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By Mroczek C. R, Evans D. A

Renison is a world-class ore deposit that has been mined for over 100 years. It currently has reserves of 5.06 Mt @ 1.88 per cent Sn and a projected mine life of 8.5 years. Recent advances in the geological understanding of the deposit have been associated with detailed structural and geophysical investigations accompanied with the discovery and exploitation of the Rendeep orebodies. Mineralisation is linked to the forceful emplacement of the Devonian Pine Hill Granite that resulted in a complex brittle (-ductile) deformation of the Eo-Cambrian host stratigraphy. Dilation jog development on the Federal-Bassett Fault in the Federal and Rendeep areas provided access for cassiterite-rich magmatic hydrothermal fluids responsible for carbonate replacement Mineralisation.

Jan 1, 1997

By Lawson F

Synthetic calaverite (Au Tez) has been prepared and its physical properties checked.Simple flotation tests indicate that the recovery of calaverite should be possible using n-butyl or sec-butyl xanthate collectors under approximately pi I neutral conditions with a copper sulphate activator.Roasting calaverite in air at moderate temperatures resulted in its decomposition with the formation of elemental gold and tellurium dioxide.In alkaline oxygenated cyanide solutions, both gold and tellurium tend to dissolve. At pHs less than 14, about 50 per cent of the tellurium remains as elemental tellurium; however in very strongly alkaline solutions, essentially all of the tellurium is converted to the soluble tellurite ion (TeOl-).However, even at high pHs, the solubility of gold in the cyanide solution is still low due almost certainly to passivation effects.

Jan 1, 1991

By Trumpff H

Opencast Lignite Mining requires topwall strata of seams to be fully depleted and footwall aquifers sufficiently depressurized. To prevent a spread of the cone of depression into protected wetlands some distance away, alternatives had been investigated such as closing water works, underground slurry wall barriers and recharge by infiltration. As a result of these investigations, the infiltration method has been chosen and in a first phase during the next decade it will utilize as much as 55 x 106 m3/year. Using this approach, the survival of the wet lands is assured.

Jan 1, 1988

By J Safarian, M K. Kar

Bauxite residue is one of the most important by-products from the alumina industry with no commercial use till now. The utilisation of bauxite residue through pelletising with different lime additions, hydrogen reduction, and smelting has been studied in this work. Three different types of green pellets were made with varying calcite-to-bauxite residue ratio and subsequently sintered at elevated temperatures. The sintered pellets were isothermally reduced at 1000°C under hydrogen gas followed by smelting of the reduced pellets in argon at 1500°C. Smelting of the reduced pellets leads to the recovery of metallic iron and the formation of a leachable calcium aluminate slag. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterise the phases and microstructural analysis. The iron produced in the smelting process has a high purity, above 99.5 wt per cent. While the iron content of the slags is quite low, and the slags shows variations of krotite (CaAl2O4), gehlenite (Ca2Al2SiO7), and perovskite (CaTiO3) phases based on the variation of calcite addition. It was found that the more calcite addition in pelletising yields higher percentage of krotite phase as compared to lower calcite-containing pellets. Employing quantitative XRD analysis, the krotite phase fraction was found approximately 85 wt per cent for higher calcite-added pellet, and around 74 wt per cent for lower calcite-added pellet. FactSage™, ver 8.1 (Thermfact and GGTTechnologies) thermodynamic software was used to evaluate the obtained experimental data, they both revealed that the

Jun 19, 2024

AustraliaÆs current interest in renewable energy is based on a desire to reduce the countryÆs greenhouse gas emissions. Wood from sustainable sources offers a unique opportunity to combine greenhouse gas benefits with other significant environmental and social benefits, including salinity mitigation, carbon sequestration, soil replenishment and rural industry. The challenge is to make renewable energy from wood in a cost competitive manner, so that this broad range of benefits may be best realised. Bioenergy and carbon products are of great interest as new, commercial forestry products that can drive large-scale environmental tree planting:In Western Australia, Enecon has worked with Western Power Corporation to build the first full-scale plant for integrated processing of mallee eucalypts, to produce activated carbon, renewable power and eucalyptus oil. It is intended that this plant is the first of a number of such plants to help catalyse environmental tree planting in Western Australia. New technologies being developed overseas may provide competitive bioenergy in areas where traditional markets for wood do not exist. For example, pyrolysis converts wood into a bio-oil that may be transported to remote sites for power generation in gas turbines. Pyrolysis also produces wood char. Pyrolysis and wood-to-ethanol technologies, coupled with short rotation coppicing trees, offer the long-term prospect of large-scale production of renewable fuels around the country.

