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Some 800 analyses for Cu, Zn, Pb, Ag, Fe, S, CaO, MgO, C02, Si02 and Al203 were used to examine the elemental constitution of the Mount Isa ores, and, for comparison, those of the Northern Leases area.Lead: zinc relations show little order from sample to sample, but means of large zones (Le. individual orebodies) show a highly linear inverse relationship. Lead: silver ratios are fairly constant from sample to sample, and means show a highly linear direct relationship.Sulphide sulphur appears to be related to carbonate and alumina abundance, sulphur decreasing systematically with increase in the ratio CO2:AI203. In all graphs involving members of the group CO2-A203-S the lead-zinc and copper ores conform to the same simple trends, confirming that the two ore types and their host rocks are genetically closely related. The earlier deduction of a volcanic-sedimentary origin for the sulphides of the Black Star orebodies appears compatible with present findings.On the basis of such an origin, the pattern of sulphide occurrence and mineralogy in the Mount Isa district is possibly related to the configuration f the upper surface of the "Eastern Creek Volcanics", the facies patterns of the overlying sedimentary rocks, and to the oldest faults affecting the two.INTRODUCTIONStanton (1962) described and interpreted the chemical constitution of the Black Star No. 2 lead-zinc and the 650750 copper orebodies at Mount Isa. The investigation has now been extended to the other principal orebodies of the area.The earlier study showed that the host rocks of the two adjacent Black Star orebodies were constitutionally closely related, and suggested that this was probably due to their original formation in contiguous zones of sedimentation. On this basis the silica-dolomite of the copper ore appeared to represent the slightly more shoreward, "limey" member, probably a fairly massive algal calcareous sediment laid...

Jan 1, 1963

By Wilson D, Kirkland J

Compressed air energy storage (CAES) uses low cost off-peak energy to compress air and pump it into pressurised underground storage. Expanding the air through a modified form of gas turbine generates electrical energy when required. While generating power, a CAES station consumes approximately one-third of the gas required for the equivalent installed capacity of a conventional gas turbine. Air can be stored in underground rock caverns, caverns in salt domes, or in aquifers. Existing CAES power stations use caverns mined out of salt domes. Aquifer storage for CAES has been proposed, but not yet implemented. The groundwater in the aquifer would be displaced during air injection and when required the air would be extracted using the natural hydro-static pressure. Victoria has no salt domes, but has aquifers onshore in the Gippsland Basin with geological dome structures of suitable depth, discovery pressure, porosity, permeability and caprock for CAES development. Field tests costing several million dollars would be required to prove the suitability. The most suitable aquifer is near Seaspray, where several dome structures exist. The aquifer, comprising of coarse sands capped by coal and mudstone, is some 600 metres deep with a hydrostatic pressure of 6.3 MPa. Computer simulation of injection and extraction of air from the aquifer under various combinations of horizontal and vertical wells, permeability and tubing head pressures indicated the largest aquifer structure had the capacity to sustain a 300 MW station. A well field comprising of 24 directionally driven wells with a horizontal exposure to the aquifer would achieve the air flow rates required. Using plant similar to that recently installed at McIntosh Alabama USA, would mean high capital costs compared to standard gas turbine plant. However, a review of modem gas turbines indicated that they could be easily and economically adaptated to CAES duty. Adapting a 120 MW gas turbine would give 344 MW output. A separate air compression plant would be used. Economic evaluations indicate that, for gas prices above $1.95 per GJ, a 344 MW CAES plant is more economic for intermediate/reserve load duty than simple cycle gas turbines.

Jan 1, 1992

By K L. Brown, J L. Mauk

Sulfide-rich scale occurs in steam and water lines at the Ohaaki geothennal field,Taupo Volcanic Zone, New Zealand. Precious metals show very high concentrations around areas ofpressure reduction (Au 15500 ppm, Ag 68800 ppm). Pyrrhotite dominates at the orifice plate due to low PH2s1PH2 conditions. Sulfide mineralogy in the scales is consistent with alteration mineralogy of the reservoir rocks. Separated steam then produces a mainly pyrite/magnetite mineralogy, with lesser chalcopyrite, where textures reflect high flow rates and high levels of supersaturation. This study outlines the effect that pressure and subsequent temperature decreases have on the mineralogy, chemistry and textures of sulfide scales.

