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By Blair JR

The tunnel alignments investigated for the Gosford Regional Sewerage Scheme are located in the Terrigal Formation and are covered for most of their length by a thick blanket of soil and weathered rock. The following techniques were found to be most effective in geotechnical investigations for tunnelling in this area: air-photo interpretation, seismic surveys to pinpoint drilling targets, in-situ measurements of strength,deformation modulus and permeability in cored holes, and the construction of rock- mass models. Cross-hole seismic modulus measurements, surface resistivity soundings and electric well-logging techniques were found to have limited applicability due to adverse local conditions.

Jan 1, 1976

The mining, metallurgical, and petroleum industries can be viewed as financial or as social institutions or both. The differences between these two conceptions of their businesses will influence their environmental and social actions. During the next 10-20 years western industry will be subject to a drop in the growth of a more highly educated labour force and to the emergence of holistic economics, new national goals, and a new ecological perspective. The profitability of the mining industry may therefore be influenced by the human side of its business to a greater degree. The increas- ing human, social, and environmental responsibilities can be discharged by improving the miner's equip- ment; by learning to look at situations through the eyes of all those involved; by developing common `languages' which governments and the public can understand; and by mediating where feasible on the international scene.

Jan 1, 1978

By McNay L. M

Two field studies to monitor fill pres sures and vein-wall deformation were conducted in mines of the Coeur d'Alene mining district in Idaho. Both operations employed cut-and-fill mining techniques in nearly vertical veins aver- aging 10 feet in width, and backfilled with classified mill tailings. Hydraulic pressure cells were used to measure transverse, longitudinal, and vertical pressures within the backfilled stopes. Rock bolts extending into the manways and mechanical closure devices were used to monitor vein-wall convergence. Continuous recorders were used with selected pressure cells to prolong the life of the installation. Transverse pressures in excess of 600 psi and stope wall closure up to 22 inches were re- corded. Closure rates were higher at midheight of the stope than they were near either sill, indicating that the vein walls react similarly to a beam supported on each end.

Jan 1, 1973

This paper looks at the development in management education for engineers at the undergraduate level with particular reference to mining engineers. The management core content of the engineering degree course at Ballarat C.A.E. is described is some Detail.

Jan 1, 1986

By Teniswood CF, Sheppard I, Mason LG

An industry initiated project, sponsored by the National Energy Research Development and Demonstration Council, has worked for two years in developing design guidelines for underground coal mining machinery.Continuous miners and shuttle cars were selected for the initial development of design guidelines as these machines were linked with 7500 lost workdays and 490 reported injuries during the preceding two years.

Jan 1, 1991

By Fee DJ

Some four hundred million tonnes of low rank sub-bituminous coal occurs in four separ rate lobes at Leigh Creek. These deposits are in a sparsely populated pastoral area remote from industrial centres. Early development was retarded because of high mining and haul- age costs and the availability of other fuels. The search for additional fuels after the second world war led to thorough investigations into the burning characte-,istics of the coal and the discovery of shallow coal suitable for open out mining. The development of the field included the establishment of water supply, improved rail facilities and a town.

Jan 1, 1975

Giving the keynote address in the final session of a conference dealing with closely related topics has a disadvantage in that much of what can be said has been said. It also has an advantage, however, because it presents the speaker with the opportunity to integrate and analyse the material presented by the various speakers. I would like to look to the near future in Aust- ralia and the United States of America, to the risks, problem areas, and changes of a rapidly evolving post-industrial era-an era we are begin- ning to experience where industry no longer `calls the tune'. We miners have been quick to point out and emphasize, that ours is a `high-risk' industry in the world of business and commerce. Yet, clearly those who have survived, and been successful, have learned to anticipate and cope with risk and change. This ability has been a distinguishing feature of the industry's leaders who, in market studies and commodity selection, exploration and development, mine planning, metallurgical pro- cessing, and general administration and operation 1. identify areas of risk or inevitable change, 2. analyse, test and quantify those factors of risk or change, and 3. design methods, systems, equipment to elim- inate, moderate, or control or economically compensate for predicted risks or changes.

Jan 1, 1978

Selective open pit mining for gold has been in progress at Harbour Lights since the onset of mining in March 1985. Selective mining techniques used are similar to those in other recently opened gold mines in Western Australia. However certain practices have been introduced to accommodate the irregular distribution of mineralisation and comparatively high mill tonnage throughput. These include selective mining with large bucket excavators, sequential waste stripping - ore mining normal to the strike of the orebody and sample line preparation and ripping on bench floors. Application of these selective mining practices at Harbour Lights enables the operation to maintain delivery of approximately forty by 50-tonne truck loads of ore to the mill crusher everyday, with limited rehandling of material through ore stockpiles.

Jan 1, 1986

Although a small quantity of lc,;v viscosity index ' (L.V.I.) oils are presently manufactured in. Australia, lubricating oil refining methods are assuming gxeater significance since in 1964 Australia will be locally refining the bulk of its requirements and some companies may be exporting a surplus. New plants are ' planned to refine mainly high and medium viscosity index oils from imported crudes and the paper describes typical techniques used òto: produce. thes& oils. .

