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By Shining Z

The strength and deformation of more than two hundred coal samples have been tested in the condition of triaxial compression. The regression equation showing the relationship between coal strength and pressure in the pores, as well as confining pressure, was obtained. The appropriate calculation for stress-strain curve was carried out. Further, an analysis shows the variation of coal strength and its modulus of elasticity in methane medium.

Jan 1, 1992

By Kelly GD

Prior to 1986, users of satellite based remotely sensed data were almost exclusively reliant on the United States Landsat series of satellites to monitor our Earth's resources. This situation changed when France, Belgium and Sweden launched SPOT-1 in 1986. The year of 1988 saw the Japanese also enter into the earth resource satellite business. The Japanese launched an earth resource monitoring satellite with an emphasis on marine resources, hence the name MOS-1 (Marine Observation Satellite). Many more remote sensing instruments are planned for launch by these nations and others in the next 10 years.

Jan 1, 1990

By Riel RG

Nickel and cobalt mineralisation at the Murrin Murrin deposits, in the North Eastern Goldfields region of Western Australia, occurs within laterites developed on Archaean serpentinised peridotite units. Lateritic weathering of the peridotite has produced a resource of 116.8 Mt at 1.10 per cent Ni and 0.082 per cent Co (resource at May 1996 with a 0.8 per cent Ni cut-off; see Fazakerley and Monti, this volume). The mineralogy of the Murrin Murrin laterites was investigated to identify the minerals hosting significant Ni mineralisation. Laterite profiles were studied using X-ray Diffraction (XRD), impregnated polished thin sections, and Energy Dispersive Spectroscopy (EDS) Electron Microprobe analysis, of RC percussion drill chips. This paper summarises the results of these studies, and briefly discusses the nature of the minerals hosting Ni mineralisation.

Jan 1, 1996

By Baafi EY

Deposits of gold, silver and other precious metals often display a high variability of grade values, usually a very low average metal content and are frequently not easy to sample reliably. The characteristics, together with the volatility of precious metal prices, make evaluations of precious metal deposits extremely difficult to make. Geostatistical estimation techniques can be used to make grade estimates of precious metals and to assess the reliability of these estimates. Two case studies are presented.

Jan 1, 1987

The Mungana group of mines, in the Chillagoe district, yielded 334,000 tons of ore giving 31,831 tons of lead, 7,907 tons of copper and 3,228,600 ounces of silver. The Girofla mine produced approximately 220,000 tons of ore, and with the Lady J ane mine supplied most of the ore from this centre. The deposit was discovered in 1888, but active development did not commence from the main shaft until 1898. A subsidiary of the New Chillagoe Railway and Mining Co. Ltd., the Mungana (Chillagoe) Mining Co. Ltd., worked the mine from 1902 until 1914, selling copper, copper-lead, lead ores and fluxes to the smelters at Chillagoe. The smelters stopped operations in 1914 when the richer ores of the Girofla had been worked out and production from the Lady Jane had ceased due to heavyground and fire. The Girofla shaft was 823ft. deep with a cross-cut at 810ft. At the 710ft. level contour drives had delineated the orebody, which had been stoped about 10ft. above the level. Except for flux ores which had been stoped only for favourable smelter tariffs, the orebody was practically exhausted above the 610ft. leveL Under company ownership the mine yielded 139,265 tons of an average grade of 4.QlYr copper, 16.2% lead and 12.5 oz. per ton silver.In 1921 the Queensland Government re-opened the mine and worked it until 1927. The North Lode (Fig. 2) was discovered almost immediately at the 100ft. level and was worked down to the 410ft. leveL The ore from this branch and the completion of the stope at the 710ft. level yielded about 80,000 tons of ore averaging 0.4 copper, 9.8 lead and 7.8 oz. per ton silver during this period.

Jan 1, 1953

Throughout 1992 Pasminco conducted field trials of the Mobile Miner MM130 at Broken Hill. The goal was to develop the machine to achieve acceptable reliability and establish production rates.

