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Hydrometallurgy has a history of over 300 years with copper leaching and cementation having been exploited in Spain as far back as 1670. Since then, hydrometallurgy has become an integral, expanding branch of extractive metallurgy. This paper reviews major developments in hydrometallurgy over the past century with emphasis on recent commercial developments and their impact on the mining and metals industries. The environment in which these developments has taken place has changed significantly in the past two decades and many factors, often non-technical, have emerged as constraints on the operation of existing plants and the expansion and development of new hydrometallurgical operations. Finally, a number of possible new developments that will shape the future of hydrometallurgy in the new millennium are discussed, particularly as they relate to the assimilation of technical advances in other areas of science and engineering. The impact of current trends in the education of hydrometallurgists and the provision of research in support of these future developments is also addressed.

Jan 1, 2000

To meet the objectives of sustainable development, mining projects must be executed with minimal environmental risks and impacts. To allow proper actions to be taken, it is helpful if the environmental challenges associated with a mine development project can be predicted early during exploration activities. Signs of impending environmental problems like acid rock drainage and metal leaching are often revealed in the occurrence of natural acid drainage, formation of efflorescent salts and their associated ecological effects. Other subtle clues can be deduced from anomalous geochemistry, detailed textural features of mixed sulfide assemblages and miscellaneous environmental data sets covering the target areas of exploration. A more practical tool, however, is the development of comprehensive environmental ore deposit models containing relevant information on ore genesis, applicable mining, processing and waste management options and their environmental implications according to deposit type. Not only will such models facilitate communications among independent groups of personnel involved in a mining project to come up with schemes to ensure better environmental performance of the overall project, they will also facilitate decision-making if a mine development project should be pursued further or valuable resources be redirected to other more favourable targets.

Jan 1, 2003

The Nelson province was chosen as the prime area for rhenium sampling, based on its mineral associations. Sample preparation involved benefication by grinding and flotation. A modification of published procedures for rhenium analysis was developed and the results compared with those obtained for molybdenum on the same samples using atomic absorption spectroscopy. The results of the analysis for both metals is discussed and the relationships between rhenium and the molybdenum mineralisation of this region is commented on. A metallogenic province is defined for molybdenum and rhenium and the tectonic setting for this is discussed. Some consideration has been given to rhenium possibilities in Fiordland and the Coromandel Range.

Jan 1, 1980

Australia today is one of the leading countries in the fields associated with the mineral industry, an industry which accounts for over 50% of overseas income and revenue to government. This is no accident. In order to be competitive in what was recog- nised very early in the country's history as a highly profitable busi- ness, the Australian mineral industry (mining, extractive and refining metallurgy) has traditionally been very innovation con- scious, a characteristic which has been evident from the begin- ning of the industry or very nearly so: Australia's geographic isolation and the dispersion of the mineral industry over wide distances made an exchange of ideas difficult and often impossible. One needs only to look at the inaugural address given by Sir Henry Ayers, the first president of the then Australasian Insti- tute of Mining Engineers, in Adelaide on 4th April, 1892 (1) "There is probably no other pursuit which depends more on its productive development and profitable results than in the extent and application of the scientific and mechanical knowledge possessed and exercised by its manager." and "Having in view the value of the mining industry of Austral- asians, they should be urged to apply their best skill with all the scientific and mechanical knowledge obtainable to its future development."

Jan 1, 1988

By Walker V

The 'MAGNADET' to provide a safe enhanced protection extraneous currents, electricity and radiodetonator was designed electric detonator with against the effects of current leakage, static frequency energy.It has found a particular niche in shaft sinking operations and Mount Isa Mines initiated trials of the system in 1983 as part of the design work for the 3000/3500 orebody access shaft.Initial surface blasts indicated a number of significant advantages which were confirmed during the bench and concrete phase of the M37 shaft sink. The application of 'MAGNADETS' was later extended to the horadiam phase of the project.Details of the exploder capacity calculations for the various M37 round designs are included with the paper.

