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By Milner A, Brockway D, Hodges S

The combustion of brown coals in Latrobe Valley power stations produces approximately 500 000 tonnes of solid wastes each year. This material, which includes precipitator ash, char and furnace ash, is hydraulically sluiced to large ashing ponds and the supernatant solution is ultimately discharged to the sea. There are significant operational and capital costs associated with the current ashing system. The ash produced from the Latrobe Valley coals is unique and has a wide variety of potential applications including soil conditioning, concrete and cement extenders, fillers in non-metallic materials, components of building products. In addition, with the application of appropriate technology, it is possible to extract char, sodium sulphate, calcium carbonate and magnesium metal (as the chloride) in substantial quantities from the ash. Research has been carried out to explore the prospects of these various options for ash utilisation. The research has focused on detailed characterisation of the ash material and the potential extraction efficiency for various species under various conditions. From this work a conceptual process has been developed and subsequent studies have been directed towards understanding variables and optimising operating regimes for product extraction. Currently, the work is concentrating on the separation of char, the development of high-grade carbon products and the extraction of sodium sulphate.

Jan 1, 1992

By Miller F. S

The famous Golden Mile of Kalgoorlie in Western Australia was, between 1888 and 19ft, one of the richest and most important gold camps in the world. Annual production, which reached a peak of nearly 1,300,000 oz. in 1903, however dropped to below 400,000 oz. after 1920.Depression seized the camp, and many mines closed down. The output from this old field is now steadily mounting under the stimulus. of a higher price for gold. In 1935 300,000 oz. of precious metal were recovered and the future is bright. Total production from the field is 21,400,000 oz., whereas something like £23,600,000 have been paid in dividends.The Golden Mile has been studied by many geologists. Their somewhat diverse findings were published for the most part in the Australian technical press which, unfortunately, is not sufficiently represented in foreign libraries.The following article is based on an eighteen months' study in the district for Gold Mines of Kalgoorlie Ltd., preceded by four years' experience with almost identical rock types in the, Porcupine district of Ontario. The excellent record of observed fact left by previous invesigators, augmented by talks with observant mining men...

Jan 1, 1937

Gold in the stibnite veins of Costerfield, Victoria, was described in 1922 1, prior to any mineragraphic examination, as (a) free yellow gold (b) free rusty gold and (c) combined gold. The free yellow gold occurs in quartz and will amalgamate with mercury. The free gold of dull, rusty or copper-red colour occurs in massive stibnite and has been stated to resist amalgamation with mercury. The dull colour is only skin deep and the colour is bright when the rusty gold is scratched. The appearance of the rusty gold is spongy or cellular and it generally occurs near small cavities in the stibnite. The suggestion that the cellular character indicated the removal of a certain amount of stibnite leaving a residue of se.condary gold cannot be sustained.It now appears probable that the rusty gold is formed by the primary dissociation of a gold antimonide and is distinct in origin from the normal yellow gold which is deposited with quartz or stibnite from auriferous mineral solutions.The combined gold referred to in the earlier paper was the gold contained in the stibnite as revealed by assay. Such gold was at first thought to be either dissolved in the stibnite or else present as free interstitial particles too minute for observation in transmitted light in thin sections.Subsequent examination of numerous polished,surfaces disclosed the small particles of gold occurring in the grain boundaries in aggregates of fine grained stibnite 2. The assumption that all the gold in the stibnite, as revealed by assay, occurred in this way is now known to be incorrect, because limited amounts of a gold antimonide have been found in the veins.

Jan 1, 1952

The Beckman Air Comparison Pycnometer is as accurate as the specific gravity bottle for the determination of the volume of fine powders, or particles, up to 50 c.c. in volume. The determination using the air comparison pycnometer is performed in a much shorter time.A graph of density versus iron content for samples from four different iron ore deposits shows that iron contents can be obtained to within 4 per cent iron. Field geologists should be able to obtain quick and relatively accurate iron contents of ore samples using the air comparison pycnometer at these deposits.INTRODUCTIONA Beckman Model 930 Air Comparison Pycnometer was purchased to decrease the time required for the determination of the volume of stones and powders. The liquid displacement method was used previously and the time required per determination varied from a few minutes for stones to half an hour, or more for fine powders. With the air comparison pycnometer, the determination takes approximately 2 min and can be quickly checked for accuracy by a further determination. The total time for weighing, determining, and checking the volume is no more than 5 min.DESCRIPTION AND PRINCIPLE OF OPERATION OF PYCNOMETERDescriptionThe air comparison pycnometer measures the volume of materials, in c.c., by determining the amount of air displaced.A diagram of the main components is given in Fig. l.Cylinders A and B are equal in volume and each has a piston which is moved by turning a handwheel attached to a geared shaft. The measuring piston shaft is geared to a 5...