Jan 1, 2006

The late 1960's and 1970's saw the initial development of the coal resources of the Bowen Basin of Queensland. The projects developed relied on large scale, open-cut operations using draglines for overburden removal and, in the majority of cases, project viability could be established based solely on those open-cut operations. Many of the mines developed in the 1980's have the same characteristics.Unlike these mines, the German Creek Mine has limited open-cut reserves at low overburden to coal ratios, and planning of the complex involved a large open-cut mine capable of developing early cash flow, with phased introduction of underground mining to replace open-cut capacity as the strip ratio increased.

Jan 1, 1985

By Parsons A. E

The application of known pelletizing tech- nology was successful in the agglomeration of zinc concentrate into pellets of minus 6mm siz- ing using fine zinc calcine and sulphuric acid as binder. Subsequent roasting trials conducted in a 0.3 m diameter fluid bed reactor, showed that the pellets satisfactorily withstood hot physical abrasion during fluidization. Fines generation was low and the pellet calcine was hard, possessing excellent handling properties. Results of laboratory scale static pellet sinter- ing tests showed conclusively that the deterior- ation in sinter physical quality experienced with fine calcine was not apparent when the calcine was added to the mix in pellet form. Based on the results of small scale exper- imental work, a one tonne per hour pilot plant was constructed and operated. Several thousand tonne of pellets were produced-for fluid bed roasting in Badische Analin and Soda Fabrik (B.A.S.F.) turbulent layer (T.L.) roasters previously designed for roasting iron pyrite concentrate. Continuity of the T.L. fluid bed roasting operations was achieved when the waste heat boilers were replaced with atmospheric coolers and thus eliminated the problems of gas flow restrictions. Sinter plant trials were conducted over a period of two weeks with the addition of pellet calcine to the sinter feed. Results showed a marked improvement in sinter plant performance, and as a result of better bed permeability, increased sinter production was achieved, with- out significant deterioration in sinter quality.

Jan 1, 1974

By Loo C. E

Thirty two polyacrylamide flocculant samples were selected from the wide range offered to the Australian coal industry. An extensive test program was conducted to consider the properties of the flocculants, the substrates, the process conditions and the water chemistry encountered in coal preparation plants. The study indicated that flocculants with molecular weights of 12 to 14 million and degree of hydrolysis around 40% gave the best "average" performance over a wide range of process conditions. The pick-up and filtration of fine coal was demonstrated on a pilot scale to be a critical function of flocculant properties. This study also showed that the agitation intensity during flocculation was a critical parameter in determining the settling rate of the slurry and the clarity of the resulting supernatant. An electronic meter to measure agitation intensity was designed, constructed and tested to demonstrate how, for the first time, laboratory results can be implemented in operating plants.

Jan 1, 1989

By Johnson N. W, Quast K. B

Over the years there have been occasional references in the literature to the activating effect of cyanide in galena flotation with xanthates. These have usually been associated with the processing of lead-zinc or copper-lead-zinc ores. Bubble contact curves for the pure galena-xanthate system show a flotation edge at pH 10.4 independent of sodium cyanide concentration which was thought due to hydroxyl ion, not cyanide ion.Flotation tests were conducted on samples of Mount Isa lead-zinc ore using varying concentrations of sodium ethyl xanthate and sodium cyanide. At low collector concentrations, galena recovery kinetics improved with sodium cyanide addition, and the higher the cyanide concentration, the higher the galena recovery rate. At higher collector concentrations, galena recovery rate was independent of sodium cyanide addition.For a given collector addition, the lead grade-recovery curve shifted to an improved position with increasing sodium cyanide level. For the same recovery there was an increase in the lead grade with increased sodium cyanide addition, and this increase was most dramatic at high sodium cyanide concentrations.The presence of sodium cyanide during the grinding of Mount Isa ore caused surface passivation of the iron sulphides and possibly the sphalerite.These sulphides, therefore, reacted with less of the oxygen present in the pulp, hence more oxygen was directed to the surface of the galena. This resulted in an enhancement in the total amount of xanthate adsorbed on the galena that is reflected in the improved flotation response of that mineral.