Jan 1, 1993

British Coal has always been a big mining company and its management has been beset with many of the problems one would associate with such an undertaking. These include its accountability to Government, its market vulnerability to competing fuels and to imported coal and its relationship with its workforce but also with its own history and size. As a fragmented private industry up to and including the Second World War, it was starved of capital and its management developed an historic relationship with its workforce which was often counter productive to success. Once nationalised, it contributed greatly to post-war industrial regeneration, investment was forthcoming to reconstruct existing mines, sink new ones and to mechanise production operations. British manufacturing companies contributed to this mechanisation drive, the very success of which drove up production and productivity and against a declining market, contributed to the reduction in size of the industry. Production machinery design evolved in the 1960s with close collaboration between manufacturers and users such that an inevitable proliferation of machinery types and specifications developed to meet local needs. Longwall mining internationally outside Western Europe only became significant in the 1970s. It became apparent that international operators demanded higher levels of plant performance from British manufacturers than British Coal did. This was the birth of the "heavy duty" plant concept. As international performances outstripped our own then British Coal moved in to invest in itself, in this heavy duty. This re-investment commenced in the mid 1970s but only gained real momentum in the 1980s when it became a virtual re-equipping exercise for the whole industry.

Jan 1, 1988

By Ritchie IC

Spiral separators have been used to treat heavy mineral sands in Australia for some thirty-five years. They were used as the primary treatment method until the advent of the Reichert cone, which largely replaced them, due to its compact design and relative ease of operation. Spirals continued-to be used as the final cleaning stage before dry separation of the heavy minerals as they remained the most efficient separator for this purpose.

Jan 1, 1986

By Neville WE, Parkinson J

One of the earliest recorded risk management schemes was implemented by the boatmen of the Yangtze river some 4,000 years ago.. Between them they arranged for shipments to be split up in such a way that a load was divided five ways: if one was lost, then 80% of the shipment got through. Bottomry contracts were in vogue in Babylonian times with similar systems being used in India, in 60OBC and 4th century Greece. One of the first accepted mutual insurance ideas came in 1835 when a mill owner in America negotiated a lower insurance premium in return for installed fire safety measures. Approximately 20 years ago risk management as a philosophy was developed in the U.S.A., the philosophy followed to England and hence to Australia about 10 years ago. The business climate which induced the philosophy of risk management was that of "tight money". The definition of "assets" was then broadened to include earning capacity, skilled personnel and in a negative sense, a corporation's liabilities. In more affluent days losses were comfortably absorbed into the ongoing business expenses, the more prudent managers took out insurance which "covered everything" at a suitable premium. Statistics are available to indicate that a high percentage, (over 60%) of businesses which suffer massive plant damage due to fire, do not restart operations, or in the event of restarting have closed operations within the next 2 to 3 years - in spite of collecting an insurance payout.

Jan 1, 1986

By D A. Kepert, D Clark

During early 2004, Fortescue Metals Group (FMG) began an aggressive exploration and drilling program in the Chichester Range, targeting iron enrichment developed in the Nammuldi Member at the base of the Marra Mamba Iron Formation. The timely recognition by FMG of distinct zones of (hypogene) microplaty hematite (mplH) enrichment overprinted by extensive supergene mineralisation led to an early reappraisal of the geological history of the area and characterisation of the possible structural and stratigraphic controls on mineralisation. Regionally, the Chichester Range dips gently at less than 5¦ to the south, however, detailed mapping shows that this regional limb is overprinted by low amplitude, long wavelength, north/south to northeast/southwest trending folds. The locations of major structures in the Marra Mamba Iron Formation, combined with spectral analysis of known mineralisation, allowed extrapolation and prioritisation of exploration target areas. The delineation under cover and understanding of these structures was enhanced by detailed airborne magnetic data. Recognition that supergene mineralisation was associated with a palaeotopography that continued significantly under cover to the south under sediments of the Fortescue River valley led to the discovery of extensive supergene mineralisation together with additional mplH mineralisation. A model for the landscape evolution and preservation of enriched Nammuldi Member was generated in order to help communicate both the complexities involved with targeting drill holes beneath cover and the potential limits to the lateral extents of mineralisation.

Jan 1, 2005

This short paper outlines the authorÆs views regarding the progress we have made as an industry in managing mining assets over the past 500 years. It represents a personal view û but one founded in fact-based observations of mining companies and of the mining industry in general. There is no doubt that AgricolaÆs views as expressed in De Re Metallica (1556) were visionary. There is also little doubt regarding another issue û that whilst a great deal has been learnt about the management of mines since AgricolaÆs time, observations suggest that best practice management is the exception rather than the rule across our industry. Although insights regarding the successful management of mines have become apparent, we still witness unnecessary errors in our industry that lead to the loss of shareholdersÆ funds. By highlighting some aspects of current best practice, particularly in the arena of operations management, it is hoped that this short paper contributes a small step along the next 500-year-long learning curve. The paper concludes with a brief description of the progress and impact of continuous improvement initiatives at Kalgoorlie Consolidated Gold Mines (KCGM). Located in the Kalgoorlie Goldfields, KCGM is currently AustraliaÆs largest gold mine producing over 800 000 ounces of gold per annum. Improvement initiatives at KCGM look set to deliver some $100 million in value over life-of-mine.

