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By M Ujihira, M Komazaki, K Higuchi, D F

A diesel engine with a misfiring cylinder is likely to break down in a short time when the engine is used without maintenance. The authors have developed a method of detecting the occurrence of cylinder misfiring and specifying the misfiring cylinder by using wavelet analysis and statistical analysis on the root mean square (r.m.s.) values of two kinds of acceleration waveforms. This detection method is considered superior to traditional methods, which require several accelerometers, especially in terms of simplicity. Since the development of the method, research has been conducted on semi-automatic processing of measured signals and signal transmission from the worksite to a remote office. Field tests confirmed that 1 + 105 points of dynamic data could be transmitted through the mobile multimedia network within 15 minutes, and the time for signal processing was within 15 minutes. Final determination on the condition of a diesel engine in heavy machinery could be achieved within 30 minutes. Shortened processing time is expected by improvement of the processing software.

Jan 1, 2003

By Rankin W. J

Increasing concern with the emission of sulphur dioxide from smelters and roasters has caused renewed interest in processes which can use waste sulphur dioxide, such as the sulphation of nickel laterite ores. The process described here proposes to by-pass the production of sulphuric acid and react laterite directly with a sulphur dioxide containing atmosphere. A thermodynamic analysis identified operating windows in which nickel sulphate forms while iron oxide (the major impurity in most laterite ores) remains stable. The initial assumptions included unit activity of all species except nickel oxide. The lowest possible nickel oxide activity (while maintaining selectivity) increased with increasing temperature, indicating that selective sulphation is favoured by low temperatures. The temperature of interest was found to be between 500 and 800¦C. Calculations show that a feed gas containing ten per cent SO2, five per cent 02, balance N2 requires a temperature greater than 650¦C for selective sulphation of nickel. Laboratory experiments showed that the assumption of unit activity of ferric sulphate was unrealistic above about 680¦C due most likely to the formation of solid solutions which decreased the ferric sulphate activity. Results are presented which illustrate the limiting equilibrium sulphur trioxide partial pressures at 700 and 730¦C below which selective sulphation occurs. Cobalt extraction was usually between 80 and 95 per cent under conditions yielding selective sulphation, whilst nickel extraction was about 50 to 75 per cent depending on temperature and choice of upper limit of iron extraction. An operating diagram is presented for a limonite ore and shows that the optimum reaction conditions are 680¦C and an input gas containing 20 per cent SO2. Under these conditions nickel, cobalt and iron extractions are 73, 95 and two per cent respectively.

Jan 1, 1996

Epicentres of recent shallow earthquakes in the region (3-12¦S, 126-150`E) were plotted to identify the various plate boundaries in the region, in particular the southernmost one marking the northern edge of the Australian plate. New and published fault plane solutions were examined to determine the style of faulting and state of stress along the Australian plate boundary. From east to west the boundary is first a subduction zone along the Solomon Islands, then a spreading centre across the Solomon Sea, a zone of compression and left lateral strike slip along the Papua Peninsula, almost pure thrusting across the centre of New Guinea and lastly left lateral strike silo through Irian Taya to the outer Banda Arc. The principal stress is very consistent, trending NW to NNW in a near horizontal plane, from the triple junction of the Pacific, Solomon Sea and Australian plates in the east to the Banda Sea in the west. Only along southern Solomon Sea plate margin which is a divergent boundary, is the stress different in type and direction.

Jan 1, 1987

The Australian gold industry has in recent years experienced a tremendous growth period, though not to levels prevailing at the turn of the century. There are, however, a number of dynamic factors at play which collectively indicate that it would be unwise to assume that this growth will be maintained; indeed the future discovery of viable new deposits may be insufficient to prevent an industry decline in Australia.The higher gold prices of the 1980's together with technological advances, made previously worked mining centres areas of excellent prospectivity. These resources, signposted for us by the oldtimers, are being rapidly depleted. Whilst there can be no doubt that these resources can be replaced the real question is whether it is economic to explore for new deposits when it is likely that:The cost of future exploration will increase as exploration must focus on grassroot areas with few signposts. Almost by definition this primary exploration effort will be subject to a lower success ratio.The cost of future exploration will increase as new deposits will be located in more remote areas and at depth.

