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By G Billing a, D Gribble, E Hall, D Varga

The theoretical benefits of electronic detonators have been reasonably well documented. To support this, a practical comparison was made between the performance of the standard shock tube system, NONEL, and a high precision electronic system, HotShotÖ, at the Sunrise Dam Gold Mine. The expected benefits from electronic detonators to Sunrise Dam were identified prior to the trial. Based on these, a number of objectives were set to demonstrate the value of the HotShot system. These are an improvement in fragmentation leading to an increase in productivity, less oversize rehandling, increased throughput and more uniformity in muck pile movement. To maintain the integrity of the trial, the nominal timing of the shots was kept exactly the same, thereby restricting any performance improvements to the precision of the electronics. Accordingly, adjacent shots were chosen with consistent geology. Video footage was taken of the blasts and vibration monitoring was carried out by fixed geophones throughout the mine. Spot heights of the muck pile swell were taken immediately after the blast and heave profile graphs were generated for comparison. Video footage was taken for a period of three hours for both shots to analyse cycle times of the excavator and trucks. PITRAM data was also collected for analysis. As far as practicable, the ore was taken to the same finger on the run-of-mine (ROM) pad to assist in single sourcing for the crusher and to allow oversize to be separated out. From specific metrics taken during the trials, it was shown that the expected improvements due to the high precision timing of electronics were realised in all areas.

Jan 1, 2007

By Floyd JM

Conventional smelting reactor systems were designed to recover only one main element from their feedstocks. They did not possess sufficient flexibility to allow optimisation of co-production of multiple values from a complex feed.New reactors such as Sirosmelt and Top Blown Rotary Converters are providing new possibilities for making separation between components and this is of great significance for the complex feeds which are becoming prevalent in the metal extraction industry.Process routes using chemical procedures which take advantage of the flexibility of these reactors will be discussed in relation to a number of possible feedstocks.

Jan 1, 1985

The current boom conditions in the Gold Mining Industry, open cut low grade gold mines have become the initial cash flow source for most companies. To achieve the required cash flow the head grade needs to be maintained at the required level. The methods of grade control to achieve .the planned head grade have evolved various systems, one of which is the Ditch Witch Trencher. The application of this machine has revolutionised open cut grade control and Geology and this paper records the various methodologies developed in the Eastern Goldfields of Western Australia.

Jan 1, 1987

By Partridge AC

The measurement of particle size is very important in many industries. Comments in this paper refer principally to the Mineral Industry and in particular to Coal Mining and Coal Preparation. The objective is to indicate the importance of particle size in process design and process assessment and to describe techniques for particle size measurement and the presentation of results.

Jan 1, 1984

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

Subsidence prediction methods can be divided into two basic types: empirical and analytical. Empirical methods are based largely on a combination of experience, intuition and observations from a large number of observed subsidence data. They are simple in their application, but they are not based on any principle of mechanics. Analytical methods are based on equivalent material modelling principles, where the ground surrounding the extraction is mathematically represented by idealised materials that deform according to the principles of continuum mechanics. Wide applicability and improved understanding are the principal advantages claimed for this approach. In NSW, significant progress has been achieved in the area of subsidence prediction during the last ten years. Empirical prediction curves are available in NSW for predicting the ground movement in the Southern and Newcastle Coalfields. A' comparison of subsidence values predicted from these curves with the actual monitored values indicates that the curves are adequate for use in conjunction with the existing damage assessment methods. Future research for improving the existing empirical prediction curves can only be justified if it is cost effective. There are several numerical models currently in use in NSW for predicting subsidence. The models do not appear to be superior in their ability to predict subsidence when compared with the empirical curves. the performance of these models will no doubt improve along with advances in defining strata properties and failure mechanisms.

Jan 1, 1991

By A J. Moore

Predictive assessment of surface blast vibration requires the identification and quantification of significant factors, and the summation of their combined effect. Methods available for the prediction of significant factors are described, and examples are given of the combined use of these methods to evaluate alternative proposals.

Jan 1, 1999

By Carter A. C

The increasing need for alternative energy sources as well as the less clearly perceived but equally increasing demand for non-fuel minerals has resulted in extensive exploitation of near surface deposits. Many such deposits have depleted reserves and mining corporations are increasingly turning their attention to deposits, with thicker overburden, less competent materials, steeper dips and more complex structure. These deposits pose mine layout, geotechnical and equipment problems as well as the need for large outputs to achieve economies of scale. The paper describes the major problems and operational solutions for such deposits using continuous excavation and transport equipment.

