with the middle Palaeozoic granitic rocks, although most authors have suggested a genetic correlation with hornblende and/or biotite granodiorites.Although few analyses are available, the granodiorites that are spatially associated with gold deposits exhibit similarities to granitic rocks from gold provinces elsewhere. These features suggest a possible genetic relationship between gold mineralization and the granodiorites.The composition of granitic rocks may be used as an aid to exploration in delineating areas of potential tin and gold mineralization in granite terrains.

Jan 1, 1970

It is difficult, and probably inadvisable, to frame rigid rules for the valuation of alluvial deposits, for such deposits are very diverse in type, varying, for example, according to the mineral sought and according'to the complexity of the deposit which, on one hand, may be a narrow welldefined alluvial strip at the bottom of which is a continuous mineral lead, or, on the other, may be a broad alluvial flat with discontinuous patches of the valuable mineral occurring at different levels throughout the alluvium.However, some definite procedure in valuation must be adopted when dealing with anyone deposit, and the fundamentals of such a procedure are applicable to almost all alluvial deposits.The methods described in this paper are based very largely on the valuation of a specific deposit and, although an attempt has been made to keep the discussion as general as possible, it contains some statements which, if traced to their origin, spring from the writer's association with that deposit. Such statements must be interpreted with sufficient flexibility to be appropriate to whatever area the reader may have in mind.The subject of valuing an alluvial deposit falls naturally into two divisions: The valuation of each borehole; the valuation of the deposit as a whole. The following discussion is therefore dealt with under these two headings.Some general matters are mentioned in a third section.

Jan 1, 1950

Evaluation of Grinding Medium Wear in Stirred Mills The standard fine grinding machines in the minerals industry are stirred mills whose performance largely depends on the competency of the grinding medium. Medium wear in stirred mills is one of the key parameters for medium selection. A wear evaluation methodology is developed and applied in this paper to measure the wear rate of river sand using a laboratory batch stirred mill. The procedure is demonstrated by testing the sand medium in a 0.55 kW batch stirred media detritor (SMD). The sand wear rate determined in the laboratory batch mill is successfully scaled up to that determined on a full-scale Metso 355 kW SMD mill.

Sep 13, 2010

A consideration of mining ventures and the changes of an environmental nature that occur. The paper is introduced with a general statement claiming recognition that mining ventures are important to human well-being but that these need to be justified against the environmental changes that they bring about. The various factors that need to be considered are cited followed by an historical review of mining activities. The various environmental issues are discussed under three headings; socio-economic, physical and biological, prior to reviewing the world's demand for minerals including fossil fuels. In conclusion guidelines for appraising mining ventures relative to environmental changes that may occur, are given.

Jan 1, 1981

Validation and Simulation of Optimised Compressive Crushing Ores and aggregates are used in countless applications all around in the society. The frequent and escalating usage of these natural resources requires efforts aimed at not only making do with what is available, but also undertaking actions to improve the production yield and the processes involved. This strive to improve the performance and efficiency of existing crushers and crushing processes has brought about research concerning optimisation of crushing plants as well as theoretical optimisation of crushing. Previous work shows that different applications and different materials require different compressive crushing in order to accomplish a theoretically optimal size distribution. These optimisation results, obtained by genetic evolutionary algorithms and evaluated with so called fitness functions, convey the theoretically optimal number of compressions and their corresponding compression ratios. Presented in this paper are thus some laboratory crushing tests, which are conducted in order to validate a set of previously optimised crushing sequences. More specifically, interparticle crushing sequences are carried out in a Piston-die testing equipment, where samples are sieved between each compression. The subsequent analysis of these results shows good correlation with model predictions, which combined with a comparative study between presented optimisation results and measured data from a real crusher indicate a significant potential for improvement. However, before redesigning crushers according to what is theoretically optimal, the resulting impact as well as the effects on the outcome of a crushing plant must be examined. Crushing plant simulations using the software PlantDesigner« are consequently performed. Models of existing crushers are altered, resulting in changed particle size distributions from some of the crushers in a crushing plant. Thence, it is concluded that significant gains can be made in terms of capacity, process yield and energy consumption.

Sep 13, 2010

By Holla L, Tyminski A

Stowing has been successfully used in many countries as a means of controlling surface subsidence, minimi ing incidences of spontaneous combustion, maintaining gate road stability and maximising coal recovery.Australian experience in stowing is limited but in the future increased extraction of thicker and/or multiple seams by longwall operations and resolution of conflict of alternative land u'ses may necessitate the use of stowing in coal mining. At present there is little incentive for mining companies to introduce and operate a stowing system because costs have to be borne by the individual companies and benefits spill over to society and the State. Cost sharing by the industry and State incentives may overcome the problem of cost disincentive.