Jan 1, 1963

THE furnace described in this paper was installed and has been used by the writer for the melting of rich gold-bearing material, and has given complete satisfaction. It may, therefore, prove of interest to other metallurgists who are faced with a similarproblem. A furnace of this type should be most suitable for the reduction of "cyanide preeipitate," "charcoal ash," "anode sludge," &c. formerly the melting was done in fire-clay crucibles, using coke or crude oil as fuel, but this method is costly, slow, and unsatisfactory. A small water-jacketed blastfurnace was also tried on this material after briquetting it, but was discarded in favour of the electric furnace. The furnace may be described as a simple form of the Heroult resistance furnace, with an adjustable upper electrode and a fixed bottom electrode. This is in accordanee with Stansfield's classification of electric furnaces. The heating is mostly due to the resistance offered the current by the molten slag. The melting chamber consists of a steel drum 14 in. in diameter and 21 in. high, and is lined with silica bricks specially made to fit the shell. The internal diameter is G in. The bricks contain 92 % silica, are made from calcined quartzite bonded with fireclay, and are similar in composition to those used for lining steel converters. They are set in a mixture of finely-ground quartzite and clay, and well dried out. The shell is bolted to a steel plate, which forms the decking of a truck running on rails, so that the furnace can be moved under ahood for carrying off the fumes. A cast-iron slag spout is bolted to the shell below the tapping hole, which is 4 in. from the bottom of the shell. Opposite this another hole 1 in. in diameter is drilled through the shell and lining for the passage of the lower...

Jan 1, 1918

Raw materials account for over 60 per cent of the cost of hot metal production in classical blast furnaces and the principal cost component is cost of coke. Dependence on coke is a traditional weakness of blast furnace ironmaking and while efforts have been made to evolve alternative ironmaking technologies which do not use coke, such as direct reduction, smelting reduction, and the more recent method of making iron carbide, blast furnaces continue to be the most efficient means of producing bulk hot metal even today. Coal injection, to the extent of 150 - 200 kg/t of hot metal, has been one of the major innovations made in blast furnaces to decrease cost and to reduce the dependence on coke. This has, however, given rise to more stringent coke property requirements (which often means more expensive coke) - a `tail spin' of Sorts!

Jan 1, 1999

Organisations are starting to develop processes for achieving sustainability principles they have defined for their organisation. The foundation for these principles is now well accepted. The definition of a sustainability framework is a good starting point for any project. The delivery of the framework requires the organisation to think differently about how project objectives can be met. New tools are becoming available to help achieve the sustainability outcomes for the projects. This paper will examine the project building blocks that are necessary to ensure the sustainability framework can be achieved for the project. These include new approaches to decision-making processes and evaluation tools and when to apply them. An integrated approach with shared expertise to project delivery, which is applicable to the whole supply chain, will be discussed. This will cover sustainability procurement, integrated waste management, cleaner production and eco-efficiency, sustainable products and disposal. A project toolkit will be presented and some key project tools identified. The need for management support in undertaking these new approaches is critical, as is the need to develop partnerships and cooperative management to facilitate delivery.