Jan 1, 1998

By Larkin F, Farrer E, McGhie R. R

The Electrolytic Zinc Company of Australasia Limited commenced productive operations during February, 1936, at the- Rosebery and Hercules mines, which are situated near Rosebery, Tasmania. At this time it was decided that before re-organizing the steel sharpening shop a test should be made of the relative merits of conventional drill-steel and detachable bits. For this purpose Ingersoll-Rand type"I" thread centre hole.jackbits were selected and seventy-two of these were tested against conventional steel. Results indicated that, under the conditions pertaining at these mines, j ackbits should prove more economical than conventional drill-steel bits, and that a large-scale test, under working conditions, should be made. This was done by gradually replacing conventional drill-steel with jackbits at the Rosebery mine. Results were satisfactory and by the end of 1936 both mines were using only the jackbits.

Jan 1, 1939

By Ross R

Although mining is an old industry its management is quite a new science, and its complications are now being recognised as demanding expert knowledge in many branches of technical and professional education. Not the least amongst these isaccountancy, for probably its most important problem is "How to control the expenditure." Unlike most businesses a mining company stands almost entirely in the light of a purchaser in the world's markets, and not as a seller, except say for product so the established and perfected systems of modern industries cannot be adopted for mining purposes. For this reason it has been left for late years to consider the matter seriously, and now a number of well-managed concerns have devised costs systems to suit their own requirements.Very little, however, has been published and even that is disjoined and difficult to make use of. Some of the costs systems in vogue, although elaborate and imposing, are not of very great value for keeping check on wasteful expenditure, or for displaying the commercial effect brought about 'by any particular change in practice, or by an addition or alteration to a portion of existing plant.

Jan 1, 1912

By M Lentz

This paper will discuss the issues associated with blasting in an urban mining environment that have been addressed by Winstone Aggregates at the Mt Wellington Quarry. These issues include - control of vibration and air overpressure, repeatability of shot performance, fragmentation on an extremely low maximum instantaneous charge, compliance with Territorial Authority regulations and perception. Over the last two years, in order to address these issues, Winstone Aggregates have undertaken a programme of continuous improvement, which has included; ò implementation of new technology; ò revising site procedures; ò conducting an investigation into the structural response of local buildings; ò investigating safe extrapolation; ò extensive public consultation; ò establishing credibility during the consent process; ò identification of perception issues; and ò building relationships and trust with neighbours. The issues addressed at the Mt Wellington Quarry have increasing significance for traditionally rural mining operations, as the input of the local community being urban or rural, increases. New and existing operations have the potential to adopt best practice now, building trust with the community and raising the profile of the industry.  

Jan 1, 1999

To optimise the haulage of the large tonnages produced from stopes in this high production gold mine, an ore pass and feeder system was introduced. This ore pass was designed and developed in 2006 and the plate feeder installed and commissioned soon after. Cavity Monitoring Surveys (CMS) have been undertaken of the ore pass since it was commissioned. The original thickness that was surveyed of the pillar between the ore pass and decline in 2006 was approximated to be 19 m. Throughout its use large blocks of rock were reporting at the plate feeder. This was the first indication that the ore pass was failing somewhere between the tipping level of the 9410 level and the plate feeder at the 9330. Even so CMS surveys were not taken systematically to firstly identify the area of failure or for monitoring. In August 2008 after implementing management systems, large blocks were still reporting to the plate feeder. The decision was made to empty the pass enough to carry out a CMS survey of the area. Subsequently it was discovered that the area of failure was between the decline and ore pass and that since the first survey the pillar thickness had been reduced to approximately 9.7 m. Further management controls were put in place to slow movement of the material and to limit the use of the 9410 tipping level, but this did not alleviate the rate of failure entirely. The results of an initial inelastic numerical model indicated that most of the pillar was damaged and that failure into the decline likely if no changes were made. The numerical modelling predicted that even if material was no longer passing through the ore pass interaction between the voids was unavoidable and would most likely result in instability. The ore pass and plate feeder are an integral part of the haulage system for the remaining life-of-mnie. Two solutions were sought to firstly reinforce and stabilise the pillar between the ore pass and decline and secondly to rehabilitate the ore pass or find an alternate design that could still utilise the plate feeder. This paper summarises the analysis and resulting rehabilitation that was used to accomplish this.

