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By Floyd JM

Pilot plant trials showed the effective ness of the submerged lance SIROSMELT technology for altering the composition of iron blast furnace slags as a preliminary step to produc- tion of formed materials. Mixtures of oil and air were injected into a bath of liquid slag to provide the heat required for melting the additives and to provide very turbulent conditions which resulted in complete dissol- ution of added fluorspar within one minute and almost complete dissolution of silica in two minutes. Sulphur lost during injection was readily made up by addition of pyrite or pyrrhotite. A stable foam could be readily made and broken down and the foamed slag appeared suitable for extrusion or forming into shapes.

Jan 1, 1979

Over the last few years several important developments have taken place in the Electro- lyte Purification Plant at Copper Refineries Pty. Ltd. A fully automated system for the continuous removal of arsenic has been develop- ed. A submerged combustion process for the removal of nickel has been developed to a stage where patent coverage has been obtained in most of the copper producing countries. A plant has recently been commissioned for the production of Tetra Cupric Arsenate, which it is hoped will find a ready market in the timber preservation industry.

Jan 1, 1974

A resume covering currently accepted views on blasting vibration measurement, human response, and criteria for damage is presented as background information for readers who are not conversant with blasting vibrations. This is followed by sections on vibration level estimation and blasting techniques to control vibration. Emphasis is placed on making use of the scatter in the delay intervals of half-second delay detonators, the use of smaller explosive charges for early delay numbers, and the non- use of zero-delay (instantaneous) detonators in cer`a. n cases.

Jan 1, 1976

This paper outlines the aims, objectives and means by which a life of mine land use plan was established for Comalco's bauxite mine at Weipa. Comalco realises the need to strategically plan for future mining activities and still minimise the impact of operations on the natural resources of the region. With this realisation long-term forward planning has been implemented to improve the Company's ability to select future sites for mining, industrial use, agriculture, town expansion and conservation purposes.The knowledge of mineral, water, soil and animal resources has expanded dramatically in the past decade. During 1990 Cornalco purchased Geographic Information System technology which has allowed previously collected resource data to be presented in map form. These maps as part of the Life of Mine Land Use Plan are both information based and strategic which can be efficiently updated. The maps allow a broad audience from engineers, geologists, environmental scientists and site managers to government officers and the general public to comprehensively view and scrutinise the operations.

Jan 1, 1992

This paper examines the various stages of development and design work which were necessary to develop the cemented rock fill system for copper mining at Mount Isa. The reason for a cemented sand fill development program together with details of the test work undertaken are briefly outlined. The testwork associated with the selection of a suitable local rock to supple- ment the cemented hydraulic fill is discussed, as is the method for underground placement and mixing of the graded rock with the cemented hydraulic fill. The design features of the final system which incorporates a graded rock handling system and a cemented hydraulic fill reticula- tion system is outlined.

Jan 1, 1973

By Williams SR

Column Flotation cannot be used indiscriminately. Based on extensive pilot plant experience at Lakefield Research, a number of limiting parameters have been identified for the application of column cell flotation. Parameters of importance are the use of wash water, flotable mineral content, pulp viscosity, type of mineral selectivity being sodght and degree of mineral liberation. The paper discusses when wash water should be used and the positioning of a column within the circuit as this is important to maintain a sound water balance for the circuit and prevent excessive circulating loads. Other areas of debate are pulp chemistry, very low and high weight recovery, for which the conventional column is a poor selection of equipment, and treatment of complex ores, where the separation of valuable minerals is more difficult than non-sulphide, sulphide mineral separation. Based on these observations, the application of column flotation must be carefully considered or can be optimised.