Jan 1, 2004

This paper deals with the application of table flotation to two unusual mineral dressing problems. Both problems involved the removal of interfering minerals at sizes too coarse to normal froth flotation.The first problem was the removal of arsenical minerals from Broken Hill gravity concentrates without further size reduction. Table flotation without grinding of the original concentrates gave almost complete rejection of the arsenic from the concentrates. A typical test result was a reduction of arsenic in jig concentrate from 0.75% arsenic to 0.007% arsenic.The second problem was to develop a method to produce a high grade calcium carbonate concentrate from coastal dune sands containing about 10% silica and about 80% calcium carbonate. The sands were about 30 mesh British Standard Screen (B.S.S.), and for economic and other reasons it was stipulated that the separation be made without grinding. Again, table flotation gave excellent results. A concentrate was produced containing 99.62% acid soluble material, representing a recovery of 98.69% of the calcium carbonate in the feed with a rejection of 96.44% of the silica.The investigations' were carried out at the Kalgoorlie Metallurgical Laboratory, under the Department of Mines...

Jan 1, 1954

Ultrasonic Extinction for High Resolution Particle Size and Concentration Analysis

Sep 13, 2010

By Lamont G

The significance of blasthole stemming in determining blasting efficiency has been extensively studied for small diameter holes using gelignite explosives. Recent developments in blasting technology with the use of large diameter holes and low cost blasting agents have not included studies of the effectiveness of different types of stemming materials. A review of previous measurement techniques and the relevance of these earlier results to present stemming practice is presented in this paper. A survey of operating mines in Australia provided information for this analysis. The value of stemming in reducing blast noise and improving blasting efficiency is generally accepted but the use of bulk-loaded explosives in underground operations has resulted in the practice of eliminating the use of stemming material.In surface operations drill cuttings are used for stemming on the basis of availability rather than efficiency in providing resistance to movement. The development of laboratory testing techniques, based on noise level and borehole pressure measurements, to evaluate the relative efficiency of different types of stemming materials is described. The results of an extensive series of tests with ANFO explosive showed similar trends tothose obtained from earlier published results with gelignite type explosives. Conclusive quantitative results on the relative effectiveness of different stemming materials will require minor modifications to the existingequipment. Observations and the results of pressure measurements indicated the presence of shock wave effects which caused the ejection of the top section of the stemming column when using coarsely fragmented material.

Jan 1, 1979

Although AustraliaÆs coal mining industry is currently experiencing a pleasing period of price relief, long-term trends toward lower real prices will surely continue. Higher price levels attract expansion by existing operators and market entrance by new operators. History clearly demonstrates the relentless long-term march toward ever lower real prices. Therefore, the need for economic returns applies constant pressure to improve productivity. To be sustained, high productivity requires a systematic response based on a solid understanding of critical productivity determinants. The most powerful determinant of productivity is now widely understood to be workplace culture. Culture largely comprises a combination of behaviours, symbols and attitudes. This paper will examine and review scienceÆs latest discoveries in human behaviour. It will provide a proven, practical framework for understanding behaviour and applying this knowledge. Significantly, it will highlight why conventional approaches toward improving productivity often provide disappointing economic returns. The modern understanding of behaviour factors will cover coal face operations. More importantly, because executive and managerial levels in coal mining have significantly greater impact on industry and mine productivity the paper will concentrate on leadership. Particular emphasis will be placed on use of modern systems and in particular use of what are by far the most powerful drivers of behaviours û measurement, analysis and reporting systems. The paper and presentation will show how conventional systems rooted in antiquated American legislation from the early 1900s stifle productivity improvement and drive suboptimal and even counterproductive behaviours. These commonly used systems will be compared with accurate and effective modern methods for assessing performance to improve productivity. These principles are proven in all industries and effective application in mining will be highlighted. Actual results will be used to demonstrate practical approaches successfully applied in both metal and coal mining in Australia and overseas.

Jan 1, 2005

A discussion on simulation tools to aid the development of robotics platforms is presented. The focus of the work is towards mining robotics platforms where operations are typically in unstructured, unpredictable environments and a high degree of dependability in their operations is required. It is argued that a test-based development approach leads to more robust solutions and faster development cycles than traditional single-track field-only development and that the key enabling technology for this development paradigm is the judicious use of simulation tools. The future direction of simulation for use in online applications such as active planning and as a means to assist tele-operation in high latency communication applications is also brief y considered together with the requirements for a useful simulation environment in terms of the simulator architecture. Finally, a case study is presented on the application of the discussed methodologies to an unmanned ground vehicle (UGV) for earth-moving tasks, which is being developed in an accelerated time frame with a transient development team.

