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A study of the effect of nickel on the cupellation process has shown that a very low "nickel limit" must be imposed for cupellation (0·08 grams nickel or 0·05 grams when copper is present). In the presence of slightly greater amounts of nickel, lead tends to spreadon the cupel with detachment of drops from the main lead pool. In crucible fusions nickel contaminates the lead button to a small extent, and this contamination is increased.in the presence of either iron or copper. Nickel also causes "shotting" of the lead, this effect being more apparent in the presence of iron.Both the spreading during cupellation and the shotting during crucible fusion are considered to be caused by adsorption of insoluble NiO at the Pb-PbO interface, lowering the interfacial tension.Excess litharge crucible charges are' fused at 116boC. to eliminate shotting. A brief· soaking in molten basic litharge slag effectively reduces the nickel content of lead buttons. The solubility of silver in litharge slags is considerably decreased in the presence of nickel. Corrections can be applied for silver losses in slags but these corrections are not as accurate as with copper ores.INTRODUCTIONThis paper on the effects of nickel on fire assays for silver is the second of an intended series describing investigations into the fire assaying method.In the first paper, discussing the effect of copper on fire assaying processes (Guerin, 1957), it was shown that certain elements, because of their relatively low affinities for oxygen, will tend to contaminate the lead button during crucible fusion and scorification. Nickel, having a slightly greater affinity for oxygen than has lead, would be expected to be oxidized and slagged readily, and would not be expected to appear in the metal phase (lead button) to any appreciable extent. Thus, judged solely on this basis of...

Jan 1, 1960

By S C. Sc, J Young, N Belluz, D Nicholas

The heavy sulfide zone (HSZ) of the Grasberg deposit has the geometry of a funnel and is located at the contact of the mineralised intrusive and the relatively barren sedimentary rock types. The geometry and the rock properties associated with the HSZ plays a significant role in pushback design and sequencing. Most of the HSZ has relatively low strengths which must be considered in slope design and management. This paper presents the open pit mine geotechnical and planning design considerations associated with the HSZ.

Jan 1, 2007

A major new mine to be developed at Pike River during 2005 has been designed to have a minimal impact upon the environment, and an overall net conservation gain. The Pike River Coalfield is located on the West Coast of the South Island of New Zealand on the top of the Paparoa Range approximately 46 km north east of the coastal town of Greymouth. Pike River Coal Company Ltd (PRCC) holds a 40 year mining permit over the coalfield.   In October 2004, the Minister of Conservation granted PRCC access through 1.25 km of Department of Conservation land via an access agreement, and the Environment Court issued a number of consents for the development and operation of the mine, in addition to some existing consents.   The underground mine at Pike River is located under land administered by Department of Conservation, and has been designed to avoid or mitigate adverse environmental effects and integrate into the natural bush surroundings. The mine process has been designed to operate within an environmentally sensitive area and will incorporate technologically advanced methods of mining and processing. The mine process involves hydro mining of the coal, and transportation via a 12 km coal water slurry pipeline, to a dewatering complex located on PRCC land. This will ensure that traffic in the Pike River Catchment up to the mine is minimised.   An extensive series of management plans and monitoring programmes will be used to ensure that the environmental effects of the mine activities are minimised, by evaluating the performance of managerial procedures, and physical mechanisms in place to avoid or mitigate the effects. Trial mining and substance management plans in conjunction with an orthophoto and surface monitoring protocol will ensure that surface features, and water ways are protected from any adverse effects. The Blue Duck enhancement, and pest and predator control programme will help ensure that an overall net conservation gain is achieved.   Developing transparent working relationships and good communication with Department of Conservation, Iwi (Ngati Waewae and Ngai Tahu), and local environment groups has been and remains very important in the development of this project.

Jan 1, 2005

The epizonal Ag-Pb-Zn vein deposit at San Bartolome is characterised by a base-metal sulphide assemblage containing the spectacular development of interpenetrating, bladed networks of pyrrhotite which have been replaced by marcasite and pyrite. A similar assemblage displaying the same crystal habits and textures are also a diagnostic feature of the Sn and Sn- Ag deposits of Bolivia. On this basis, it is reasonable to conclude that both deposits were formed from fluids of similar nature and origin. Although no economic accumulation of Sn is known in San Bartolomr, further comparison of the geologic setting, age, mineralogy, fluid inclusion data and magmatic association of this deposit with the Bolivian systems has highlighted additional similarities consistent with a hypothesis that more extensive Sn mineralisation might exist in the San Bartolomd area.