Nov 25, 2010

By Innes J. A

The structural variations occurring in pellets of finely divided mixtures of iron ore and coke breeze, metallized by firing at elevated temperatures, have been examined microscopically. For any given pellet composition, time and temperature are the two most important factors in determining the development of the bonding processes.INTRODUCTIONThe success of sintering and pelletizing processes in the agglomeration of fine iron ores for blast furnace use has brought about rapid changes in thinking relative to methods of preparing furnace burdens. Increases in productivity with the use of sinter emphasize the advantages of a stable, uniformly sized furnace feed. Current practice is to produce a self-fluxing sinter containing most of the lime requirements of the furnace incorporated as a stable medium (Figgis and Charker, 1962). The elimination of fine material from the burden allows greater stack permeability and smoother operation.Sintering and pelletizing of iron ores with or without the incorporation of fluxing compounds has conditioned operators to the extent that it is now considered possible that all components of the burden may eventually be beneficiated in one form or another. Investigations are in hand to improve the quality and sizing of coke, which occupies the major part of the burden volume (Callcott, Innes and Brown, 1961; Innes, Gregory and Worner, 1963). Interest is also being revived in methods of pre-reducing iron ores prior to charging to the furnace (Hansen, Melcher and Fine, 1961). Recent experiments in a small experimental blast furnace (Melcher, 1963) show that charging of semi-metallized pellets can give rise to a production increase of 55 per cent...

Jan 1, 1963

By Schlanger H. P

A theoretical model for gas outbursts in underground coal mines is as follows. An outburst is the structural failure ofcoal due to excess stress resulting from body forces caused by gas pressure gradients. These body forces influence the stability of a mine face in the same manner that gravitational body forces affect the stability of the roof of a mine. The magnitude ofthese body forces can be appreciated when it is realized that for an average density coal, the gravitational body force is equal in magnitude to the force from a gas flow with a pressure gradient of 14 kPa m-I. Gas pressure gradients and the resultant stresses within a seam can be calculated with numerical methods. Thus, providing the necessary parameters can be measured or estimated, in principle the theory can be applied to compare the outburst risk of various mining arrangements.

Jan 1, 1985

Marble deposits of dolomitic variety are available in large quantities in India and for extracting these deposits diamond wire saw cutting machine is mainly used. Cutting performance of the diamond wire saw machine depends on rock parameters, machine parameters and operational parameters. Rock parameters related to physico-mechanical properties, such as, compressive strength, tensile strength, shear strength, modulus of elasticity and abrasion resistance of marble play role in determining cutting rate and beads wear rate. Thus, this study was undertaken to determine the relationship between different physico-mechanical properties and cutting performance. This work also aimed at enhancing the cutting performance of diamond wire saw in dolomitic marble deposit. Study was conducted in the field at three different zones having deposit of soft, medium hard and hard dolomitic marble. During the study, cutting rates and wearing of diamond beads were recorded in the field. Physico-mechanical properties were determined in the laboratory. The results obtained were subsequently evaluated by using statistical analysis. Study revealed that these properties of marble play a significant role in the performance of diamond wire saw machine. Predictive equations for the wearing of diamond beads and cutting rate were developed based on regression models. Results of this study will be of ample use for operators of wire saw to achieve maximum cutting performance and for manufacturers in designing the diamond beads.

Dec 6, 2010

The Golden Cross mine commenced production in December 1991. Both open pit and underground mines produce 1000 tonnes of ore per day. Mining techniques are discussed along with results and variations to proposed methods of extracting the ore.

