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By Paterson R. G, Compston W

The Mine granite at the Ardlethan tinfield is dated by Rb-Sr on a muscovite concentrate at not less than 417 ± 2.5 Ma (2s), consistent with the intrusion of this granitic body into folded Late Ordovician sediments. A combination of Rb-Sr and K-Ar evidence suggests a slightly younger age, 41O ± 2.5 Ma, both for the neighbouring Ardlethan Granite and for the hydrothermal alteration of the Mine granite, with which the tin is associated.On this basis, the somewhat high 206Pb/204Pb of two galena samples from within the hydrothermal alteration zone is best explained by an increase in U/Pb of order 10 per cent during a geochemical event in the Late Precambrian, in the rocks which eventually yielded the Pb to the mineralising fluid. This earlier event probably increased Th/U in these rocks as well, by as much as 5 per cent. If these reconstructions are valid, the lower-than-average U/Pb implied for the original Precambrian source rock bespeaks a mantle component of marginally greater proportion than for "average orogene".

Jan 1, 1982

Collecting the clay fraction of active stream sediment from a flowing stream for geochemical analysis i a difficult process. One either takes a sample of dry fine-grained sediment from the stream bank (dry weather and dry sample are uncommon in parts of New Zealand and Tasmania), or dredges up a sample of sand and mud out of the stream.The latter method produces a soggy ample bag full of mud and sand, with varying amounts of gravel, depending on the size of the stream. The water can be filtered from such a sample by means of a Buchner filter funnel, but is difficult to obtain a vacuum in the bush. This problem can be solved by using a small hand- queeze bellows such as used in priming petrol pumps on outboard petrol motors. The common laboratory hand bellows is not powerful enough.A 70 mm diameter two-piece polythene Buchner filter funnel (Fig. 1) can be used. A length of rubber tubing is fitted around the inlet valve of the hand bellows and this valve is then jammed into the pipe at the bottom of the filter funnel (the polythene pipe may be trimmed with a knife to fit over the inlet valve of the bellows). The vacuum is generated and maintained by squeezing the hand bellows.The technique of collecting a sample of the clay fraction is to dredge a sample of the fine-grained active stream sediment out of the stream with a container, such as a plastic mug. The sample is agitated to get the clay fraction into suspension and the muddy suspension is then decanted into the Buchner funnel. The desired clay fraction is obtained as a thin film on the filter paper.If the "fines" are also required, a filter of nylon bolting cloth (stretched across the mouth of a short length of 80 mm diameter polythene pipe and attached by rubber bands or a concentric polythene pipe) can be placed over the mouth of the Buchner funnel and the whole sample of stream sediment...

Jan 1, 1969

Pyrite Bioleaching and Slag Neutralisation - Two Treatments in a Single Process for Recovering Valuable Metals from Both Materials Very often the production of copper sulfide concentrate yields pyrite concentrate as a by-product. This is the case at the Knre mine in northern Turkey. This kind of concentrate may contain low grades of valuable non-ferrous metals. Bioleaching of such pyrite concentrates is a processing technique to solubilise metals like copper, zinc or cobalt in a sulfuric acid pregnant solution. The pyrometallurgical processing of copper sulfide concentrate produces slag that still contains valuable metals in varying concentrations. Slag is used in many ways: as aggregates, ballast, pavement material, in cement production and glass making. Due to its relatively alkaline nature, it can also be used to neutralise acidic solutions. A preliminary study of the bioleaching of the pyrite concentrate (Co 0.28 per cent, Cu 0.56 per cent and sulfur as sulfide 42.6 per cent) produced at Knre has been undertaken with the assessment of the neutralisation of the acidic bioleach solution by using old slag (Co 0.29 per cent, Cu 1.70 per cent and sulfur as sulfide 0.89 per cent) stockpiled on the site. The main conclusions of the study were as follows: Knre pyrite was amenable to bioleaching at 40¦C. Cobalt solubilisation directly related to pyrite degradation reached a maximum yield above 90 per cent. Final copper recovery was limited to approximately 66 per cent not directly related to bacterial growth and pyrite oxidation. Slag could be used as a substitute for limestone as a neutralising agent in the bioleaching tanks. Cobalt and copper could be recovered from pyrite concentrate and slag simultaneously from both materials. A pre-feasibility study is underway to carry out a preliminary cost estimate of an installation for cobalt and copper production from these two materials processed in a single operation.