Jan 1, 1962

The north-eastern half of the Yilgarn Block of Archaean Rocks lies in the and zone of Western Australia. In recent years a large number of gold mines have been established there, all requiring water supplies from local groundwater. The groundwater sources that have been utilised canprise bedrock, pre-Quaternary channel deposits, and Quaternary alluvium. In the search for groundwater each type of occurrence is considered, and the choice is made on the supply potential and logistics. This paper deals with groundwater in bedrock. Using examples, sane principles of the geology of groundwater occurrence are illustrated.

Jan 1, 1988

Western Mining Corporation (W.M.C.) operates a nickel refinery at Kwinana, 30 km south of Perth. The refinery commenced pro- duction in May 1970, with a rated capacity of 15 000 tpa of nickel metal. A hydrometallurgical route was chosen as the most expedient way to produce nickel metal at a time when world demand for nickel was outstripping the supply. Later events dictated that an increase in production from the refinery be achieved. To this end, matte produced from Kalgoorlie Nickel Smelter, which was commissioned in 1972, was used in varying proportions as a complement to the concentrate initially utilised as input to the refinery. The effect of matte addition was to increase the capacity to 30 000 tonnes of nickel per annum. This was accompanied by other benefits which were 1. reduction in energy consumption per unit of nickel produced, 2. improved metal extraction, 3. improved precious metal recovery, 4. reduced production of ammonium sulphate by-product. Refinery operating results for the years 1970 to 1983 show how matte feed has improved refinery performance in these areas.

Jan 1, 1984

The problems arising in the excavation of hard rocks with the use of mechanical tools consist chiefly in a slow advance rate accompanied by an intensive wear due to the toughness and abrasiveness of the rock. In order to allow the further extension of mechanical excavation beyond the limits of the presently available technology, the assistance of waterjet aiming at improving the performance of the equipment while reducing the wear rate of the tools, has been recognised as one of the most interesting technical solutions. The paper illustrates the improvement of the performance of both disk cutters and picks obtained with the waterjet assistance at the Waterjet Laboratory of the University of Cagliari on a medium-hard rock.

Dec 6, 2010

By J Aitchison, G Clarke

A reappraisal of the stratigraphy, new regional kinematic analysis and thermobarometric data allow a new interpretation of the metamorphic zoning and tectonic structure of the Upper Eocene high-pressure metamorphic core complex of northernNew Caledonia allow a three steps evolution to be proposed: 1. subduction and understacking of previously thinned continental crust elements; 2. subduction blocking due to the crustal thickening; and 3. crustal thinning and extensional detachment during the diapir-like uplift and unroofing of the eclogitic core. Steps 2 and 3 may be partly contemporaneous. Such a model accounts for the thermobarometric and radiochronologic data, and also for the weakness of substratum deformation during the emplacement of the ophiolitic nappe

Jan 1, 1995

By Barclay C, Jacobsen M, Towsey C

The Emperor Gold mine at Vatukoula, Fiji, is a nine million ounce gold telluride deposit. In January 1992, the mine was on the verge of closure when the current management team took charge. Losses had been incurred for two consecutive years and the published resource amounted to less than five years of production. Relationships with the workforce, the government and the general public were poor. Today, the mine has recorded three consecutive years of profit, has resources that will support the operation for at least 20 years and has excellent relationships with employees, government and the general public.

Jan 1, 1997

For the last decade Australia has been the leading exporter of both steam and coking coal. In the ten-year period 1989 - 1998 steam coal exports increased by 93 per cent and metallurgical coal exports increased by 50 per cent. However, profitability of the steam coal sector has been disappointing. The coking coal sector, especially the hard coking coal segment, has fared better but its profitability was more because of its ability to maintain relatively high prices rather than its inherent productivity. Until quite recently the Australian coking coal sector was widely expected to be able to maintain this comfortable state without undue effort for the three major æpartnersÆ; the companies, the State Government and the unions. But coking coal could now be heading down the path followed by steam coal that ends with long-term over-supply and, despite steady improvements in productivity, poor profitability. Steam coal entered the ænewÆ era of long-term over-supply some years ago. Over-supply was due to the rapid increase in production in Indonesia, often from new mines and Australia. AustraliaÆs production rise was underlain by the apparent belief that the best way to lower costs was to increase production. In the first couple of years costs didnÆt fall much but the additional tonnage was sold at lower and lower prices into the spot market. By mid-1998 the difference between the contract price set with Japanese utilities and spot sales was often in excess of $US12 per tonne. Japanese contract prices and tonnages have since fallen significantly. Steam coal has moved from being a product to being a commodity. Any profits are due more to the low Australian dollar rather than inherent mine productivity. Seaborne coking coal trade has been dominated by Australia, Canada and the USA, with the USA becoming less competitive. Unfortunately, when the Queensland capacity expansion was well down the pipeline, the Asian financial crisis occurred and the Japanese economy entered what appears to be a long-term recession. Contract prices fell 18 per cent, tonnages decreased and some mines have been reclassified as supplying lower priced coking coal. The paper analyses past and expected future trends in labour and mine productivity, rail freight and FOB export port cash and total costs of the Australian steam coal and coking coal sectors and discusses the market outlook for Australia. The future economic viability of the industry is analysed and discussed in the light of the rapidly changing global environment.