Jan 1, 1986

Carbonatites - igneous carbonate-silicate rocks - host the world's major resources for niobium, phosphorous and REE (rare earth elements).Carbonatites represent the least common products of mantle and igneous processes and their emplacement is principally controlled by lithospheric domes and rift structures. Intrusive carbonatites frequently comprise carbonate-amphibole-apatite-pyrocWore assemblages, occur as plugs, cores, dykes, sills sheets, veins, pipes and irregular bodies, are gecichemically anomalous (Ba, Ca, Cl, F, Hf, Mg, Nb, P, REE, S, Sc, SO4, Sri Tb, Ti, D, V, Zr), are associated with alkaline silica-undersaturated igneous rocks forming carbonatite complexes, and display large, intensive alteration haloes. Also carbonatites are similar to limestones, prone to weathering, and may form thick laterite profiles.Magmatic ores (pyrocWore, apatite, bastnaesite, monazite, magnetite, baddeleyite, phlogopite, fluorite, calcite) and weathering related residual and supergene ores (pyrochlore, apatite, magnetite, anatase, vermiculite) are currently being mined on all continents except Australia. Australia is underexplored for carbonatite associated primary magmatic and especially residual-supergene ore deposits. Chances are very high for the finding of new carbonatite, occurrences and associated ores.

Jan 1, 1994

Violarite, (Ni,Fe) 3+x S4, is a ubiquitous secondary mineral in the supergene alteration zones of massive nickel sulphide deposits in Western Australia. It is formed by the pseudo- morphous replacement of pentlandite, pyrrhotite and/or millerite, and retains the textures typical of these precursors. Although the composition of the first-formed violarite is related to that of its precursor, supergene enrichment results in an increasing nickel:iron ratio toward the top of the supergene profile. In pentlandite-pyrrhotite ore, the replacement of pentlandite by violarite releases some nickel, which is consumed by the partial conversion of the pyrrhotite to iron-rich violarite. In pentlandite-millerite ore, on the other hand, the pentlandite, on conversion to violarite, appears to release excess iron that participates in the partial conversion of millerite to nickel- rich violarite. The characteristic textures exhibited by the secondary violarite and its replacement products in supergene and gossanitic deposits overlying massive nickel sulphide ores generally enable the original mineralogical compositions of the primary ores to be inferred.

Jan 1, 1973

By A G. Dempster, N Barnett, J Oh, S Saydam

NASA’s Artemis III mission is expected to return astronauts to the surface to explore and sample the lunar volatiles by 2026. These volatiles are anticipated to provide scientific insights as to how the Moon was created and economic value to off-Earth operations. These same volatiles can pose health implications to astronauts and Earth based personnel handling lunar regolith samples. Using Australian, USA and NASA airborne contaminant exposure limits and the Lunar CRater Observation and Sensing Satellite (LCROSS) measurements of lunar volatiles in the Cabeus crater ejecta, the minimum mass of lunar regolith that can be safely handled by humans on Earth and in spacecraft can be calculated. This analysis determined a 0.15 grams pure sample of Cabeus crater regolith within a cubic metre of air has enough volatiles to exceed safe working conditions, and 14.9 grams of pure Cabeus crater regolith per cubic metre of air can impact human life. The intent of this analysis is to assist safe handling and exposure calculations for the safe handling procedures of lunar regolith containing volatiles.

Sep 1, 2024

Intermontane valleys form unusual features of compressive mountain belts both in the sharp topographic break they represent and in the strike-slip displacements often associated with the valleys. Such strike-slip motion seems hard to reconcile in the actively deforming Andes where reconstructions have indicated nearly perpendicular Cenozoic plate convergence. Detailed study of a part of the Argentine Andes between latitude 31-33¦S suggests that, although strike-slip displacements may have largely created a prominent intermontane valley system, no Holocene strike-slip displacements are observed amid the relatively active compressional deformation along the mountain belt flanks. New plate reconstructions, treating the Nazca plate as two microplates separated by fractures along the Nazca Ridge, predict large components of strike-slip motion between the South American and Nazca Plates for the period from 10 to 5 Ma. These reconstructed plate motions are consistent with strains derived from recent kinematic analyses of minor faults along the southeast margin of the Puna plateau and the general timing of tectonic phases in the Andes.

