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By Webster SS

This paper uses computer modelling tech- niques to compare and contrast anomaly patterns obtained with fluxgate (vertical field) and proton precession (total field) magnetometers at typical latitudes in northern and southern Australia. The use of these modelling tech- niques is suggested as an aid to magnetic interpretation and field examples are included from Tasmania and the Northern Territory.

Jan 1, 1975

Filter Presses are used in a wide range of process industries where high quality filtration at elevated pressure is required. This is mainly due to the fact that modern presses are fitted with polypropylene filter plates which combine excellent corrosion resistance with high mechanical strength. Filtration pressures of 15 Bar at ambient temperatures are common ensuring low residual moisture content and easily manageable filter cakes. Recessed polypropylene chamber plates have been in use for the last 15-20 years and have replaced plates and frames almost entirely. The latest development in plate technology is the polypropylene membrane plate. These provide lower moisture content cakes at significantly higher capacity than recessed chamber plates. Because of their stayboss-free construction, membrane plates provide excellent cake washing facilities which make them suitable for a wide range of process applications. Membrane plates are available both as fixed and exchangeable membrane types. Overhung membranes can be fitted to existing plates manufactured in cast iron or plastic to enhance the performance of existing presses.

Jan 1, 1989

By Stewart A. M, Price D

This paper presents recent findings concerning longwall caving mechanisms relating to Australian mining conditions and their effect upon longwall support requirements and behaviour. The findings are based on a program of intensive hydraulic support monitoring in a variety of Australian mining conditions coupled with geotechnical observations.

Jan 1, 1992

By Budden J. R, Rhodes M. K

Bacterial oxidation technology was successfully applied in a mine site pilot plant for the treatment of refractory gold concentrates. The bacterial culture was proven capable of selectively breaking down the refractory sulphide minerals to release the gold. Gold extractions greater than 90 per cent were possible when oxidised concentrate was leached with cyanide solution. The pilot plant was designed using data scaled up from laboratory testing and sized for transport by standard vehicles. The bacterial culture used to break down the refractory gold-bearing mineral was a natural mixed culture able to withstand temperatures up to 55¦C, thus making the technology particularly suitable for use in Australian and in some North American gold mining regions. The pilot plant was operated at the mine site over a six month period. Performance of the bacterial oxidation technology under site conditions was as predicted from the laboratory testing. It was demonstrated that the culture was robust under normal site condi- tions and that the culture could withstand wide variations in the feed and the operating conditions, while still achieving satisfactory oxidation levels. The technology was able to be utilised by site operators and supervisors with minimum intervention. Design data for a commercial facility was collected for a number of different concentrate samples and a feasibility study completed. Estimated capital and operating cost have been obtained.

Jan 1, 1991

Subsurface information from the "Upper Coal Measures" of the Sydney Basin is interpreted by means of structure contour maps, isopach maps and geological cross- sections. Particular reference is made to recent coal drilling operations by the New South Wales Department of Mines. The study is restricted to the onshore portion of the Sydney Basin.

Jan 1, 1972

By Nemick JA

Recent advances in computer simulation together with field measurements of caving and microseismic activity about longwall panels, has allowed a much better understanding of the caving process and the variability due to geology. The joint research between SCT Operations and CSIRO Division of Exploration and Mining has initiated new methods of computational modelling predicting various caving patterns and strata failure far ahead of the longwall face. This work was validated by field measurements of caving and microseismic activity at the longwall face.The rock fracture distribution and the caving characteristics of a range of strata sections have been simulated by computer methods. Validation studies of the method were addressed together with case studies. The interaction of caving with support convergence and face control is presented. The method allows the simulation of longwall support behaviour under various geological conditions. The system also allows a prediction of the monitoring data, which is best suited to give an early warning of weighting events or signal various key caving characteristics.

