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By S M. C Verryn

The amount of raw material used in the production of cement can be reduced by partially supplementing it by pozzolanic waste material without changing its properties negatively. This paper discusses results of an investigation using slag from the Pt industry, from the production of steel using Midrex processes as well as fly ashes from different coal power plants in South Africa. These are blended in a 20 per cent slag or fly ash to 80 per cent cement ratio. The properties of the mixtures depend on the phase composition, chemistry, grain size and the sources of the materials. The results are promising, but show variable behaviour depending on slag and cement composition. Compressive strength tests as well have heat flow curves showing the hydration behaviour, indicating that 20 per cent addition of slag or fly ash to ordinary Portland cement is viable. There is a large potential to use slag in cement mixtures and this study can be used to develop cements that will positively influence CO2 emissions and help to reduce large slag and fly ash stockpiles.

Jan 1, 2008

By W Lunwongsa, S Meffre, S Nuanla-ong, K Zaw, R James, A Salam

Gold and silver mineralisation at the Chatree low sulfidation deposit is hosted in andesitic volcanic and volcaniclastic rocks and characterised by multiple hydrothermal alteration assemblages and quartz-carbonate (chlorite-adularia) replacements, veins and breccias. The ore-bearing veins are influenced by intersecting structures and host rock lithologies. Emplacement of the host succession occurred at 250 ¦ 6 Ma (dated with laser ablation ICP-MS U-Pb zircon techniques), which was closely followed by mineralisation at 250.9 ¦ 0.8 Ma based on the analysis of adularia from coarse-grained quartz-sulfide (chalcopyrite-pyrite- sphalerite) veins using laser ablation Ar-Ar methods. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Studies of the morphology of seamounts within the Hawaiian, Line Islands, Gilbert and Phoenix Seamount groups indicate that the morphology and size distribution of seamounts vary significantly from one seamount group to another. The Line Islands group appears to be the most complicated of all the groups studied thus far. This group is complicated by reactivation of volcanism, which has superimposed volcanics on sedimentary rocks. These seamounts display abundant volcanic features on their summits. Seamounts within the Hawaiian seamount chain display a marked absence of volcanic features due to the . presence of thick carbonate caps. Reef platforms and sealevel benches are very common on these seamounts but are absent from seamounts in most other seamount chains in the central Pacific. Slope angles vary regionally between seamount groups. The minimum slopes are found on Necker Ridge in the central Pacific basin. The maximum slopes are found on ridge-crest seamounts. Roughness increases proportionally with mean slope angle.

Jan 1, 1987

By Wilson O. A, White R. W G

The Mount Morgan mine occupies a unique place in the mining history of Australia and although not as glamorous during the second phase of its existence, it made a significant contribution to the technical and financial history of the nation throughout its life. The stories of the intrigue surrounding its discovery and early operation, the enormous return received by its original investors in its first five years as a public company, its influence on the local, national and international scene to its final closure have been documented in many publications, the most recent and authoritative being by John Kerr (1982). Institute publications as far back as 1911 have documented details of the mining, metallurgical and engineering practices of the two companies which worked the 100 or so acres which were alleged to be `the richest single gold mine in the world'. Within the Institute records appear the names of Presidents, Institute Medal recipients and others connected with Mount Morgan who have played an important part in the Institute history.

Jan 1, 1993

By Jena P. K

Smaller deposits of high grade chalcopyrite or the concentrates of low grade and complex copper bearing ores, can be subjected to extraction processes other than smelting and converting. Low temperature chlorination and segregation processes are among those mentioned in the literature. In the present work, extraction of copper from a Brazilian chalcopyrite concentrate by slurry chlorination with chlorine gas at room temperature, dry chlorination by chlorine gas in the temperature range of 350 to 450¦C and segregation roasting of the calcined concentrate in the temperature range of 650 to 800¦C have been carried out. The effect of several experimental variables on the extraction of copper has been discussed in all these cases. Under optimum experimental conditions, 100 per cent Cu extraction was possible by either slurry or dry chlorination processes and around 86 per cent Cu by segregation roasting. For all the three cases, possible methods have been suggested to trial the studies on a pilot scale to assess their technoeconomic viability.

