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By Ramsay WRH

The Mount Stavely Volcanic Complex compri- ses one of a number of northerly trending fault bounded greenstone occurrences in Western Vict- oria, of probable Cambrian or older age. The greenstone belt is coincident with several linear positive aeromagnetic anomalies, which outline the surface and subsurface extensions of these greenstones. Mapping at Mount Stavely has identified serpentinite, variolitic basalt, two-pyroxene and pyroxene-hornblende andesite, dacite, rhyodacite and their pyroclastic equiv- alents. Chemically and mineralogically the volcanics constitute a calc-alkaline assemblage. The mineral potential of the region has been enhanced following a discovery by Pennzoil of Australia Limited near Ararat, of sulphide min- eralisation containing approximately 1 million tonnes at 2.7 percent copper. The volcanic environment of the Mount Stavely Volcanic Complex is discussed in terms of similar environments found in Canada.

Jan 1, 1982

The central thickened discharge system of tailings disposal takes advantage of the natural beach slope formed by sub-aerially discharged tailings, and the non-segregating properties of thickened tailings, to create a homogeneous conical stack. The need for containing embankments can be largely avoided leading to capital and operating cost savings. Methods for estimating beach slopes and tailings density, essential parameters for the design of such a system, are described. Case histories from three mining operations are used to illustrate the application of the technique, There are also seen to be potential advantages in the areas of water management, seepage, and rehabilitation. Laboratory and in-situ testing enable parameters to be determined.

Jan 1, 1991

The distribution of p(~rphyt1 copper deposits, in time as well as place, is used to propose an occurrence model based on the genesis models of Sillitoe and Rona. A magmatic source of the metals is accepted. The characteristic metallogenic epoch and the migration of the mineralization event along an elongate metal province are explained as the result of subduction of an obliquely- oriented strip of mineral-enriched material on the oceanic plate. Two mineral-enriched trails emanate from a hot-spot source of high-intensity hydrothermal activity in an oceanic rift. Because the whole plate system moves relative to hot spots, the hydrothermal source appears to migrate along the rift, and the two trails are not parallel to transform faults, but form a broad "V" centred on the hotspot. Source loci are spaced at intervals of about 3000 km, resulting in the possible repetition of metallogenic epochs, in a subduction zone province, at about 100 m.y. intervals. The position of the mineral-enriched strip can be found graphically, given ages of a series of deposits in a province, and the plate convergence vectors. This knowledge provides an exploration tool at regional scale and, by reflection across the rift, the potential for exploration is extended across oceans. The model has implications for commodities and deposit types other than porphyry coppers.