Jan 1, 1998

By Kato Y

As a direct result of the Mining Industries need to improve efficiency and production in Open Pit type operations, the size of haulage units have increased dramatically. This trend has continued such, that the majority of dump trucks operating in Open Pit operations are in the 170 ton class. Continued mining in existing locations has meant that the increase in vertical lift and resultant grades, and increases in hauling distances are making electric drive systems unsuitable. This is largely due to the electric drive systems heat limitations on major propulsion components. With these mining requirements in view and the present limitations on electric drive systems in mind, Komatsu have been developing the Komatsu HD1600M. A diesel powered mechanical drive dump truck capable of operating in deep pit operations. This presentation introduces: Komatsu HD1600M Dump Truck

Jan 1, 1982

By Koh P. T L, Varnas S. R

Fluid flow, heat transfer and combustion in a nickel flash smelter have been investigated by numerical modelling and flow visualisation. The three-dimensional numerical model incorporates turbulent two-phase fluid dynamics, radiative heat transfer and combustion. The main features include the use of the k-E turbulence model, the Lagrangian tracking of particles, radiative heat transfer based on the spherical harmonics method, and chemical reactions. The predicted flow fields are in good agreement with data obtained from a series of flow visualisation experiments on a cold water model. The interaction mechanism between the fluid flow and the solid particles is examined for a range of particle sizes both with and without injected oil in a series of simulations. The heat transfer in the shaft is dominated by combustion and radiation, whereas the ignition of particles is influenced by the particle size and the added oil. Flow and temperature fields for both gas and solid particles are presented as well as the fraction of sulphur removed from the particles.

Jan 1, 1992

By Drain P, Dibdin T. R

THE completion of the Linda incline man and supply haft at the Mount Morgan Gold Mining Oompany's mine led to an investigation of the various safety gears in general use in mining shafts. One of these gears completely fulfilled the necessaryconditions. This paper endeavours to give a description of the man car and safety gears now operating in the before mentioned shaft, together with the main considerations leading to their design and sub equent adoption. Fig 1 diagramatically shows a longitudinal section of this shaft.

Jan 1, 1911

By Yan D. S

The removal of antimony from a refractory gold-bearing stibnite ore by roasting and selective chlorinating roasting was investigated. The influence of roasting temperature, roasting time, roasting atmosphere and type and amount of chlorinating agents on antimony removal were studied. The laboratory studies carried out included roasting tests of 4 g samples in a laboratory rotary kiln, followed by 400 g samples roasted in a fluidised bed. The test results revealed that antimony was efficiently removed by roasting at temperatures over 800¦C in a nitrogen atmosphere. The most efficient volatilisation of antimony was achieved with the addition of ferric chloride at temperatures between 350-600¦C.

Jan 1, 1995

The mechanisms of fragmentation in homogeneous materials and structured rock mass are reviewed. A method previously used to predict vibration damage to the remaining rock is extended and shown to be valid for the prediction of fragmentation in the rock mass removed by blasting. The effectiveness of different explosives in different types of rock blasting is discussed.

Jan 1, 1990

By Alwan M

At Binebase mineralisation is hosted within an andesitic Neogene volcaniclastic succession on Sangihe Island, Indonesia. Two major alteration types occur; an initial widespread phyllic assemblage of quartz -illite with chlorite, smectite, gypsum and pyrite, and a superimposed quartz - barite - sulphide assemblage. The phyllic alteration arose from a neutral to weakly acidic hydrothermal solution of greater than 200 degrees C, and the quartz - barite - sulphide assemblage arose from a cooler slightly more acidic fluid. This second alteration event is interpreted to have selectively replaced permeable volcaniclastic breccias and coarse lithic tuffs within the altered sequence. Gold and silver mineralisation is associated with the latter alteration, and is locally controlled by the degree of silicification and sulphide abundance. The sulphides present are pyrite, covellite and chalcopyrite. The sulphides are very fine grained with colloform and framboidal textures and were deposited contemporaneously with the bulk silicification of the coarse sediments. A large portion of the mineralised rock has been oxidised to a quartz - barite -limonite - goethite - jarosite assemblage.Coincident gold, silver and antimony geochemical soil anomalies gave the best correlation with anomalous gold and silver grades in bedrock as identified by drilling. Resistivity proved a reliable geophysical method for delineating zones of silicification.