Sep 13, 2010

A summary of a proposal to develop a 20 000 tpa underground gold operation in a Forest Park. The environmental constraints are severe and affected the mine development planning and choice of mining method. The mine will use trackless methods to access the narrow 1.5 m ore shoots, and to mine ore by cut and fill methods. The use of Microscoop and CT 1700 HE electric LHDs for mucking, together with special drilling attachments for drilling, is central to efficiency and small Kubota diesel haulers will be used for carrying ore to surface.

Jan 1, 1986

THIS tunnel, which is an adit 7000 ft. long, was undertaken by the Mount Lyell Mining and Railway Company Limited to connect its treatment works with the North Lyell mine at depth, with a view to effecting economies in transport and drainage. The work was carried out at high pressure throughout from both ends, and although the ground in the mine end was intensely hard, good progress was made, and driving was completed in less than fifteen months.The Mount Lyell mining field is situated in the west of Tasmania, about 20 miles inland, the only means of access being the Mount Lyell Mining and Railway Company's 3 ft. 6 in. gauge railway which connects with the Government railway system of the State at Strahan, on Macquarie Harbour. The region is mountainous, and presents many difficulties to the road and railway engineer. The West Coast range running north and south in a succession of bold prominences, which rise up to 4000 ft. above sea-level, forms the backbone of the district, and on its foothills the Mount Lyell mines are situated. The railway terminus at Queenstown...

Jan 1, 1929

Flow Sheet Simulation of Municipal Waste Treatment Processes

Sep 13, 2010

Societal expectations about how the industry operates and treats its people will be a key driver in the development of the Australian mining industry over the next 20 - 30 years (Moffat, Mason and Littleboy, 2009). Understanding these expectations will be critical in maintaining what much of the minerals industry calls its 'social licence to operate', or its public acceptance or approval. Yet what constitutes this social licence is poorly articulated, with little published research exploring the concept at a local operational level or at the national level in Australia or internationally. This research aimed to explore the societal expectations of the mining industry in Australia and test a participatory methodology to articulate them. Three workshops were conducted with a sample of 24 members of the 'Australian voting public' to explore community objectives for the onshore exploration and mining industry, and the underlying expectations for how the industry should operate in the future. Qualitative analysis of this data revealed three overarching objectives for the onshore mining industry held by participants. They thought that the industry should: advance Australia's national interests (including social well-being); minimise environmental impact, and; act in a socially responsible manner. Within each of these three key themes, or objectives, a number of tensions were evident in the views of participants regarding the trade-offs they are willing to make to secure economic benefit from mining, as well as the basic conditions for socially acceptable mining. These data provide an insight into the conditions for a national social licence in Australia for the mining industry, and the means for its realisation.

Jun 1, 2010

Small scale' table concentration tests have many critics. Many metallurgists consider that such tests are of problematical value because of the difficulties involved in conducting and interpreting them.Many kinds of small-scale ore dressing tests are difficult to conduct, and there is, perhaps, good reason for thinking that table concentration tests are amongst the most difficuIt.Interpretation of results from small-scale tests is the responsibility of the metallurgists and engineers in charge, and it is often held that small-scale table concentration tests are particularly difficmlt to interpret.TESTING FOR TABLE CONCENTRATIONOn analysis it appears that the difficulties encountered in conducting small-scale table concentration tests are of three fairly distinct kinds. Firstly, there are difficulties due inherently to the smallscale nature of the operations; for example the smaller width of all mineral bands on the table and the less complete separation due to the shorter length of travel between the feed and discharge points.Secondly, there are the effects of batch operation owing to the fact that the mineral particles behave differently during the initial period when the sample is just beginning to spread over the table, the middle period when feed and discharge are even and continuous, and the final stage, when the last of the sample has been added and the table is beginning to empty itself.

Jan 1, 1954

By L Barro

There is currently a worldwide interest in coal-oil technology as the search continues for alternative energy sources to reduce the consumption of petroleum crude. An important aspect of this coal-oil technology study is to obtain information on the flow properties of coal-oil slurries. While some work has been reported on the flow behaviour of black coal-oil suspensions, very little work on brown coal-oil suspensions has been reported. In this paper flow characteristics of brown coal-oil suspensions for various coal concentration and temperatures have been presented. A capillary rheometer, designed to handle settling suspension, has been used for determining rheological properties. Brown coal of 0.0725 mm average particle diameter has been used in this work. The oil was a coal derived product having a boiling point range of 234¦C - 319¦C. Apparent viscosity of all suspensions was found to increase on storage due to ageing. Ageing might have occurred due to physicochemical interactions between coal and oil. Flow behaviour of some suspensions changed from Newtonian to non-Newtonian on storage. Apparent viscosity increased sharply with increase in solids concentration and suspensions at higher concentration behaved as non Newtonian liquids. Viscosity decreased with increase in temperature; rate of decrease slowed down with increase in temperature.

