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By Harris R. W

Any defect activity resulting from an applied stimulus on a structure will generate a stress wave which travels in the medium under the laws of acoustics, thus the name of acoustic emission (AE). AE techniques can therefore provide information on the deformation of both surface and below ground structures. Two operating coal mines were monitored from the surface, and both mining activity and post mining microseismic activity were detected. The nature of the detected AE signals demonstrated that there were a range of deformation mechanisms in operation and that some predictive capabilities were possible with the Technique.

Jan 1, 1992

A Study on Process Mineralogy and Mineral Processing of Complex Carbon-Bearing Cu-Pb-Co-Ni Multi-Metal Sulfide Ore by Bulk Flotation

Sep 13, 2010

A review is presented of techniques cur- rently in use, or being developed, to enable the determination of virgin rock stress at consid- erable depth (> 1000 m) from small diameter sur- face drill holes (

Jan 1, 1975

By W R. Hancock

Control of complex machinery through the internet is investigated through the construction of a vehicle prototype developed using off-the- shelf hardware. The vehicle was able to be controlled remotely through the use of a client side interface connected to a steering wheel and foot pedals. By attaching sensors to the vehicle, data could be collected from which one could infer the effectiveness of such a control system. The effect of latency on control was monitored by the introduction of an artificial latency, simulating a wide variety of internet-related issues, such as unstable connections and dropouts. Sensor data could then be used to gain an understanding of how the system could be improved though either control or interface design. A path tracking experiment was conducted to gather controllability data and it was found that such a system is plausible within a reasonable range of latencies. It is expected an area of future research would be an extension of this current project, applying the information gained to real world control systems.

Jan 1, 2008

By Allchurch P. D

At Perseverance a reserve of 45 million tonnes at 2% Ni was indicated by drilling. Holes were drilled in trellis pattern on section lines 61m apart to assess shallow mineralization. To explore at depth holes were spaced 122m apart, collared vertically, then allowed to deflect under controlled drilling conditions. The mineralization may be divided into the three homogeneous classes of soarsely disseminated, heavily dissem- inated and massive sulphides. In the standardised sampling and assaying procedures used to assess the deposit, attention was always paid to these fundamental ore types. All sampling and assaying processes were continuously monitored by checks. Sampling and sample preparation errors were small, to judge from the differences between results of original and check samples. Assaying errors, determined from analyses made by independent laboratories using different methods, slightly exceeded sampling errors. Comparison of underground core, c'iannel, and grab sampling, suggests that core sampling tends to undervalue.

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

By M Bannear, J-F Wilhelmy, R Jones

Mineralogical study of the interactions between fluxes and iron-oxides helps to understand how magnetite oxidises to haematite during pellet firing. Samples of OneSteel magnetite pellets tested at COREM pilot plant were collected after three firing steps and were studied mineralogically. Preheated pellets revealed no particular microstructures related to the composition of fluxes but were more affected by their bed position. After kiln firing, the impacts of lime and magnesia became more apparent. Magnetite oxidation is complete in the cooling stage. The position and the microstructure of the residual magnetite can bring useful information that could æcompleteÆ the view of the firing cycle.

Jan 1, 2007

By Penny T. G

BHP Diamonds and their joint-venture participants DiaMet Minerals, Chuck Fipke and Stewart Blusson are currently developing Canada's first commercial diamond mine in the arctic barren lands of the Northwest Territories (NWT) of Canada. The paper reviews the early history of the project leading up to the discovery of the first kimberlite pipe in September 1991, diamond exploration techniques and the subsequent advanced exploration and development work carried out at the site. In many aspects, this exploration work represented a development project in itself. Coinciding with the advanced exploration work, the project team prepared an Environmental Impact Statement (EIS) and went through federal review of the project at the highest level. External affairs strategies regarding the federal review and aboriginal land claim issues were crucial components to the approval process. Upon approval in principle by the

Jan 1, 1997

The South Comet mine is an underground silver-lead-zinc mine located on the West Coast of Tasmania with an annual production in the order of 35 000 tonne per year. All ore mined is shipped to the Rosebery mill by road, a distance of 17 km.

Jan 1, 1993

By Madgwick J, Pracejus B

The microbial, microaerobic, biodegradation of cryptomelane-rich and pyrolusite-rich samples of manganese oxides was studied in repeated five-day static batch cultures over II weeks. Manganous ion was leached/reduced faster from the cryptomelane-rich samples (average 510 mg Mn2+/1/d) than from the pyrolusite samples (average 442 mg Mn2+/1/d).Cultures contained 20 per cent (w/vl) manganese mude, five per cent (w/v) molasses nutrient and the end-of-batch bacterial cell numbers were approximately 1010 cells/ml. The cryplomelane-rich sample incubates became more acid with time than the pyrolusite-rich incubates. The breakdown of pyrolusite proceeds in a relatively uniform way, while cryplomelane indicates a stepwise destabilisation.