Jan 1, 1990

By Erceg MM

The Waft River gold deposit is hosted by low grade metasediments which have been intruded by a dacite/andesite porphyry complex. Wafi River is classified as a high sulphur, epithermal type gold deposit having: a high sulphur content, a close association with calc-alkalic igneous rocks, zoned advanced argillic and argillic alteration, and enargite group minerals. Gold occurs as minute inclusions in pyrite and pyrrhotite within intermediate dickite/kaohnite - interlayered illitic clay alteration zones. Central leached silicic, alunite and pyrophyllite zones and peripheral chloritic zones are low in gold. The gold mineralisation at Wafi is interpreted to have been predominantly caused by mixing of hot upwelling acidic magmatic mineralised fluids with cool, neutral meteoric/hydrothermal fluids within permeable sediments. Locallised high grade breccia zones are encountered within the porphyry. An initial resource in excess of I million ounces Au has been defined.

Jan 1, 1990

Having provided basic data in the main paper I would now like to move on to discuss these areas in broader terms and to examine the various coalfields in terms of their tectonic setting and depositional environment and ultimately to make some brief comments on the factors which may have controlled deposition.

Jan 1, 1975

Recognition is the most important aspect in the use of breccias as an exploration tool. Ore-hosting breccias occur in a wide variety of environ-ments, shapes, compositions and characteristics, but generally present favorable loci for the deposition of ore mineralization in epithermal, porphyry copper-gold-molybdenum, massive sulfide, carbonate-hosted, sedimentary lead-zinc deposits and others.

Jan 1, 1990

In the last two decades, equipment used in the coal mining operations has become much more sophisticated. The way that work is organised and performed in the industry has also changed significantly. Changes in equipment specification or procedures inevitably means that the risk associated with that equipment or procedure also changes. In an attempt to address this the Joint Coal Board Occupational Health and Safety Trust (JCB) commissioned the University of New South Wales Mining Research Centre and Mine Site Technologies to perform a feasibility study into the development and deployment of Virtual Reality (VR) based training simulators in the New South Wales coal industry. The main aims of the study were to identify, the key providers of VR Technology, the VR options available to the JCB and the information that would need to be included in any simulator. It was anticipated that a critical assessment of these components would produce a format for a cost effective, state of the art simulator that could be readily accessed by all mines. The expectations of the feasibility study were that VR should offer three-dimensional (3D) simulations that are interactive, high-resolution models of real environments based on best practice Safety Management Plans. It was anticipated that the simulations would allow trainees to experience the consequences of poor decision-making and allow them to learn from their mistakes in a safe and forgiving environment. It was envisaged that such simulators would become an addition to the existing training methods used in the industry.

Jan 1, 2003

The emerging discipline of ægeometallurgyÆ is not new but is becoming increasingly recognised as a discrete and high-value activity that reflects an ongoing commercial and cultural trend towards more effective mine site integration and optimisation. The AMIRA International P843 æGeMIIIÆ project (Geometallurgical Mapping and Mine Modelling) is a major new cross discipline research collaboration designed to provide support for this emerging industry trend. The project is currently supported by 18 global mineral companies and involves collaboration between the CODES Centre of Excellence (University of Tasmania), JKMRC and BRC (University of Queensland) and CSIRO Exploration and Mining. These groups represent recognised research excellence in the fields of economic geology, automated core logging, advanced microscopy and process mineralogy, mineral processing, mine planning and resource optimisation. The needs and challenges of geometallurgy as an integrated activity will be outlined together with the ongoing contribution and aims of the AMIRA P843 æGeMIIIÆ project. The main emphasis is on development of predictive geometallurgical indices for key processing performance parameters that reflect inherent geological variability. The ultimate aim is to provide predictive indices of geometallurgical performance that can be confidently embedded into resource models and used for risk-defined mine planning and optimisation.