Jan 1, 1987

By M Logsdon, T R. Clark, T I. Mudder

Oxidation of pyrite and other metal sulfides is accelerated by the activity of acidophilic iron- and sulfur-oxidising microorganisms. The ideal biocide for controlling biocatalysed acid rock drainage (ARD) would be inexpensive, inhibitory toward sulfide-oxidising bacteria at low concentrations, relatively non-toxic toward non-target organisms, degradable in the environment outside the zone of application, stable and long-lived in the impacted environment, sufficiently mobile to penetrate into piles of waste rock or tailings, and effective regardless of the metal sulfides present. A potent agent for combating ARD that fits these criteria is the thiocyanate anion (SCN-). The objective of this study was to determine the effectiveness of thiocyanate in controlling or preventing ARD within several types of sulfidic waste rock and tailings. Results were evaluated within a context encompassing process water and solids management strategies employed at different precious and base metal mines. Sulfidic rock was treated with solutions of potassium thiocyanate and subjected to accelerated weathering tests in lab-scale humidity cells, trays, and columns. Certain tests also utilised solid phase copper thiocyanate (CuSCN) to evaluate a ærelease on demandÆ strategy. Leach solutions were analysed for parameters indicative of ARD including pH, redox potential, conductivity, acidity, sulfate, iron, and certain heavy metals. Two larger scale field tests were also initiated by personnel at separate mines using, in the first case, ore containing a pyritic component in large columns and, in the second case, waste rock containing base metal sulfides in lined pits. Humidity cell tests showed low concentrations of thiocyanate solution applied to pyritic waste rock could reduce ARD formation by 90 per cent or more compared to untreated controls, with the residual release of ARD components (eg sulfate, Fe, acidity) probably reflective of strictly chemical oxidation of the sulfides by molecular oxygen. Thiocyanate applied at a concentration of 22 mg/kg to waste rock from a base metal mining operation in large laboratory scale columns reduced acidity and sulfate release by 75 per cent to 80 per cent compared to untreated controls. This extent of reduction in ARD may not meet discharge water quality criteria, but has the potential to significantly reduce lime consumption and sludge production in a conventional neutralisation facility. The use of a solid-phase metal thiocyanate compound (CuSCN) at a dosage of 194 mg/kg pyritic ore resulted in the following per cent reductions in leach solution parameters in comparison to controls: sulfate (78 per cent), acidity (93 per cent), dissolved Fe (99.4 per cent), and dissolved arsenic (99.9 per cent). This compound has the further advantage of being relatively stable until needed, dissolving only in the presence of an acidic and oxidising ARD solution. If this line of investigation progresses favorably, it offers the possibility of an ARD prevention technique that may be applicable in some settings. Mine-site pilot scale tests with pyritic ore resulted in reductions in sulfate (56 per cent) and Fe, As (66 - 68 per cent). In sum, thiocyanate at relatively low concentrations dramatically reduced ARD from sulfidic rock in a simulated heap. The pilot test using waste rock containing base metal sulfides has begun only recently. A preliminary process design and cost estimate was made for fullscale application of thiocyanate to waste rock at a hypothetical gold mining operation producing 5000 tpd of ore and 10 000 tpd of sulfide containing waste rock. The combined capital and operating costs for the full-scale thiocyanate application facility were about $US 0.25/tonne of waste rock and $US 0.50/tonne of ore. Although thiocyanate is readily available commercially, it also occurs in process solutions associated with certain types of mining processes. Such solutions after selective treatment might be recycled to sulfidic waste rock or tailings, rather than being treated for thiocyanate degradation.

Jan 1, 2003

Maps of mineral grade used to assess mineral reserves are most commonly generated using one of the many estimation methods available such as inverse distance weighting or ordinary kriging. Most such maps incorporate a degree of spatial smoothing which is an integral part of the averaging process. In deposits with highly variable grade which include many gold deposits, this smoothing can mask the detailed geometry of the mineralization at the economic cutoff grades being considered. In underground mining, a knowledge of this geometry is important in the choice of mining method and thus in the assessment of the minable reserves.The method of conditional simulation in geostatistics can be used to generate maps of grade which reflect the actual spatial variability of grade as measured through the variograms of the drill hole data. Simulated maps can provide a number of equiprobable images of the mineralization geometry from which a more appropriate mining model of the mineralization can be developed. Multiple simulations can also be used to assess the uncertainty existing in the current knowledge of the reserves.

Jan 1, 1990

The value derived by good mine planning is often underestimated as many mines steer their attention to the more immediate and more easily recognised successes made by the day-to-day operational æbush fireÆ fighting. Similar to machine maintenance, the efforts made to quickly rectify short-term breakdowns are well recognised; whereas the value derived from the work in planning, scheduling and undertaking preventative maintenance is not so obvious or readily quantified. Too often the focus of the business shifts to building and supporting an efficient operations team at the expense of developing a highly experienced team of mine planning practitioners that are well trained with procedures and purpose-built tools to develop optimum mining strategies. A resource has an inherent value based on its quality parameters and its likely mining conditions. How well that value can be unlocked is governed, to a large degree, by the proficiency of the mine planning practitioners, as they, essentially, set the foundation of the mine business and the path along which the mine will operate. The importance of having a well documented and procedural mine planning methodology that integrates both a thorough technical and economic understanding of the resource cannot be over emphasised. The aim of the mine planning process is to develop a robust mine design and production capability which can best cater for future uncertainty whilst providing the best opportunity to maximise cash flow into the business. The planning process must be transparent and auditable, clearly summarising the process steps and assumptions made to arrive at a justifiable and defendable outcome. To provide maximum value to the business, the planning process must be repeatable and scalable to enable easy replication throughout the different mines and projects within an organisation. The diminishing numbers of highly experienced personnel within our industry, coupled with the growing pressure to clearly demonstrate that appropriate due diligence has been exercised, means that well documented and monitored mine planning processes using purposed built and innovative tools need to be developed to ensure optimum outcomes.