Jan 1, 1980

By Grieveson P, Rajakumar V

The reduction of an ilmenite concentrate with coal at 1000, 1050 and 1100¦C was investigated using thermogravimetry and X-ray diffraction, optical microscopy and electron probe microanalysis of the product. The effects of temperature, coal particle size, addition of ferric chloride and preheating of the concentrate in argon on the reduction kinetics and mechanism were determined. The rate of reduction increased significantly with temperature and was enhanced by the addition of the catalyst. The morphology of the iron was primarily determined by the degree of weathering of the particle. Significant coarsening of iron was obtained in the dense particles by the addition of ferric chloride. The sequence of reduction and the enhancement in the rate of reduction by preheating the concentrate in an inert atmosphere are discussed.

Jan 1, 1991

By Roach C

Exploration on the Callide Coalfield by Thiess Bros. Pty. Limited had reached the stage in mid 1976 where there was a need for a comprehensive appraisal of the coalfield geology. Exploration strategy in 1977 - 1978 was defined by the selection of the most attractive targets. All available literature, reports and plans were reviewed and borehole records assessed. The geology of the coalfield was placed in its regional setting and the genesis of the Callide Coal Measures described in a structural and sedimentological context. Their general form and extent was then examined by the technique of stratigraphic analysis through the interpolation and extrapolation of the available data. A "localized" reserve classification was drawn up and reasonable estimates of the various geological reserves produced, in terms of their reliability and depth of overburden. Quality trend maps were also produced. The resultant "base map" was virtually a summation of all the information to June, 1977, and the basis for the exploration programme in the 1977 - 1978 financial year. The technique allowed for "base maps" to be produced at almost any stage, each one a refinement of its Predecessor.

Jan 1, 1978

By M L. Habner, S D. Munro

In a gold CIP/CIL circuit, adding new circuit water to a final tails thickener and then directing the thickener overflow to the head of the circuit significantly reduces the cyanide concentration at the TSF discharge spigot. The new water is used to dilute the final tails. The dilution and recycle of the tails in this manner may have the added benefit of reducing reagent consumption, in some cases to the point where the reagent savings justify the expenditure and Cyanide Code compliance is achieved at no extra cost. Potential circuit configurations and water recycles can be modelled by splicing a flowsheeting and thermodynamics package, such that changes to the composition of the water can be reduced to chemical speciation with a Gibbs free energy minimisation enabling a complete understanding of the circuit water chemistry.

Jan 1, 2007

By Warren M

Many Australian tunnelling and mining companies regularly investigate different methods or equipment in an attempt to keep ahead of their competition. Sometimes the result is a new approach or process which wins a tender or provides an advanced solution to a problem.The Australian Government has a policy of encouraging forward thinking among Australian companies and provides a range of incentives. One of these incentives is currently available retrospectively to 1985 - 86, and the registration process is relatively simple with only one form to be completed. Companies who investigate methods of raising productivity could be reimbursed for the costs of the investigation.

Jan 1, 1993

Arising from prospecting success, the underlying worth of the shares of a publicly listed mining exploration company can increase many-fold. Prompt and accurate reporting during the exploration stage is therefore essential. While there is scope for varying degrees of optimism or caution in statements about the future economic prospectivity of a mineral deposit which has been discovered, the directors of a mining exploration company have both a legal and ethical obligation to keep their shareholders and the general public fully informed as to the state of progress of, and significant factual results arising from its exploration efforts. Suggestions are made as to the desirable form and content of exploration reports up to and including the time when the orebody has been delineated in terms of assured tonnage and grade. The benefits which will flow from this greater disclosure are discussed.

Jan 1, 1979

The continuously growing coal mining industry of India presently includes shovel dumper combinations in open cast mines, sometimes with dragline mining of overburden, together with the whole range of longwall and bord and pillar underground mining, continuously undergoing fuller mechanisation. This transition from "low tech" to "high tech" systems is now monitored for reliability and provides bases for comparisons of downtime relative to age and make of equipment, whether imported or indigenous, including spare parts, as well as frequencies of particular failures to allow analysis and progressive improvement. Varying geologies complicate technology and equipment requirements, especially in underground mine,s with minimal technological standardisation, but now, reliability in South Eastern Coalfields Limited has been given more importance and superior technological back-up is being developed.

