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By Lin Bin, Qain Minggao, Qu Qundi, Yao Zhichang

This paper describes the application of a 89C52 chip microcomputer in hydraulic pressure information monitoring system of powered supports in a coal face, and the details of circuit and software of a monitoring system substation. Each substati

Jan 1, 1998

By Gole MJ

The Goodyear nickel prospect is located 45 km southeast of Kalgoorlie (31.04¦S, 121.80¦E) near the eastern boundary of Hampton Area - East Location 45 (Figure 1). Nickel mineralisation was discovered on the Goodyear prospect in March 1996 when a reverse circulation drillhole (GYC5), initially drilled in December 1995, was deepened to meet a minimum footwall penetration requirement of 20 in that had been set for the drill program. Approximately 3 in of sulphides averaging 4.9 per cent nickel was intersected from 296 metres down-hole, this being within 2 in of the first end-of-hole. Hole GYC5 was part of an eight hole drilling program undertaken by Titan Resources in late-1995. This program was designed to test whether nickel mineralisation in the Dunlop prospect, discovered by the Western Mining Corporation - BHP Camylia Joint Venture immediately east of the East Location 45 boundary, continued across the tenement boundary. The area targeted by the initial drill program had been explored by Western Mining Corporation in the mid-1980s using extensive surface sampling and a drilling program that included 17 RAB and percussion drillholes. None of these holes intersected nickel Mineralisation.\

Jan 1, 1996

Computers and other microprocessor technology lead the world of technological change. Nevertheless, the real advances in the world at large are not necessarily in the computer industry, but in the industries whose economics benefit most by the advances that this computer revolution makes possible. The minerals industry has always been in the forefront of this advance. Technological change in the era preceding the industrial revolution, and the mining industry's part in it, provides an instructive lesson for what is happening today. Strong parallels can be drawn for predicting future advances. With each technological advance allowing more efficient production comes a re-alignment of economics - absolute and relative changes to prices, to quantities demanded, and to other market characteristics. This re-alignment applies not only to the mineral industry, but also to the world at large. Adaptability, rather than technical advancement per se is the key to survival and growth in a changing world. 'Adaptability' as a concept is easy to support. As an operational philosophy it is not so easy to implement. As a goal for planning, it is much harder to quantify. A fixed scenario of a future world may provide helpful guidelines, but a scenario that demands adaptability to an uncertain future world is much less definite. Of course, everyone else in the world is also uncertain about the future, and they are making their plans using different assumptions. This virtually guarantees that our future will turn out different to our expectations. This is in part what Hayek (1945) calls the 'knowledge' problem. Until now, most of the planning and technical research undertaken in the world has ignored this problem. This ignorance is a luxury that we can no longer afford. The paper looks at the history of technological change and highlights the characteristics of successful technological revolutions. 'Adaptability' to unforeseen circumstances is the key to success in this environment. The paper examines the knowledge problem from the perspective of the mineral industry, and suggests a number of directions for maximising the returns from application of computer technology in this important area.

Jan 1, 1995

By Savory P. J

Uranium mining operations commenced at Ranger mine site, Jabiru NT Australia in May 1980. The Ranger orebodies, totalling approximately 110 000 tonnes contained U305 had been indicated by airborne radiometric survey in 1969 and confirmed by drilling the following year. Both diamond and percussion drilling methods were used to define the mineralisation and samples were analysed using a combination of radiometric and neutron activation techniques. Ore reserve estimates were calculated from conventional and geostatistical methods, and following the mining of 15 million tonnes of ore, reconciliations with before mining estimates are well within acceptable industry standards. In-pit grade control employs radiometric techniques including a radiometric truck discriminator built in Australia to mine specification to meet production requirements and improve productivity. Environmental requirements associated with uranium mining are a daily consideration.

