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By V P. Beskrovnaya

Tests for the development of a metals recovery technology from samples of a Russian gold-bismuth deposit were carried out. Gold, silver and bismuth assay reported 5.6 g/t, 3.0 g/t and 0.08 per cent, respectively. Two flow sheet options were pilot plant tested: gravity/cyanidation of gravity tailings with subsequent flotation of cyanidation/carbon-in-pulp (CIP) tailings, and gravity/flotation concentration with cyanidation/CIP of concentrates. Option 1 results showed lower gold, silver and bismuth recoveries (81.3 per cent Au, 55 per cent Ag and 74.0 per cent Bi) due to low flotation efficiency for cyanidation tailings. Therefore, a flow sheet involving gravity/flotation concentration to produce bismuth-gold concentrates (0.8 per cent Bi) with subsequent cyanidation/CIP was recommended. Gold, silver and bismuth recoveries obtained by this method to the combined gravity/flotation concentrate were 90.2 per cent Au, 83.3 per cent Ag and 80.2 per cent Bi of the ore, respectively. Overall gold, silver and bismuth recoveries were 83.0 per cent Au, 40.5 per cent Ag and 80.2 per cent Bi, respectively. Gold and silver recoveries to the cathode precipitate were 92 per cent Au and 48.6 per cent Ag (per operation). Reagents consumed for flotation were 0.1 kg lead acetate/t ore, 0.4 kg butyl xanthate/t ore, 0.2 kg T-80 frother/t ore, 0.02 kg sodium hexametaphosphate/t ore, 0.15 kg copper sulfate/t ore. Reagents consumption for cyanidation was 0.42 - 0.48 kg NaCN/t ore and 0.2 kg CaO/t ore. It was recommended to deliver bismuth concentrates after hydrometallurgical treatment to a smelter. Overall bismuth recovery including bismuth recovery achieved by pyrometallurgy was 60.0 per cent. However, it was obvious that delivery of bismuth concentrates to a smelter and their commercial treatment would be very expensive due to relatively high mass pull of bismuth concentrates (7.6 per cent of the ore weight). For this reason, thiourea leaching and hydrochloric acid leaching with subsequent cyanidation/CIP were investigated as alternatives to cyanide leaching. These two alternatives were proposed to enable optimal recovery of valuable metals from concentrates on-site. Recoveries obtained by thiourea leaching were 91.2 per cent Au, 90.5 - 91.9 per cent Bi and 77.0 - 78.1 per cent Ag. However, that method required considerable capital and operating costs. As an alternative, hydrochloric acid leaching with subsequent cyanidation was investigated. Test results showed improved gold, bismuth and silver recoveries, which were 94 - 95.9 Au per cent, 94 - 96 Bi per cent and 76 - 78 Ag per cent, respectively. Hydrochloric acid consumption was 100 kg/t concentrate or 7.6 kg/t ore. Current efficiency during electrowinning was about eight to 12 per cent. A recommended flow sheet involving hydrochloric acid leaching of concentrates, electrowinning of bismuth from solutions, recycling solutions after electrowinning and cyanidation of hydrochloric acid leaching cakes is described. Overall recoveries achieved by the proposed flow sheet were as follows: 84.8 - 86.5 Au per cent, 75.8 - 76.9 Bi per cent and 63.2 - 64.9 Ag per cent. Based on results from these tests, initial data for a bankable feasibility study and plant designing were developed.

Jan 1, 2007

By P Vasconcelos, M-F Zhou, X-F Zhao

The eastern part of the Yangtze craton (eastern China ) is marked by a number of medium to small size porphyry Cu-(Au-Mo) deposits. A detailed geochronological study and existing data suggest that these deposits were emplaced in the 144 - 136 Ma interval. They are spatially and temporally related to voluminous mafic and alkaline magmatic rocks ranging in composition from gabbros, syenites, A-type granites and their volcanic counterparts. This indicates that the porphyry Cu-(Au-Mo) deposits in the eastern Yangtze craton were generated in an intra-craton extensional tectonic setting, which is distinctly different from the compressive environment of oceanic or continental arcs of the Pacific Rim where numerous giant porphyry Cu deposits were formed. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Erceg MM

