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Self Advancing or "Poweredtt supports are a successful means of supporting roof and designs have reached the stage where adequate support capa- bility is available for all conditions. Some designs have resulted in equipment being too difficult to transport underground and too complex to maintain. Current trends are reducing those problems and simplicity in hydraulic systems is now the keynote of both supplier and user. There is a good possibility that the "Shield-Chock" support will be the universal design of the future. So-called t'shortwall supports" have been developed to the point where they can be applied with a high degree of confidence to conditions of great variety. Develop- ments by manufacturers and practices of users related to maintenance should result in consistent achievement of designed performance.

Jan 1, 1974

By M Fisher, P Bradley, D Rogers

New England Antimony Mines has operated the Hillgrove Gold Plant at Hillgrove in New South Wales since 1969, producing stibnite and arsenopyrite products by selective flotation. Gold is present in the ore as fine free gold, gold associated with stibnite and gold associated with arsenopyrite, with some ten to 20 per cent of the gold reporting to the antimony stream and 35 - 50 per cent reporting to the arsenopyrite stream. Opportunity to process the arsenopyrite concentrate for onsite recovery of the gold values to improve upon the ten per cent recovery achieved by conventional cyanidation was recognised and subject to comparison with biological oxidation, roasting, nitric acid oxidation, low temperature oxidation (Activox«) and conventional pressure oxidation. Following further testwork and a feasibility study, a 7500 tonnes per annum concentrate feed pressure oxidation autoclave circuit was constructed at Hillgrove and commissioned in October 1999. The plant has operated at the close to design capacity since commissioning whilst optimising various operational and metallurgical aspects. The last three years has seen the process achieve an overall gold recovery of greater than 90 per cent for oxidised concentrates.

Jan 1, 2002

From a personal view that encompasses both research and assessment of major projects the author outlines the two competitive pressures that will force more rather than less metallurgy viz the increasing difficulty in purchasing the latest overseas developments and environmental concerns. This paper then goes on to argue that Australian metallurgy or more precisely process engineering may be in a unique position to deliver the required results.

Jan 1, 1993

By Hall K

The Osborne copper gold mine, 100 per cent owned by Placer Pacific Limited, is situated 195 kilometres south east of Mount Isa. The orebody is broadly categorised into three main ore zones; oxide, transitional and sulphide copper. Copper oxide

Jan 1, 1997

One common public perception of mining is that financially it is an extraordinarily risky business. Another and contrary view, in certain circles, is that price risk and other financial risks can be relatively easily removed or shifted by a number of schemes or devices. In reality, beyond the orebody discovery stage, mining need not be any more risky than most heavy industrial businesses. Nevertheless, as stated by Rappaport, (1986): Risk is a parameter of central importance in establishing the economic value of any asset. The level of risk is determined both by the nature of the firm's operations and by the relative proportions of debt and equity used to finance its investments. These two types of risk are commonly referred to as 'business risk' and 'financial risk' respectively. The term financial risk is used somewhat more loosely herein to recognise the reality that any risk inadequately addressed in the design, construction and operation of a mining project can have significant financial consequences; usually negative. For instance, a specific area of business risk in mining is often called technical risk which definitely has severe financial consequences if not managed correctly. The various risk shifting, hedging and risk management tools available all have their place and range from merely useful to almost indispensable. However, in the long-term, financial risks are maintained at acceptable levels by the application of sound, more fundamental business management principles. There are many with a vested interest in perpetuating a perception that the conceptual foundations of sound management practice are extremely complex. In reality, most management concepts are prosaic, but their application requires incredible discipline and hard work. There is no magic formula or 'silver bullet'. It appears that a company whose activities are restricted to mining can analyse the range of risks specific to mine development and operations more clearly than companies in which mining is just one of many businesses. The almost universal failure of large oil companies in the mining business is probably the best example of lack of any clear comprehension of fundamental business characteristics and risks. Conversely, in regard to risk management, choosing to be in other business as well as mining does nothing to reduce the risks of the mining business. The individual shareholder can probably make such 'diversification of portfolio' decisions better than most management teams. It could be argued that diversification across a number of disparate businesses may actually increase overall corporate risk due to lack of management concentration and focus. These differences between the perceptions of financial risks and the realities in mining need to be further elaborated in relation to some uncompromising business concepts.