Jan 1, 1980

This article focuses on TurkeyÆs gold potential with respect to exploration, development and operation after 1985. Apart from TurkeyÆs geology, which offers a substantial number of volcanic-associated gold (Ag) and gold-copper (Au-Cu) projects, there are numerous other factors which make the country a favourable place for mining. Turkey has a mining history which goes back to pre-Roman times and an excellent mining code which ensures security for long-term production. In the country, the Government and local villagers are very positive and the country works extremely well logistically with excellent road and telecommunication links. The opportunities for new discoveries in Turkey are very high. Moreover, Turkey has its eyes turned west as it moves towards joining the European Community and it is no surprise that international companies believe it has got its timing as well as its partner relationship right. Newmont, Teck Cominco, BHP Billiton, Rio Tinto, Eldorado Gold, etc all have direct or indirect interests in Turkey, as do an increasing number of midtier and junior exploration companies. Turkish Koza Gold Mining is the first Au producing company of Turkey. The Eldorado Gold owned 245 t Kisladag Au deposit in Western Turkey is currently also producing Au. In the meantime Anatolia Minerals Development is advancing the 131 t resource at the C÷pler Au deposit in North Eastern Turkey. These are significant world-class deposits. Further encouragement for investment in the Au mining sector has been provided by the introduction of a new mining law in 1985. Foreign investments in the country were encouraged and have seen a rapid increase in the last two decades. Gross domestic product (GDP) growth is in excess of five per cent per annum, inflation is down from 70 per cent to single figures, the budget deficit has been cut by 40 per cent to 11 per cent and industrial output and productivity are increasing rapidly. Turkey is politically and economically stable, is a member of the European Customs Union, has a supportive mining legislation, is highly prospective and under-explored and hosts significant recent gold discoveries.

Jan 1, 2007

By Lawrie D. C

Finely ground beryl was decomposed by mixing with ground limestone and soda ash and heating at 900°C for 4-6 hr. The sintered mater:al was then crushed and leached by boiling under reflux with 5N sulphuric acid for up to 4 hr. The liquor containing Be, AI, Fe and other elements as sulphates, was separated from the residue which consisted mainly of silica and gypsum, either by filtration or bydecantation washing.The clarified leach liquor was first treated to remove Fe+++ by contacting with a primary amine-kerosene solution in 2 countercurrent stages. The iron free liquor was then passed to a 4-stage counter-current extraction unit where it was contacted with O·5M di- (2 ethyl hexyl) phosphoric acid (EHPA) in kerosene. Under the operating conditions, 99 per cent of the Be and 7 per cent of the Al was extracted.The Be and Al were stripped from the organic phase by sodium hydroxide solution of suitable concentration to form soluble "beryllate" and "aluminate" respectively. Most of the Be was subsequently precipitatedas Be(OH)2 by heating the alkaline solution to 90°C, the Al remaining in solution. After filtration and washing, the Be(OH)2 could be ignited directly to BeO at about 1000°C or used as a feed to further purification stages if required.A small counter-current extraction unit was operated continuously using liquor derived from the sintering and leaching stages. Dataobtained in batch laboratory tests were confirmed. A product obtained by ignition of the washed "beryllate" precipitate contained more than 99 per cent BeO.INTRODUCTIONIn 1958 an investigation was commenced into the recovery of beryllium oxide from beryl, as part of a programme to utilize mineral resources of South Australia. A survey of the literature indicated that little work had been done on direct solvent extraction of beryllium from aqueous liquors, so it was decided to apply the experience gained in this field in uranium processing to the current problem.Preliminary extraction tests on solutions of beryllium...