The Red Dome deposit is located about 15 kilometres by road west of Chillagoe in far north Queensland. The deposit is within a well known band of mineralisation which is adjacent to the Chillagoe - Mungana railway line. Earlier this century several mines were operating in this area, some of which were supplying feed-stock to the copper smelters which were operating in Chillagoe at that time.The area around Chillagoe has long been an interesting geological region with numerous locations exhibiting significant gold and base metal mineralisation.The Red Dome area of some time, however it was not became involved that the apparent. The upsurge in seventies added further investment.mineralisation had been known for until Noel Adam, a prospector,true potential of the area became the gold price in the late encouragement for additional

Jan 1, 1986

Members of The Australasian Institute of Mining and Metallurgy are engaged in locating, extracting, processing, marketing and converting the worldÆs mineral wealth for its consumption in a useful form. We have an ethical responsibility as professionals to carry out our roles in such a way that we seek to optimise the recovery of that wealth for the benefit of the community, not only now, but also in the future. To be able to optimise, we must be able to measure with confidence the value of the commodity through the various stages of treatment from discovery of a geological anomaly to the end use. This introductory paper will provide an overview of some aspects of the issue, including the possible extension of the coverage of The InstituteÆs Codes to production accounting and reporting.

Jan 1, 2002

First of all, I should like to thank you for theopportunity to be with you tonight and tocongratulate the Kalgoorlie and Perth branchesof the Australasian Institute of Mining andMetallurgy in initiating this most importantConference.It could not have been better timed.Gold is riding a crest of the wave, leading theresurgence in the State's mining industry.The strong and stable economic policies whichhave been pursued both by the Burke LabourGovernment in this State and by the HawkeGovernment in Canberra, whilst they have ofcourse only been part of the reason for thestrong recovery in the mining industry - a l o tof it being due t o international factors - havecertainly assisted and ensured that the miningindustry in this state has been able to takefull advantage of the changed world situation.

Jan 1, 1984

By M Maslowski, J B. Gemmell, D R. Cooke, C Zesati, J Castorena

The Palmarejo, Guadalupe and La Patria Silver-Gold epithermal vein deposits occur in south-westernChihuahua state, Mexico. The veins are hosted in a volcano-sedimentary sequence that comprises andesitic to basaltic resedimented volcaniclastic rocks, together with less abundant coherent and pyroclastic facies and minor red-beds. The host sequence is part of the Lower Volcanic Series, and formed in a magmatic arc environment during the Late Cretaceous to Early Tertiary Laramide Orogeny. The Lower Volcanic Series is overlain unconformably by an extensive sequence of Miocene rhyolitic ignimbrites, known as the Upper Volcanic Series. At this time, it is uncertain whether epithermal mineralisation was related to andesitic intrusions (85 Ma) and/or Oligocene rhyolitic dykes (25 Ma). An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Hall ST, Miles NJ

Recently an inorganic salt, sodium polytungstate (SPT), has become available that allows the preparation of non-toxic solutions of relative densities up to 3.1. It is relatively expensive and at the higher relative densities achievable, highly viscous. Alternative inorganic compounds may in the future be identified that overcome these limitations. The Australian Mineral Industries Research Association Ltd (AMIRA) has initiated a project to examine possible alternatives. However, it has been found that by the addition of finely divided ferrosilicon to solutions of SPT, relative densities of up to 4.0 can be achieved. A laboratory technique for density fractionation of sized mineral samples utilising this finding has been developed. This is currently being extended to study the potential applications of such liquids and suspensions in dynamic systems for mineral, coal and recycled waste separations.

Jan 1, 1993

This paper addresses the unique environ- mental programmes which prevail at Ranger and their importance in the future profitability, of Ranger Uranium Mines Pty Ltd. (RUM) Industrial relations, general safety, and occupational health have long been regarded as part and parcel of the concept to 'manage for profits'. More recently, the need for environmental protection has also become an important management consideration. This is particularly so at the Ranger Uranium Mine where environmental protection is very closely and continuously regulated. Since the commencement of operations at Ranger some three years ago the company has operated within these regulations and demonstrated clearly that yellowcake can be produced efficiently, economically and safely. The company also recognises that in order to ensure continuity of production, it will have to continue to operate within these strictly supervised Regulations.