Jan 1, 1992

By R C. Owen, M A. Ward

The paper describes the application of New Zealand's environmental impact assessment procedures to a proposed gold and silver mine in the North Island of New Zealand. The project is described and a summary is provided of the statutory permits or consents that are required prior to operation of the project. Emphasis is given to the requirement for environmental impact assessment and the preparation of a formal environmental impact report. The company's approach to impact assessment is described, with examples of how this assessment and the identification of management alternatives influenced the engineering design of the project. This paper was prepared as a contribution to a working session of the International Association of Impact Assessment VII Annual Conference, July 1988.

Jan 1, 1988

The role played by lawyers in business has, in the course of the last 15 to 20 years, changed perceptively. This development has coincided with, and indeed has been a reflection of, the changing nature of Australian business, especially as the mining industry established its predominance in the Australian economy. The nature and extent of governmental regulation of business, too, has changed markedly. As a consequence, there has been a qualitative'change in the nature of commercial law practice. For the needs of business to be met, lawyers have had to develop specialist skills in new areas. Furthermore, there has been the emergence of the "in-house" lawyer, who increasingly plays a primary rather than a subordinate role in corporate law practice. There is no evidence to suggest that this trend, which is by now so well established, will prove to be ephemeral. Instead, with all indications pointing towards even greater governmental regulation of business activities, the intimate role of the lawyer in business seems entrenched.

Jan 1, 1980

Alliance Gold Mines was established in the early part of 1994 to acquire the assets of Diamin Resources NL at Maldon, Victoria. These comprised Exploration Licence 3422, some 20 sq km in area and enclosing the main part of the Goldfield, and a CIP plant - with a nominal capacity of 250 000 tpa - which was commissioned in 1988. Between 1988 and 1992 Diamin had mined - by open pit methods - and milled around one million tonnes of low grade gold ore, and recovered 55 000 ounces of gold. By 1992 the known shallow resources had been depleted. Historical gold production from the Maldon field is about 1.75 million ounces, at the surprising average recovered grade of 28 g/t. The last significant mine closed in 1926: since then there has been no comprehensive exploration program, though Lone Star Exploration NL tested part of the field for shallow open-pittable resources in the 1970s and Carpentaria Exploration Company Pty Ltd carried out widely-spaced drilling on the three main reefs from 1979 to 1982. Diamin (1983 - 1994) commenced a careful compilation of old mine records and newspaper clippings, and drilled several cored holes.

Jan 1, 1996

By Roderick W. F

The equipment and procedures used for green pellet production on a laboratory scale are given, together with a description of the straight grate pellet strand analogue which has been developed to examine the response of various ore types to heat hardening. The capabilities of the analogue are illustrated with data obtained from the balling and drying studies using a manganese ore. Differences in inter-batch pellet quality are discussed, and method of minimising the experimental error that can arise from these differences is Presented.

Jan 1, 1974

By Lai KF

The Hellyer orebody is a fine grained, massive sulphide Pb-Zn-Ag- Cu-Au deposit located in western Tasmania. Initial testwork showed that the orebody would be difficult but not impossible to treat by conven- tional flotation. A staged programme-of work was commenced to demon- strate that marketable concentrates could be produced with satisfactory recoveries. Following laboratory testing of drill core to define two flowsheets, bulk samples of Hellyer totalling 20,000 tonnes were trialled at 6 tph in the Cleveland concentrator over six months. The high through- put and extended duration of the trials ensured maximum confidence in the results and that scale-up to subsequent plants would be with a mini- mum of risk. The milling trials were successful and the Cleveland concentrator was expanded in early 1987 to treat 250,000 tpa of Hellyer ore to produce 85,000 tpa of bulk concentrates. Late in 1987 construction commenced on a 1 mtpa concentrator at Hellyer to produce separate copper/silver, lead, zinc and bulk concentrates.