Jan 1, 1987

By F Sahlström, E M. Jolis, V R Troll, E Jonsson, K Högdahl, C Harris

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Bastnäs-type magnetite-skarn-hosted rare earth element (REE) mineralisations are located in the Palaeoproterozoic Bergslagen ore province, central Sweden, and occur along a ca 100 km long belt of 1.90–1.87 Ga metavolcanosedimentary rocks. Ten different Bastnäs-type deposits have been sampled in order to assess the origin of ore-forming fluids in these systems. Magnetite and quartz have d18O values ranging from -2.3 to +1.1‰ and +7.2 to +8.3‰ respectively. Mineralised carbonates have d18O values between +5.8 and +7.2‰ and d13C values between -5.4 and -3.3‰. Temperature calculations based on the O-isotope composition of mineral pairs, combined with available fluid inclusion data, suggest primary mineralisation at ca 650–400°C. For these temperatures, calculated equilibrium fluids have d18O values that range from those typical of magmatic fluids (+6 to +8‰) to lower values (down to +3‰). Variation in carbonate O and C isotope data are consistent with interaction between local Palaeoproterozoic carbonate rocks (d18O = +12.5 to +19.6‰ and d13C = -1.8 to +1.7‰) and fluids of a magmatic origin. It is suggested that the Bastnäs-type REE-magnetite mineralisations formed as a result of reactions between local carbonate units and high-temperature, magmatic-dominated hydrothermal fluids during 1.90–1.87 Ga (Svecofennian) syn-volcanic activity.CITATION:Sahlström, F, Jonsson, E, Högdahl, K, Harris, C, Troll, V R and Jolis, E M, 2015. O and C isotope study of Bastnäs-type rare earth element mineralisation, Bergslagen, Sweden, in Proceedings PACRIM 2015 Congress, pp 439–444 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Since 1865 when Congress moved to create a Federal Mining Bureau, successive legislations have given rise to the current '!Federal Coal Mine Health and Safety Act, 1969. Coal beds from 22 feet to 20 feet thick are mined under covers from 50 to 2800 feet with full and partial pillar recovery equally popular and accounting for a total of 54% of the mines. Pillar recovery and roof support practices vary, and each operator must submit an overall roof control plan (within specific guidelines) for approval before undertaking any development. The guidelines relate to dimensions of openings, details of support, sequence of extraction, limits of extraction and caving details. Experienced and professional staff of M.E.S.A. provide roof control plans and make inspections and grant-approvals of principles of support and minimum support in pillar extraction, with provision for modifications with time. Guidance is given with training programmes and standards of supervision. All of these aspects are approached in the spirit of the Congress declaration that the first priority and concern must be the health and safety of the miner.

Jan 1, 1974

Interest in mineral sand mining in the south west corner of Western Australia began in the late 1940's and significant production commenced in 1956. Early land use conflicts arose because of conservation implications (Ludlow tuart forest), expanded to include post-mining rehabilitation requirements (the Wonnerup mine near Busselton) and today include some agricultural/mining disputes. These latter conflicts are largely caused by the need for mining companies to secure longer-term reserves. To date, deposits containing mineral valued at A$440 million have been sterilized and are unlikely to become available in the future. There is additional pressure being placed on presently available reserves and a pessimistic picture could be drawn, whereby the southwest mineral sands industry ceases to exist by the year 2010. However, sensible land use planning, the support of policticians and the community, and responsible attitudes towards compensation and rehabilitation could, in combination, see the industry maintain significant mineral output until the middle of the 21st century. Examples of deposits sterilized by adverse land use will be given.

Jan 1, 1986

By Bilbrey J. H

Land utitized duxting the past 45 yeans by the mining industty in the United States con all puxpos ez to tal4 neatly 4 million sexes. Ob this axes, 13 pexeent is used bon dL4posal ob bLne -sized mtinexal wastes dL4eaxded by one milling plants. These wastes, especi- ally the inactive taLeLng4 ponds, xequixe some type ob stabULzation to pxevent aix and watex pollution. Because these tailings ponds axe locat- ed undex wideey vaxyting etLmctLe conditions and thetix physical and chemi- cal ehaxactexti5tLes axe not constant, many methods have been developed by the Fedexal Buxeau ob Mines and oXhex inve4- ttigatoxs box 4tabLtLzLng taLtLngs. This papex detfnea.e4 the magnitude ob the pxoblemz associated with the xeelametLon ob milling plant wastes and discusses the vaxtious methods that have been developed and used. Data bxom selected Buxeau o4 Mines taboxato&y xeseaxch pxojects and a s.abAJLzetLon field txtial axe pxesen.ed.

