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The scope, pace and depth of mining is creating a need for improved ground control strategies to meet mine safety standards. Ground control and associated conservation problems relating to subsidence and the disposal of mining and metallurgical wastes can be resolved by mine filling with selected reject materials. The lack of suitable criteria to evaluate the applicability of such materials and especially cemented forms of fill is considered. Sulphide wastes, which are prone to oxidize, and cement are inexpensive mine fills, but their incorrect use can give rise to problems which are briefly described. Research work concerned with the utilization of sulphide wastes such as mill tailings, to produce fill with self-cementing properties has shown that the development of cohesion and strength is attributable to natural oxidation processes controlled by the physical and chemical composition of the fill mass. The cementing is caused by a number of oxidation products, and is most effective when the mineral pyrrhotite is present. The concepts of fill design are outlined and various criteria for assessing durability and deformational properties are proposed. Specimens prepared in the laboratory are capable of attaining unconfined compressive strengths up to 28 MN/m2.

Jan 1, 1973

By McGregor GW

The Utah International group of companies has a wide geographic spread of operations, including a significant interest inAustralia's largest coking coal operation in Queensland, steaming and coking coal mines in USA, a copper mine in Canada, a half interest in an iron ore operation in Brazil, a number of smaller operations, and a significant portfolio of undeveloped properties in South America, South Africa and South East Asia.The opportunity to acquire this group of companies presented an immediate problem to BHP in that it was regarded as too large for BHP to absorb by itself. In addition, there was a concern that such an acquisition would increase BHP's coking coal exposures to unacceptable levels. Despite these dilemmas, BHP was keen to acquire Utah.A plan was therefore developed and agreed to by General Electric (GE) (the then owner of Utah) which would give BHP nine months in which to put together a consortium to share in the ownership of the Queensland coal assets (plus coal assets owned by BHP), and to arrange a project financing for use by BHP and the consortium. BHP would own 100% of the rest of the assets.

Jan 1, 1985

I propose to speak today about our mineral heritage. In common usage "heritage" refers to the past. It means the discoveries, the developments, the mines and the processing plants, the benefits, the consequences, and the human experiences flowing from these. The history of the industry, inseparable from the history of the countries in which The Institute operates, is a rich background of which we can all be proud.But there is also a much wider meaning to mineral heritage. Our past has left us with the ab\lity to create and operate world scale enterprises generating wealth for the community, the ability to offer satisfying and challenging careers in a wide range of skills to our young people, and the willingness to follow adventurous and challenging vocations in remote areas, away from the big cities, at a time when the mentality of many is to get the most for the least effort and at the least inconvenience to themselves. The industry continues to be the repository of the pioneer spirit and a vital contributor to improving the life of the people in our countries.Thus, while our mineral heritage has much to do with the past, an essential part of it is how we use this rich past to build and shape our future. It is in this broader context that I am speaking today.

Jan 1, 1990

Although the effects of sea level changes on ore concentration processes are to some extent obvious with certain deposits, e.g. beach placer deposits, they have been largely overlooked with others such as Mississippi Valley type lead-zinc deposits. It is contended that sea level variations may have more profound effects on a wide range of deposits than has previously been appreciated. These deposits include not only placer'and residual deposits but also stratiform copper deposits, Mississippi Valley type deposits, stratiform manganese deposits and Minette type iron deposits. Sea levels in paralic basins profoundly affect the influx of 'detrital sediment, and this has to be suppressed to allow for the accumulation of thick rich deposits of coal evaporites, phosphate or metalliferous sediment. Emergence can be associated with oxidized waters, erosion, and,solution of soluble rocks. Submergence can reverse the Eh trend and can lead to preservation of ores. Both realms of surficial sedimentary environments and subsurface diagenetic environments can be affected by changes in water pressure, gas pressure (pC02), Eh, pH, and temperature as sea levels fluctuate. Even relatively small sea level changes may have profound effects. For example, there is some evidence to suggest that when the level dropped below 100 metres about 10,000 years ago, the Red Sea became isolated by the sill at Bab el Mandeb in the south, and evaporated away to leave a series of shallow lakes. The Red Sea is 1 to 2 km deep. It was at times such as this that the well-known copper-zinc mineralization developed in the Red Sea trough. Changes in sea level also affect the stability field of gas hydrates which can yield large volumes of gas leading to mass movements on the sea floor (Warnke, 1986).

Jan 1, 1987

By S Brochot

In cases where coarse gold is present in a deposit, it is usual to use the screen fire assay (SFA) method to analyse the samples. There is no doubt that this method is more accurate than the standard fire assay (FA) and reduces the risk to have a systematic bias. Nevertheless, the difference between the analytical errors of both methods can be glossed over when the overall sampling error is added to obtain the measurement error. In that case, the advantage of the SFA cannot justify its higher cost.The current paper attempts to address this question in the case of a gold ore deposit with visible coarse gold in various sampling situations (drill core sampling in exploration, blasthole or chip sampling in mining exploitation). The overall measurement error is estimated taking into account the analytical error and all the sampling error components following the Pierre GyÆs theory of sampling.Firstly, only the last sampling stage is considered when the pulverised sample is processed either to obtain one analysis sample for a FA or to be screened and subsampled for a SFA. The calculated measurement error clearly shows the advantage of the SFA specifically in presence of coarse gold. Secondly, the half core sampling is studied to explain the observed discrepancies when controlling the second half core. Finally, the blasthole sampling is treated using in situ heterogeneity models to show that the relative advantage of the SFA is hidden by the large overall sampling error.In conclusion, the choice of the assaying method is discussed at the light of the overall measurement error and in accordance to the analysis objective.CITATION:Brochot, S, 2012. Standard fire assay or screen fire assay? Application of the overall measurement error approach to choose the most appropriate method, in Proceedings Sampling 2012 , pp 135-142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By D Ryan