Jan 1, 1993

By Phillips RN

Semi-confined, trachy-andesite sills which overlie the German Creek Seam, within the critical tensile strain zone, form major groundwater hazards to longwall mining at the German Creek underground mines. The water contained in these aquifers is normally neutral, but highly saline. Techniques used to detect aquifers include routine air-lift pumping in exploratory drill holes, downhole geophysical and geological logging and upstage packer testing. Hydraulic constants are calculated from pump-out and pump-in test results. Hydraulic parameters for the calculation of mine inflow rates are determined from pump-out test results because these tests appear to be more representative of aquifer drainage during goat dewatering than pump- in testing. During mining of the first longwall block at Central Colliery, caving fractures intersected overlying aquifers after the longwall had retreated 40m, and mine water inflow rate rapidly increased from less than one litre/sec to 25 litres/sec. The amount of water pumped out of the mine during first panel extraction was 140 megalitres with drawdown occurring over an area of 168 hectares. In the Southern Colliery area approximately 324 megalitres of highly saline water which is actively stored in the Aquila Sill area will be pre-drained from six well points prior to longwall mining. With effective pre-drainage from surface drill holes, maximum inflow rate into the mine during initial goafing can be reduced from 165 litres/sec to about 45 litres/sec.

Jan 1, 1988

By Abraham B. K, Jensen B, Gillies A. D S

The aim of the research was to investigate the feasibility of using an impedance cell and ratio-transformer bridge to measure solids content in coal slurry pipelines. It appeared that this technique could be developed to measure variations in conductance which correlate with solids content. Successful implementation of the measurement technique would have a variety of applications in existing coal wash plants and the potential for automatic process control. A small pilot plant was designed for a feasibility study. This was a closed loop system in which the coal was uniformly dispersed in a tank with a variable speed agitator and then circulated through an external pipe returning to the top of the tank. The impedance cell was located near the end of the external pipe. Slurry concentrations were varied from clean tap water to 50 per cent solids by weight with the addition of weighed quantities of dry coal dust. Ratio-transformer bridge measurements showed that variations in individual observations were equivalent to measurement errors of about two per cent. These probably reflect variations in concentration of the mixture in the pipe. Data for increments in concentration of one per cent indicate that this is about the limit of resolution of the current system. The paper discusses the principles of operation of the impedance cell and measurement system. Results from the pilot study and proposed improvements in the impedance cell design are examined.

Jan 1, 1995

By Paterson M. R, Spencer P. A

Vitrokele technology is a resin process that can be applied in gold plants to reduce both capital and operating costs. The Vitrokele resin can be used for both precious metal recovery and for recovering free and combined cyanide from effluent streams. Vitrokele resin has been extensively tested at pilot plant level and is now applied successfully at a commercial heap leach facility in Zimbabwe where it is used in place of activated carbon for recovery of gold from pregnant leach solution. Significant capital cost savings were achieved by installation of a resin plant instead of a conventional carbon adsorption plant. Operation to-date has not seen any significant physical or chemical degradation of the resin either in terms of adsorption capacity/kinetics or physical appearance/size. This gold recovery process is equally applicable to slurry streams where it would be implemented in stirred tanks with interstage screens in a similar manner to a conventional carbon adsorption plant.

Jan 1, 1996

By Misra VN

The carbon-carbon dioxide reaction is the rate determining step in industrial processes such as the rotary kiln direct reduction process for iron ores. The use of brown coal as a reductant in the rotary kiln process has been shown to result in higher throughputs and lower kiln temperatures. No experimental data has been reported on the effect of coal type or the use of brown coal chars. Methods of carbon-carbon dioxide reacti- vity measurement are discussed. None of the methods have been related to direct reduction practice. No standard test has been developed to assess the reactivity of brown coal chars to carbon dioxide. For routine comparative work the gas analysis method of Okstad and Hoy appears to be the most suitable although some modification to the experimental conditions is required. For detailed kinetic studies direct weighing techniques are to be preferred. The factors affecting the reactivity of brown coal char to carbon dioxide are reviewed. Numerous factors such as the origin of the coal, pretreatment and ,physical and chemical differences have been found to affect the reactivity of brown coal chars but no data has been reported on the effect of coal type on reactivity to carbon dioxide.