Jan 1, 1985

By Kerr M. H, Slaughter P. J

Design of the new cemented hydraulic fill plant was based mainly on experience with a succession of previous fill plants. Two stage cycloning of combined concentrator tailings was introduced. Design of the two stage cyclone configuration was assisted by computer simulation of cyclone performance. Cementing additives, namely Portland cement and ground copper reverberatory furnace slag, drawn from bulk storage, are pre-slurried prior to mixing with hydraulic fill. Quality control of fill being sent under- ground is achieved by a series of automatic control loops. Plant instrumentation was given prime consideration during the design phase. Inventory checks of all mass flow metering equipment are made at regular intervals. Fill is pumped to boreholes at several locations. Details of the equipment and operating procedures for the plant are Discussed.

Jan 1, 1973

The excessively high cost of production in underground coal mines has made the survival of many coal mines around the globe economically non-viable. The global competitive coal market speaks itself of the desirability of a lower operating cost in conjunction with a higher productivity performance, particularly in underground coal mines, and calls for an optimal production planning under a host of constraints. Such a task of optimal planning is not an easy exercise like that of traditional planning based merely on intuition, experience and subjective judgement. It essentially demands a thorough understanding of the complex interaction of mine sub-systems for judicious application of optimisation tools and techniques available with operations research. A few large mines around the globe have made an effective use of a sizeable number of operations research packaged programs for optimal decision-making (Grayson, 1989). The success of practical applications of operations research techniques made in a variety of mining problems in large mines in different parts of the world will hopefully make inroads to smaller mines in years to come. The present paper is an addition in the series of such applications of operations research tools to mining problems, particularly with reference to an underground coal mine in India. The paper is based on research work (Jawed, 1990) and deals with the development and use of a mathematical model for production planning in underground coal mines under multiple objective environment subject to a host of constraints.

Jan 1, 1995

By K Paki, K Parker, J F. Dupont

The Mount Charlotte grinding circuit at KCGMÆs Fimiston mill was recently equipped with three 650 mm CAVEX cyclones in order to improve the overflow P80, reduce the fines bypass to the underflow and improve the underflow density/recovery of water to the overflow. After the first two sets of surveys were conducted air core boosters (ACBs) were installed on the 650 mm CAVEX cyclones in an attempt to further increase their performance. JKTech was approached to assist with the examination of the data obtained from the surveys; this data was intensively modelled to determine, to a high degree of confidence, the impact the changes to the cyclones had on the classification and the benefits to the plant. This paper outlines the outcomes of the trial and the methods used to determine those outcomes.

Jan 1, 2007

Although giant strides have been made in the Australian mineral industry over the past quarter of a century in terms of mineral discoveries, self-sufficiency of commodities, contributions to exports and other aspects, there are unhealthy signs emerging which require attention. For instance there are 20 out of 34 discoveries of base metals, uranium and nickel which for a number of reasons await development. Some of the reasons for the standstill in the mineral industry are partly economic, partly due to competing land use, uncertainty in applying or, recognising the principle of crown ownership of minerals, and to some extent lack of appreciation of two closely related exploration activities referred to as development exploration and assessment Exploration.

Jan 1, 1979

By Manzoori AR

From a detailed combustion testing program and earlier experience with Leigh Creek coal, the Electricity Trust of South Australia (ETSA) gained a wide insight into the use of low rank coal fired boiler plant. This work is fundamental for the selection of boiler design parameters and other details which in turn determine the correct coal deposit selection for future power station development. In addition it gives boiler designers a good indication of the measures required to give reliable plant operation. Extrapolation from experience with existing plant, the designers main source of information, was not considered appropriate because of the lack of experience with similar coals. Brown coal beneficiation is also being assessed by ETSA in an attempt to improve the coal quality by the pretreatment of the raw coal prior to combustion in future coal.fired boilers. ETSA is also involved in the development of circulating fluid bed and gasification processes to determine whether these alternative processes are a more viable method of utilising the South Australian coals than pulverised fuel firing.