Following a long period of increase, there has been a reduction in exploration expenditure and activity in Australia over the past two years. During the post Second World War period, exploration was largely driven by mining companies seeking resources to satisfy an increase in world demand, while increasing their asset base as a result of mineral discoveries. In general, return on investment to shareholders was not the major driving force. With the exception of gold the mining industry has been faced with a long-term fall of metal prices in real terms. As a result the net profit return on average shareholderÆs funds in the Australian minerals industry has fallen from over 20 per cent in 1990 to less than five per cent today. Mining is now competing for funds with communication and finance based industries yielding high returns on shareholder investment. Shareholders and superannuation fund managers seeking a high return on short-term investments have indirectly reduced the funds available to the mining industry. Globalisation of the mining industry is leading to the rationalisation of the Australian mining industry as witnessed by mergers and acquisitions of local companies by foreign investors. The return on capital invested in the Australian mineral exploration industry must improve if the industry is to be competitive on a worldwide basis. Failure to achieve this will result in capital flowing overseas or to other industries. Relatively short-term upswings in metal prices which are generally driven by threats to the supply base (eg strikes, mine closures, increases in country risk) often lead to increased capital raisings for exploration funding. As a consequence of the time taken to raise the capital and increase exploration activity, measured exploration activity lags the metal price increases. There are also lags between commencement of exploration and discovery and ore production. In the case of gold exploration expenditure peaked six years after the price rise of 1980 Companies persevering with exploration in the current difficult period will be rewarded because they will be able to capitalise on future metal price rises and a minimised time lag.

Jan 1, 2000

By U Dzharlkaganov, B Bekmurzayevand M

The principle conception is presented of timely planning of winning operations in complex-structural blocks and faces in week-24-hourly regime. For adequate description of complex interconnections of open cast operation in space and in time and solving of optimisation problems in timely regime it is necessary using of complex logical and calculation procedures.

Jan 1, 2003

A unique opportunity is presented to Australia by recent developments in the Carpentaria and Mount Isa Mineral Province.Unique in two ways:The size, diversity and multiplicity of mineral finds in the region, and the continuing prospectivity.The approach being undertaken to accelerate development, increase the value generated for all stakeholders, and the value added in the region.

Jan 1, 1993

By Lin C, Jiaxiang D

A series of experiments were carried out with Hallimond tube in order to test the effects of different reagents. A good result has been obtained when potassium-n-butyl xanthate is used as collector for molybdenite and graphite complex are depressed by the depressor mixed with nigrosine and iron (III) chloride. The separating mechanism has been studied with help of many modem instruments.

Jan 1, 1993

The Paracale gold region had been known for hundreds of years, but the first professional attempts to work the lode and alluvial deposits were made only in the 1890s by the London-based Philippines Mineral Syndicate. Complex ores, transportation problems, and the Philippine Insurrection halted operations. Ultimate success went to American firms, though Frank Karuth's Philippines Mineral Syndicate had pioneered the field.

Jan 1, 1987

By B J. van Loggerenberg

The capital cost of major items of mining equipment is very high. The operating cost of such equipment is also high. It is therefore important that such expensive equipment is used productively. To this end mine management uses production data systems and management accounting systems to monitor events and provide data for analysis to enable management to make operating and business optimisation decisions. This could be done better if there was an understanding of productivity in terms of its utilisation and efficiency components. What has been missing has been a methodology to properly account for the productivity of equipment in terms of its contribution in dollars to the costs and profit of the mine. An explanation of the Productivity Accounting methodology will be given. It will then be shown that productivity has two components, that of capacity utilisation and efficiency. These are defined and the dollar contribution of each to costs and profit shown. The efficiency component tracks the effect of proportional changes in input cost quantities used in the mining process as mining production changes. The capacity utilisation component tracks the effect of step changes in the input cost quantities used in the mining process as mining production changes.

Jan 1, 2003

By Lewis RW, Wilson GI

An ore reserve estimation is only as meaningful as the quality of the data used. All required information needs to be collected in a careful and systematic manner, and be rigorously checked and verified before estimation commences. In addition to geological, assay and location data, a large variety of other information is required for the estimation process. This includes mining, metallurgical and environmental parameters. Though outside their usual area of responsibility, geologists should be involved in the selection and collection of this additional Information.