Jan 1, 1984

By Summers DA

Faculty at the University of Missouri-Rolla have carried out research on the application of high pressure water jets as a means of excavat- ing coal for over 15 years. During the course of this time, a number of different concepts have been explored--the most recent of which has been to use high pressure water jets as a means of extinguishing an underground coal seam fire. This paper will examine the use of some of these technologies and will consider the results as a basis for discussion of further applications of water jets in the future. The structural pro- perties of coal which distinguish it from other adjacent geotechnical material and provide a considerable advantage to water jet cutting, will also be presented and the advantages of using this tool will be discussed.

Jan 1, 1986

By Brown P. L

A study has been made of the geochemistry of the Ronneburg mine district as input to the overall management strategy for the rehabilitation of the mine site. The study drew on the geological data and information store developed over the 40 years of mineral exploration and mining at Ronneburg, and on chemical data from the literature which described the chemical processes of weathering, oxidation, dissolution and precipitation of minerals. The geochemical processes were divided into three groups based on their rate of reaction. Fast processes were assumed to proceed to equilibrium and were modelled using equilibrium chemistry equations; slow processes were assumed to be proceeding at a quasi-steady state rate and were modelled using chemical rate equations; very slow processes were assumed to have no role in describing the geochemistry for rehabilitation purposes.

Jan 1, 1995

By Watkins JR

The educational system is a dynamic; a flow resource that can be significantly shaped, changed and - refined by educationists. This paper analyses these various facets of geo- science education in Australia. The Australian educational philosophy is essentially a laissez- faire model, a free market approach without any real government or professional directive or stratagem. Students are therefore free to choose their own educational pathway dependent only upon their ability and the access to courses. Geological education at the tertiary level in Australia is described and critically analysed. There is a real need for a rationalisation of geological education in Australia, and this rationalisation should include not only the number of courses offered but should also aim to fully define both the philosophy and purpose of geological education and the accreditation procedures for the Students.

Jan 1, 1986

By James DG, Turner JH

This paper describes laboratory testwork for the beneficiation of a medium grade iron ore, using Wet High Intensity Magnetic Separation (WHIMS). Factors leading to the selection of machine type for this method of separation are discussed and the design of the WHIMS section flowsheet of an iron ore beneficiation production plant are described including methods to achieve operational flexibility and adequate protection of the WHIMS separating chamber. The results of the commissioning and operation of the production plant over several years are described, together with experience developed in plant operation. Data on recovery of hematite over the full range of size fractions treated is presented and compared with data in the literature. Potential methods of improving plant performance are discussed. KEYWORDS: Iron ore beneficiation, plant design, wet high intensity magnetic separation.

Jan 1, 1993

By Madgwick J. C

Bacterial leaching of museum grade chalcopyrite and chalcopyrite concentrates at low sorptive relative humidities (55-91 per cent rH) was demonstrated. Optimum release rates were 13 and 27 mg/gram/100 days copper (Cu++) at 91 per cent and 80 per cent rH and 12 and 33 mg/gram/100 days iron (Fe++) at 80 per cent and 73 per cent rH for concentrate and "pure" chalcopyrite respectively. The optimum copper release rates occurred between 73 per cent - 86 per cent rH and 30-40 mM acid concentrations. Bacterial copper leaching rates were some twenty times slower for emersed copper concentrates, at low relative humidity, compared with submerged cultures. Bacterial copper solubilization was almost quantitatively inhibited above 150 mM acid levels (< pHO.8).

Jan 1, 1984

By Sheridan GD

Fifteen samples 'of clays and shales from the Adelaide area were selected from a total of 84 as representing material of possible value for the manufacture of light-weight aggregate. A detailed examination of the bloating. characteristics of these revealed four likely to be suitable. for expansion.' in a rotary kiln. One of these, a Tapley. Hill shale., was-fired in an 8 in. diameter rotary kiln, but con-tinuous bloating without ring formation in the kiln was not achieved. Steam,,-oxygen,, sulphur dioxide and carbon dioxide have been, suggested. as the agents of bloating. An examina-tion of .. the evidence : `leads to the conclusion that carbon dioxide derived from. carbonate minerals is likely to be the principal bloating agent. Attempts to bloat clays by the addition of mica were.not successful.