Jan 1, 1987

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

By P. S. B. STEWART

As part of a continuing study of mechanisms of breakage, the grinding at Nairne Pyrites Pty. Ltd. was traced by the addition of barytes and the results compared with parallel small scale laboratory tests. It was confirmed that the same basic mathematical functions described the behaviour of the full scale ball mill as those established in the small scale mill. However, an additional classification function was required to define the behaviour for the rod mill and was evaluated as a function of size from the experimental data. The classification and grinding of the pyrites ore was assessed from steady state size distributions around the circuit.

Jan 1, 1971

Several glacial episodes have been distinguished in the Shotover Valley. These produced fluvioglacial aggradational deposits downvalley from the terminii, commonly with well-preserved terrace treads, as exemplified near Skippers. Chronological links can be determined between the Shotover tills and sediments and assessed equivalent deposits in the Wakatipu Basin/Kawarau Valley region through axial valley profiling. Constructed relationships suggest older Shotover events were probably large and left little detrital deposits within the valley. In contrast, the younger advances were smaller and valley-constrained. They are modelled as being wholly of Waimea or Otira Glaciation age, advances from the latter period producing the visually distinctive flights of terraceremnants. Both the terraces and the inner gorge, now occupied by the Shotover River, have been extensively worked for alluvial gold. Enrichments in the former environment have predominantly been as bottom or intermediate lags produced during degradation phases of catchment erosion. Surface lags have been locally targeted. Placer mining in terrace areas involved both tunnelling and sluicing techniques. In the modem river the greatest concentrations were on the schist or false bottoms, although flood gold has always contributed to the returns. Placer mining techniques here were highly variable.

Jan 1, 1998

I find that during the short time I have been in this district, the majority of boilers are, and have been, receiving very bad usage owing to the difficulties which they have to contend against, viz., oil and bad water. Oil on the heating surface of a boiler is of a highly dangerous nature inasmuch as it allows the surface to become overheated, owing to the water not coming into direct contact with the plates, and it naturally follows that when the crown sheets of a flue or firebox become overheated, you lose a considerable amount of the strength of the plate, and the flue or crown comes down. Referring to the oil question, I find that too much care cannot or exercised on the part of engine drivers in order to minimise as much as possible the internal lubrication of the various engines under their control. For I consider that it is here that the most of the trouble is caused. My reasons for stating such to be the case, are:-That the majority of enginedrivers before coming to this field have been used to driving engines that have been exhausting into the atmosphere, and probably they have been taught that it is far better to use a little extra lubrication than to have a hot bearing. So far so good. But one thing that must not be overlooked is that on these fields the conditions are altered in this respect, as the majority of engines in this district are not exhausting into the atmosphere, but are condensing their exhaust steam and using the water so condensed for feed purposes.

Jan 1, 1901

By P Illig, R Newberry

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Recent exploration efforts in Eastern Interior, Alaska have discovered significant ca 72 Ma Au-Cu-Ag sulfide-amphibole skarn mineralisation within metamorphic rocks of the Yukon Tanana Terrane, 20 km SE of Tok, Alaska. Contango ORE, Inc’s 1.1 Moz Au-equivalent Peak deposit skarn discovery is hosted by an argillaceous marble layer in quartzite and micaceous quartz schist. This skarn mineralisation is both younger and much more Cu-rich than the typical ca 90 Ma Au intrusive-related gold deposits in the Tintina Gold Belt (eg Ft Knox and Pogo). Silicates at the Peak skarn are predominantly high Cl-, randomly oriented, Fe-rich amphibole, lesser chlorite and minor (<1 per cent) residual clinopyroxene (Hd80–90). Amphibole is ferroedenite to hastingsite and contains up to 4.2 wt per cent Cl-. Pb-Zn-Sb veins are most distal and cut schist wall rocks and amphibole skarn. The predominant sulfide mineral is pyrrhotite, with subordinate arsenopyrite and lesser chalcopyrite, native gold, minor pyrargyrite (Ag3SbS3), trace Jonassonite (AuBi5S4) and maldonite (Au2Bi). Native bismuth, galena, hedlyite (Bi7Te3) and Joseite-A (Bi4TeS2) are also present.Unmineralised garnet (Ad38–43) + pyroxene (Hd60–63) and pyroxene-rich (Hd76–80) skarn occurs in different fault blocks from the Peak skarn and represent proximal skarn related to different intrusive centres. Amphibolites in the region are true metabasites, display metamorphic fabrics and lack the high Fe-Cl compositions of the amphiboles in mineralised skarn. Residual clinopyroxene in the Peak skarn is rare, and most of the hornblende is coarse radial splays that shows no evidence for replacement of pyroxene. Consequently, we propose that the sulfides and hornblende were mostly direct replacements of argillaceous marble and not formed by retrograde alteration of pyroxene-rich skarn. The high-Cl amphiboles indicate that the fluids were Cl-rich and presumably carried Cu via Cl complexing, unlike the Cl-poor fluids associated with ca 90 Ma Cu-poor deposits of the region.CITATION:Illig, P and Newberry, R, 2015. Amphibole Au-Cu skarn and massive sulfide replacement at the Peak deposit, Eastern Interior, Alaska, Peru , in Proceedings PACRIM 2015 Congress, pp 415–422 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Techniques Used and Problems Encountered in Normal and Reverse Circulation Drilling at the Mt Roseby Project, Cloncurry, North West Queensland