Jan 1, 1987

The history of civilisation continues to register a steady tide towards the urban life as the basis of its social organisation. The manifestation of this movement is a continuous growth and increasing density of population in our towns and cities, as the favourite space for the development of humanity. Naturally, this trend raises a certain number of problems which grow proportionally with the size of the city. The use of the underground space has an important role to play in solving such urban problems. But various issues must be taken into account when developing urban underground space.

Jan 1, 1999

Operation of the tankhouse at the Electro lytic Refining and Smelting Company's works has been improved, but further automation is re- quired to cut the labour intensive nature of the routine tasks. Anode quality, both chemical and physical, plays an important role in efficient refinery practice, and impurities such as lead, antimony and nickel have required careful monitoring for smooth operation. The gradual replacement of copper blanks by titanium has markedly improved the quality of starting sheets, but problems have been ex- perienced with surface preconditioning of the titanium blanks. Polishing with emery paper proved to be a successful technique.

Jan 1, 1976

An efficient stores organisation is essential for an efficient undertaking. Unless the stores organisation is able to meet the requirements of its requisitioners promptly and economically, the undertaking as a whole cannot function efficiently.Delays or errors in supply of material, or substitution due to lack of material availability from the stores are costly and must be eliminated. This then makes the objective of a store, to supply on demand at the cheapest possible price, those items of stock which it is organised to carry, also to procure as quickly as possible and at the lowest price those special items required which are not normally carried in stock. To do this it is necessary to set up a stores organisation consistent with the size and requirements of the undertaking. Stores organisations vary with the nature of the undertaking they are designed to serve. In the case of the Broken Hill Associated Smelters Pty. Ltd., an organisation has been established to meet the operating and maintenance requirements of the Port Pirie Works. These embrace the particularly wide range 0:1; activities associated with roasting" blast furnacing and refining the lead concentrates from the Broken Hill Mines in a continuous metallurgical process producing a variety of refined metals; also many associated activities including power production and engineering maintenance and construction.

Jan 1, 1951

Many problems occur in recruiting staff to remote mining operations, relating to both domestic and works environments. These are stated, together with steps which have been taken to overcome them. Geographical and climatic conditions applying to the Agnew mining operation are described. Company policies have been established to define criteria for selection of staff, and to define methods by which the criteria are applied.

Jan 1, 1980

As the awareness and concerns on subsidence issues increase, there are clear, challenging and credible community expectations for responsible mining, public safety, optimal resource recovery and effective land use and environmental management, coinciding with a changing and strengthening regulatory environment being implemented by the NSW Government. This paper discusses a number of areas where cultural changes in the mining industry will assist with improved subsidence management to meet the enhanced standard.

Jan 1, 2003

A method of assessing the blastability of a rock mass is presented which makes use of five, readily available, simple parameters. These are the Rock Mass Description, Joint Plane Spacing, Joint Plane Orientation, Specific Gravity Influence and Hardness. For a particular rock mass a value is assigned to each parameter and the Blastability Index is calculated from these values. Application of the Index in blast planning and computer modelling is discussed.

Jan 1, 1986

By See J. B

The zinc-nickel alloy process, TECHNIGALVA, was developed for the control of the thicknesses of zinc -coatings on reactive silicon-killed steels. These are steels containing between 0.04 and 0.15 per cent silicon which have become more common in recent years as more steel is produced by continuous casting. The introduction to this paper will review the current status of this process in Europe, North America and Australasia. It is well known that the presence of silicon at certain levels in steel can cause sufficient growth of intermetallic phases during galvanising to form a grey coating of excessive thickness. This type of coating is undesirable because it is brittle and has poor adhesion to the steel base. Since the early-1980s a widely accepted practice for suppressing the reactivity of steels containing silicon during general galvanising has been the addition of approximately 0.1 mass per cent nickel to the galvanising bath ie the TECHNIGALVA process. The paper will also discuss metallurgical aspects of the use of nickel in galvanising such as the mechanisms by which nickel suppresses reactivity, the structure and composition of the ternary Zn-Fe-Ni drosses formed when using nickel and the use of nickel in the galvanising bath at a level of about 500 ppm to give thinner, smoother and brighter coatings on steel.

Jan 1, 1993

By F De Beurs, S Davies

With the emphasis on CO2 emission legislation and the increasing price of traditional fossil fuels like coal, oil and gas, the use of alternative fuels is becoming more and more attractive for the industry, particularly for the cement industry. The variety of materials burnt in the kiln is enormous and varies from tyres, to animal meal and other waste material or by-products that would otherwise end up in an incinerator or landfill facility. This wide variety in materials demands thorough analysis to determine what elements are present in the organic matrix. The elements present may have an influence on the process or the quality of the cement. Toxic or environmental unfriendly elements may be incorporated or dissolved in the clinker phases; whereas volatile components may be present in stack emission to the atmosphere. X-ray analysis is already the key to elemental analysis in cement production, and is used here to determine the composition of these alternative fuels. The XRF spectrometer configuration used in this study is designed to overcome the difficulties associated with the analysis of strongly varying light organic matrices containing heavier elements in minor and trace-level quantities. Heavy element specific excitation conditions and three-dimensional polarised optical geometry increased the signal to background ratio and improved detection limits compared to conventional XRF spectrometers.

Jan 1, 2008