Jan 1, 2009

Techno-Economic Evaluation of a New Early Removal Process to Treat High-Arsenic Copper Ores

Sep 13, 2010

Thank you for asking me to address you. The topic may sound formidable. Those of you with determination to go somewhere in your careers will understand that by taking geoscience, mining and metallurgy courses as students, you are declaring your intere

Jan 1, 1994

By Clifford C. E

1 eat my peas with honey I've done it all my lifeIt makes them taste rather funny But it keeps them on the knife.Innovation is that elusive characteristic which involves the determination of multiple and unique response to a problem, and then commitment to and action from the best of the alternatives.

Jan 1, 1993

This paper presents the descriptions of a final year geological engineering project at the Royal Melbourne Institute of Technology involving the correlation of borehole and mapped ground conditions and their statistical Analysis.

Jan 1, 1994

In his introductory remarks Mr. MacKellar referred to three types of development which may be considered to compete with mining for land use. 1. Total Development - in which he cited urban development, and intensive agriculture. 2. Partial development - in which he cited pastoral, and in this category would come National Parks. 3. Non development - in which category would fall the primitive or wilderness areas.

Jan 1, 1971

Zinc enters into solution on aeration of sphalerite in deionised water. It has been observed that less zinc dissolves in a copper vessel than when the same operation is carried out in a glass vessel of similar shape and size.

Jan 1, 1980

Many of the recent major achievements of our industry were visions of our forefathers in the 1800s. Only recently has technology been able to meet the vision of our predecessors. This paper follows the development of selected aspects of tunnelling from the 1800s to present day. It appears that, at the turn of the century, technology is beginning to catch up with our vision and we are able to put our ideas to work more quickly.

Jan 1, 1999

By Kelly BJ, Smith GA

The recommendations of a recent American report on "Better contracting for Underground Construction" are considered in relation to Contracting practices on major Australian projects by representatives Of the "classical trilogy" - the Owner, Engineer and Contractor.

Jan 1, 1976

There has been much debate in the past as to whether the Australasian Institute of Mining and Meteorology ("AusIMM") should issue valuation guidelines in addition to the ASX and NCSC requirements. My experience in preparing independent expert reports has been that "best practice" sets higher standards than any laws or requirements set out by the ASX and NCSC. This is where I see the AusIMM coming in.

Jan 1, 1989

The success of the In-Plant dust collection at the Albion Reid Quarry Plant situated at Para Hills, South Australia, is discussed in the light of co-operation at the design stage with particular emphasis on the duct- work and filter design. Other dust control facilities at the Plant are mentioned.

Jan 1, 1976

-in 1961,.West Australian Petroleum's Eneabba. No. 1 bore encountered twenty-two' seams of coal totalling forty feet in thickn' ss between the..'depths of 6373 feet and 64,/,1 feet. 0n'ana:lysis; this coal had a. similar calorific value (8000 - 9000 B.

Jan 1, 1964

Circuit alterations and adoption of more compact items of equipment have made it possible to increase the capacity of the King Island Scheelite concentrator, both with regard to head grade and feed tonnage, while at the same time increasing total recovery and reducing maintenance costs. The present operation is described, with particular emphasis being placed on alterations made during the last two years to achieve capacity Goals.

Jan 1, 1977

Following plant trials in 1972 Mount Lyell installed an AMDEL On Stream Analysis system for measuring copper and density on the flot- ation feed and final plant tailing streams, in August 1973. As a result of poor performance of the final tailing system these probes were changed over to the rougher tailing stream, back to the final tailing stream and finally to the final copper concentrate stream where the system is currently performing satisfact- orily. The history of the development of the system to its current operational status is Described.

Jan 1, 1978

The Department of Mineral Resources is the lead agency in mine site environment management and control in New South Wales. The Department introduced a Mining, Rehabilitation and Environmental Management Plan (MREMP) process several years ago in order to integrate the activities of other government agencies who may have a material interest at the mine site. The MREMP process has resulted in a spirit of trust and co-operation between agencies and between agencies and mining companies. The spirit of co-operation has been reflected in greater public confidence that mining is environmentally responsible.

Jan 1, 1995