Jan 1, 1988

The geochemistry of waste rock from mining operations is critical to the development of acidity-related environmental problems during mining operations, and following mine closure. Failure to recognise the potential for waste rock to produce acidic oxidation products may cause mobilisation of heavy metals into ground and surface waters, and create heavy metal levels in soils which are toxic to plants, causing the failure of revegetation programs. Although more usually associated with wet tropical environments, the potential exists for these problems to occur even in and regions such as the Eastern Goldfields region of Western Australia unless appropriate pre-planning is undertaken.Acidity-related mine waste problems can be extremely expensive to rectify, but can be avoided by waste rock characterisation, and pre-planning of waste rock deposition based on this information. Integration of knowledge of waste rock geochemistry with geotechnical engineering, and application to likely problems, is essential for the successful planning and implementation of cost-effective strategies to avoid problems occurring. Pre-planning to avoid problems is likely to be significantly less expensive in most cases than remedial actions to rectify problems after they have occurred, and in fact may involve no additional cost if it requires only rescheduling or redesign of existing or planned Activities.

Jan 1, 1993

The purpose of this paper is to provide some practical commercial advice in relation to issues of access and trespass during exploration. It is not my intention to provide a detailed analysis of the applicable law because this is not the appropriate forum for latin maxims and turgid case studies. Instead I will explain the issues in sufficient detail to enable those who are not familiar,with the legal concepts to understand their obligations and responsibilities in relation to exploration activities. Take as an example a situation where a company (for the sake of attempted light relief, called Rogue Mining) holds an exploration tenement adjacent to one held by Lamb Exploration. In conducting aerial exploration activities over its own tenement Rogue overflies the tenement held by Lamb, doesn't turn off its equipment and accidentally collects data in respect of the adjacent land. In analysing that data it becomes apparent to Rogue that there is a substantial anomaly on the adjacent land of which Lamb is apparently unaware. Rogue subsequently negotiates to purchase an interest in Lamb's tenement.

Jan 1, 1995

Projects to be undertaken in remote locations require special attention with regard to constructability from the very first stages of design. This is to ensure not only that the project is compatible with the environment in which it' is proposed to be built, but that it does not require facilities or special construction equipment and expertise that is not available in the proposed location. This paper draws on experiences gained on projects in Alaska, Northern Canada, South East Asia, outback Australia, and more recently Bougainville, in Papua New Guinea, where over the past 5 years Minenco has undertaken in excess of A$120 million of work on a number of different projects for Bougainville Copper Limited Although many of these projects have been close to large populous cities, which have been served by regular shipping and airline services, the locations have not had the availability of construction facilities which exist in major cities of Australia and thus can only be considered as remote locations by current day standards. As a result, every nut bolt and washer has had to be brought to the job site by the construction company. No hardware or electrical warehouses existed for those forgotten half dozen high tensile bolts, spring

Jan 1, 1986

Organic dyes such as nigrosine and sun yellow act as depressants for carbonaceous particles in the, flotation of sulphide ores. Depression is achieved when initially hydrophobic organic surfaces are made hydrophilic by preferential adsorption of dye molecules. Experimental studies, mainly on Mount Isa ores, indicate that dyes are adsorbed as planar anionic micelles attached to carbonaceous surfaces by van der Waals and ion exchange attractive interactions. Relationships appear to exist between the amount of organic matter on the surface of ground particles, the surface area of the particles, the "saturation" adsorptions of dyes, and the degree of difficulty experienced during froth flotation.

Jan 1, 1975

By D Stow, R Goodridge, K J. Molloy

A range of explosives has been specifically developed for soft ground blasting. These explosives can be used in both wet and dry blasting conditions, range in density from 0.3 - 1.2 g/cc and range in VoD from 2 - 4.5 km/s. This range of explosives has the potential to be tailored to ground type and is predicted to be suitable for a variety of applications which include: blasting in soft to medium overburden, coal blasting, wall control, and low vibration blasting. Trials have been conducted in several applications with encouraging results. Several cast/throw blasts have been conducted with these products partially replacing either ANFO or Heavy ANFO. The results from the blast have been equivalent in cast (per cent) and at reduced cost per unit volume. These products have also been used in presplit blasting and have again achieved equivalent or better results when compared to conventional presplit blasting at a lower cost per unit volume. This product has also been used in a vibration sensitive area replacing traditional explosive products, and generating excellent fragmentation and digging whilst maintaining vibration limits. This new range of products, NOVALITE, has shown great potential in many applications either reducing cost per unit volume, improving wall quality or improving productivity in environmentally sensitive areas.