Jan 1, 1995

By Conley R, Payne I

The Vickery Coal Mine commenced open cut mining operations in May 1991. All overburden and interburden is drilled and blasted for excavation by dragline or hydraulic excavator. The mode of operation adopted from the feasibility studies requires that throw blasting of the overburden be used to assist dragline productivity.This paper reviews the development of the drilling and blasting practices with particular emphasis on the throw blasting of the overburden and optimisation of costs. This review includes analysis of the pre-production drilling and blasting feasibility studies by comparison with actual results.

Jan 1, 1992

By R Turner, P Hatherly, T Medhurst

Borehole geophysical logging data are routinely acquired during exploration of coal deposits in Australia. These data are commonly used qualitatively to identify and correlate coal seams and geotechnically significant interburden rock units. Some quantitative analysis, such as using sonic logs for rock strength estimation is becoming increasingly widespread. This paper discusses results from a project aimed at expanding the quantitative approach to more detailed mineralogical and lithological analysis, which leads to improved geotechnical characterisation for mine planning and mining hazard reduction. A standard suite of wireline logs measuring density, natural gamma, sonic and neutron were analysed from three coal mines in the Bowen Basin. Thirty-nine samples from cored sections of the boreholes were analysed by X-ray diffraction, spectral gamma counts and hyperspectral scanning. Using a standard petrophysical approach to calculating porosity, shale and matrix components from a combination of density, natural gamma and neutron logs, a good correlation with observed mineralogy was demonstrated. However, unusual mineralogies such as heavy minerals or low-potassium clays may distort this analysis. Simultaneous evaluation of all available geophysical logs by modern data mining methods was able to show how these ambiguities may be solved.

Jan 1, 2006

By D W. Airey

Frictional rock bolts are widely used because of their low cost. However, they have a thin wall section that makes them prone to corrosion, and they cannot be relied on to provide long-term ground support. It is difficult to assess the capacity after the bolts have been installed as they can only be pulled out if this has been allowed for during insertion. The questions of how long can the rock bolts function effectively and the effectiveness of various surface coatings, which can have significant cost implications are, investigated in this study.A series of accelerated corrosion tests have been performed on frictional rock bolts. The rock bolts, typically 900 mm long, have been inserted into concrete cylinders produced using a styrofoam insert to create the hole for the bolt insertion. Strata rock bolts with four surface coatings have been tested: uncoated black steel, galvanised, enduro (plastic coated) and coated with a proprietary aluminium/zinc alloy. Tests have been performed on two diameters of bolts. Following insertion of the bolts, the concrete cylinders were placed in a large drum filled with saltwater and current was applied to accelerate the corrosion process. The rock bolts were then extracted at various times after the commencement of corrosion. Comparison of the insertion and extraction resistances shows that corrosion initially increases the bolt resistance and that substantial section loss is required for the bolt resistance to drop significantly.CITATION:Airey, D W, 2014. Laboratory corrosion tests of frictional rock bolts, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 257–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By K Dagdelen, I Traore

This paper presents an iterative net present value (NPV) maximisation method to determine the optimum surface to underground transition depth for an orebody to be mined by multiple open pits and an underground mine. The determination of transition depth from open pit to underground mining is based on global production scheduling optimisation of open pit and underground mines using mixed integer linear programming. The method is applied to a case study coming from a gold mining complex with six open pits and a large underground mine using longhole open stoping. The results indicate potential improvements of the NPV of global operations when compared to the traditional techniques based on independently optimised open pit first, followed by underground mining.CITATION:Dagdelen, K and Traore, I, 2014. Open pit transition depth determination through global analysis of open pit and underground mine production scheduling, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 195–200 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By Cook B, Cunningham J

At Mount Isa Mines, a system has been developed for general monitoring of underground mobile equipment. It can provide unit condition monitoring data such as oil pressures and motor temperatures as well as production type information such as unit location and load. The system does not rely on an expensive data communications infrastructure, using instead inexpensive radio base stations which automatically transfer data from mobile units to a surface database server on the company-wide computer network. This paper includes a general overview of the system and a discussion of the practical benefits it is expected to generate.