Jan 1, 1987

The Golden Cross mine is a Joint Venture between Coeur Gold New Zealand Limited, as Manager, and Viking Mining Limited The mine is targeting Zero Lost Time Accidents as a goal. The Golden Cross operation produces gold and silver from both underground and open pit. The mine is based on an epithermal gold-silver deposit. Treatment of ore is on a campaign basis for each ore type (ie underground or open pit). Milling is conventional SAG Mill and Ball Mill grinding circuit followed by carbon in pulp recovery of gold and silver. All tailing materials are treated through the Cyanisorb process to reduce cyanide levels prior to being discharged into the tailings dam.

Jan 1, 1995

By Jensen B

The approach of using the Coward Triangle for the analysis of flammable mine gas mixtures has been examined for its application, to the flammability of coal dust/gas/air mixtures. Explosible lean limit and rich limit concentration data for dust/methane/air mixtures are examined and illustrated using co-ordinate geometry. It is concluded that a three-dimensional envelope representing hybrid explosible mixtures can be drawn. The dimensions of this explosive zone will vary with the characteristics of the coal dust and the gaseous composition of the mine atmosphere. Further research is needed to establish these dimensions for important mined seams.

Jan 1, 1994

Coal mining safety and health legislation is more than typical of safety legislation which has been born of adversity. Indeed, in the main it has been the child of disaster. Requirements which now appear obvious were indeed only occasioned by either social injustice or more commonly by great disasters. Even then changes were often made only after months or years of deliberation by committees. Early mining legislation in New South Wales benefited from the experience in Great Britain. The pioneers of our industry were miners from there and brought with them the basic British legislation, so we started with knowledge gained the hard way. A review of accidents statistics provides a measure of the effectiveness of mine safety legislation, but unfortunately rules cannot control human nature. Miners, managers and inspectors must work as a team to make mines safe and new legislation in New South Wales is planned to this end.

Jan 1, 1975

By J Sarvinis

The design and operational aspects of fluidised solids transfer-cooling devices will be discussed in this presentation. The devices include air slides and fluoseals (also called seal pots, loop seals, etc), which are widely used in metallurgical plants and other processing plants. Cooling can be achieved while solids are transported in the solids transfer devices. The units combining solids transfer and cooling provide compact and clean plant layouts and also reduce capital and operational costs. Fluidised devices provide excellent gas-to-solids and gas/solids-to-surface heat transfer rates, hence high cooling efficiency. Fluidising gas, such as air, nitrogen or other gases, can be used as direct cooling mediums. Coolants such as water, steam and other liquid or gas cooling fluids can be used as indirect cooling mediums via tube coils immersed in the fluidised solids. The fluidised transport devices share some common features with fluidised bed equipment. The air slide is similar to a linear fluidised bed while the fluoseal is similar to a circular fluidised bed. Therefore fluidised bed design techniques are applicable to the design of the air slides and fluoseals. The heat and mass balance and temperature profiles of the devices concerned will be discussed in the presentation. The design criteria and operational philosophies of the critical components such as tuyeres and air spargers will also be discussed.

Jan 1, 2006

During conventional eddy current separation, a repulsive force is applied to metallic particles by placing them in a rapidly changing magnetic field generated by a spinning magnetic rotor carrying an arrangement of alternate magnetic poles. This method works effectively for larger non-ferrous metallic objects, such as aluminium cans, but as the metallic particles become smaller, the bulk repulsive force on the particles is increasingly replaced by a rotational torque. Therefore, for small metallic particles it makes sense to use particle rotation, rather than particle repulsion, to effect a separation. Eddy current separators using particle rotation are similar in construction to present separators, but are designed to produce a rotating field of essentially constant angular velocity and field strength. Practical and economic particle rotation eddy current separations are possible down to particle sizes of about 200 ¦m, but separations, at probably uneconomic rates, can be carried out on particles as small as 50 ¦m.