Jan 1, 1992

By Y Ren

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Aug 12, 2013

By Graylin R. K, dea T. R, O&apos

The Wolgan Seam of the Upper Permian IlIawarra Coal Measures of the Western Coalfield of New South Wales consists of high volatile, low sulphur, medium hard coking coal with high fluidity. This seam, 1·8-2·4m thick, in the Wolgan area, dips gently at 1°_20 ENE and lies at 160-440m below the deeply dissected surface of the western margin of the Blue Mountains plateau.A detailed study of the deposit has revealed that the Wolgan Seam consists of four main coal plies separated by three distinct stone bands. Each of these subunits is lenticular and displays individual physical, chemical and mineralogical characteristics which exhibit distinct spatial distribution patterns across the area. Most noticeable is the presence of long linear ESE-trending zones of low ash - high volatiles - high fixed carbon - high fluidity which delineate the major distributary pattern within the deltaic environment of coal formation.This seam contains some of the highest fluidity coal in the world.The Wolgan area, close to the western margin of the Sydney Basin, is characterized by:I. a regional, closely spaced, homogenous joint fracture pattern dominated by an orthogonal pair set trending 3400 and 0700, to which the face- and butt-cleat directions respectively of the Wolgan Seam are sub-parallel, and2. a more widely spaced, heterogenous, cross-cutting pattern of regional structural fractures. Zones of bad roof conditions are probably associated with these lineaments which are subvertical and trend in three majordirections, viz., 005°,035° and 115°.

Jan 1, 1980

Much attention in controlling blast vibrations has been centred on the probability of causing damage to structures in the area adjacent to where blasting is carried out. In most cases these structures are residential properties and the effect of the vibrations on the occupiers has not been studied to any great extent. This paper looks at the sources of disturbance caused by blasting and their psychological effect. A comparison of ground vibration levels for compliance is examined within the framework of structural and human response.

Jan 1, 1998

Since its inception in 1962, the Julius Kruttschnitt Mineral Research Centre has adopted the view that an effective method of training highly qualified engineers for the mineral industry is the pursuit of postgraduate research programmes conducted in operations, that is, in the mines and processing plants of the industry which the research serves. The paper describes how this is achieved in practice, at little or no cost to the taxpayer, and explores the strengths and weaknesses of this approach in the context of a dual mission for the Centre: 1. The postgraduate training of engineers for the mineral industry. 2. The production of useful R &I) for the mineral industry. Topics discussed include financing, relationships with industry and Government, the maintenance of academic excellence, research style, the marketing of research, and limits to growth.

Jan 1, 1989

By J Ward, B Rohrlach, B Rosero, J Silva, O Poma

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Alpala copper-gold deposit is a recent, high-grade porphyry Cu-Au discovery located in the Imbabura Province of north-western Ecuador. The deposit lies along the crustal-scale Chimbo-Toachi Fault Zone within the Dagua-Piñon terrane, which is an oceanic plateau accreted to the South American convergent margin in the Late Cretaceous. The deposit is hosted by quartz diorite stocks that intrude andesitic volcanic breccias of the Oligocene to mid-Miocene San Juan de Lachas Formation. Miocene-age calc-alkaline plutonism is associated with porphyry Cu, Cu-Mo and Cu-Au deposits in southern and northern Ecuador. The Alpala deposit lies along a sector of the Miocene arc that has recently been underplated by the Carnegie Ridge seamount chain that induced shoaling of the subducted Nazca plate beneath northern Ecuador.Surface expressions of the deposit were recognised in May 2012 during follow-up of stream sediment anomalies, when outcropping sheeted and stockwork porphyry-related veins were discovered in Quebrada Alpala. The roots of a NW-trending, structurally-controlled lithocap were recognised over an area of 4.5 × 0.9 km. The remnant lithocap exhibits well-defined mineral zonation mapped by TerraSpecTM analyses on grid soil samples. Soil sampling, heliborne magnetic surveying and channel sampling defined initial drill targets.Seven diamond drill holes were completed in the year from September 2013. Drill hole CSD-13-005 intersected 672 m grading 0.93 per cent Cu and 0.91 g/t Au in high-temperature, inner propylitic and locally potassic-altered quartz diorite intrusions. Overlying hydrothermal clay alteration assemblages define the base of the lithocap. A NW–SE trending footwall structure defines the south-west margin of the deposit. Drill hole 5 intersected high-grade sheeted ‘B-type’ and ‘C-type’ veins (Gustafson and Hunt, 1975) that lie along the south-west margin of an 1100 × 500 m magnetic anomaly that is the focus of ongoing exploration.CITATION:Rohrlach, B, Poma, O, Rosero, B, Silva, J and Ward, J, 2015. High-grade porphyry copper-gold mineralisation in north-west Ecuador – The Alpala Cu-Au porphyry discovery , in Proceedings PACRIM 2015 Congress, pp 369–376 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Sheng-Hui X

