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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

By Shining Z

The properties of coal or rock containing gas are very important both for studying coal and methane outburst mechanism and for controlling underground rock in mining. The rheological fracture properties of coal containing gas were studied to obtain its rheological fracture principle both in microscopic scale and in macroscopic scale. The application of this principle is successful in explaining coal and methane outburst mechanism and for putting forward a rheological hypothesis of coal and methane outburst.

Jan 1, 1992

By Seeley D, Buckley N, Goodall J

Improving the performance and reducing the costs associated with export logistics chains is critical to the competitiveness of export coal mines. The fundamental practices associated with the use of export logistics chains made up of mine, trucking, rail and port operations are being challenged by the advent of third party operators on rail systems and the use of the Internet.Whilst individual mines can improve their processes to drive down their mining costs, they face major challenges in their endeavour to improve the performance of export logistics chains and reduce the significant logistics costs of moving coal from the mine to export ships, via the shared infrastructure of rail systems and ports. There is an increasing realisation that global competition is not only between mines but between coal export regions that are defined by their rail system and ports infrastructure.

Jan 1, 1998

Existing fluid flow techniques may be readily applied to the design of ranges for seam gas drainage. The Reynolds number characterises the flow regime within the pipe and it can be used in conjunction with data on absolute pipe surface roughness to determine the system friction factor. The application of the solution to the isothermal compressible flow equation utili- sing Moody friction factors and the concept of equivalent length of pipe for fittings and valves provides a practical method for sizing gas ranges. The physical capacity of a range can be decreased by the existence of significant quantities of water in the range and also by the ingress of air into the system at poor pipe joints etc. Both problems can be elimin- ated by adequate attention to design detail.

Jan 1, 1982

Mill liners provide the wear-resistant surface within grinding mills, they also impart motion to the mill charge, ie the grinding process, by providing the key between the charge and mill shell, and, at the discharge end, they remove the ground contents of the mill. As semi-autogenous grinding (SAG) mills have grown in size the process aspects of liner design and their impact on mill performance have become particularly important. While feedback from practical experience is critical to good mill liner design, increasingly sophisticated computer-based tools are being developed to assist in mill liner design.

Jan 1, 2007

By Canterford J. H, Bologiannis F, Smith A. N

The Mutooroo copper mine is one of a number of deposits that have been evaluated by Adelaide and Wallaroo Fertilizers Ltd as a source of feed for the production of high- purity copper oxide at their Burra plant. For this deposit, the technique of solution mining or in-situ leaching appeared ideal. The Mutooroo production circuit and the results of the process optimization and environmental monitoring programmes are outlined. At the end of the experimental period described here, the production liquor typically contained I g/litre copper, yield- ing in excess of 5 t/month of cement product containing about 80 per cent copper. The environmental monitoring programme provided clear evidence that there had been no un- acceptable alteration to the properties of the groundwater in the country rock surround- ing the mineralized zone. It is anticipated that the experience gained at Mutooroo will be of considerable help in the development of other solution mining operations.

Jan 1, 1983

By McNicol J. H

Using a small scale laboratory pilot plant a series of tests have been conducted with the aim of investigating the influence of the zinc/acid ratio on the efficiency of zinc electrodeposition from an acidic sulphate solution. The results have shown that current efficiency is increased as the zinc/acid ratio is increased with no evidence of an optimum zinc/acid ratio. However the choice of a zinc/acid ratio for full scale operations must be a compromise between other parameters, spent electrolyte acidity and power efficiency, which also impact upon plant performance. The effect of various impurities has also been monitored and antimony, nickel and tin have been shown to be deliterious to current efficiency.

Jan 1, 1989

Computer simulation of the control systems for the heavy media coal washing process have been presented in this paper. The simulation model applies the Simulink module of the Matlab 5.1 software package and allows monitoring of variations of a

Jan 1, 1998

The developments in hydrocyclone classification in the milling circuit at Bougainville Copper Limited are discussed. A major change in cyclone size and improve- ments in operating conditions have been made. Test work has been carried out to assess the classification performance of a modified Linatex cyclone, Wemco cyclones and a two stage cycloning circuit. The use of a scalping cyclone, to remove coarse material from the present overflow product for regrind, has also been investigated.

