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Perhaps the only thing certain about an address that purports to look into the future of any human endeavour is that time will prove it :.o be inaccurate. In undertaking the dubious, but oft-times necessary business of prediction, thr, historian will base his/her forecasts on tr-ands of the past, the speculator on current events, and the politician on what he/she would dearly like to see happen. The thoughts expressed in this address seem to have arisen through exercising a combination of all three of those philosophies but, hopefully, with a smat- tering of pragmatism.

Jan 1, 1988

By Sauer P

The paper deals with the method of operat- ion, types of construction and sizing of screening machines as well as the selection of suitable screen decks. The application of novel screening mac- hines in hard coal preparation plants is explained in detail by way of examples.

Jan 1, 1984

Revegetation at Perseverance Mining's Nagambie Gold Project is an excellent example of cost effective revegetation in the Central Victorian Goldfields. Work has centred on waste rock dumps, vegetative screens, amenity planting and revegetation trials on cyanide heap leach pads. A wetland is under construction and in consultation with farmers, waste heaps were planted with perennial pasture species.The area treated to date is 18 hectares comprising: 16 hectares of pasture and two hectares of trees/understory. Direct seeding and tubestock planting has cost $16,464. Cost effective revegetation demands careful planning from the EES stage onwards. The Government agreed rehabilitation plan should be comprehensive, realistic and above all flexible. This document must be kept in mind during the mining operation.

Jan 1, 1992

By Brinkmann J. R

In the narrow stopes of South African gold mines, rockbreaking is carried out by drilling and blasting with safety fuse and igniter cord being used as the initiation system. The fuse/gniter cord system is used primarily because of its low cost, however several limitations of this method include: inaccurate delay time, unreliable firing, inflexible application to varied configurations, and the absence of dynamic interaction between holes. Alternative initiation systems that incorporate millisecond timing are being developed to overcome the limitations of fuse(tgniter cord systems. Current investigations by the Stoping Technology Division of the Chamber of Mines Research Organization (COMRO) into the effects of millisecond initiation are being conducted at a deep test site. Experimental blasts using various millisecond delays and the independent firing of holes with fuse/igniter cord are being studied in order to quantify the influence of delay time on the blasting process and to identify the best methods of applying millisecond initiation systems. The effect of design variables such as delay time, hole firing pattern, stemming, and panel layout are discussed. Blast results including throw distance and direction, muckpile profile and rock cleaning times are used in the discussion of different combinations of blasting variables.

Jan 1, 1990

In 1980 Pancontinental Mining Limited decided that while the Jabiluka uranium project was still a major focus of the company's efforts some diversification was necessary. At this time it was decided to include precious metals in Pancon's exploration and acquisition objectives. As a result the now Paddington Gold tenements were acquired, explored and developed. Today, it rates as the 6th largest gold mine in Australia and at an expanded throughput of 1.2 million tonnes per year of ore it will produce about 110,000 ozs of gold per year. Following extensive exploration activities by Pancon's Exploration Division the Operations Division continued with development drilling finally proving up a reserve of about 8.4 million tonnes at an average grade of 3.2 g/t. An in- house preliminary feasibility study was followed by a two phase feasibility study by Davy McKee. This resulted in a recommendation to the Pancon Board of Directors to develop Paddington with an annual throughput capacity of 875,000 tonnes. This paper describes the acquisition, exploration and development of the Paddington project. It goes on to

Jan 1, 1986

This paper presents the findings from an experimental study of the effects of shock and gas penetration breakage mechanisms in rick blasting. A blasthole liner method, which realistically seperated these two basic sources of energy in blasting, was developed and utilized. The use of four different explosives with contrasting detonation behaviour produced a wide variation in the nature of explosive energy transfer to the rock. Through extensive field experiments it was found that, relative to low VOD dynamite, the high VOD emulsion imparted greater shock to the rock and therefore produced finer fragmentation and greater back damage. The comparatively lower heave energy of the emulsion caused less immediate blast results were obtained with watergel and ANFO explosives, which have detonation behaviour and energy partitioning charecteristics lying between emulsions and dynamite.