Jan 1, 1993

By Hodkinson I, Teale GS

Mount Leyshon is an open cut-heap leaching operation that commenced production in early 1987. Open pit reserves are 6.3 m.t. grading 1.8 g/t Au and 4.8 g/t Ag and expected annual production is 68,000 oz. of gold. Gold mineralisation is hosted in breccias, porphyry plugs and basement rocks interpreted as the roots of a multi-phase Permian phreatomagmatic breccia complex. Mineralisation has the form of veins, cavity fillings and disseminations and is localised by late stage trachytic dikes and sills and dike-like bodies of milled breccia in the northwest corner of the complex. The sequence of mineralisation includes: I quartz-chalcopyrite-molybdenite stockwork veins and pyrite-gold veins with potassic alteration II quartz-chlorite-carbonate-basemetal sulphide-gold veins and cavity fillings with sericitic alteration III quartz-basemetal sulphide-bismuth-sulphide -electrum veins, veinlets and dissemin- ations with sericitic alteration. Mineralisation is interpreted to have formed at 500-300¦C from a predominantly magmatic hydrothermal system related to the porphyry intrusive bodies. Mount Leyshon is a phreatomagmatic breccia with a very different origin to the Kidston magmatic hydrothermal breccia. However the mineralisation style and origin is quite similar.

Jan 1, 1987

Mineral resource and ore reserve classification defines the risk associated with quoted resource tonnes and grades, allowing the interested party to make a judgement as to the `worth' of the resource statement. The JORC Code and Guidelines (1992) are now well entrenched as the foundation upon which gold and base metal deposits in particular are publicly reported. There are three categories of resource, namely Measured, Indicated or Inferred reflecting decreasing levels of confidence. The ore reserve, that is the economically mineable part of the resource, is classified as Proven or Probable and can only be drawn from the Measured and Indicated resource categories. As summarised by Stephenson (1995), resource/reserve classification has been an issue ever since the earliest days of mining in Australasia where, like elsewhere in the world, the industry, for a long time, lacked firm reporting guidelines. Those currently adopted in Australasia as the minimum standards for companies reporting to the Australian Stock Exchange (ASX) have been developed and revised since 1972 by The Australasian Institute of Mining and Metallurgy (The AusIMM), the Australian Institute of Geoscientists (AIG) and Australian Mining Industry Council (AMIC). Debate is now underway in terms of adopting an international code. The Code specifically does not attempt to regulate either the classification technique nor the method of estimation of the resource/ore reserve, but rather places the responsibility for this task on a `Competent Person' whose experience will decide the appropriate approach for a given commodity/orebody. The Competent Person must be a Corporate member of either The AusIMM or AIG with five years experience `relevant to the style of mineralisation' under consideration.

Jan 1, 1996

Total extraction is a misnomer and invariably some coal losses occur in the mining of pillars. "Fulls" pillar extraction is by the pocket and fender method, the splitting method or the open end method, with extraction in the pillar, and in rows of pillars in planned sequence, using combinations of coal and timber and roof-bolts for support. Where circumstances dictate, partial extraction is used, leaving behind portions of pillars in large blocks for support. The use of such extraction plans and supports as minimum guidelines has contributed greatly to safety in United States Coal Mines.

Jan 1, 1974

By McGill RA

The Ranger Uranium Mine is surrounded by a World Heritage National Park. The strict environmental controls under which the mine operates are based on scientific and social requirements. Release of non-process storm runoff water to the Magela Creek during flood discharge and under controlled conditions has been identified as Best Practicable Technology for the operation of the water management system. Social and political factors have limited this release to a wet season with an Annual Exceedance Probability of one in ten. The first-generation trigger mechanism was based on a percentile analysis of monthly rainfall. The second-generation trigger is based on cumulative monthly volume increase in the retention ponds and is considered to be more applicable to the operation of the mine water management system.

