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By Guvenir HA

This paper summarises a cost optimisation procedure by minimising the total drill metres and the overbreak that occurs in tunnel excavation in medium strength rock (uniaxial compressive strength

Jan 1, 1995

Over a four year period from 1984 to 1987, a broad range of ground conditions were experienced in recovering old workings at the Walhalla mine in central-eastern Victoria. Access to the ore zone was gained via old workings and new development. The work included: Recovery of vertical and inclined shafts. Recovery of collapsed winzes. Recovery of level drives and crosscuts. Spiling through broken ground and old mullock. Pre-grouting of caved zones. New development using small-scale rail equipment and "bobcat" Loaders.

Jan 1, 1988

The physical phenomena which influence gas flow in the bosh and hearth of a blast furnace are discussed including the hold-up of slag as a mechanism which can result in a flooding condition. An equation is defined which describes the limitation to wind volume arising from the flooding condition. Implications of the various factors influencing bosh and hearth gas flow on furnace operation are discussed. Coke quality is shown to be the most important factor in the aerodynamics of these zones and coke requirements are defined for the Port Kembla No. 5 BF which has an inner volume of 2670 m3.

Jan 1, 1975

By Li T

Mining of the southern 1900 copper Orebody presented a challenge due to the complex geology, geometry and simultaneous extraction of the nearby lead/zinc/silver orebody. An integrated and co-operative approach was adopted, involving geology, geomechanics, mine planning and production personnel. Successful extraction of the first 1900 Orebody stope, T496, together with the extraction of the first two lead/zinc/silver panel stopes in the immediate hangingwall of the 1900 Orebody stope was achieved as a result of this approach.

Jan 1, 1995

By Mernagh T, Large R. R, Ryan C. G, Huston D. L

The Tennant Creek goldfield is one of the largest gold producing districts in Australia, and major deposits, including Gecko, Juno, Orlando, Peko, Warrego, Nobles Nob, Golden Forty, Argo, TC 8 and White Devil have produced more than four million ounces of gold over the past two decades. Gold-copper-bismuth mineralisation at Tennant Creek occurs in lenticular, ellipsoidal or pipe-like bodies of magnetite-hematite ironstones which are hosted in turbiditic sedimentary rocks of Proterozoic age (Large, 1975; Wedekind, Large and Williams, 1989; Le Messurier, Williams and Blake, 1990; Morrison, Donnellan and Hussey, 1992).

Jan 1, 1994

By Wilson GR

Pellets were produced from carefully sized iron ore and silica sand fractions, under controlled moisture conditions, using a sealed balling drum. The strength of these pellets was measured as a function of moisture content and particle size. The results showed that the strength of the pellets could be adequately described by a model which equates the strength of the pellets with the negative pressure developed within the porous mass, provided that the particle size distribution was narrow and the mean particle size relatively large. However this model failed to account for the observed strengths of pellets produced from systems containing even small quantities of ultrafine particles (

Jan 1, 1972

By Whiten WJ

Although cone classifiers have received little attention in the modelling of mineral processing units they are one of the oldest non-mechanical classifiers. Their use has enjoyed a revival in recent years because of their low cost of installation and operation. In this paper the development of models for cone classifiers is reviewed and a new model is proposed. The experimental work, data collection and analysis are briefly described, and the new model is presented and discussed. The data used in the model development are made up from three distinct experiments using different units in each case. There are 21 data sets from a 3 m cone treating the tailings in a copper concentrator, 24 data sets from a 0.3 m pilot-scale cone, and 29 data sets from a laboratory glass funnel (0.(Y73 m diameter) used as a cone classifier, giving a total of 74 data sets. The model structure was developed from an analysis of particle settling in classifiers, using specialised model building software. The size of a particle settling in a separator and the forced flow through the apex of the cone were related via hydrodynamic dimensionless groups to the operating conditions of the unit. The model predicts the separation efficiency using the following four parameters: efficiency curve shape factor, cut-point, underflow density (per cent solids) or underflow pulp velocity. The model covers a range of feed flowrates from 1.2 to 5000 1/min.

Jan 1, 1993

By Hendrix J. L, Nelson J. H

A study was conducted to examine how pretreatment of carbon-bearing gold ores with chlorine enhances gold recovery by cyanidation. It is hypothesized that metal species (including iron and copper) dissolved during chlorination adsorb on the carbon surface hindering the adsorption of dissolved gold. To test the hypothesis, samples of several sulfide minerals were subjected to reaction with sparged chlorine gas to determine which, if any, dissolve faster than gold under these conditions. Then, a synthetic carbonaceous refractory gold ore containing pyrite, chalcocite, activated carbon, and gold was subjected to gas sparging. The results of these experiments showed that chalcocite and arsenopyrite dissolve so that metal (copper and iron) is put into solution slightly faster than gold under the same chlorination conditions. Also, it was observed from the experiments that gold adsorbs on activated carbon during chlorination, but is replaced by copper and iron as the chlorination process dissolves more of the chalcocite and pyrite. The study concluded by investigating ferric chloride addition prior to chlorination to hinder gold adsorption on activated carbon.