Jan 1, 1994

By Royston, Woods R

ANI Bradken Vortex Pulp Lifters and Grates, both as original equipment and retrofitted to existing SAG mills, are now in field operation. The development of the Vortex leading curve pulp lifter was based on an analysis of traditional radia

Jan 1, 1997

By D Wiseman, R Dunne

Flash flotation is a process that is included in many new mineral processing plants as part of the grinding circuit. Some of the valuable minerals can often be liberated at coarse sizes and will remain in the recirculating loads of the mill until they are reground small enough to report to the cyclone overflow. In addition, minerals of high density report to the cyclone underflow despite being fine in size. This can lead to overgrinding and makes the recovery of valuable fines by flotation difficult. Flash flotation is used to remove the readily floated coarse particles as early as possible and can therefore prevent overgrinding. It thus has the added potential to improve materials handling of the concentrates in such processes as filtration. The merits of including flash flotation within an integrated comminution-conventional flotation circuit is not easy to determine experimentally. Simple batch flotation tests are unable to provide any measure of the possible or probable improvements that are likely to occur from this circuit configuration. As a consequence expensive pilot plant programs are resorted to, to provide the information that will justify the inclusion of flash flotation into a comminution-flotation circuit. Those who have been involved in such pilot plant programs will know of the difficulty in stabilising the circuit as well as selecting the appropriate operating parameters (eg amount of concentrate to be removed in both the flash flotation and conventional flotation circuits). The interactive nature of this circuit (grinding, classification and flotation) is the root cause of these difficulties. Computer simulation, based on information derived from laboratory batch test work or plant and laboratory data, offers an alternative means by which an initial assessment of the merits of a flash flotation circuit can be determined. It can also provide the basis and focus for pilot plant testwork. Recently MacKinnon, Yan and Dunne (2003) developed a model that allows the performance of a flash flotation to be obtained within a closed circuit grinding operation. This paper provides details of an extension of this model to incorporate the interaction of flash flotation on the downstream conventional flotation circuit and allows æwhat ifÆ scenarios to be explored. Details of the laboratory batch test work methodology and the pertinent data derived from these tests that are used in the models and simulation are provided.

Jan 1, 2005

The mining, metallurgical, and petroleum industries can be viewed as financial or as social institutions or both. The differences between these two conceptions of their businesses will influence their environmental and social actions. During the next 10-20 years western industry will be subject to a drop in the growth of a more highly educated labour force and to the emergence of holistic economics, new national goals, and a new ecological perspective. The profitability of the mining industry may therefore be influenced by the human side of its business to a greater degree. The increas- ing human, social, and environmental responsibilities can be discharged by improving the miner's equip- ment; by learning to look at situations through the eyes of all those involved; by developing common `languages' which governments and the public can understand; and by mediating where feasible on the international scene.

Jan 1, 1978

By Hutchinson H

Froth flotation is applied to mineral sand concentrates in order to produce commercially viable xenotime concentrates. Experiments indicate that a xenotime product containing 38% Y203 at 47% recovery or 34% Y203 at 83% recovery can be obtained from a 27% Y203 feed. The process involves a primary stage of reverse flotation at which oxide and silicate gangue is floated, and secondary stage of direct flotation at which xenotime is floated. Of the various collectors screened an amphoteric compound was found to be effective at both stages. This was made possible by the addition of sodium silicate at the second stage, which acted as depressant for the remainder of the gangue. Similar studies on a low grade feed material were somewhat unsatisfactory as the grade achieved fell short of what was targeted.