Jan 1, 1980

By E P. Donohue

Changes to water industry practice are required as a consequence of the Council of Australian Governments water reform agenda which binds all states and territories to a range of measures intended to drive new efficiency, sustainability, higher value use and proper provision for environmental needs. Queensland is implementing its reforms program through its water resource planning process, a legislatively underpinned program that provides for a new level of social, economic and environmental security. A water resource plan for the Fitzroy Basin has been finalised and its implementation plan, which details infrastructure operational arrangements for the basin, is due to be released later this year. The mining industry is a major contributor to the economy of the Basin, and although a comparatively minor water consumer, is now aligning its water use practices with the stateÆs maturing integrated resource management paradigm. This new culture presents both challenges and opportunities. Water reform in the Fitzroy basin is well advanced. The processes and institutional arrangements that have been developed are of significant importance to the aspirations of current and future minerals development. This paper outlines the current status of those reforms and the likely institutional framework for the near future. The paper also discusses how the reforms impact on the availability, access and security of water available to mining interests.

Jan 1, 2003

The proximity of the Town of Kalgoorlie to the Mount Charlotte mine necessitates that charge weight per delay be limited in order to keep surface vibration levels within acceptable limits and to reduce damage to underground workings. The mining system requires that large mass blasts must be used to recover pillars and therefore a large number of separate delays are needed. Until recently all blasting has been done electrically, fired from mains, but with the introduction of large diameter blastholes (165mm diameter) this firing system was inadequate. Various firing systems were considered, but after extensive trials a non-electric sequential firing system was chosen. This system fulfilled all criteria of blast design, was relatively straight forward in charging technique and had a very simple primary initiation system. Although initially designed for large mass blasts, the non-electric firing system is now used for all large hole blasting and in a simpler form for small (57mn diameter) holes.

Jan 1, 1982

By H Arvidson, D Guibal

This paper presents updated interpretations of controls on mineralisation in C Deposit and highlights structural features that influence the geometry of mineralisation domains used in resource estimation. The Area C mining lease is located in the central Hamersley Province, ~100 km WNW of Newman, Western Australia, and contains resources of approximately 1100 Mt of Marra Mamba and Brockman iron mineralisation. C Deposit is located within Area C, on the northern limb of the Weeli Wolli anticline, and mineralisation is hosted predominantly in the Mt Newman Member of the Marra Mamba Formation. Production from C Deposit began in August 2003, following mining of a 950 000 tonne bulk sample in 2002. Recent mapping in the bulk-sample pit and updated interpretations by BHP Billiton geologists have highlighted the significance of structural controls on mineralisation in C Deposit and their influence on the thickness of mineralisation, which ranges from 20 to 80 metres. Structural controls on the geometry and continuity of mineralised domains include south-dipping thrust faults that developed along the Mount Newman/West Angela contact, folds associated with thrust fault development, steeply dipping stratigraphic contacts in the hanging wall of the thrust faults, and gently north-dipping stratigraphic contacts. Thrust faults and folds in C Deposit are significant for two main reasons: their formation resulted in the thickening of the main ore-hosting units in the Mount Newman Member; and faults and folded stratigraphic contacts provided conduits for supergene metasomatic-enrichment processes that produce high-grade iron mineralisation.The implications of this interpretation for the definition of the resource estimation domains are discussed, and suggestions are made for a better integration of geology into the data acquisition and estimation process.

Jan 1, 2005

The Southwest Pacific is a region of active volcanism and geothermal systems. Only in New Zealand have the geothermal systems been exploited for electricity generation and industrial processing. At present, approximately 280 MWe of geothermal electricity is generated in New Zealand. A considerable amount of further exploration work is required before the total geothermal potential of the region can be assessed and before the significance of these resources can be judged against other local energy sources.