Jan 1, 2001

This paper addresses; land use, rehabilitation and the State/Federal regulatory process, in light of Australia signing various international conventions and agreements in the area of environmental protection. The conventions on biological diversity, climate change and the implications of the Rio and Agenda 21 declarations are examined. The implementation of these initiatives through the Inter-Governmental Agreement on the Environment, and through legistlative mechanisms at Federal and State level is explored.Particular attention is given to the biodiversity strategy in context of the need to integrate economic aspirations and environmental concerns as a basis for sustsainable development. The paper concludes with a brief comparison of the major approval processes in each State, relating to mining environmental issues.

Jan 1, 1992

The completion of the 3rd expansion at Queensland Alumina added 725,000 t.p.y. capacity to what was already the world's largest alumina refinery. Rated design capacity is now 2.0 million t.p.y. The expansion was achieved by adding a separate liquor circuit, interconnected with the old at strategic points. This effectively linked a new facility to the existing plant. The resultant problems in controlling plant flow highlighted problems which required considerable operator retraining. The process control problems caused by an inexperienced work force are discussed as are some of the solutions now under study at Q.A.L.

Jan 1, 1974

By W Farnworth, D Fergusson

Estimation of productivity is a key factor in the design of hydraulic mines and in assessing their economic feasibility. A published Russian formula for hydraulic mining monitor cutting rates overstated productivity by up to 2 tonnes per minute (251%) when applied to Solid EnergyÆs hydraulic mines. A new formula, taking into account additional productivity factors, was derived by Solid Energy and produced an acceptable correlation between predicted and actual cutting rates inNew Zealand and overseas hydraulic mines, with an average error of approximately 0.1 tonnes per minute.   Another key factor in hydraulic mine design is the transport of coal slurry via flumes. Solid Energy carried out a series of 80 full scale tests in a surface flume installation, varying the gradient and coal:water ratio. Both steel flumes and plastic-lined flumes were evaluated. A modification of the Chezy Open Channel Flow formula, including a factor for slurry density, gave a reasonable correlation between actual and predicted flows. It is believed that this Solid Energy formula is suitable for the design of flume installations for hydraulic mining.

Jan 1, 2004

By van Eck M, Orr T, Eggleton R. A, Taylor G

The Charters Towers locality has been a historically renowned gold producing region and discovery of new ore deposits during the past decade have renewed exploration interests in the area. Further mineral exploration with conventional techniques is hindered by the presence of Cainozoic sedimentary deposits and volcanic flows overlying a major portion of the basement geology. Mineral exploration thus warrants new, innovative and cost-effective methods to probe beneath the Cainozoic cover in an attempt to discover new orebodies. There is growing awareness of the role of weathering as an agent of chemical dispersion into the cover sediments as well as a producer of supergene deposits in tectonically stable cratons (Butt and Zeegers, 1992). Consequently, landscape evolution coupled with regolith geochemistry is one of the methods increasingly being used to identify relevant sampling media to explore beneath weathered cover sediments and deeply weathered bedrock terrain (Anand, 1993). The aim of this paper is to describe and elucidate the regolith - landscape features of the region and combine geochemistry to assess the pertinence of the same on mineral exploration strategies in the Charters Towers area.

Jan 1, 1997

By Lawson F

Pyrite concentrate and calcine from the Nanjing Lead-Zinc-Silver Mines, China, were leached with aqueous cyanide and thiourea solutions. More than half of the contained gold and silver was able to be extracted from the roaster calcines. The very fine dissemination of precious metal grains, high roasting temperature (850 - 900°C) and residual sulphur are believed responsible for the Iow extractions.A recovery of about 70 per cent for both silver and gold was able to be obtained with cyanide and with thiourea leachants when the pyrite was roasted in the laboratory at temperatures between 600 and 650°C.Thiourea, as an alternative leachant, has received much attention recently and a series of constant potential leaching tests was conducted.When the thiourea to formamidine disulphide mole ratio was about two, the precious metal extraction was greatest. In the Nanjing calcined material, this occurred at a potential of about 210 mV relative to a standard calomel electrode.

Jan 1, 1987