Jan 1, 1995

By Chung S

The problems associated with equating calculated and measured properties of explosives with blast results are examined. The results from six full-scale test blasts in a limestone quarry are described. The purpose of the full-scale trial was two-fold, i) assess the role of varying aluminum levels (10% maximum) in a given explosive in terms of blasting performance, and, ii) find correlation between calculated, as well as measured properties of explosives and the resulting blasting performance. Each blast consisted of 36 holes, initiated with short period detonators in a staggered 3-row 2.4 m x 2.7 m (burden x spacing) pattern. Each 75 mm diameter borehole with no subgrade contained on the average 22 kg of 65 mm diameter cartridged explosive. The bench height was 6.3 m, with an average collpr of 1.2 m. The calculated and mgasured properties of explosive included, strength, detonation and explosion pressure, VOD, plate-dent depth, underwater bubble and shock energy, and the total energy efficiency. Each blast was instrumented to measure detonation velocity, initiation sequence, muck pile motion by means of high-speed photography and blasting vibrations. The post-blast measurements included photogrammetric survey of muck pile for size distribution on surface, muck pile profile, as well as the extent of backbreak. The results showed that the overall blasting performance of the explosive in question was nearly commensurate with the level of aluminum in the explosive, and there was excellent correlation between the underwater test properties and the blast results. The study also exemplified the need for more extensive post-blast analysis than is usual practice, for quantitative assessment of blasting performance of explosives and providing the necessary data-base for calibration of blasting models.

Jan 1, 1990

In 1953, Dr N Fisher of the Bureau of Mineral Resources, acting on behalf of the Society of Economic Geologists, which is considering the sponsoring of a uniform system of nomenclature for ore reserves, enquired from The Australasian Institute of Mining and Metallurgy whether it had ever considered this subject and particularly whether it had ever set up any standard definitions or specifications with regard to ore reserves.As this had not been done, but was thought to be desirable, the Council of The Institute appointed a Committee consisting of H H Dunkin, Associate Professor of Mining Engineering, University of Melbourne (Convenor); E A Rudd, Professor of Economic Geology, University of Adelaide; J D Campbell, Chief Geologist of Western Mining Corporation; and the writer, to consider the report on this subject.In December 1953, the Committee submitted its frrst report to the Council and this report (reproduced here as an Appendix) was widely circulated among member companies and engineers, with an invitation to comment on the proposals. A large number of replies was received and studied.After studying the replies the Committee issued a second report, in part as follows:From these replies we have learned that the suggestions made in the frrst report of the Committee are unacceptable to most of those interested, on one or all of the following grounds:a. number of categoriesb. defmition of categoriesc. nomenclature.It is also apparent that all alternatives suggested in the various replies would likewise be unacceptable to the majority of those replying.As a result, we have come to the conclusion that neither this Committee nor any other could at present and in the present state of opinion on the subject make recommendations regarding classification and nomenclature of ore reserves which would be acceptable to a sufficiently large proportion of members.It seems to us now that the objective of a widely applicable and acceptable system of classification and nomenclature, one that could be endorsed by The Institute and ultimately become standard practice in the industry, requires more than compromise between present conflicting views... it requires first a foundation of substantial agreement on the essential facts, implications and range of ore reserve estimation. This does not yet exist and it is evident that much additional analysis of present practice and opinion must be undertaken before any further systhesis is attempted.

Jan 1, 1994

Low-grade, porphyry copper type mineralization at the Moonmera prospect is related to the intrusion of a granodiorite porphyry mass into the Upper Permian "Gracemere granodiorite". Significant copper mineraliza- tion appears to be associated with the alteration assemblage quartz-sericite- kaolinite. The ore shell is surrounded by a zone where montmorillonite and kaolinite are in greater abundance and this assemblage is over- lapped, mainly at depth, by potassium feldspar alteration. Secondary biotite is abundant throughout the mineralized zone. Preliminary sulphur isotope results on the sulphide mineralization are compatible with a magmatic origin for the sulphur.

Jan 1, 1974

The Lower Palaeozoic Woolomin Association is composed of chert and jasper (often radiolarian), siliceous argillite, the mafic volcanics with associated hyaloclastites, and occasional greywacke and limestone lenses. Several "Cyprus-type", conformable pyritic copper (+/- zinc and cobalt} sulphide lenses are spatially related to individual mafic volcanic units and manganiferous chert and/or jasper. The Association has been interpreted to represent an oceanic crustal remnant generated either in an island arc environment (Herbert, 1981) or at a divergent plate boundary (Scheibner and Glen, 1972; Leitch, 1974a, 1975) later to be obducted, or tectonically emplaced, into continental crust; the adjacent Peel Fault was considered to be the palaeo-obduction zone (Scheibner and Glen, 1972) and the associated alpine-type mafic/ultramafic complex, an ophiolite (Crook and Felton,1975).

Jan 1, 1990

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

The geological features of the destructive plate margins of the southwest Pacific favour the formation of porphyry type deposits. The major controlling factor favouring the formation of gold-rich deposits of this type is a dense crust. This results in shallow intrusion of large magma bodies beneath andesite stratovolcanoes. Where the intrusives have near vertical sides, the comparatively low temperature of transfer of volatiles from the solidifying melt favours the partitioning of gold into bubbles of volatiles. They reduce the viscosity and density of the melt, resulting in the upward movement of a mineralised melt. With the drop of pressure with upward movement the bubbles separate into a two phase mixture, triggering freezing of the mineralised melt and the formation of a gold mineralised stockwork.