Jan 1, 1990

The moisture content of clean coal contributes significantly to the product's transportation costs, handleability characteristics and/or energy value. A major contributor to the total moisture is the ever increasing proportion of fine coal in

Jan 1, 1994

By P Cavieres, R Dunlop, S Gaete

El Teniente Mine started the exploitation of the primary rock in the beginning of the 1980s decade, using caving methods. Since the beginning the mining activities have induced seismicity including some occasional rockbursts. Owing to the relevant damages, the mining operations were stopped in some production sectors. This paper describes the concepts that have been used in order to control the induced seismicity based on the strategies for controlling the rockmass breaking process, which depend on mining parameters. It also presents the main concepts applied in the Teniente Sub6 sector design and the experience collected during its sector exploitation.

Jan 1, 2000

By McHaina D. M, Hardcastle S. G

A description is given of an investigation into the feasibility of using controlled recirculation of warm exhaust air into the cold intake air of underground mines during winter. Canadian mines can experience inlet air temperatures of minus 30 ¦C and less, requiring them to pre-heat their intake air. The use of controlled recirculation would reduce the inlet air quantity and thus reduce heating costs which exceed $1M on some mines.

Jan 1, 1988

By Large RR

Underlying the 15 million tonne, high grade Hellyer volcanogenic massive sulphide deposit of western Tasmania is an extensive, well developed, and well preserved stringer system. Pervasive alteration of the footwall mafic volcanics occurred as the hydrothermal system initiated. Mineralogical zoning exists within the footwall alteration pipe, with a central siliceous core giving way to zones of chlorite, chlorite-carbonate, sericite-chlorite, and finally sericite-quartz on the margins (stringer envelope zone). However, the alteration morphology and zonation is not symmetrical around the central siliceous core; eastward the alteration zones are steeply dipping and terminate abruptly under the massive sulphide, while westward they extend out under the ore body in a blanket fashion. Geologic evidence indicates that the pervasive alteration started with the development of sericite-quartz which was subsequently overprinted by chlorite and finally quartz-sericite as the hydrothermal system became focused towards the centre of the stringer system.

Jan 1, 1990

The reduction in man's contribution to the Greenhouse effect will only be achieved by a number of small steps. Some steps will absorb carbon dioxide (CO2) from the atmosphere in slightly greater quantities, others will reduce the amount of carbon dioxide generated. This paper deals with the reduction of carbon dioxide by improving the combustion efficiency of petroleum fuels. Until recently most reductions in fuel consumption and air pollution have been brought about through mechanical adjustments to combustion equipment. Since the development of tetraethyl lead, little has been done to chemically modify combustion reactions to improve fuel efficiency or reduce emissions. During the past five years Australian laboratory and field trials with ferrous picrate treatment have demonstrated significant and economic gains in the combustion efficiency of diesel fuels. These studies have revealed that even under ideal conditions in diesel engines, carbon monoxide (CO) momentarily saturates the combustion chamber. This state reduces combustion rates, peak pressure and power and increases the risk of pollution. Theoretical, laboratory and field data are presented which support the mechanism by which the ferrous catalyst accelerates the oxidation of CO to the terminal CO2 thus reducing fuel consumption and the undesirable combustion products accompanying the CO saturation of combustion environments. While this paper deals principally with diesel fuels commonly used in mining operations, the catalytic effect of the ferrous ion is also shown to significantly reduce fuel consumption by petrol engines thereby promising a means to reduce the much larger contributions to the Greenhouse gases by automobiles.

Jan 1, 1989

By Martin T

High methane content of the medium volatile metallurgical coal mined from the Coal Basin mines causes very difficult mining conditions. Rapid desorption into the mine ventilation system limits coal production, requires huge fresh air quantities and creates mine safety problems. In workings deeper than 2000 ft (600m) gassy coal and heavy cover create outbursting conditions. Cross-measure methane drainage has reduced ventilation requirements on advancing faces, but degasifica- tion of virgin coal is needed to improve mining Conditions.