Jan 1, 2004

By P Mason, J F. Huntington, K M. Scott

Short-wave infrared (SWIR) spectral reflectance of the hydrothermally altered volcanic rocks in the footwall of the Hellyer Zn-Pb massive sulfide deposit was measured with a portable PIMATM infrared spectrometer. The Al-OH absorption band was used to derive information on the cation composition of white mica. The wavelength range of the Al-OH band from 2194 nm to 2222 nm reflects variation in the number of octahedral Al (Alvi) in white mica from 3.9 to 3.2 (based on four octahedral cations per formula). This Alvi range indicates a substantial compositional variation, covering most of the compositional region between muscovite (Alvi = 4.0) and phengite (Alvi = 3.0). Moreover, the spectral reflectance data show that the compositional variations of white mica are spatially related to the hydrothermal alteration zoning, such that the white mica of more phengitic composition tends to form in the main upflow fluid channels in the centre of the footwall alteration system. The results suggest that the octahedral Al content of white mica, which is spectrally definable by the wavelength of the Al-OH band using a field instrument such as the PIMATM, can be used to map fossil hydrothermal systems and potentially as vectors to mineralisation.

Jan 1, 2004

Thank you for asking me to address you. The topic may sound formidable. Those of you with determination to go somewhere in your careers will understand that by taking geoscience, mining and metallurgy courses as students, you are declaring your intere

Jan 1, 1994

By Sparrow G. J

In a recently completed AMIRA project, 20 samples were searched for gold mineralisation using the automated location facility (ALF) for rare phases on a scanning electron microscope in the CSIRO Division of Mineral Products, Melbourne. The samples were submitted by mining companies in Australia, and Papua New Guinea, and included crushed ore samples, cyclone overflow and underflow products, a flotation concentrate, and 12 tailing samples. Their gold contents ranged from 600 to 0.2 g/t An. Native gold and gold minerals including a gold telluride, gold-silver tellurides, and a gold bismuth mineral, were located in the samples as free grains and associated with other minerals such as pyrite, magnetite, hematite, ankerite, copper sulphides, silicate minerals, and quartz. In the highest grade samples, both micron sized and 200 ¦m grains of gold were found with ALF. It would be difficult to locate such d wide size range of gold in a manual search. Gold mineralisation was located in the tailing samples assaying 0.4 g/t An and higher. In several tailing samples coarse grains of native gold over 40 p.m in size were located. One grain was estimated to have contributed 40 per cent of the gold in the sample. As well as locating gold mineralisation, the ALF examination resulted in the identification of uranium, mercury, and bismuth minerals in the samples. Knowledge of the distribution of these minerals in processing streams could be important in the operation of a concentrator.

Jan 1, 1992

By S Coughlan

"A personal account of my journey from a student from suburban Melbourne in the 1970s through 40 odd years in and around the mining industry including the important events that have moulded my thinking and, as result, have formed the guiding principles of the mining contracting business and related entities that make up the Byrnecut Group. On reflection the game of chance has played a big part in the journey, from the selection of initial study based on my parents financial capability and the one and only offer of early employment by Western Mining Corporation where the formative phase of my career took place in what was the vibrant can do environment that existed in Kambalda in the 1970s and early 1980s. Subsequently the unplanned meeting with Frank Lubbock drawing me back to Kalgoorlie from Fiji in 1987 and the resultant formation of a private mining contracting business, the excitement of the mid 1980s Kalgoorlie mining environment followed by the turmoil of the 1987 stock market crash where business survival was the game, resulting in a relationship with the German based Thyssen Group.Thereafter the development of a large privately owned international multifaceted mining services group and the principles behind that growth. These include: development of strategic personnel and retention of those personnel cashflow management and debt within a private company scenario recognising opportunity for synergetic growth but insisting on market forces driving those business elements, as opposed to internal divisions group-wide sustainable business systems, particularly in relation to leading safety and training processes innovation and renewal to provide the elusive advantage in a competitive market the role of entrepreneurial small businesses in development of technology.The above principles combine to make a margin in a cut throat contracting environment, competing on the world stage against other contractors and owner mining options.CITATION:Coughlan, S, 2014. A miner’s journey, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