Jan 1, 1992

By Piotto P

Pit optimisation algorithms are designed to produce a pit with maximum value, but for certain minerals like iron ore, limestone, coal, etc, it is also necessary that the designed pit contains ore which meets the customer's chemical specifications. This paper describes a technique of using linear programming for blending optimisation and the Lerchs-Grossmann algorithm (as in Whittle's 3D software) for pit optimisation in tandem, to achieve pit designs of targeted grade specifications.

Jan 1, 1996

The traditional concept of optimum drill and blast is that it is achieved when ore is produced at the lowest unit cost and, because of the complexities of most mining operations, represents a band which extends either side of an overall cost m

Jan 1, 1998

By Standish N

The heterogeneous reactions of carbonaceous materials with oxidising gases are basic to all combustion phenomena and to many gasification processes. The carbon- carbon dioxide reaction at elevated temperatures (Reactivity) plays important roles in many metallurgical operations like iron blast furnace and ferro-alloys smeltings, zinc and lead smelting, alumina reduction, cupola operation and direct reduction processes. The stoichiometry but not the mechanism of the reaction between CO2 and carbon is represented by the equation (Boudouard reaction) CO2 + C 2CO (1) This reaction is more complex than that between carbon monoxide and metal oxides, which involves essentially a transfer of oxygen from the oxide to carbon monoxide to generate carbon dioxide without any change in gas volume, whereas the volume of the product gas of Equation (1) is twice that of the reactant gas. In the present paper an attempt has been made to review critically the reactivity measurements of various carbonaceous materials in carbon dioxide atmosphere. Steps in C-CO2 reactions, surface reaction mechanism, role of mass transfer on reaction kinetics, dynamic oxygen exchange reaction and rate equations and rate controlling steps are discussed. Various methods of reactivity measurements with their pros and cons are also presented. Effects of pertinent process variables on the reactivity of carbon are also described in detail.

Jan 1, 1986

The Mobile Miner MM130 (Figure 1) is designed to tunnel or mine in hard rock. It has a 4.1 m diameter cutterhead mounted on a horizontal axis which in turn is perpendicular to the line of the machine. The cutterhead rotates at 15 rpm and is supported on a boom which swings the cutterhead through a horizontal arc.

Jan 1, 1993

By Hart A. T, Lanigan P. G

BHP is currently undertaking research into plasma are metallurgical processing at the Central Research Laboratories (CRL), Shortland. The use of high intensity plasma arcs for melting and smelting has a number of advantages, including; the ability to control atmosphere and furnace operating conditions, total enclosure, high temperatures, versatility, and low in-process inventory in a compact system. The intensive conditions, achievable in a plasma furnace system, make it particularly useful for the smelting and melting of difficult-to-treat materials, such as ore and metallic fines and refractory ores. Two transferred arc plasma smelting furnaces have been set up at CRL; a 100kg furnace is used for small scale melting and smelting studies and a 1 tonne furnace for pilot scale plasma processing studies and equipment development. Power is supplied by a 1MW GEC thyristor DC power supply. A 220kW DC power supply is available for "off site" pilot process trials and demonstrations, and a 150kW non-transfered are plasma torch is also available for other studies. The facility has been designed to allow maximum flexibility in researching and developing applications in metallurgical processing and transferring developed technology to company operations. The objectives behind the development of the facility, details of the facility and an outline of current research areas will be Discussed.

Jan 1, 1987

The purpose of this paper is to present a detailed account of the development of the Blasthole Diamond Drilling method of stoping now used at the property of Big Bell Mines Limited, in Western Australia.The ore body is one of the large low grade gold deposits of this State, being a continuous lens 1,850 ft. long and ranging in width from 15 ft. at the ends to 120 ft. at the widest part, the average width being 59 ft. It was first worked in 1913 by a local syndicate, and up to 1924, when operations ceased, 64,448 tons of 3.4 dwt. ore were mined from a shallow open cut. Between 1928 and 1932, 15 deep diamond drill holes were put down to test the ore body at vertical depths ranging from 100 to 700 ft. On the information gained from these drill holes, Premier Gold Mining Co. Ltd. began underground explQration. A level was driven at a depth of 253 ft. and crosscuts put out to the full width of the, orebody at intervals of 100 ft. along the strike, all ore broken being put through a sampling plant. On completion of this sampling,' Big Bell Mines Limited was formed as the operating company, and a plant with a capacity of 1,000 long tons per day was erected and mining and milling operations were commenced in 1937. Ore was first mined from glory hole stopes, 65 ft. long, separated by 35 ft. pillars, by benching using conventional steel with changes up to 20 ft., all broken ore being hauled to the main shaft on the...