This paper introduces a new coal-based rotary kiln process of DRI production - the CRIMM process, which is developed by Changsha Research Institute of Mining and Metallurgy in the past years. Its main features are the use of composite pellets (in rotary kiln). The process consists of preparation of pellets from iron concentrate and coating of coal on their surfaces. The new process is able to overcome a series of defects of the conventional coal-based rotary kiln processes. A continuous test was conducted using an experiment rotary kiln (-0.6;, x 3 m). TFe of the magnetic iron concentrate used in the test is 67.25 per cent. TFe of the product DRI is 88.54 per cent, MFe is 84.11 per cent, S and P are less than 0.02 per cent. The metallisation ratio of pellet is 95 per cent. The pellet power ratio is less than 0.3 per cent. The utilisation coefficient of rotary kiln is 1.3 t/m'-d. The overall recovery of iron concentrates is 99.7 per cent. Two small industrial plants using the CRIMM process are being set up in China. Their coal consumption can be decreased to 520 kg standard coal per ton DRI respectively.

Jan 1, 1999

By R Fury, I Skepper, D White, G Miller

Although the Pressure Acid Leaching (PAL) of nickel laterites has been conducted at Moa Bay, Cuba, since the early 1960s, the commissioning delays generally encountered by the æsecond generationÆ of PAL lateritic nickel producers in the late 1990s have demonstrated the potential complexity of the PAL process and the importance of technical risk management in maximising the realised project value. This paper describes some of the strategies used by the Ravensthorpe Nickel Project (RNP) to manage the technical aspects of the Ravensthorpe project risk. Central to these strategies is the use of Front End Loading (FEL) to deal with issues early in the development phase, when changes to the project structure can be made most effectively and cheaply. Such an approach requires a management philosophy that recognises risk as a potential cost, which accepts responsibility for dealing with risk, and which is prepared to provide adequate resources for risk management.

Jan 1, 2004

By Olliver J. G

Over 400,000 tonnes of kaolin, sillimanite, mica, kyanite, feldspar and rutile have been mined from the unique Williamstown orebodies since their discovery in the early 1900's. Numerous companies; both large and small were associated with the early development of these deposits but since the formation of Australian Industrial Minerals in 1947, this company has been the only significant producer. A combination of mining and management problems almost forced closure of the mine in the late 1970's but this was averted by a changed attitude towards mine planning. Mine development is now based on detailed geological and technical investigations, exploration for additional ore reserves is being conducted and laboratory and pilot scale studies are being undertaken to utilise both low grade ores and waste materials. The professional approach to mine and market development will ensure that Williamstown mineral products will continue to be available for many years.

Jan 1, 1989

East Otago gold deposits are hosted in Otago Schist that is the metamorphosed equivalent of Permian-Triassic Torlesse terrane greywackes. Relatively undeformed Torlesse sequences in Canterbury have <l m - 50 m bedding, with c. 500 m - l km and c. three kilometre scale units, typically either: 1) thick-bedded, massive, sandstones; 2) thin-bedded sandstone-argillite flysch; or 3) siltstone- or argillite-dominated units. Such lithological layering in Otago was intensely folded, deformed, and overprinted by metamorphic fabrics during Jurassic-Cretaceous regional metamorphism. Although primary sedimentary structures can no longer be recognised, a æghostÆ lithological variation is still present in Otago represented by psammitic (sand-derived), interlayered (sandstone-siltstone derived) and pelitic (siltstone-mudstone derived) schist. Lithological æunitsÆ in the schist are typically either 20 100 m or c.1 - 2 km thick, and are oblique to faults and shears hosting gold mineralisation at Macraes, Barewood, Nenthom, and Oturehua. Lithological variations and folds in lithological units are important in the along-strike distribution of gold in these deposits, and in the development of relatively high-grade pods and shoots at l00 m - 1.5 km scales. Ramps, flats and step-overs (known to be locally important for controlling mineralisation) are commonly located at lithological boundaries, presumably by local refraction of faults or shear zones as they propagated through folded stratigraphy. The various lithologies have also responded differently to deformation, causing variations in permeability that affected the penetration of mineralising fluids. Mapping lithological variations in barren host-rocks, either directly+ by fieldwork or indirectly by aerial geophysics, is a key to understanding and predicting the distribution of gold at mine and deposit scales.

Jan 1, 2001