Dec 6, 2010

By P B. Hills, R J. Walton

Geotechnical instrumentation has been implemented as a key step for monitoring and optimising an engineered mine design for managing seismicity at the Beaconsfield Gold Mine. Measurements of displacement, stress change, ground control element load and seismic response of the rock mass allow for back analysis and calibration of critical parameters for feedback into the engineering design loop. Instrument clusters are installed in strategic locations prior to the commencement of stoping in order to determine the nature of the response of the rock mass to stoping. A selection of instruments including instrumented cable bolts and rod extensometers, resistance wire extensometers, hollow inclusion stress cells, vibrating wire stress meters and resistance wire extensometers are used to gather data through a data logging system. The rate at which data is recorded is adjusted to provide more information during periods of anticipated rapid change such as around stope firings or during periods of high seismic activity, and less information during periods of anticipated quiescence. The twofold purpose of the instrumentation is to calibrate the numerical modelling output which forms the basis of the engineered mine design, and to provide an alert mechanism where the behaviour of the rock mass is not what was anticipated, or where the impact of that behaviour may compromise the integrity of the engineered ground control system. The paper describes the location of instrument clusters with respect to stoping, the type of instruments employed and the method of data acquisition. It provides examples of results obtained and illustrates the way in which that information is used to optimise the mine design and manage seismicity.

Jan 1, 2008

By Clarke P. E

At the end of the recent war, reports became available from Europe of the use of tungsten-carbide inserts in percussion rockdrill bits. These bits were used with small size rockdrills, so that the only advantage gained from the use of the harder, abrasion resistant, tungsten-carbide appears to have been the greater life of the bit. Larger machines, such as used in Australia in conventional practice, had to be discarded to protect the relatively brittle tungstencarbide inserts and the vulnerable bonding with the bit body.As it had been found in machine shop practice that some grades of tungsten-carbide had been produced with considerably improved toughness, it was decided by Gold Mines of Australia Ltd. that drilling practice with tungstencarbide bits warranted detailed examination under Australian conditions, and that drilling tests should be undertaken at Morning Star (G.M.A.) Mines N.L., for which it acts as General Manager and Consultant.These investigations progressed through three stages:1. Preliminary Investigations and Tests.When the investigations were initiated no commercial bits were available in Australia, and manufacture was commenced with improvised equipment from virtual scratch. These early tests indicated that the use of 3 in. bore rockdrills in conjunction with tungsten-carbide insert bits was a 'possibility, and that it was unlikely that a small bore...

Jan 1, 1950

The first mention of gold in Western Australia was in 1848 when some specimens of copper ore, which are believed to have come from the Murchison district, were sent to Adelaide for assay. Gold was present in these specimens, but no particular interest seemed to be attached to this fact as the search at that time was mainly concentrated on base metals and coal. Interest appeared to be shown in gold in 1852 when several parties moved out eastwards from York looking for goldbearing country. Though these parties inmany cases were very near to what is now known as the Yilgarn Goldfield, nothing was found.The next record of gold was reported in some specimens which were brought in from Cardup, some 25 miles from Fremantle. Though this area was investigated, it would appear that all the gold had been contained in the specimens and nothing further was found, though the report had been the cause of a small rush of people interested in gold.From time to time specimens had been brought in by various people from the district east of Northam, and in 1861 a reward emanating from private sources was offered for the finding of gold within a radius of 150 miles from Perth. The Government at this stage took an interest in exploration for gold and in the same year supplemented this privately offered reward on a £ for £ basis. The Government also, about this time, commissioned a practical miner, with prospecting experience in the Eastern States, to examine the country between Albany and Northam with a view to the possible existence of goldbearing veins in that area. His report, however, was entirely unfavourable and nothing further was done. In 1873 a quartz lode was discovered near Albany arid a company was formed to work...