Jan 1, 2000

Economies in cemented fill demand the utilisation of the full potential of the portland cement component of the mix. If declined tailings are used, it is desirable to establish the optimum particle size distribution. Pozzolic materials and slags are. very useful additions to increase the amount of cementitious material through reaction with calcium hydroxide produced by hydration of the cement. It is also essential to check out the presence of substances which may seriously affect the setting and hardening of the cement or the durability of the cement bond. The importance of quality control in the preparation of cemented fill cannot be over Emphasised.

Jan 1, 1973

By Goto T, Sato K, Mori N

A field investigation by making use of the seismic method has been carried out in order to comprehend the mechanism of rockburst and gas outburst and their predictive measures. The seismometers were so arranged both on the surface and underground as to enclose a mining panel. Seismic signals detected by the array were recorded and processed by the 32-kwords computer system. At present the system is available for analysing the source location and Richter's scale of each event and for visualizing the distribution of seismic foci and released energy at any mining stage. The magnitude distribution of events can be regarded as a comparable index of the seismic activities among mining panels. An analysis of the spatial density distribution of seismic energy in the mining panel can be useful to distinguish a highly stressed zone from stress released areas. The energy released curve or the rate of energy release determined from seismic data is also a good indication of the seismicity.

Jan 1, 1980

By Kellerwessel H, Oberheuser

Since its invention by Professor Klaus Schonert of the University of Clausthal, Germany, high pressure rolls comminution has attained near total acceptance as the preferred method of size reduction in the cement industry. Over 300 units have been manufactured worldwide. At locations where the system has been installed, considerable energy savings have been realised. These energy savings are generally in the range of 20 to 30 per cent compared to conventional ball mill circuits. However up to 50 per cent power saving has been achieved at some installations. This technology, with the exception of the diamond industry, has up to now had only limited success in ore processing. This has mainly been attributable to the abrasiveness of ores encountered in this industry leading to high wear rates. These high wear rates have given rise to an unacceptably short life time of the wear surface of the rolls, requiring regular replacement. A new wear surface has been developed which has shown to give a ten-fold increase in service life over conventional surfaces. This, together with developments made in machine design now give the units the ability to attain the high availabilities demanded by the mining industry, and therefore to allow this industry to achieve the considerable operating cost savings offered by the high pressure rolls.

Jan 1, 1992

Pasminco is actively addressing the optimal utilisation of the known orebody at the Broken Hill mine, in addition to actively exploring for economic mineralisation in the region. As part of the policy of better utilising the known mineralisation a major upgrade of geological systems at the mine was initiated. The software chosen for this change was Maptek's Vulcan, mainly because of the ease of use of this package. Rather than having numerous data sources in varying software packages the mine aimed to limit interfaces and packages. The decision to upgrade the mine's software was not taken lightly, especially in view of the inature stage of Broken Hill mining operations. However, the current mine life of Pasminco Broken Hill mine is I I years, which is longer than many new mines setting up in Australia today. Also, a more sophisticated system brings with it a better understanding of the economic mineralisation, possibly extending the mine life further. The process of moving the Broken Hill databases into Vulcan was a huge task which included, database transfer, digitising, wire framing, modelling and eventually ore resource calculation. To ensure the validity of the new ore resource accounting system, the existing system was run as a duplicate for the introductory year, providing a comparison and if necessary a safety net. The benefits of such a change, however, became apparent almost immediately. Area geologists realised the opportunity to revise geological interpretations in their areas of responsibility, enabling them to obtain a better understanding of orebody morphology. Three- diniensional analysis provides an excellent method by which review of ore targets both in the underground and mine lease exploration areas can he made. As each new find of mineralisation enters the system and hopefully extends the mine life, the opportunities for further mineral exploration in Broken Hill area by Pasminco are enhanced.

Jan 1, 1997

The original design of the Bougainville Copper Limited (BCL) concentrator took cognisance of the constraints imposed by the topography, the need to minimise capital cost, and the need to allow for plant expansion which, it was known, would be necessary to maintain copper and gold production as head grades declined.At the same time as spare slots have been taken up with additional equipment, technological innovations have been embraced whenever there appeared to be a chance of improving the productivity ofexisting equipment, or replacing it with a more efficient alternative.There are many examples of this in the BCL concentrator in the areas of process control, process design, instrumentation, materials handling, equipment design and wear part technology.Current process developments also pursue the latest technology. The development of the Omnicone crusher, flotation control, tailings water reclamation, and the variable speed gearless drive on the No. 13 mill are prime examples.

Jan 1, 1986