Jan 1, 1991

By R Lastra

Applied mineralogy involves conducting investigations on ores, minerals and materials to solve problems encountered in mining, metallurgy, processing, industrial minerals, environment, health and other fields. The investigations are performed to determine the mineral behaviours during processing by using every mineral and ore characterisation technique and appropriate instruments. As the field is young, new techniques and instruments are still being developed. This paper attempts to convey the scope of the field by:describing the capabilities of the respective research instruments for determining mineral characteristics, summarising investigations of gold as an example of applied mineralogy studies of precious metals, andpresenting a case history where applied mineralogists worked closely with mineral processing engineers on a base metal ore and mill products to help the engineers optimise their processes for maximum recoveries.

Jan 1, 2008

Reverse circulation (R.C.) drilling or the dual tube method as it is quite commonly known, has a unique place in conventional mineral drilling. It can be classified half-way between open hole drilling at the lower end of the scale and diamond drilling at the upper end. The system basically consists of two tubes, one inside the other, with compressed air flowing between the inner and outer tubes. Sample cuttings return up the inner tube through the head of the rig and via a hose to a cyclone where the sample is collected. This system means that the cuttings are free of contamination as they are at no time in contact with the outside formation of the hole.Reverse circulation drilling is divided into two areas: R.C. Roller and Blade for softer formations; and R.C. Percussion for harder formations.

Jan 1, 1986

The Golden Pig Mine is wholly owned by Bunnine Operations Limited and is located in the Yilgam Goldfields at Southern Cross, Western AustraliaThe paper briefly describes the geology and history of the operations. Mining is by shrink stoping, both hand held and mechanised. Advantages and disadvantages costs of the mining system are discussed.

Jan 1, 1993

By P D. Franzmann, D J. Readett, J Peterse

A better connection between laboratory- and pilot-scale test results, and heap bioleaching performance can be achieved by generating reliable information on the fundamental microbial, chemical and physical processes that occur in heaps and incorporating this information into a comprehensive and robust model. More efficient heap bioleaching, particularly of chalcopyrite, has the potential to add value to the mining industry as well as deliver attractive environmental and social benefits to the communities within which those companies operate.The results of fundamental chemical and microbiological studies of the leaching mechanism, the temperature dependence of chalcopyrite bioleaching, and the optimisation of leaching conditions are described with examples from full-scale heaps. The development and application of a number of novel techniques and tools has assisted our understanding of heap subprocesses mineralogy, hydrology, chemistry and microbiology. The heap bioleaching model HeapSim, which embodies a large number of effects not previously accounted for in other models, continues to be refined and has been applied successfully to the study of several heap bioleach systems.

Jan 1, 2004

Where tunnel rounds are based on the burn cut, faster advance could often be achieved by increasing blasthole diameter from (the conventional)

Jan 1, 1981

ADDRESS BY THE PRESIDENT OF THE INSTITUTE (MR. C. H. MARTIN) IN PRESENTING THE CERTIFICATE TO SIR MAURICE MAWBY, C.B.E.Members of The Institute, distinguished guests of which there are many, ladies and gentlemen, you are welcome. And might I add a special welcome to Lady Mawby and Lady Fisher and to Sir George's only son, Peter, who with his wife, Betty and one of Sir George's three daughters, Helen, are present this evening, and also to Sir Maurice's son, Colin, and Colin's wife, Jay, also in our company.The family presence must surely be a great source of pleasure and satisfaction to all those so intimately concerned.It is hardly necessary for me to state the sole and only reason for our presence here tonight, which is to confer on Sir George Fisher and Sir Maurice Mawby Honorary Membership of The Australasian Institute of Mining and Metallurgy, and at the same time to acknowledge two people who have rendered great service to the mining industry, albeit tinged with sadness to all of us in the knowledge that from now on their influence may diminish. It is now my pleasure to introduce, although that is hardly necessary, Sir Maurice Mawby, the second member of the duo we honour here this evening, and whose contribution to the mining industry is also beyond assessment.

Jan 1, 1976