Sep 13, 2010

By Misra V. N

Davis tube tests were conducted on a Koolanooka magnetite iron ore sample, supplied by Kingstream Steel Ltd, to determine the optimum grind size, maximum iron recovery and the cleanness of the products from low intensity magnetic separation (LIMS). The ore sample contained 38.6 per cent iron, 37.8 per cent silica, 6.5 per cent magnesia and 0.54 per cent alumina. XRD and microscopic examination showed that the main minerals in the ore were amphibole (42 per cent), magnetite (39 per cent), and quartz (14 per cent). Amphibole, (Mg, Ca, Fe),Si8O22.2(OH), containing 50.3 per cent SiO2, 35 per cent FeO and 11.5 per cent MgO is the main gangue mineral in the ore, and about 30 per cent of the total iron in the ore is contained in the amphibole. Heavy liquid separation tests showed that it is very difficult to separate iron from silica by gravity separation to obtain a high quality iron concentrate. Three grind sizes were initially tested, ie 45, 38 and 20 ¦m. It was found that grinding to 100 per cent -38 ¦m (P80 of 29 ¦m) appeared to be the best option for liberating the magnetite from gangue minerals. The iron recovery to the LIMS magnetic product for the 100 per cent -38 ¦m sample reached 73 per cent and the iron content was 65 per cent. Further test work suggested that the optimum grind size was a Psu of 25 ¦m.

Jan 1, 1999

By Mann V. I

The Mount Isa property has been in operation since June, 1931; during this period operations have changed from the production and treatment of carbonate ores to the mining, milling, and smelting of sulphide ores. This change involved revision of ore-extraction methods.Stoping methods have been designed to apply to parallel lodes ranging from 10 ft. to over 100 ft. in width and dipping at 50° to 60°. The hardness and strength of the ore and enclosing wall rocks, together with the strength and thickness of the country rock between lodes, have permitted the selection of a sub-level stoping method for mining the sulphide ores.

Jan 1, 1938

By Lottrey A. L, Sowerby B. D, Cutmore N. G

On-line monitoring of low rank coal quality during input to a process has the potential to provide benefits through: ò anticipation of coal quality variations prior to utilisation; ò provision of a tool to help determine the influence of coal quality on process behaviour, and ò provide a direct measure of coal quality for pricing. Moisture and ash are the two most significant coal quality parameters for combustion. They determine the energy content which can be derived from the coal and the problems arising from the presence of ash in the process (eg ash fouling, corrosion, erosion, particulate emissions and ash disposal). Extensive pilot-scale testing and full-scale experience has shown that specific coal/ash constituents (eg Na2O/ash ratio, acid-soluble aluminium, silica, sulphur contents, etc) are also important for the behaviour of Latrobe Valley brown coal during combustion, ash formation, deposition and removal of ash in precipitators and furnace ash hoppers. This paper discusses the range of on-line analysis techniques which have been investigated and their application to low rank coal analysis. Preliminary results from a joint SECV/CSIRO project which aims to develop two separate advanced instrument systems are also presented. These systems are based on: ò microwave attenuation and phase shift - for direct determination of moisture content; and ò inelastic neutron scattering - to provide total hydrogen, carbon, chlorine and ash contents, with potential for calculation of moisture content, specific energy, sodium content and Na20/ash ratio using correlations.