Jan 1, 1990

By Dyne GD

From experience in the design and operation of power station combustion facilities in most mainland Australian States, involving a wide range of black coals and lignites, and in the specification and procurement of coal supplies for power station use, techniques for the optimisation of coal resource development and power generation utilisation have been developed to ensure compatibility between characteristics of the selected coals and power station design. These techniques include computer data bases for resource data handling and computer simulation of coal-fired boilers for determining coal property cost effects. Data Base Systems allow results of coal analyses to be efficiently handled, to assist in the review of the relevance of resource data to the coal sections proposed to be mined and the coal fractions proposed to be marketed. Data Base Systems also facilitate the marshalling of coal quality data into basic utilisation format to enable a proper utilisation review and analysis of the certainty and scatter of coal properties. Computer simulation of the effects of different coal properties on the capital and operating cost of power stations is achieved by establishing conceptual design parameters of the major items of plant to relate the variations in coal specification to equipment size and type. Variations in power station budget costs can then be determined using the computer model for variations in coal specification.

Jan 1, 1983

By Corbett GJ, Leach TM

A continued exploration programme has further defined the geology of the Tolukuma vein system, verified the resource indicated by Newmont, and identified potential for additional mineralisation. The resource at Tolukuma Hill, designated as zone C, is a mine recoverable 432,000 t at 18.1 g/t Au & 46 g/t Ag. Mining will be by a combination of open pit and underground at a rate of 100,000 t per annum. Processing will be by SAG mill, gravity circuit and CIL plant. A diatreme breccia, localised at an intersection of structures and a relationship of gold to base metal sulphides, are indicative of a strong porphyry association. Typical epithermal features such as crustiform banded quartz and quartz pseudomorphing platy calcite are also present and locally contain lesser gold mineralisation. Pre-existing dilatant structures have acted as a host to the ore fluids, resulting in the formation of the semi-continuous Tolukuma-Gulbadi veins over a 1100 in strike. A fluid flow model suggests that mineralizing fluids were sourced from a diatreme margin and migrated laterally along dilatant structures. Bonanza gold grades are interpreted to be derived through fluid quenching in the flexure between a hanging wall split, which hosts much of the Tolukuma Hill resource, and the feeder graben structure. Thus, the relationship between the pre-mineral structural geometry and fluid upflow at the margins of a diatreme breccia, controls the ore setting.

Jan 1, 1995

By Dunbavan M, Mallett C. W

The sequence of development and back analysis of the failure of a spoil pile in the 1B pit of the Moura Mine are given. The mode of failure was a two-wedge mechanism with a basal slip plane passing through a clay band about 2 m below the pit floor. Remedial actions for improving spoil pile stability are discussed.

Jan 1, 1981

By Jefferson CW

Middle-to-Late Proterozoic stratigraphy and metallogeny in the eastern part of the Canadian Cordillera and in South Australia are strikingly similar. In both areas, thick, predominantly shallow-water strata and their contained mineral deposits can be divided into three sequences (A, B, C) that record episodic and prolonged continental rifting. It is proposed that Adelaidean strata of Australia were deposited adjacent to Belt-Purcell, Mackenzie Mountains and Windermere strata of the Canadian Cordillera within an epicontinental trough of a "Hudsonia" regacontinent. With the final rifting of this trough, the paleo-Pacific ocean was born. By Early Cambrian time, Australia- Antarctica was on the trailing "east" side of the nascent megacontinent, Gondwana, and was being modified on the "west" by accretion in the Pan-African event. North America, more or less surrounded by trailing edges at this time, was analogous to the Cenozoic African plate. This hypothesis accommodates the available paleomagnetic and radiometric data. It has implications for pre-Pangean plate tectonics, paleogeography, and the predictive metallogeny of both areas.