Jan 1, 1988

The need to schedule ore production to make maximum use of the strength gained by cem- ented fill during curing is discussed, to show how cement content and hence fill cost can be kept down for any particular operation. Results from laboratory testwork on Isa Mine fill conducted by the author while employed by Mount Isa Mines Limited form the basis of the Discussion

Jan 1, 1973

By Thompson IR, Solomons SS

Underground mining with the cut and fill method has been declining during the past decade or so, being replaced mostly by sublevel open stoping methods. During 1983 the Australian Mineral Industries Research Association Ltd. (AMIRA) commissioned a review of the method, with the aim of compiling the state-of-the-art, indicating future trends and recommending topics for research that would be needed to support this future mining. Mines using the cut and fill method in Australia and three other countries were visited to compile current practices and expected developments.Cut and fill is mostly used where geological and ground conditions are unsuitable for open or caving methods. These range from narrow, irregular orebodies to wide, massive orebodies where pillars are retained in ore. There is significant potential for improvement and further development of the method. It may then be used in a broader range of conditions and for orebodies that may not otherwise be viable to mine.

Jan 1, 1985

The calibrated thermal IR data of part of Cambay Basin is used to determine surface temperatures and to detect the heat flow. Applying the conductive heat flow continuation technique, the three dimensional configuration of the hydrocarbon bearing reservoir was defined. The zone delineated by the present study coincides with the oil-bearing structures inferred by seismic survey. The results indicate the possibility of the technique as an effective tool in hydrocarbon exploration.

Jan 1, 1986

Coal Mining Land Use on the southern coalfields often preceded other land uses. Over the past century overlying land use has altered significantly, particularly with water supply storage development, road system building, railways, pipelines, electricity reticulation schemes and general urban develop- ment. National Parks were declared over coal bearing lands. Little regard was paid to the coal under the land surface by land developers, Government instrumentalities, central planners and the Metropolitan Water, Sewerage and Drainage Board and others, and little value was placed on this valuable energy source. These bodies derived no benefit from the under- lying mineral. In these circumstances, mine operators and such surface land users were put into adversary roles. Mass sterilisation of coal resources resulted. The loss of reserves continues, although the problem has become better under- stood. An Energy Impact Statement (EIS) submission by all surface land developers has been proposed as a means to justify the impact of the development on the coal reserves Beneath.

Jan 1, 1979

The major copper orebody at Mount Isa is being extracted at a rate of four million tonnes per year. The method used requires an equivalent rate of back filling with (mainly) cemented fill. There were three major incentives for developing this mining system. The first was the prospect of high ultimate recovery of the orebody. The target is 100% recovery. Also the proposed stoping layout appeared to offer significant advantages in development and production costs. Finally, extensive subsidence above the northern end of the orebody could have disturbed permanent surface installations and jeopardised a possible future open cut. The full implications of this ambitious strategy were not apparent in the early years. Now, after twelve years of production the benefits are being realised and they can be weighed against the costs. Probably the most interesting result which comes from this analysis is the significance of cutoff grades and dilution factors in balancing mining and filling rates.

Jan 1, 1980

By James S. E

Financial risk of environmental problems is the key to many important business decisions within the mining industry. Massive uncertainty makes it difficult to choose a strategy for managing environmental problems to reduce corporate financial exposure to environmental impairment. A correct and practical method exists to clarify the risks and help make decisions. A case study on an insurance problem illustrates the method.The approach used is to translate existing data on environmental problems into probabilistic expressions of financial risk, and organise the expressions to reveal alternative solution strategies for the insurance problem.

Jan 1, 1993

By McGaffin I, Loah J

PT Newmont Minahasa Raya (PT NMR) is an Indonesian joint venture subsidiary of the Newmont Gold Company of Denver, Colorado, USA. PT Newmont Minahasa Raya operates a 700 000 tonne per annum gold plant in the Minahasa region of North Sulawesi, Indonesia. At full capacity the plant is expected to produce an average of 150 000 to 180 000 ounces of gold per year until the year 2007 based on current existing reserves.Exploration began in 1986 and high grade mineralisation was discovered in 1988. Subsequent drilling defined a resource of approximately 2000 000' ounces. Reserves as of 1 January 1997 were 7 035 000 tonnes grading 8.46 grams per tonne, for 1 913 000 contained ounces. Metallurgical testwork commenced in 1991. Construction of the plant started in late-1994 and the first gold was poured in March 1996.