Jan 1, 2000

A simple and rapid method for delennining gold and silver in carbon samples is described. The method involves dissolution of carbon ash in a strong oxidising medium of aqua regia and hydrofluoric acid. Gold and silver are determined in the resultant solution using atomic absorption speetrometry (AAS). The method is efficient and reproducible. Gold results are comparable to the standard fire assay results, with agreement of results within ± 5 per cent. The co-efficients of variation for gold and silver are 0.37 and 0.39 per cent respectively for six replicate analyses. The analysis of gold and silver in a batch of ten carbon samples can be completed in approximately four hours.

Jan 1, 1992

Proper technical appraisal of a coal deposit and the determination of optimum open- pit mine design can only be made after detailed examination of a number of interrelated geographical and geological factors. Initial evaluation of the geography and the overall attitude of the coal measures can often determine the most likely coal mining technique. Conclusions reached in the early stage of the investigations frequently dictate the quality and quantity of particular types of data required from further drilling of the deposit. In many cases, insufficient information relating to the overall engineering aspects of a coal deposit is derived from drilling. Little or no attention is paid in the exploratory phase to such things as the specific gravity of selected overburden samples, floor conditions, clay content of the overburden and selected strength tests on cores. This is a direct result of geologists treating coal deposits purely in geological terms without sufficient consideration being given to the engineering parameters required for a proper evaluation of the deposit.

Jan 1, 1977

The Lower Palaeozoic Woolomin Association is composed of chert and jasper (often radiolarian), siliceous argillite, the mafic volcanics with associated hyaloclastites, and occasional greywacke and limestone lenses. Several "Cyprus-type", conformable pyritic copper (+/- zinc and cobalt} sulphide lenses are spatially related to individual mafic volcanic units and manganiferous chert and/or jasper. The Association has been interpreted to represent an oceanic crustal remnant generated either in an island arc environment (Herbert, 1981) or at a divergent plate boundary (Scheibner and Glen, 1972; Leitch, 1974a, 1975) later to be obducted, or tectonically emplaced, into continental crust; the adjacent Peel Fault was considered to be the palaeo-obduction zone (Scheibner and Glen, 1972) and the associated alpine-type mafic/ultramafic complex, an ophiolite (Crook and Felton,1975).

Jan 1, 1990

Trucks are the primary means of bulk material transport in Open Pit hard rock mines worldwide. They are considered to be the most- flexible system available. The large number of trucks used in some mines provides flexibility. Spare units allow for the reduced availability of the single units. Trucks have however very poor energy efficiency. Only 40% of the consumed energy is for transport of the payload, the remaining energy is required to move the dead load of the trucks. With the increase in cost, pressure, mine operators are now looking for alternative methods to make their operation more economical. Energy conservation and increasing haulage distances and uphill haulage are major factors in many well established operations. New methods have already proven themselves as more economical alternatives. Belt conveyors are an alternative means of transport with much higher energy efficiency. They use up to 80% of the consumed energy for transportation of the payload. Energy costs for conveyors are 30% of the energy costs for trucks on level transport and as little as 15% for elevating payloads. Belt conveyors require much fear spare parts and wear components than trucks. A factor of one to two times applies for level transport and ten to twenty times for uphill transport.

Jan 1, 1986

By S Tavelli

This discussion will present a case study in developing solutions to a metropolitan quarryÆs public relations, legal, environmental, and productivity problems. It details an extensive and detailed project to address the blasting practice in a medium sized quarry that is surrounded by residential and industrial zones. The principle work was done over four months duration during the normal production season. It included detailed drilling and blasting audits for baseline information. In addition, geologic characterisation, seismic modeling, correction of deviations from best practices, and implementation and monitoring of precise electronic timing to provide dramatic solutions for the quarry. The quarry is in the near suburbs of a large metropolitan city. It is framed on two sides by residential municipalities and on two sides by industrial zones. At the start of the project, the quarry was in court as a result of the lawsuit by one of the neighboring towns that was suing to close the quarry. The lawsuit had progressed to the advanced stage where in the Judge had appointed an arbitrator to make the decision of continued operation. This arbitrator was to observe our progress and recommend to the Judge the disposition of the case.

Jan 1, 2004