Jan 1, 2008

By Shrivastava P, Humphreys M, Guibal D, Deraisme J

Customer requirements concerning the final products of iron mines are extremely stringent. Because of this, there is an ever-increasing need for mine operators to monitor and strictly control the quality of their product. This quality, as measured by the stockpile grade variability, is the result of a very complex process, where natural characteristics (the orebody and its geology) are transformed through the mining technique (open pit, shovel and truck fleet, blending into stockpile). The only way to reproduce and hence to control the variability of such a system, which is composed of several interactive sub-processes, is by simulation. A complete simulation of a Hamersley Iron Pty Ltd (HI) ore deposit has been undertaken to forecast the impact and cost of various mining methods, mining schedules and product stockpile sizes on variability of chemical and physical characteristics of the products. The mining simulation was made on a conditionally simulated orebody. On a range of criteria, the simulation was considered to fulfil the objectives set and was a valuable aid to analysis of product grade variability, operating and capital costs, selection of equipment, mine scheduling and setting of product grade targets.

Jan 1, 1994

By Tonks E. E

The earliest discovery and mining of coal in the northern area of the Greta Coal Measures at Anvil Creek in 1862 was by William Farthing, however, some official records attribute the discovery to Thomas Frost in 1864. Frost's discovery was examined by William Keen, government examiner of coalfields, and further prospecting was carried out. This was followed by the pioneering work of C S Wilkinson, government geologist in 1884. Subsequently in 1886 C S Wilkinson entrusted a detailed survey of the coalfield to the then geological surveyor, T W Edgeworth David.The outcrop of the Greta Coal Measures around the Lochinvar dome was mapped by Edgeworth David and as soon as he reported his discovery, the Department of Mines reserved in the interests of coal mining an area of 23700 acres, which extended between what became the South Greta and Abermain No I Collieries.

Jan 1, 1993

The Manto Verde copper mine (Atacama Region, Chile) is due to go into production in 1996. It will produce 40 000 tonne/year of copper cathode by heap leaching/SX-EW. Mineralogical studies were undertaken in conjunction with the metallurgical testwork program to characterise the ore and its response to leaching by dilute sulphuric acid. The leachable copper mineralogy is dominated by the oxide copper minerals: brochantite and malachite with minor chrysocolla and atacamite. The gangue minerals include abundant orthoclase, specularite, quartz and chlorite with minor muscovite and trace smectite clay, calcite and limonite. The study showed that complete or partial decomposition of calcite, chlorite, smectite and wad consumed acid and generated solution impurities (Ca2+, Fe2+, Mg2+, A13+, K+, Si4+ and Mn4+2+ ). Although these were manageable at Manto Verde, their uncontrolled build-up could have affected the operation in several ways: the degradation of heap penneability and fonnation of crud in the SX plant from the precipitation of gypsum, goethite, colloidal silica and jarosite; and the entrainment of contaminated pregnant leach solution in the SX organic resulting in the transfer of impurities to the electrolyte and subsequent effects on cathode quality and electrowinning efficiency. In conclusion, process mineralogy played an important role in understanding and managing potential mineral-related problems in the heap leaching and SX-EW recovery of Manto Verde ore.

Jan 1, 1994

Brunswick Mining and Smelting Corporation Limited operates a large base metal property near Bathurst, New Brunswick in eastern Canada. Nominal capacity for the underground mining operation and concentrator is 10 250 DMT/day. Four concentrates are produced by differential flotation technology to recover minerals containing copper, lead, zinc and silver. Two characteristics of the Brunswick ores have a major impact on mineral processing operations. The mineralogy of the ore is complex with a total sulphide mineral content of 85 per cent. In addition, the ore is extremely fine-grained, and satisfactory liberation is difficult to achieve. These characteristics directly influence flotation selectivity and thereby affect metallurgical performance. Significant improvements in metallurgical performance have been achieved through the application of basic grinding and flotation principles using conventional milling equipment. Current operating practice and the metallurgical advancements are detailed.