Jan 1, 1982

By B C Tanda, E A. Oraby, J J. Eksteen

"Base metal and precious metal deposits are well known for their significant geometallurgical variation throughout the volume of the proven resource. At the metallurgical level, the plant normally processes an upper oxidised layer, a transition zone and a sulfide zone, often leading to different processing techniques for the different zones. A novel processing approach is presented whereby alkaline leaching with glycine is used to leach base and precious metals, using a copper-gold ore deposit as a case study. Glycine is a cheap, non-toxic, non-volatile, highly water-soluble crystalline solid produced industrially in bulk quantities. As a chelating ligand it forms a number of stable glycinate complexes with Ni, Co, Cu, platinum group metals (PGMs), Au, Ag, Zn, Pb, Hg and Cd, with broad stability regions over an extended temperature-pH-Eh range, allowing dissolution of these metals in the neutral and alkaline regions (pH 7–13). It has been shown that this lixiviant system can leach the metals from their oxide, oxy-halide, basic sulfate, carbonate, native and various sulfide forms, including refractory sulfides such as chalcopyrite. Extraction of the metals from their soluble glycinates is easily achieved using a range of solvent extraction and precipitation processes, and the glycine remains stable in aqueous solution for recycle and reuse. Minerals bearing metals in Groups 1 to 8 of the periodic table are normally unaltered. This technology therefore provides a highly selective leaching environment for the extraction of numerous scarce metals of economic interest, with minimal interaction with gangue minerals, whilst using environmentally benign reagents. Problematic leach residues such as jarosites, elemental sulfur and silica gels are averted through this processing approach. This technology allows hydrometallurgical processing that is much less domain-sensitive in the geometallurgical sense, and utilises essentially the same key reagents for the whole deposit.CITATION:Eksteen, J J, Oraby, E A and Tanda, B C, 2016. Developing Robust Hydrometallurgical Processes to Recover Metals from Deposits with Large Geometallurgical Variation, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 15–20 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By M A. Tuck

Atmospheric air on a moisture free volume basis consists of approximately 21 per cent oxygen. The current minimum threshold for oxygen in Australia is 19.5 per cent. Atmospheric air generally will also contain water vapour and will also pick up further moisture as it flows around a mine ventilation network. This paper details the results of a study to determine how much oxygen depletion can occur due to the sole impact of increasing the moisture content of air and the potential impacts of this on ventilation system design. The study shows that the moisture content can have a significant impact on the oxygen concentration in mine air. The main factors controlling the impact are the barometric pressure, dry bulb temperature and relative humidity of the air.CITATION:Tuck, M A, 2015. What is the oxygen depletion potential of ?water vapour?, in Proceedings The Australian Mine Ventilation Conference, pp 173–176 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Matsushita Y, Maeda M, Sano N

The present study was carried out to explore the possible separate recovery of iron and phosphorus (as gas) from BOF slag using graphite crucibles or graphite powders in the presence of a tin bath. The last is consider- ed to enhance the activity of phosphorus in iron reduced from slag or not to absorb the phosphorus vapour readily. When the slag was reduced in a graphite crucible in contact with a tin bath, the phosphorus reduced from the slag was carried away in CO explosively generated by the reduc- tion of iron oxide. When graphite powder was used as the reductant instead, 78% of the phosphorus was removed from slag, only 3% of which was absorb- ed into the tin bath. The rest left the system as gas. Gaseous dephosphorization depends on the area of contact between slag and reductant as cll n.u the amount of the latter. the reduction behaviour was directly observed, using an X ray transmission technique, to conlirm the reaction mechanism.

Jan 1, 1980

This paper will trace the development of underground coal mining machinery from the days of the tiny air-powered machines to today's 60-ton electric-powered continuous miners. Some important design features which have made the modern fixed-drum continuous miner a success will be examined.