Jan 1, 1990

By Hayes P. C, Matthew S. P

The product morphologies formed on the reduction of dense wustite crystals are classified into three types, A) porous iron, B) porous wustite covered with dense iron, and C) dense wustite covered with dense iron. The mechanisms of formation of these structures and the effects of impurity elements on the product morphologies are discussed.

Jan 1, 1985

Reconnaissance geochemical exploration in the vicinity of low angle detachment faults which bound the core of the Paparoa metamorphic core complex yielded Au up to 14 ppm, with 35% of greywacke, granitoid and quartz vein samples in the northern range exceeding the 0.01 ppm detection limit. Au is associated with Ag, As, Sb and Cu anomalies consistent with epithermal-type mineralisation. The Ag and Cu anomalies also distinguish this mineralisation from older, mesothermal Au deposits widespread in the Ordovician 'slate belt' greywackes, which comprise much of the upper plate of the core complex. Baryte, molybdenite, fluorite and stratiform U mineralisation in the northern Paparoa Range may also be related to hydrothermal activity along the detachment fault zones.

Jan 1, 1995

By Gunther L. M, Rich N

Remapping of the Burdekin Basin has resulted in the subdivision of the three formations (megafacies) previously recognised in the Late Devonian Dotswood Group. Nine dominantly volcaniclastic facies are now identified within the three megafacies, representing coastal plain, floodplain lake, alluvial plain, ephemeral lake and alluvial fan depositional environments. The Dotswood Group was deposited during a major regressive phase that began at the end of the Givetian, continued throughout the Frasnian and ended in the early Famennian.The proposed depositional model completes a southeasterly progradation of coastal plain facies over shoreline and nearshore marine facies established in the underlying Fanning River Group. Uplift and associated acid-intermediate volcanism to the south of the Burdekin Basin, resulted in the deposition of a volcanogenic alluvial fan facies locally preserved along the southwestern margin of the basin. Tuffs and ?ignimbrite were deposited in widespread floodplain lakes which lay behind the coastal plain. An alluvial plain traversed by southward flowing rivers, formed the northern margin of the basin.

Jan 1, 1990

The environmental and social responsibilities of the mining industry have long been recognized by the industry itself, but during the past decade it became one of the main targets for the more radical members of the community. This came as something of a shock to an industry which had always considered that it had acted responsibly within the standards of the day. As far back as early 1968, the Australian Min- ing Industry Council (AMIC) was clipping from newspapers the odd letter written by environmen- talists and critics of mining activities. In those days every such letter was carefully studied to ensure that AMIC, if not having the answers, at least had an understanding of the types of argu- ments then starting to be used against mining activity and in favour of environmental preserva- tion. Within 18 months, the infrequent letter to the editor had become a flood of such letters and feature articles, and the environmentalists' attack on mining activities had been launched in all its Vehemence.

Jan 1, 1978

By Jay W. H, Brown L. J

Several case studies are examined in which analysis of treated ores and extracted metal species by Mossbauer spectroscopy provides information not available by other competing techniques. The cases include poorly crystalline, surface iron oxides in titanium minerals and chalcopyrite, gold in ores and bacterially oxidised ores and the adsorbed species from gold extracted from cyanide and chloride solutions onto activated carbon and polyurethane foams. Some limitations on the use of the technique in terms of sample size, sensitivity and counting time are also discussed.

Jan 1, 1997

By Geoff Baldwin

The use of monitors to assess equipment performance is carried out on a routine basis in many industries. The benefits gained through process control in knowing exactly how the equipment is working far outweigh the initial capital costs of the monitor. In the mining industry several dragline monitors have been developed and installed on equipment through out the world, but to date none has been fully accepted by the industry. This paper describes the use of a sophisticated monitoring system which incorporates an onboard processor to assess both dragline and blast performance. The results of a case study are presented and an indication of the potential of the monitoring system to optimise mine production is given.