Jan 1, 1993

By M Saghaeian, A H. Baladastian, A Dehghani Ahmadabadi, V Sheikhzadeh, R Hejazi

This research was done to reduce silica from mixed hematite concentrate of Barfkar Iron Ore Sample and increase Fe grade using reverse flotation method (Depressing Hematite and floating Silica). The used sample in the reverse flotation tests was a mixture containing two types of hematite concentrates (Spiral cleaner concentrate and Slon-VPHGMS cleaner concentrate) with the percentage of 16 per cent and 84 per cent, respectively. Fe grade of two samples was 59.31 per cent and 57.52 per cent and SiO2 grade was 5.83 per cent and 6.71 per cent, respectively. After mixing, the Fe and SiO2 grade of the mixed sample was measured at 58.10 per cent and 6.20 per cent. For flotation tests, effect of variable operational parameters including feed size distribution (d80 = 130 microns and d80 = 53 microns), pulp solidity (25 per cent and 30 per cent w/w), pH (9.70, 10.20 and 11), Sodium silicate as a dispersant (500, 1000 and 2000 g/ton), Starch as a depressant (500, 1000, 2000 and 3000 g/ton) and EDA as a collector (180, 300, 400 and 500 g/ton) were investigated. For evaluating the influence of Sodium silicate and Starch dosage, initial flotation tests were performed on the main sample (d80 = 130 microns). These two parameters had no significant effects on the yield, Fe, and SiO2 grade of flotation concentrate based on test results. In the next step, screen analysis was carried out on the main sample for mineralogical studies. Accordingly, the suitable size distribution for releasing Fe and SiO2 particles was smaller than 53 microns. Therefore, the sample was crushed until d80 = 53 microns. Then, supplementary tests were performed on the crushed sample for studying the pH range, pulp solidity, and EDA collector dosage. After doing silica removal flotation tests based on the designed pattern and comparison of the results, the conditions consisting of size distribution d80 = 53 microns, pulp solidity 25 per cent, pH 10.20, Sodium silicate 1000 g/ton, Starch 1000 g/ton, and EDA 500 g/ton was selected as optimum values. In the last test, Fe and SiO2 grade was measured at 60.00 per cent and 3.93 per cent, respectively, and Fe recovery was obtained at 74.93 per cent.

Aug 24, 2022

By Kubo H, Ninomiya R, Ojiro T, Sato T

New high-strength Zn alloys for moulds are demanded from the automobile and electric industries in Japan, because the s rength of Zn moulds is still not high enough for the mass production. There are two approaches to improve the strength of Zn alloys. One is to increase the Al content. ZA alloys (ZA-8, ZA-12, ZA-27) were developed through this approach. The other is to increase the Cu content. But it is known that an increase in Cu generally depresses the castability of Zn alloys, so that the alloys with increased Cu have been rarely studied until now. In this study a reconciliation between the strengthening and the castability of Zn alloys by enriching both with Al and Cu has been attempted. Accordingly we have studied on the Zn alloys containing 4 to 25 mass per cent Al and to 24 mass per cent Cu have been studied. Their fluidity, which primarily corresponds to the castability of the alloy, were measured first and 19 alloys were selected based upon their fluidities and casting temperatures. Mainly the mechanical properties of all 19 alloys were tested and some were found to be excellent in both strength and castability. Z1009 (Zn-IOAI-9Cu-0.02Mg alloy) cast in a sand mould has the tensile strength of 360 MPa while ZAS (Zn-4AI-3Cu-0.04Mg alloy), which is the most popular alloy for moulds, is 215 MPa. Z2520 (Zn-25AI-20Cu-0.02Mg alloy) cast in a sand mould has a Vickers hardness of 178, compared to 107 for ZAS and 104 for ZA-27 (Zn-27AI-2Cu-0.02Mg). Furthermore the castability of Z1009 is as good as that of ZAS. The underside shrinkage occuring in casting ZA-27 is restrained in Z2520.

Jan 1, 1993