Jan 1, 1976

By Biswas AK, Hayes P

During the reduction of iron oxide pellets in the blast furnace it has been found that catastrophic swelling (up to 300% volume increase) can occur. Although the burden preparation conditions can be designed to avoid this phenomenon the exact reason and mechanism of the swelling has yet to be clearly identified. Swelling of the burden is undesirable since it reduces the interparticulate voidage in the blast furnace thus reducing gas flow through the stack resulting in low production rates of iron. The present study differs significantly from previous experiments in that reduction is carried out on single crystals of wustite thus the problems of control of gas composition and specimen preparation are minimised. The microstructures formed on reduction have been examined by optical and scanning microscopy. Pure wustite and wustite doped with various levels of CaO have been examined after reduction in controlled CO-CO 2 gas mixtures at 968¦C. The catastrophic swelling on reduction coincides with the formation of an unusually open iron structure in which the iron appears as whiskers or needles as previously reported. The spacing and thickness of the needles are shown to vary with impurity content and gas composition. Metallographic examination has shown in addition, however, that the whiskers do not necessarily constitute the only product form of the iron produced and in CaO containing wustites with less than - 2% CaO there is a transition from needle growth to porous growth of iron. Thus the % swelling of the oxide particles is dependent on the initial size of the oxide grains. Samples of FeO - 10% CaO exhibited a previously unreported product inorphology associated with the nucleation of 2CaO.Fe203.

Jan 1, 1980

We operate a 50 cubic metre per hour mobile alluvial tin mine on small scattered deposits in the Irvinebank area. Wash is loaded by a Cat. 950 front end loader into the bin of a screening section and screen undersize is pumped to a separate jig unit. Both units are rubber tyre mounted and are shifted once a month when the haul distance gets to about 150 metres. The shift takes about 8 hours.The screening section is sited close to the face with a ramp for dumping in and a one metre drop for the screen oversize which is removed by the loader.A reciprocating plate feeder with variable rate hydraulic drive, feeds wash onto a horizontal 1.2 metre x 2.2 metre two deck Kinergy screen. Minus 10 millimetre undersize is pumped by a Warman 6/4 sand pump with a 37 kW variable speed Reeves Motordrive to the jig unit.The jigs are placed 20 to 70 metres away so that tailings will run back into previously mined ground. Reject stone is used to impound the sand and mud, allowing the water to filter through and return to the feed water pump.An MTE trapezoidal module is used as a primary jig. Hutch product is pumped to an eight cell clean-up jig which we developed ourselves along MTE lines. It has a trapezoidal shape and sawtooth stroke provided by cams. Clean tin is taken from the first four spigots. These consist of clear plastic tubes fitted with taps so that there is no water loss except when the tin is drawn off. Fine concentrate from the last four spigots is put over a curvilinear table which sits on a steel base packed with earth.

Jan 1, 1986

Mine dewatering has long been a problem with mines and some of the shallowest mines have the biggest problems. Machinery was developed by the ancients for raising water by rope buckets with treadmills or by horse whim. From the 1700's on into the early part of this century, massive cornish pumps or equivalent were the vogue powered by steam. One Australian mine pumping system was claimed to be the largest in the world just after the turn of the century. It was installed at Beaconsfield in Tasmania and the mine, like so many other mines of the period, were beaten by problems and cost associated with mine dewatering. The owners of that mine are looking at the feasibility of dewatering using surface drilled wells. Much simpler and smaller pumps are the order now and it is feasible to use boreholes instead of shafts to contain the pumps or else to use the holes to convey discharge waters to the surface from pumps located in drives or stopes.