Jan 1, 1963

Pyrite is a significant gangue sulphide mineral in the Ok Tedi copper ore. Its presence in the flotation concentrate is not entirely desirable since it lowers the grade of the final copper concentrate. Lime depression of the pyrite has been practiced with some success. However, it has been observed that at the pH for pyrite depression a significant amount of the pyrite particles still float. To obtain further insight into the problem this work has been conducted to determine the composition, natural floatability and xanthate flotation behaviour of the various types of pyrite in the ore. The flotation results show that while some types of pyrite float well at high pH values, others are readily depressed. The implications of these results for Ok Tedi flotation plant have been Considered.

Jan 1, 1997

The Amacan Copper Project was constructed in the Philippines by a Finnish-Filipino Consortium during the years 1979 - 1982. The project involved a turnkey contract for a mine and a concentrator to process 25 000 tonne per day of porphy- ritic copper ore at a grade of 0.45% Cu. The orebody is located on Mindanao, the southernmost island of the Philippines, in rugged, mountainous terrain approximately 1 000 m above sea level. The adopted design principle was based on an efficient, straightforward installation utilising a minimum number of items of equipment each with high unit capacities. The consortium faced many problems which resulted in lengthy delays in construction and finally led to the client taking over responsibility for the completion of the project. The concentrator was successfully commissioned in July 1982.

Jan 1, 1986

By Thornber MR, Davidson LR

The cause of spontaneous combustion of pyritic black shale has been studied by calorimetry and other techniques. The conditions required for ignition to occur are: 1. A critical mass of pyritic black shale. 2. Acidity. 3. Fine shale particle size. 4. A high ambient temperature. 5. The exclusion of air during the preparation of a calorimeter charge. The reaction is characterised by an initial incubation period during which an unknown phase is produced. The build up and oxidation of this phase results in a chain reaction culminating in ignition. The mechanism is believed to involve the interaction of pyrite, sulphuric acid, ferrous sulphate, or meta-stable oxysulphates, with ammonium nitrate. The recommended strategy for prevention of premature detonation is to neutralise the acids in the shale with quick and slow release alkaline materials.

Jan 1, 1986

By R Loweth

The application of discreet event simulation has matured in modelling manufacturing systems for production analysis. This simulation tool was used in studying a number of mining operations, especially material handling processes. The study of truck-shovel operation including equipment matching, selection, and production estimation utilised the discrete event simulation for providing valuable decision-making information. The sophistication of the available simulation tools grew over times, and simulation driven animation was used to facilitate the validation and visualisation of the simulated system. This form of visualisation enhanced the simulation use greatly. First of all, it provided a communication medium to transfer information to the non-technical managerial personnel as a better decision-making tool. Moreover, the animated visualisation provided a validation tool to check the working of the simulated system and interaction among its components.

Jan 1, 2003

By Goldstone A

The paper introduces a newly developed multi-function test rig for fracture grouting. This test rig has many functions and its performance is consistent. It can control and adjust accurately the opening degree of fissures and static pres- sure; it can measure automatically the quantity of grout injected; it can measure precisely pressure drop of grout in fissures; it can test the results of injection, including effective dispersed distance, anti-filtration capacity of consolidated body, mechanical strength, etc. It can inject a single or two grouts into one or several fissures at a pressure of 16 MPa. Therefore, it is an ideal test rig for fracture injection. The paper depicts all the components of the test rig, its performance and application of the results obtained from fracture grouting tests. Examples are briefly described.

Jan 1, 1988

By McPherson M. J

This paper describes a major ventilation study for the expansion of the El Teniente mine operated by Codelco, Chile. El Teniente is one of the world's largest under- ground mines. The design effort was under- taken in three stages and involved a partial mine ventilation survey with network simula- tion, detailed stope ventilation investiga- tions, and design of the entire mine ventila- tion circuit based on production plans to achieve 112,000 tons per day by 1995. The partial ventilation survey provided values of representative friction factors and resistances for typical ventilation raises and airways. These values were used to conduct detailed modeling of the block caving levels to investigate the most cost effective and practical means of providing the required ventilation. The results of these analyses were extrapolated to the proposed expanded mechanized zones.

Jan 1, 1988