Jan 1, 1956

Maori economic development still remains an enigma to many people some 157 years after the signing of the Treaty of Waitangi. It has only been in the last decade as a result of increasing pressures from Maori to recognize and settle grievances arising from the Treaty and the resulting compensation issues that "mainstream" has begun to sit up and take notice. While Treaty settlements such as the Tainui, Ngai Tahu and Fisheries settlements have gained prominence as a source of economic potential for Maori, there are significant existing assets owned by Maori worth an estimated $4.6 billion that add an exciting new dimension to Maori contribution to New Zealand's enterprise economy.   Despite the fact that many claims have yet to be resolved, Maori are clearly shifting from grievance to development mode as evidenced by their focus on capacity building through education, strategic alliances nationally and internationally and the significant growth of nett asset worth of Maori interests in a number of industry sectors.   In essence, Maori provide a large un-tapped economic potential in New Zealand. The years of relative economic obscurity appear to have wetted their appetite for positive growth and economic independence. Given current trends, it would not be unrealistic to expect the asset base of Maori to double in value over the next decade and to see the emergence of Maori owned Corporates not only within the New Zealand economy but also trading actively in the global market place.

Jan 1, 1997

By B Clements, G Lane

The operations and project environments are very different, but overlap in many areas. The development of mineral processing projects is goal oriented, is schedule focused and is a contractual environment. The operating environment for a mineral processing plant is oriented around longer-term commitments, focused on delivery against budget expectations, and an environment heavily influenced by long-term personal relationships, community relationships, and people issues.Further contrast is evident in the way expenditure is managed. Projects commit large amounts of money quickly to meet schedule-based objectives. Operations manage expenditure to minimise operating costs and are able to, or are forced to delay decisions on large expenditures. However, these two environments need to come together in many ways, ranging from greenfields plant handover to a new operations and maintenance crew, to day to day interaction and management of brownfields projects, often in close proximity.This paper considers the different perspectives people bring to projects and early operations, including the advantages and disadvantages of æoperationsÆ input to a project and models for managing value adding during project development, implementation and debottlenecking.CITATION:Lane, G and Clements, B, 2012. Operations versus projects - How do people think and what are the implications?, in Proceedings 11th AusIMM Mill OperatorsÆ Conference , pp 11-16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The literature pertaining to the electrochemical reaction at the anode during electrolytic reduction of alumina by the Hall-Heroult process is not in universal llgreement about the gaseous product. The possibility of electrochemical formation of CO at the anode was examined using existing data. Although the thermochemistry favours co-evolution of CO and CO2 with CO as the major product, the mechanism of the reaction shows this is unlikely. Since the origin of CO can be more logically explained by non-electrochemical mechanisims, it is concluded that CO2 is the only product from the electrolytic reaction at all current densities.

Jan 1, 1967

This paper endeavours to lay as concisely as possible, before the members the salient features of local gold milling practice, and to point out in what respects this practice differs from that of other large mining camps. This is essentially a free milling ore the gangue being quartz and the gold occurring in a coarse form. At times the ore crushed contains a good deal of slate, the latter imparting to the tailings a somewhat leaden hue.Small amounts of sulphides, chiefly iron pyrites, and at times smaller quantities of arsenical pyrites, zinc blende, and galena are contained in the stone. The average amount of sulphides contained in the ore cannot well be ascertained, as the concentrate obtained in all cases contain too much silica to form a basis of calculation...

Jan 1, 1902

By D A. Edmunds

The most important development that has been taking place recently relating to mining operations in New Zealand would generally be regarded as being the Resource Management Law Reform. This has been widely publicised by the Government as a comprehensive review of the laws governing New Zealand's natural and physical resources. Submissions have been sought and a free phone provided to encourage public participation. Recently a Discussion Paper has been prepared by the Core Group coordinating the review to explain progress on Phase One (Ministry for the Environment, Directions for Change: A Discussion Paper, Wellington 1988). It outlines Government decisions already taken which impinge on the Review and describes the possible models for resource management laws. However, it is possible that some fundamental practical issues of significance to the mining industry will not be addressed and may be lost sight of in the much wider issues which are to be covered. The purpose of our paper is to address one of these issues namely, the interrelationship between any new resource management legislation and the Conservation Act 1987 (as recently amended) in the context of Ministerial consents. The importance of this issue can be seen from the fact that as at 7 June 1988 there were 279 mining licence applications and 223 prospecting licence applications waiting to be determined by the Minister of Conservation. Since April 1987 only 19 mining and 13 prospecting licences have been consented to. In addition a major proportion of New Zealand's mineral resources are contained with land administered by the Department.

Jan 1, 1988