Jan 1, 1965

By P Breuer, X Dai, A Bergamin, D Hewitt

"Copper-ammonia-thiosulfate?leaching of gold has been researched for several decades as a potential alternative to cyanidation. However, this technology has not yet been applied commercially due to many challenges such as complex solution chemistry, reagent degradation and losses, system instability with losses of precious metals and difficulties in gold recovery from the leachate. Progress has been made at CSIRO in tackling some of these challenges including:better understanding and control of the leach conditions to minimise reagent losses whilst maximising gold recovery use of strong base ion exchange resins to recover the gold strategies to deal with polythionates that adsorb competitively with gold on ion exchange resins development and evaluation of process flow sheets.As a result there has been increased interest from the gold industry and renewed activities to develop thiosulfate based processes for gold recovery. One application area, which has been developed to the point of piloting, is the treatment of gravity gold concentrates using a copper-ammonia-thiosulfate leach with ion exchange recovery of the gold thiosulfate. This paper describes some of the advancements in the development of a potential process flow sheet for this application.CITATION:Dai, X, Breuer, P, Hewitt, D and Bergamin, A, 2013. Thiosulfate process for treating gold concentrates, in Proceedings World Gold 2013, pp 61-70 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

By B Watson

The ConSep ACACIA Reactor is a device, which utilises a high intensity cyanidation process to achieve very high, usually near total, recovery of gold from gravity concentrates. The process utilises a fluidised bed and a chemical oxidant to enhance the gold dissolution kinetics to the point where the bulk of the dissolution occurs in a few hours. For convenience and security, most plants operate a 24-hour turn around. The product from the process is in the form of cathode gold ready for smelting by traditional means. The ConSep ACACIA Reactor performs a two-fold role. Firstly it increases gravity gold production, leading to a decreased CIP feed grade. Secondly, it removes slow leaching components from the plant leaching circuit. This two fold benefit leads to the following efficiencies: enhancement of the dissolution kinetics; enhancement of the adsorption kinetics; reduction of the gold load reporting to the carbon; a significant reduction of the ægold in circuitÆ lockup; and removal of slow leaching entities which can also result in a lowering of the required cyanide concentrations in the leaching circuit and a subsequent reduction in overall cyanide consumption. The above benefits are discussed in this paper, with a particular focus on the ConSep ACACIA ReactorÆs role in removing slow leaching components, with data generated over a 21-month period. Improvement in overall plant recovery via removal of slow leaching gold species is achieved in two ways. Firstly, some of the slow leaching entities, successfully leached under intensive cyanidation, are not always fully leached under plant conditions. This results in a lowering of the solid tailing. Secondly, the faster leaching kinetics achieved in the plant as a result of the removal of slow leaching entities results in faster and more complete adsorption of the dissolved gold onto activated carbon. This results in a lowering of the solution tailings. The construction and operation of the ConSep ACACIA Reactor is simple. Apart from the reactor body, which is a proprietary design, all components of the system are æoff the shelfÆ or specific to the siteÆs requirements. In operation of the fully automated version, a PLC controls a series of valves and pumps but except for a daily changeover process the only operating component for the bulk of the time is a relatively small solution pump. The process can be totally automated giving the security of a æhands freeÆ concentrate handling process up to the point where the product is presented as cathode gold. The ConSep ACACIA Reactor was developed by Anglogold Australia (formerly Acacia Resources) for Union ReefÆs Gold Plant and has been in production since February 1999. It has proven to be a low cost, high recovery, mechanically reliable method for the processing of gold concentrates. Such has been the success of the plant, as of June 2003 there are eighteen full installations of the processing plant installed at mines owned and/or managed by Anglogold, Newmont, Placer Dome, Independence (formerly Lonrho), Sons of Gwalia and Harmony.

Jan 1, 2003

A combination of the needs of business, employee desires and safety and health considerations is stimulating increasing attention to the time spent by people at work and the timing of that work. Particularly we are seeing: - innovative work schedules for 24-hour mining businesses; and - response from industry to accommodate the needs, even the desires, of employees in return for systems which are more productive and more capital efficient. There appears to be an evolutionary trend for business management to become more sophisticated and responsive to the need for achieving close to best cost work schedules to sustain continuous improvement. The underlying motivating forces driving this trend for improved techniques in organising attendance at, and time spent at work, is the seemingly inseparable combination of technological advance and ever-increasing accumulation of capital. The mining industry has not remained untouched by this thrust for ever-increasing need for best use of labour, to adopt advances in technology and to provide attractive opportunities for putting accumulated capital to work. An essential component of this on-going thrust is a substantial effort by the mining industry to improve the performance of labour by providing most-productive work schedules.

Jan 1, 1996

By Bruington T, Perkins J, Hutton R

Natural resource developments are among the largest and most challenging projects taking place in the world. They involve capital intensive investment with long lead times and the management of geological, market, technical, operational and financial issues. A clear strategy is required to manage these projects and this strategy is underpinned by a development Philosophy.