By Forssberg E

This paper presents the experimental results on the effects of slurry Theology on ultra-fine grinding by a stirred ball mill. The amount of dispersant, slurry density and the particle size were selected as the parameters. The viscosity of dolomite-water slurry was measured by rotational viscometers. It was found that by adding enough dispersant, the effect of particle size from 1 to 10 pm on the slurry theology could be eliminated, but a strong effect of slurry density (tested for a range of 65 to 75 wt per cent) remained. The use of dispersant transformed the slurry from Bingham plastic flow to dilatant flow, which reduced the yield stress to zero, but increased the viscosity at higher shear rates. During the milling process, the viscosity was stable. The yield stress, however, increased suddenly from zero after a certain milling time. The mill operation stopped at the point where the yield stress increased due to poor slurry fluidity. The milling efficiency was found to be higher at a lower amount of dispersant addition or a lower slurry density within the experimental limits.

Jan 1, 1993

Hong Kong continues to display a remarkable enthusiasm for undertaking ambitious tunnelling schemes despite apparent recessions in the Asian economy. This paper provides an outline of tunnel projects currently under construction, those recently tendered and a glimpse of the extent of forthcoming projects which, according to Government sources, carry a price tag of HK$ 200B. Committed works will cost about HK$ 15B and involve a variety of TBM and drill and blast tunnels. These include the recently tendered works for KCRCÆs West Rail and MTRCÆs Tseung Kwan O railway extension, together with five no retendered TBM drives for the Strategic Sewage Disposal Scheme (SSDS) following forfeiture of the works by the Campenon Bernard-Maeda JV in mid-1997. The JV claimed unreasonable specifications leading to unacceptable levels of water inflow and dangerous working conditions. Key technical issues that are now arising in Hong Kong are:the general use of design and build contracts for bored tunnel contracts;a trend to accept TBM options for relatively short drives in urban areas;the use of æfixed-priceÆ contracts which in the current competitive market, can encourage tenderers to take contractors to take very high risks; andthe difficulty of predicting and managing water inflows in rock tunnels.This paper also includes a new empirical method of predicting water inflows in rock tunnels, and makes recommendations for managing these on-site.

Jan 1, 1999

By Lawson F

Chrome chemicals are commercially produced by the alkali roasting of the chrome-bearing ore chromite with sodium carbonate. In order to ascertain the influence on the extent of reaction of the replacement of Mg(II) for Fe(II) in the chromite spinel structure and the presence of acidic oxides in the gangue material, a series of roasting experiments was conducted using chromite materials from a number of different locations. The roast feeds and products were chemically analysed and the major compounds identified using X-ray diffraction and scanning electron microscope techniques.Mg(II) replacement for Fe(II) in the chromite structure does not appear to restrict the amount of "available" chromium for reaction.Under the test conditions, namely an atmosphere of pure oxygen, finely ground chrome-bearing material, a roast temperature of 950°C and the stoichiometric amount of sodium carbonate to react with the chromite, the yield of water-soluble sodium chromate was able to be expressed as %yield = 104.5 -1.58 × %AI2O3 - 2.23 × %SiO2 for chromite samples containing alumina in the range 7.8 to 27.8 per cent and silica in the range 2.9 to 7.4 per cent.

Jan 1, 1984

A saturated, metal-free solution of alum can be used as a fiocculant to speed up the sampling procedure during a geochemical survey of stream silts.

Jan 1, 1969

The radiolarian biostratigraphy of the western part of the Gympie Province, north of Brisbane, has been examined. This part of the province comprises mainly the Amamoor beds and the Gympie Group, which have been assigned Permian ages on the basis of localised marine macrofossils. This study has shown that the Amamoor beds and the Gympie Group include older strata than previously supposed.The Amamoor beds consist of at least two tectonic units, namely a melange unit (unit A) and a well stratified sequence of sedimentary rocks (unit B). The former unit, regarded as an accretionary subduction complex, contains chert blocks ranging from Late Devonian to Earliest Carboniferous, while the latter unit yields Permian radiolarians. Latest Devonian to Earliest Carboniferous bedded cherts occur in sequence previously mapped as Amamoor beds and Gympie Group.

Jan 1, 1990