Jan 1, 1978

Rajor intrusion-related Cu and Au dep- osits along the Cordilleran-type central Andean margin and in the western Pacific island arcs constitute a series of discrete, linear belts which correspond to limited (414 m.y.) metall- ogenic epochs. The most important metallogenic belts, all of Cenozoic age, are inferred to have been generated during relatively shallow subduction of oceanic lithosphere beneath con- vergent margins. Geological and isotopic evid- ence suggests that magmatic rocks and associated Cu and Au mineralization were derived from asthenospheric mantle sources, which were enriched in a variety of elements (metals, alkalis, S) by dehydration of subducting oceanic crust. Where exceptionally rapid, low-angle 3ubduction took place beneath very thick (>50 km) continental crust, as in the central Andean Altiplano in the Miocene and southwestern North America during the Laramide, ore-related magmas underwent wholesale crustal contamination. However, the associated Cu-Au mineralization is the same as that developed in primitive island- arc crust. In particular, the by-product Au and So contents of porphyry Cu deposits are inde- pendent of crustal thickness and the degree of crustal contamination as determined isotopic- Ally.

Jan 1, 1987

By C R. Fountain, R J. Sinclair

The zinc industry is dominated by the electrolytic zinc (EZ) process. The EZ process has a low tolerance for impurities, resulting in tight concentrate specifications. Many mining companies sacrifice zinc recovery in order to meet smelter specifications. Some have ore-bodies that cannot be economically developed because too much metal has to be sacrificed, or it is just not possible to meet the specification. The BUKA Zinc Process (BZP) has been developed as a method of producing high-quality zinc from a wide range of concentrates. It can have lower capital and operating costs than the conventional zinc and lead production routes. Advantages accrue from increases in metal recovery during concentrating, smelting and refining; the elimination of most of the capital and operating costs associated with lead smelting; reduced transport costs; lower zinc refining costs; reduced refinery residue disposal costs; and reduced future environmental liabilities. This paper describes results of testwork that has been undertaken to demonstrate the viability of the BZP on both test rig and laboratory-bench scale.

Jan 1, 1998

By Dugan K. J

Mine operators are currently in a situation where market forces are acting to reduce profit margins and at the same time, regulatory bodies are insisting on improved mine safety and stability. This means that ground support must be made more cost efficient while maximising operator and equipment safety.A key aspect of ground support efficiency is the 'in the ground' performance. This paper discusses the factors that influence the way rock bolts and cable bolts perform. It highlights the need to know how support efficiency varies in different ground conditions.

Jan 1, 1992

Mining companies around the world devote considerable effort to production reconciliation and metallurgical accounting. However, although sampling, weighing and analysis methods used to obtain the raw data for metal balancing continue to improve, they are still areas that are sadly neglected. Using the latest metallurgical accounting package to improve metal balancing is fundamentally flawed if the data used are unreliable in the first place. The basic rule for correct sampling is that all parts of the material being sampled must have an equal probability of being collected and becoming part of the final sample for analysis. If this rule is not respected, sampling bias can easily be introduced. Unlike precision, which can be improved by replication, bias cannot be reduced once it is present. Sampling and sample processing procedures must therefore be carefully designed both to minimise bias and to obtain acceptable precision. The most suitable sampling location is the discharge point of a process stream, where increments can be obtained by taking a complete cross-section of the stream with a sample cutter. Sampling devices that take only part of the stream may introduce serious bias and must be avoided. The moisture content and wet mass of the material being sampled are of similar importance to chemical analyses for determining metal content. The accurate determination of moisture content is particularly difficult, because the moisture content of samples can change after the sample is taken, eg due to moisture evaporation. Hence, moisture samples need to be taken quickly and placed in sealed bags or containers that are impervious to moisture. The moisture content should then be determined without delay. To determine wet mass, a range of weighing methods are used in industry, including weighbins, weighbridges, conveyor weightometers and platform scales. The precision and accuracy of these methods vary considerably, so it is important to select a method with the appropriate precision and ensure that the weighscale is well maintained and regularly calibrated.

Jan 1, 2002