Jan 1, 1997

By Teale E. O

The purpose of the present communication is to put on record the discovery, in October, 1916, in the Howqua district, of a new locality for the occurrence of phosphatic rocks in Victoria, and to give a preliminary description of its characters and geological occurrence. Owing to the great use of superphosphates for agricultural purposes in recent years in Australia, search has been stimulated for the discovery of local and workable supplies of phosphatic rocks. Phosphorus is an element very widely distributed in igneous rocks, usually in the form of the mineral apatite, and also occurs in sedimentary rocks and in soils as a detrital constituent. Under these conditions of occurrence, however, the amount of P 205 present in a rock or soil seldom approaches, and very rarely exceeds, 1 %. Very occasionally it occurs in such a concentrated form as to constitute workable deposits. In such cases they are usually of organic origin. Sometimes they occur as geologically recent deposits of guano or rock...

Jan 1, 1918

By T Clemens, D Trumm

Adopting environmentally acceptable practices in New Zealand is a crucial requirement for mineral wealth development. Recent planned expansions in the coal and gold industry have increasingly placed mining in the media spotlight. A lack of appropriate standard environmental guidelines has resulted in inconsistent responses and assessments of current and proposed mines. These inconsistencies have lead to delays in decisions on developing economic mineral deposits that may have only minor short-term impacts, and have also allowed unacceptable environmental management practices to continue elsewhere. A research collaboration between CRL Energy, Landcare Research, University of Canterbury and University of Otago aims to provide regulator groups and the mining industry with a unified approach to the requirements of the Resource Management Act 1991,the legislation that largely drives the nationÆs environmental policies and guidelines. The tangible outcome of this research program will be water quality and impact management guidelines integrated into a decision-making framework. The result of this unification will assist in the development of viable mineral deposits and minimise environmental impacts. The framework will be derived from a synthesis of three objectives. Objective 1 identifies potential water quality impact. This objective is based on a targeted geochemical study of the lithology and waterways of the West Coast and Southland regions. Objective 2 categorises the degree of impacts on the ecology of receiving aquatic ecosystems and determines the processes that drive aquatic ecosystem recovery. Objective 3 identifies best strategies to sufficiently manage impacted ecosystems, and to prevent future unacceptable impacts. Wide consultation with representatives of the mining industry and regulator groups will occur frequently during the development stages of the framework. It is anticipated that this multidisciplinary approach will provide a robust and coherent, standardised system that will assist in achieving industry and environmental targets.

Jan 1, 2004

By Caithness SJ, Heape JMT

Following the discovery by CRA of gold at Mt Kare, and the subsequent 1988-90 gold rush, mechanised mining of the alluvial resource is now being carried by a company jointly owned by CRA (51%) and landowners of the area (49%). Mining is currently being carried out using small gravity processing plants fed by hydraulic excavators. Use of hydraulic mining techniques will be limited to over- coming difficulties related to the high clay content of the material and the soft nature of the bedrock. Current resource estimates suggest that the alluvials will have a mining life of three to four years. During this time, exploration of the hydrothermal gold mineralisation at Mt Kare will be carried out by a wholly-owned company of CRA. It is hoped that this will lead to establishment of an economic primary gold resource.

Jan 1, 1991

Recent legislation in the environmental field gives the mining industry an opportunity to take timely action to address its image. Shifting the focus away from mining (the activity) to minerals (the resource) will enable the mining industry to stand on equal footing with other industries and will help minimise the vulnerability to political and interest groupsÆ interference.

Jan 1, 1993

By J B. Taylor

Geographic Information Systems (GIS) are being increasingly used by the mineral exploration industry in the search for new ore deposits. A mineral exploration GIS links geological and geophysical data by virtue of their geographic location in a digital map setting. Geological and geophysical data are categorised into a number of themes or layers within a mineral exploration GIS. These layers may include polygonal information such as rock type and tenements, line information such as faults and fold axes, point information such as mines and mineral occurences, and images such as gridded geochemistry and aeromagnetics. A mineral exploration GIS is a powerful tool to help the explorationist comprehend the spatial associations and interrelationships of his/her data. These spatial associations can be integrated with a mineral genesis model, to create a mineral prospectivity map to more effectively target exploration. Arguably a competent geologist who has a good understanding of the genesis of the local ore deposit types and knows their local geology backwards could intuitively derive a mineral prospectivity map. However, in an era of rapid data accumulation from many different disciplines, the ability to assimilate and understand is a huge task for any individual. A mineral exploration GIS enables the explorationist to spend more time analysing data and testing ideas, rather than finding and manipulating data into compatible formats.

Jan 1, 1994