Jan 1, 1992

Variations in product distribution in the carbon-sulphur dioxide system due to variations in reaction temperature, sulphur dioxide concentration in the feed gas, and gassolid contact time were studied in detail for a brown coal char. The results were compared with those for two wood chars, a coke prepared from Liddell coal and two cokes prepared from Ac1and coal. Conditions were chosen such that gas-solid diffusion rates did not hinder chemical attack of the carbon.With brown coal char under suitable conditions, the selectivity of sulphur in the sulphur dioxide fed, to either elemental sulphur or carbon disulphide, was in excess of 90 per cent. The wood chars gave very similar product distributions Ito brown coal char. However, the cokes from Ac1and and Liddell coals were respectively approximately three and seven times less reactive than the brown coal char.The approximate carbon holdup required to just achieve total conversion of sulphur dioxide, and thereby achieve high selectivity to elemental sulphur, is given as a function of reaction temperature.

Jan 1, 1974

The Bureau de Recherches Geologiques et Minieres (BRGM) (a French Government-sponsored geological and mining agency), through international experience gained over many years, has become very skilled in alluvial prospection, particularly for diamonds. The research laboratories within the BRGM have also been active in creating new mineral processing equipment, some of which is directly applicable to such prospection. One such development, the mobile prospection unit, is described and its application in mineral exploration is demonstrated by a consideration of the diamond search in Australia and the general exploration of the Massif Armoricain (France). Because this latter study was fundamental in the development of the concept of 'mineral-geochemistry', and its application in mineral exploration, it is also briefly described.

Jan 1, 1971

Gold was determined directly in eight different mill cyanide solutions, by atomic absorption spectroscopy in an acetylene-air flame. Some of the mill solutions were diluted with water to bring them into the most sensitive absorption region (5-50 p.p.m. Au) whereas those solutions with very low gold content «2 p.p.m.) were concentrated by evaporation.Calcium was complexed with ethylene diamine tetra-acetic acid (EDTA) to avoid the undesirable effect of a precipitate on atomization.When added to standard gold solutions, EDTA had no effect on absorption, nor did any of the impurities common in mill cyanide solutions.Known amounts of gold, ranging from 2 to 30 p.p.m., were added to mill solution'aliquots and recovered to within 100 ± 2·5 per cent. For duplicate determinations under normal worKing conditions, standard deviation was 1·32 p.p.m.Excellent agreement was found between atomic absorption gold values and accurate fire assay values.INTRODUCTIONAtomic absorption spectroscopy has been shown to offer a rapid and accurate method for the determination of trace amounts of a number of metal ions. In the field of primary metallurgy atomic adsorption has been used for routine determinations of lead, copper, silver, zinc, cadmium and iron in a variety of raw materials and intermediate products.The scope of atomic absorption spectroscopy was reviewed recently by Willis (1963).The noble metals silver, gold, platinum, rhodium and palladium were determined by atomic absorption from chloride solutions by Lockyer ·and Hames (1959). In their determination of gold down to 1 p.p.m., they found no interference from the noble metals, nor from considerable excess...

Jan 1, 1964

By K Cameron, S Strohmayr, J Wallace

In 2012, a single module heavy medium cyclone plant (HMP) was installed at the Glencore Zinc’s (then Xstrata Zinc) McArthur River lead zinc mine. The HMP formed the first part of the MRM Phase 3 Project to increase run of mine (ROM) capacity from 2.4 to 5.5 Mt/a.The purpose of the HMP is to remove liberated gangue from the crusher product at minimal loss of valuable mineral. The McArthur ores are very finely disseminated requiring a fine primary grind size prior to rougher flotation. Rejecting waste prior to grinding therefore offers significant power and grinding media savings. The plant was designed to treat only those ores with a reasonable upgrade ratio at the target zinc recovery across the HMP of 95%.On this basis, a 1.8 Mt/a single module plant was built based on 250 t/h feed rate and 82% availability. In contrast to existing base metal heavy medium plants in Australia, the MRM Flow sheet utilised the principles in modern coal heavy medium cyclone plant design. Since commissioning, the plant feed rate has been significantly increased and is now normally operated up to 540 t/h (dry basis).Although this throughput increase is partially due to debottlenecking work, it is also attributable to the conservative design parameters for base metal heavy medium cyclone circuits in comparison to those used in equivalent coal circuits.This paper discusses Flow sheet design and compares traditional base metal design parameters with those achieved at MRM and those of modern coal plants. It provides information on plant capital and operating costs and the net savings realised by its installation. In addition to power and grinding cost savings, the paper also highlights the savings in water through rejection of near dry waste and reduction of tailings pumped to the storage dam.CITATION:Wallace, J, Strohmayr, S and Cameron, K, 2015. McArthur River Mine heavy medium plant – the benefits of applying modern coal plant design principles to base metal heavy medium separation, in Proceedings MetPlant 2015, pp 311–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015