Jan 1, 1978

By Balks AI

Systematic roof bolting in Australian coal mines began at Elrington Colliery in 19)49. Since that time the proportion of the roof supported by roof bolts has increased until, in 1970, 1.5 million were installed in Australian coal mines. This rapid growth of roof bolting has meant that the range and variety of roof bolting machines has altered also. The-number of machines now available both to bore holes and place roof bolts has increased. to the point where both rotary and per- cussive machines are used extensively. Generally, until the last four years, roof bolting machinery in Australia followed the practices in vogue in the United States. However, in -recent time the particular problems of Australian coal mining have necessitated the development of equipment primarily suitable to Australian conditions.

Jan 1, 1971

Geological models for the exploration and evaluation of epithermal Au and porphyry Cu-Au deposits rely upon a classification of different deposit styles and an understanding of the evolutionary processes of deposit formation. These models guide the interpretation of subsurface deposit anatomy in order to target drill testing and assist the explorationist to focus on the more prospective projects. It is important for the explorationist to distinguish between different styles of magmatic arc Au deposits as each style displays distinctive characteristics with exploration implications. Magmatic arc Au deposits are distinguished as porphyry Cu-Au formed at depths of 1 - 2 km at the apophysis to larger, buried, magmatic sources which are also the ultimate metal sources for the varying styles of shallower level epithermal Au deposits. Low sulfidation epithermal Au deposits characteristically develop from dilute circulating meteoric waters and are distinguished as the group with a closer relationship to intrusive source rocks, and slightly higher sulfide contents (still generally

Jan 1, 2004

By Butters S. E, Deslandes J. V

The selection of loading and haulage equipment in a proposed or oper- ating mine is vital in ensuring the cost effective achievement of produc- tion targets. To assist in the evaluation of different haulage systems, a truck haulage simulation model has been developed at BHP Melbourne Research Laboratories. The operation of the model is described and exam- ples of an actual application at Mt. Whaleback Mine is presented.

Jan 1, 1989

By Gardner CE

Uranium occurrences and the probable Australian reserves are discussed and the recovery and processing methods used in treatment plants at Radium Hill and Port Pirie, S.A., Rum Jungle and Moline, N.T., and Mary Kathleen, Qid. are reviewed. The broad aspects of the application of nuclear power in Australia are then considered, and those factors of greatest significance are highlighted. It is these factors that are most likely to dictate the future role of nuclear generation in Australia. In commenting on private industry applications, the paper emphasises that each case must be considered on its own merits, and a warning is given that general statements can be misleading. In the long-term situation nuclear power is considered to be capable of playing a leading role and the discussion covers desalination and high load industries although short term applications appear difficult to justify. In non-power applications for nuclear energy reference is made to isotopes and the uses of nuclear devices in mining and civil engineering with a pertinent comment on safety.

Jan 1, 1970

Taiwan is situated between Ryukyu and the Philippines with 35,960 sq. km of area, being slightly larger than Belgium It has roughly a spindle-shaped outline with a longitudinal axis extending in a roughly north-south direction. Geologically, Taiwan is extremely complex in terms of its tectonic setting in the convergence zone between the Asian continent and the Philippine Sea Plate. To the east of Taiwan, the Philippine Sea Plate subducts beneath the Ryukyu island arc, and to the south of Taiwan the Philippine Sea Plate overrides the Asian plate along the Manila Trench. Taiwan, therefore, occupies an unstable region between these two well-defined subduction systems of opposite polarity (see the following block diagram).

Jan 1, 1987

By Geoff Baldwin

The use of monitors to assess equipment performance is carried out on a routine basis in many industries. The benefits gained through process control in knowing exactly how the equipment is working far outweigh the initial capital costs of the monitor. In the mining industry several dragline monitors have been developed and installed on equipment through out the world, but to date none has been fully accepted by the industry. This paper describes the use of a sophisticated monitoring system which incorporates an onboard processor to assess both dragline and blast performance. The results of a case study are presented and an indication of the potential of the monitoring system to optimise mine production is given.