Jan 1, 1997

The King River Power Development on the West Coast of Tasmania has involved the storage of the waters of the King River in the new Lake Burbury and their diversion through a 7 km tunnel to a 144 MW power station. The last kilometre of this tunnel descends through 160 m under a ridge before emerging from the bank of the King River at the power station site. The decreasing cover over the tunnel as it approaches the power station meant that a steel lining was required in the last few hundred metres of the tunnel. This paper describes the geotechnical investigations which were carried out to establish the necessary length of the steel lining.

Jan 1, 1993

By Finlayson E, Hilyard D, Francis G

Papua New Guinea's mainland is dominated by a foreland thrust belt, which can be divided into two zones. The "body" zone is floored by Palaeozoic granites and metamorphics of the Fly Platform (Tasman Orogen). Underlying the "tail" zone is Papuan Plateau, rifted from the Tasman Orogen during Coral Sea spreading, and believed to underlie the Papuan Peninsula and Papuan Islands region (D'Entrecasteaux, Woodlark, Misima, Sudest, and Rossel Islands). Thrusting began in the Miocene and continues today in the crust below the "body" zone. The youngest known thrusted rocks in the "tail" zone are Pliocene in age. Recognition of foreland thrusting has major implications for petroleum prospectivity of the Papuan and North New Guinea Basins, mineral exploration prospectivity, and geological terrane identification in PNG.

Jan 1, 1987

By Thornton D, Esterle J, La Rosa D

Control of blast fragmentation has a significant impact on coal mine profitability. Two approaches for the characterisation of coal blastability, particularly in terms of fines, are presented. Both approaches were implemented for the predictio

Jan 1, 1998

The effect of accurate detonator delay timing on blast results can now be studied with the development of the ICI Electronic Detonator. This detonator has an accuracy and precision orders of magnitude greater than the current range of pyrotechnic delay detonators. A series of field trials have been conducted to quantify the effect of delay accuracy and timing on blast performance. These trials have demon- strated that delay timing can have a marked influence on blast fragmen- tation, muckpile displacement, blast vibration and airblast.

Jan 1, 1989

By Takiuchi T, Kurita M, Owada S

This paper describes the possibility of the application of flotation to the separation of monazite from xenotime and of columbite from ferberite, which have been said to be difficult with generally used physical beneficiation methods. For Malaysian monazite and xenotime samples, a great difference is observed between the flotation recoveries at pH 7.5 using 1.0 x 10-4mol/1 dodecylammonium chloride (DAC). The grade and recovery of columbite in the binary flotation with both minerals result in 85 per cent and 67 per cent in the cleaning froth and 91 per cent and 51 per cent in the re-cleaning froth, without adding any scavenging stages. For monazite samples from various localities, the flotability is dominated by the electrostatic interaction between mineral surface and collector ion using DAC as collector, but the singular decrease of flotation is observed in the sample of which the crystallinity is low and the surface structure is rugged and complex. Otherwise, ferric ion in the flotation system probably dissolved from mineral is found to activate the flotation using sodium dodecylsulfate as collector. For columbite and ferberite, the separation is judged possible at pH 3.0 using 1.0 x 10'3mo1/l sodium oleate (NaOl) from the single flotation results of each mineral. In the binary flotation, however, columbite recovery in the froth is greatly diminished below that expected. This would be because NaOl is prevented from adsorbing on the columbite surface of which the charge is transformed more negative side by the specific adsorption of the tungstate ion dissolved from ferberite.

Jan 1, 1993