Jan 1, 1995

In-stope long hole drilling (face parallel drilling) is a new technology currently being applied to shallow dipping (

Jan 1, 2003

By L Grigorov, G J. Jame, A V. Nguyen

The dewetting kinetics between a small air-liquid interface and a silica (negatively charged in water) planar surface in solutions of dodecylammonium chloride (cationic surfactant) has been investigated using the Scheludko cell and digital high-speed video microscopy. The gas-liquid interface was created at the bottom of a small silica capillary of the cell and then was moved towards the silica planar surface. After the rupture of the liquid films between the interfaces, the expansion of the gas-liquid-solid three-phase contact (TPC) line was observed and recorded using a digital high-speed video microscope system, operating at 1000 frames per second. The surface tension of the surfactant solution was measured using the pendant drop technique. The equilibrium contact angle was measured using the Scheludko-Minings method with a silica micro-sphere. The TPC radius was determined as a function of time and compared against the available hydrodynamic and molecular-kinetic models. The experimental data are described very well by the molecular-kinetic model for the TPC line motion. The hydrodynamic model is in agreement with the experimental data only for a short time after inception of the three-phase contact expansion.

Jan 1, 2005

By Szymanski J

The problems associated with underground mining continue to grow in size and complexity. As a result mine management is becoming aware of the benefits that can be achieved through the use of computer-oriented tools for system analysis. When such tools are employed in conjunction with benchmarking practices, the drivers of the system that lead to superior performance can more easily be determined. This paper discusses the use of the Simulation Language for Alternative Modelling (SLAM II) in the determination of the drivers of an underground room-and-pillar mining system. The mining operations included in the model consist of extracting, loading and hauling of the coal using continuous mining equipment in a room and pillar system. Equipment specifications and mining techniques used in the model are based upon current methods employed at the existing underground coal mines worldwide. The model developed is capable of adequately predicting the operational performance of the real world system from a statistical point of view. The results from the study show that computer simulation is an excellent tool for evaluating various mine configurations and for gaining a better understanding of the mining systems.

Jan 1, 1995

The reality is that in today's world almost half of nearly six billion people on the planet do not have access to commercial energy and the services it brings. Based on UN projections, in 30 years time there are likely to be nearly three billion more people in the world, over 90 per cent of them in countries which are already economically poor. The World Energy Council (WEC), through its 102 member countries, monitors trends and developments and projects future trends. WEC is a non-governmental international body representing all forms of energy and is committed to the sustainable use of energy for all mankind. This paper is based on WEC studies and papers presented at its many conferences and congresses worldwide. Primary energy demand growth is dominated by the developing countries over the next 30 years. The world energy mix is projected to change very little over the next 30 years. Fossil fuel supplies (ie coal, oil and gas) are likely to decline from 77 per cent to 73 per cent, nuclear energy may grow from five per cent to six per cent and renewable energy sources (eg hydro, solar, geothermal, wind, tidal and biomass) could increase from 18 per cent to 21 per cent. World energy consumption is expected to grow by over 50 per cent over the next 30 years. The paper reviews changes in energy demand in the world, particularly in the Asia/Pacific region. Environmental issues are covered, as are developments such as solar energy from space and the status of renewable energy forms. Agendas for action to achieve change are also reviewed.

Jan 1, 1997

By D Craw

Interactions between structure and lithology in the Hyde-Macraes Shear Zone controlled the style of gold mineralisation at the Macraes mine. Large volumes of rock in some mine pits have most gold disseminated in hydrothermally altered schist, rather than in quartz veins. Mineralisation was initiated in the latter stages of metamorphism. Pods of massive schist rich in quartz and feldspar are surrounded by more fissile schist consisting of interlayered micaceous and quartzofeldspathic schist. Later shears have been partly controlled by the micaceous schist, and anastomose around pods of more massive schist. Micaceous schist was replaced by pyrite and arsenopyrite, accompanied by recrystallisation of phengitic muscovite under lower greenschist facies conditions. Gold occurs in sulfides and with microcrystalline quartz formed during minor silicification. Massive schist is locally mineralised along sulfidic microshears which have phengitic muscovite largely illitised under sub-greenschist facies conditions. Mineralised massive and micaceous schists were overprinted by cataclastic shears, with addition of graphite and more sulfides. Mineralisation occurred during a transition from ductile to brittle deformation regimes as the schist was uplifted in the late Jurassic.

Jan 1, 2004