Jan 1, 1948

The Engineering Chemistry Division of the Government Chemical Laboratories of WA initiated an ongoing investigation into the possible utilisation of diatomites of this State. The work has shown that local diatomites can be beneficiated by hydro or pneumatic cyc- lone separator circuitry and that the better quality head materials can be upgraded by straight and flux calcination and associated processing to the equivalent of premium grade imported products. Western Australian diatomites vary con- siderably in quality, and the degree to which they can be upgraded and the yield of useful product are influenced by the proportion of impurities and the size, type, and degree of fragmentation of contained diatoms. Conseq- uently careful assessment of ore deposits will be necessary in order to relate ore reserves to planned production. The viability of commercial production from Western Australian resources would hinge on the establishment of markets - largely ex- port - capable of supporting a production level of the order of 30,000 tonnes per annum.

Jan 1, 1979

Broken Hill has a long history of mining and it is without doubt a world-class deposit. It has seen production since 1885, notwithstanding the strikes that made the city infamous in days gone by and has given rise to three of the nation's leading mining companies; BHP, North and CRA. Prior to the formation of Pasminco in 1988, the mining and exploration activities were undertaken by separate companies who were business competitors and tended to operate in relative isolation. There were a few notable exceptions such as the Central Geological Survey of 1936 - 38 (Gustafson, 1939; Gustafson et al, 1950) and the Mine Managers' Association. The latter sponsored many university based research projects. At a local level there was good communication and cross fertilisation within this remote outback centre through personal contacts and professional bodies such as The AusIMM. Pasminco was formed by the merging of the lead-zinc interests of CRA Ltd and North Broken Hill Ltd. In Broken Hill this meant the joining together of North Mine and ZC Mines, the two largest mines then operating on the Line of Lode, to form Pasminco Mining Broken Hill Operations. The exception was the central part of the orebody, the original BHP, South Mine and

Jan 1, 1997

The Quioma Mine is located along the axis of the Cordillera Oriental, 130 km southeast of Cochabamba, South Central Bolivia. Silver, lead, zinc, antimony, and gold have been intermittently produced from veins in the Quioma area since Colonial times. Mineralization occurs within steeply dipping fissure veins transecting moderately folded Lower Ordovician sediments. Tectonic activity is early to mid-Tertiary and the vein system parallels the fold axis of a major northwest-southeast striking, doubly plunging anticline. Vein sets occur within a 2 km wide band over a strike distance of 13 km along the northeast limb of the anticline. Economic mineralization occupies syntectonic pre-mineral fault zones developed in more competent stratigraphis units of Lower Ordovician clastic sediments. Veins average 55 cm in width, although mineralized structures up to 3 m wide with a known strike length of several hundred meters have been mined. Mineralization consists of siderite, argentifferous galena, sphalerite, and quartz, with minor amounts of chalcopyrite, barite, and bournonite. Pyrite is rare except at the Boston vein where it occurs with stibnite that contains trace amounts of gold. A marked characteristic of veins in the district is evidence of repeated stages of movement during mineralization. Intrusive rocks are rare in the Quioma area. Narrow porphyritic dikes of Andesitic composition averaging 1 m in thickness have been observed. These dikes occasionally show a close spatial relationship to the veins and are often kaolinized and carbonitized. Vein and dike contacts are sharp and alteration does not appear to extend into the wall rock. Mineral zoning is suggested by antimony mineralization observed in peripheral areas of the anticline.

Jan 1, 1987

By Juniper LA

ERM Consultants Pty Ltd was established in 1980 for the purpose of introducing a disciplined coal technology and power station planning service, to support Australia's efforts in establishing a major export steaming coal industry. At that time, major coal exploration programs were mounted on more than 50 potential export coal deposits with proven open-cut reserves to export 200 Mt/a of coal. The fact that Australia achieved an export trade of only 30 Mt/a, equivalent to the energy requirements for a population of around 5 million people, illustrates the very small achievement to date. The main reasons for this small export steaming coal growth have been: 1. Failure to convince potential overseas coal buyers of the benefits of coal-fired power generation, and the ability of proper power station design to overcome environmental problems, and achieve reliable operation and long life when burning Australian coals. 2. Failure to promote Australian power engineers to advise on the use of Australian coals, resulting in Northern Hemisphere power station experience dominating in market countries. 3. Failure of governments to draw on privately practising Australian power engineers and coal technologists in technical workshops, presentations and assistance to overseas countries, to ensure that personnel whose business it was to serve the follow-on needs of countries were readily available. The result of these failures has been that: 1. Only a fraction of prospective overseas coal-fired power projects have proceeded. 2. Australia has had no influence in the design of overseas power stations to ensure that potential customers would be confident that Australian coals could be reliably burnt in their boilers.

Jan 1, 1987