Jan 1, 1990

By Sergeant G. D, Norman J. R

The importance of reducing the moisture content of fine coal, the nature of the retained water and the means of its removal are discussed. A statistical technique, using a balanced block design, was used to isolate the significant factors determining water content of a coal filter cake, The most significant factor was particle size distribution. A simplex evolutionary operation (evop) was used to determine the optimal quantities of additives required to produce the lowest moisture content for a selected coal size. For this optimum condition (18.6 lb xÇ20 per 100 lb dry coal), additions of 0.045 lb magnesium ion, 0.0026 lb separan A.P. 30, and 0.098 lb aerosol O.T., per 100 lb dry coal were required. The work illustrated the uses of statistical evop technique for the determination of optimal conditions in industrial research projects.

Jan 1, 1969

By Chapman G. J

Mining operations require detailed and precise methods and procedures for the optimum selection of ore from waste. A fundamental procedure applied to achieve this selection is accurate sampling. The key parameter to accurate sampling is an understanding of the degree of heterogeneity of the key element contained within a sampling mass. This paper will describe the methods applied for the calculation of the fundamental sampling error and the techniques used to achieve a representative sample in the Fimiston Open Pit, Kalgoorlie.The utilisation of Pierre Gy's sampling theory has optimised the blast hole sample quality and quantity for submission to the assay laboratory. This has resulted in reduced cost and optimised assay reliability in statistical terms. Similarly the analysis of exploration drill holes for resource definition has optimised drilling procedures in terms of the drilling method, sample length and sample quantity.

Jan 1, 1993

Feasibility is a value improvement process for projects. At any stage in project development, a feasibility study can be undertaken, but although the scope generally remains unchanged the extent of detail and level of accuracy usually increases with time. The main scope elements are a business definition, project description and an execution plan. The studies are designed to assess the potential of the project and to secure funding for on-going examination. Invariably, the investigations loop back to earlier stages to establish more appropriate development criteria but a critical stage is reached when a project construction decision is requested. This feasibility study requires very detailed presentation and analysis to a higher accuracy for the owner(s) and their potential lender(s).

Jan 1, 1997

The paper describes a computer model developed within the State Electricity Commis- sion of Victoria for use in open cut planning. The purpose of the model is to simulate all the typical occurrences in, and influences on, the coal supply and overburden disposal systems in order to be able to assess their performance. The model incorporates much of the long term and day-to-day operations planning logic required for the allocation of resources within an open cut. This logic takes account of power station demands, bunker stocks, plant and crew availability, the balance of reserves between dredgers, planned maintenance, etc. The perfor- mance of plant within the system is simulated using random selections from statistical distri- butions of Time to Failure and Time of Failure for each plant item. The application of the model in selecting a suitable bunker capacity in a notional open cut development is described to illustrate the potential of the model in optimising plant selection.

Jan 1, 1982

Following unprecedented high market prices for tin and gold in 1980, significant advances in both mining technology and geological knowledge took place in northeast Queensland. These led to a rapid growth in mining activity. Production of these traditional metals reached levels comparable to those of the heyday of mining activity at the turn of the century.Although tin and tungsten prices have since collapsed, the geological knowledge gained and significant discoveries made during the boom, have created a potential for mine development when prices rise again. For other discoveries which are not workable because of treatment problems, future technological advances are required to raise their potential.

Jan 1, 1990

Metsim is proving to be a powerful tool when designing a heap leach operation. The most useful outputs arc determining the fluctuations in pregnant solution recovery rate, make-up water rate, gold recovery rate. and pond levels. Detailed data are needed for input: a pad loading schedule, a mining rate schedule for each ore type, column leach test data for each ore type, column tests on water dynamics (ie hourly flow-out versus-in during saturation and drain-down), monthly rainfall and evaporation data, and proposed pond dimensions. These data allow 'what if' studies on application rates, leach rates, loading rates and other variables of interest. Examples will he given of modelling both a rectangular pad and a valley fill operation.

Jan 1, 1994