Jan 1, 1990

A Devonian metallogenic province is extended northwards from central Queen- -sland to the Burdekin Basin in the Charters Towers Gold and Mineral Field. Devonian sediments of the Burdekin Basin are intruded by mineralised quartz felspar porphyry which occurs as pebbles in Upper Devonian conglomerate. A mineralised volcanic complex lies on the crest of an anticline in Devonian sediments.Red siltstone is slurried and reduced to pyritic hornfels over folded limestone.A thick wedge of volcanogenic conglomerate overlain by marine shale lies on the mineralised rim of an ocean which suffered cataclysmic changes during Late Devonian times.

Jan 1, 1987

By Sturgul J. R

The South Middleback Ranges (SMR) operation involves the develop- ment of iron ore resources at the Iron Duke mine in the South Middle- back Ranges to replace the Iron Baron mine whose reserves are nearing depletion. The Iron Duke mine will be developed by contract to the stage where it can continue operation at full production when Iron Baron is closed. As part of the mine planning of the operation a GPSS computer simulation model was written to determine equipment requirements. The model simulated the operation of the mine with trucks transporting ore and waste to the appropriate destinations and producing a blended product in the stockpiles. A loader and two trucks would transport ore from the stockpiles to the crusher for one shift per day. The simulation shut the operation down at crib, morning tea, shift change and weekends, and also on the third shift each day. It also modelled operating delays. The results gave equipment operating hours and total output of each material type. The model was modified to produce different outputs from the mine and could be used to determine the most productive shift arrangement.

Jan 1, 1989

In 1976, The Zinc Corporation Limited Broken Hill set up a plant to re-process a hill of tailing (Mt. Keast) from the original treatment operations. With the likely disappearance of this source of feed in 1985, an investigation was initiated to determine what other feed sources might be available. This involved searching through old records and photographs as well as a subsequent drilling campaign. The paper briefly covers the history of treatment operations and describes, as a result of the information obtained, the likely future sources of feed.

Jan 1, 1983

By Teague JK, Read HW

The relationship between the maceral composition of coal and the strength of the coke produced from that coal has received a great deal of attention in recent years. Studies using two Bulli Seam coals, and blends of Bulli and Wongawilli Seam coals, from the Illawarra Measures of the Southern Coalfield of New South Wales were carried out. The optimum range of vitrinite was found to lie between 45% and 60% (mineral matter free). Above and below this vitrinite range coke strength deteriorated. I Coke strength indices increased with rank and the optimum vitrinite content increased with an increase in rank. These changes will require confirmation as trends by testing a third level of rank. It was noted that vitrinite content decreased with an increase in the specific gravity of separation of the coal. . T Use of- petrographic analyses will increase confidence in choosing coals for coking, provided the coals are well known. Such analyses offer the possibility of greater flexibility in coal purchases and the possibility of producing a marketable blend from coals, which have limited market potential. Critical base coals for blends can be conserved. Significantly more work is required before coal reserves can be utilised to optimum advantage. This work would require extension of-the studies discussed in this paper and, in particular, the testing of a wider range of rank.

Jan 1, 1970

By Campain RA, Horner NJ, Limerick JM

The review covers the different concepts of automation which are appropriate to non-ferrous smelting and the degree to which the smelter, and the furnace in particular, is amenable to total automation. Due to the problems peculiar to a smelter, it is unlikely that a fully closed loop system could ever be achieved and that the smelter will continue to depend upon extended manual control supported by computer based information sorting and optimisation.Generally, loop control is performed using Taylor's Mod III process control system. For distinct plant systems involving a combination of process loops, sequencing, and data acquisition, the company has developed its own microprocessor based systems. Process optimisation using computer based analysis of operating data is well established. Utilising this data, computer modelling provides manual set point supervision for the furnace process control system.The impact of automation on the workforce and on operating costs is also examined. Predictions on future developments in the field of automation, optimisation and sequencing are propounded and related to the non-ferrous industry at large.

Jan 1, 1985