Jan 1, 1990

The Broken Hill (BH) Block contains a wide variety of mineralization, with comrodities including Pb, Ag, Zn, W, Cu, Co and Sn. Much of the mineralization is stratigraphically controlled. Fe, Cu and Co-rich mineralization is dcminant in the Thackaringa Group; Pb, Ag, Zn and W is dcminant in the BH Group and Sn mineralization is present above the BH Group. Some mineralization occurs as concordant syngenetic deposits, but other types have been partly or completely remobilized by metamorphism, magmatic activity or hydrothermal fluids. Almost all of the non-syngenetic mineralization, including stratabound, vein and intrusive-related types, has formed from the "recycling" (remobilization and redeposition) of metals originally deposited with the sediments and volcanics of the Willyama Supergroup.

Jan 1, 1983

It is a facet of modern-day life that change, even of a revolu- tionary nature, normally passes without comment. People have become so conditioned to continuous improve- ments in every aspect of their lives that they would be surprised only if there were to be no change. This paper seeks to demonstrate the extent of technical change, and to indicate the need for a fuller advantage to be taken of the technologies available, or potentially available, to the profes- sion. It contends that the mineral industry has been particularly slow to embrace technical change, and has good reason to con- sider an improved attitude for both prosperity and survival.

Jan 1, 1988

Magmatism and mineralization are features of the New England Orogen in late Palaeozoic- Mesozoic time. Voluminous silicic and mafic magmatism, both orogenic and post-orogenic in association, was accompanied by abundant mineralization in the earlier phases. Later activity passed transitionally into less vol- uminous felsic to mafic intraplate basaltic volcanism, with possible migratory hot spot activity through the flanking Oxley and Sydney Basins. Only minor mineralization took place at this stage. A new inerpretation links these magmatic and mineralizing events to a major thermal cycle. A New England hot spot(?) complex evolved in latest Carboniferous/early Permian time. Its activity was partly obscured by orogenic magmatism as Australia moved slowly over magma sources in the deep lithosphere. In Triassic time Australia's movement changed direction and faster drift over the waning hot spot complex produced multiple migratory intraplateòactivity. The volume of magma and hence abundance of ancillary mineralization was related to age of the hot spot, speed of the continental movement over thermal sources and extent of accompanying orogenic activity. The New Eng- land Orogen hot spot(?) possibly existed for 165 Ma, with mineralization changing over this Period.

Jan 1, 1987

A Study on Process Mineralogy and Mineral Processing of Complex Carbon-Bearing Cu-Pb-Co-Ni Multi-Metal Sulfide Ore by Bulk Flotation

Sep 13, 2010

By C Fountain

It is commonly known that copper smelter terms include penalties if the concentrations of elements, such as arsenic, mercury and fluorine, exceed stipulated limits. It is less commonly known that the behaviour of these elements in the smelters can depend on the processes used to treat the concentrate. The principle behind the penalties is to compensate the smelters and refineries for additional costs caused by the presence of the penalty elements, but these costs will vary depending on the process used and the location of the smelter.The issues caused by the minor elements include effects on the occupational health of smelter workers, increased environmental disposal costs, increased operating costs and reduced cathode copper quality.The effects of minor elements can be surprising. High levels of arsenic in concentrate are considered undesirable, but some smelters add arsenic to anode copper to improve the performance of the refinery.Excess concentrations of some elements will result in rejection of concentrates by smelters. China has blanket import bans on copper concentrates with concentrations of lead, arsenic cadmium, fluorine and mercury exceeding specified levels.This paper will review the behaviour of minor elements in smelters and refineries, explaining the deleterious effects of each of them, to provide a greater understanding for people and organisations wishing to market copper concentrates.CITATION:Fountain, C, 2013. The whys and wherefores of penalty elements in copper concentrates, in Proceedings MetPlant 2013 , pp 502-518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013