Jan 1, 1988

By N F. Glenn, S Thiruchittampalam, B P. Banerjee, S Raval

The determination of shear strength parameters for the spoil material plays a crucial role in the assessment of a dump’s stability; nevertheless, their evaluation necessitates laborious laboratory experiments. In order to address this issue, Simmons and McManus (2004) formulated a framework that serves as a foundation for categorising spoils according to their distinctive shear strength parameters based on observable and tactile characteristics. This framework, previously identified as the ‘BHP Mitsubishi Alliance Coal (BMAC) Spoil Shear Strength Framework’, is now recognised as the ‘CoalSpoil’ framework. The spoil characterisation provided by the CoalSpoil framework offers benefits but is not without limitations. The examination of these attributes in the field is a time-consuming task that demands expertise. Subjectivity arises in the spoil characterisation when attributes straddle the line between two categories, such as delineating matrix-supported and framework-supported fabric structures. To enhance consistency in the spoil characterisation process, minimising human intervention is crucial to mitigate bias, classification errors, and safety risks. This study seeks to achieve this aim by introducing image-assisted and automated methods for spoil characterisation.

Sep 1, 2024

By Tapponnier P

In North Vietnam, large ductile shear zones are observed along the Red river fault and the Dienbien fault. Left-lateral sense of the Red river shear zone is related to the direction of shortening E-W. NE dipping foliation planes is subvertical. Stretching lineation is subhorizontal ( 25¦). Left-lateral slip observed in the Oligocene Yansun granites demonstrates the major tectonic phase in Neogene, The stress field established from microfaults observed in triassic limestones, Oligocene granites and Neogene Conglomerates. Measurements of striations on fault mirors are used for calculating the stress tensor and for separating tectonic phases. Two tectonic phases in tertiary are separated : first tectonic phase related to the compressive direction E-W corresponds to the major tectonic phase represented by NW left-lateral shear zone. Second phase having the compressive direction N-S associated with the right-lateral movement of the Red-river fault zone opening of the Eastern sea and the Red-river and the Red-river delta is associated with the left-lateral movement along the Red-river.

Jan 1, 1990

Dynamic shocks, which occur in mine hoisting systems have been measured by various investigators over the past 30 years. In 1966 the most intensive analytical investigations were being planned in Bochum, Germany, where equipment then was being constructed to measure the power generated in any particular dynamic shock. Between 1953 and 1956, in Broken Hill, N.S.W., accelerations of the shaft conveyances were measured and analysed. The "effective mass" of the conveyances at the time of the shock was then and still is considered as indeterminate and not easily measured. It is believed that probable peak forces can be determined by the product of the static mass and the accelerations. The subsequent problem of the elimination of the dynamic shocks becomes one of possibly increasing the frequency and thus reducing the amplitude, after identifying and evaluating the shock generators. In addition, judicious use of the clearance between the shaft conveyance and the guide, as a zone in which to absorb vibrations, is a factor which has been overlooked in earlier investigations on This topic.

Jan 1, 1971

The sampling of a run-of-mine (ROM) ore with the objective of controlling the fundamental variance associated with the sampling step is a poorly understood subject. Finding the effective sampling constant by repetitive sampling to establish the variance between nominally identical subsamples of a given mass of the ore is a laborious, time-consuming and very expensive exercise. In this paper, the run-of-mine ore is modelled using three components: ore, waste, and relatively fine material which shows significant liberation of the mineral phase(s) carrying the target analyte. The expression for the sampling constant of the mixture is developed from first principles. The form of the equation provides insight into the factors that are important in controlling the magnitude of the sampling constant and hence the fundamental uncertainty associated with a given mass of sample. The controlling factors are shown to be the size distribution of the ore/waste mixture, the proportion of waste mixed with the ore and the extent of liberation and the size distribution of the liberated material in the finer fractions.

Jan 1, 2008

By Sijing Cai, Chengpu Zhou

The requirement of mineral resources is increasing as the economy is continually increasing in China. The mining practices of various complex sulphide deposits and precious metal deposits, and the treatment of mine tailings and other industrial solid wastes, have greatly improved fill quality in the metal mines. From early-1980s, high density slurry fill, paste fill of total tailings, low density slurry fill with addition of silicate gelling agent, etc has been studied and applied, and some progress has been achieved. Today, mine tailings, slag and power plant ash are widely used as fill materials in mining. A number of cemented fill mines equipped with large capacity trackless mining machines are in production. Recently, The 3rd Chinese National Symposium on Mining with Backfill, 1995 has been held, the progress of fill technology in mines has been exchanged and summarised. In the paper, some aspects of fill technology used in the metal mines of China are briefly introduced and some applications of fill research work are presented.

Jan 1, 1998