Jan 1, 1987

There are serious problems in forecast- ing accurately and achieving this goal depends on good quality information, correct assumpt- ions and sound analysis. planner. The forecaster must focus attention on a number of key areas of interest. These areas include major economic trends and changing GNP structure, consumption time series, end-use consumption patterns and substitution potential, accurately updating data bases (up to 5 years ahead), random factor estimation and examination of both long term and secondary mine potential. While metal price forecasting has suffered due to recent uncertainties, with increased importance on planning tools and cost analyses, it is still a necessary function. Forecasting is subject to the real world and the metal industry is made up of imperfect markets in a dynamic state. The real world provides the challenge to improve the accuracy of forecasting.

Jan 1, 1983

By Landy D. M, Ward M. O, Power W. L

Geological structures are irregular and intricate, so creating a 31) solid geology model is a complicated process. A software system can only partially automate this process, since geological knowledge and experience are required. Therefore, the interaction of a geologist is critical for such a system. This paper discusses some useful advanced functions for enhancing the visualisation and manipulation of 3D solid geology models: flexible attribute display, multiple views, auxiliary display objects, and geologically sensitive operations. It also describes some experiments to explore the effectiveness of these functions and presents sample output. Most existing 3D solid geology modelling systems are implemented in an ad hoc way, which greatly reduces their reusability and extensibility. This paper presents a generic framework for 3D solid geology modelling systems, which is based on object-oriented technology. The deficiencies of current systems may be improved by using this generic framework. A modelling process based on drillhole data is discusses as a case study.

Jan 1, 1995

Numerical simulation by a finite element computer code has bee* used to identify key stages in the initiation of confined bulk explosive by cast primers. The simulations have been verified by comparison with experimental field measurements of shock arrival time versus distance above the primer for a relatively sensitive emulsion doped with ammonium nitrate prills. Further simulations were performed examining the effect of primer size in a relatively insensitive blend of ANFO and emulsion. Immediately above the primers, changes in shock velocity in the explosive were caused by the interactions between shocks originating from different surfaces of the cylindrical primers. At a distance up the explosive column corresponding to about one to two borehole diameters, the arrival of shock reflections off the borehole walls caused a sudden acceleration up to the confined steady state detonation velocity. The simulations reproduced experimental observations that primer size has only a weak effect on changes of shock velocity with distance for confined explosives. However, it was predicted that primer size has a strong influence on the intensity and duration of the pressure pulses that bulk explosive send into the rock surrounding the primer region.

Jan 1, 1990

By Mutton B. K

Hilton Mine is being developed as an integrated component of the Mount Isa operation, to achieve continuity of silver/lead/zinc production well into the next century. The mine has a chequered history from its discovery in 1947 through several periods of intense development activity, each of which has been curtailed due to the further development of the Isa Mine operation. This era has now passed; to sustain increased production rates at Mount Isa, there is a requirement for Hilton ore in 1989. The decision was made in 1983 to accelerate the programme of Hilton development by installing skip hoisting facilities in the main service shaft (P49), to facilitate the development of the mine to pre-production status. The Hilton development plan provides for the mining of selected orebodies, a broadening of the underground exploration drilling programme, and the establishment of significant mine infrastructure. Several technical challenges have been identified as important. The Hilton orebodies, although occurring in the same rock type as Isa Mine, are more faulted, jointed and intersected by intrusive dykes. The ore is more variable in terms of ore continuity, boundaries, grade and metal distribution and the mineralogy more complex. As a consequence the development of this project consists of a co-ordinated programme of mine exploration and development, rock mechanics investigations and metallurgical research and development work. Production will commence in 1986 at a rate of 1000 t/day using mechanized cut and fill techniques. It is planned to introduce sublevel open stoping and by 1996/97 the production rate will be 2.5 million t/yr.

Jan 1, 1986