Jan 1, 1991

This paper reviews hydrometallurgical processing technology for refractory gold ores, which form an increasing resource stock for gold. The reasons fQr ore refractoriness and pressure, chemical and biooxidation process options are briefly listed. Electrochemical technology, suitable for processing refractory ore is reviewed and some preliminary results for the electrochemical oxidation of slurried arsenopyrite are given.

Jan 1, 1992

By R Billingham

QueenslandÆs new safety legislation for metalliferous and coal mining (Mining and Quarrying Safety and Health Act 1999 and Coal Mining Safety and Health Act 1999, together with the Regulations) came into effect on 16 March 2001. The legislation places clear obligations on mine owners, operators and workers to have a safe place of work and to manage risks to safety and health. It also places obligations on contractors, designers and providers of services. The legislation is non-prescriptive in that it states what outcomes must be achieved and not what must be done. The key issue is that the risk of injury to people must be at an acceptable level. The legislation creates a Mines Inspectorate with powers of inspection and audit of mines, their safety management systems and the management of risks. Auditing of the risk management process is carried out against standard risk management techniques and directives for corrective action may be issued when audits reveal non-compliance or unacceptable levels of risk.

Jan 1, 2002

By Elliot B. J

Cobalt is principally produced by hydrometallurgical means from the copper-cobalt ores of Zambia and Zaire. In addition cobalt is commonly found in minor quantities in association with nickel and copper-nickel orebodies. Generally the level of cobalt common to these latter orebodies does not warrant separate processing unless the metal price reaches levels last achieved in 1979 and 1980. For pyrometallurgical processing the distribution of cobalt and the factors which affect the distribution of cobalt between matte and slag are not well understood. A limited amount of fundamental research has been completed on cobalt distribution both for simple oxide and matte systems. The paper briefly reviews the relevant literature on theoretical aspects of cobalt distribution between metal and slag and the deportment of cobalt in sulphide smelting circuits. The deportment of cobalt in the Kalgoorlie Nickel Smelter circuit is critically analysed and areas where recovery improvements may be achieved are highlighted.

Jan 1, 1989

By Scaife PH, Cripps Clark J, Cameron DB

Tuyere coke samples have been taken through the tuyere openings of B.H.P. International Blast Furnaces since 1978 with Whyalla No. 2 Blast Furnace taking samples on a regular basis since 1982. The degradation of coke during it's passage through the Blast Furnace can be measured and the relationships between these data, feed coke data and blast furnace operating data demonstrated. Tuyere coke sampling has been useful in revealing misleading external coke testing results and is still the method to monitor directly the performance of coke within the Blast Furnace.

Jan 1, 1987

By Browning E. J

The application of conventional dust control systems in British Coal mines has considerably reduced the incidence of pneumoconiosis. A number of new techniques have been developed involving extraction close to the cutting heads of mining machines which will be capable of controlling airborne dust with the greater intensity of production necessary in the present economic climate.

Jan 1, 1988

By Pollard D. M

In the batch phase disengagement test, an organic and an aqueous phase are mixed together for a known period to produce a dispersion which may be either organic continuous (aqueous phase droplets) or aqueous continuous (organic phase droplets). The continuity of the dis- persion will depend upon the method of init- iating the dispersion, the conditions under which the system is operating, such as temper- ature and impeller speed, and the properties of the liquids, such as viscosity, inter- facial tension and solute content. Once the dispersion has been agitated for the required period, the agitator is turned off and the position of the coalescence interface and the sedimentation interface recorded as a function of time. This will produce a plot similar to Figure 1, where the overall dir- ection of travel of the droplets of dispersed phase is away from the sedimentation inter- face and towards the coalescence interface where the droplets coalesce with the homophase.

Jan 1, 1987

The geology and mineral deposits of the West Pilbara Goldfield are described and comparison is made with the Pilbara Goldfield,, In the West Pilbai'a Goldfield two adjacent environments are represented by a predominantly clastic succession and a predominantly volcanic succession. These two successions are lateral equivalents and lithologically they are similar to the classical successions at Warrdiwdbna and Mosquito Creek. How- ever, no evidence of a significant erosional break has been found. It is suggested that the Archaean rocks of: the Pilbara Block represent a single geosynclinal cycle, which culminated in orogenesis, within which-local disconformities have been developed in various places: and that the sub-Mosquito; Creek unconformity at Eastern Creek may be the most widespread of these disconformities, Widespread evidence of'preconsolidation movement, aid the intrusion of igneous rock into. unconsolidated sediment, suggest that tectonism and igneous activity began at a very early stage, This was localised along lines of fracture in an unidentified basement.,.Moveme.nt was primarily vertical and persisted into the older Proterozoic, The sediments were enriched in metal by vulcanicity, chemical sedimentation, and possibly detrit`1' contribution. Diagenesis and metamorphism caused the remobòliyation of the metallic constituents of igneous and sedimentary, rocks which were then localised-in loci of dislocation-formed both before and after consolidation.,.. . . , . .

Jan 1, 1964

Environmental impact and rehabilitation on completion are primary considerations in obtaining approval for mine projects from government authorities.This paper focuses on the planning and commencement of rehabilitation during the mining of an open cut mine (Hedges Gold Mine) in an environmentally sensitive area in the southwest of Western Australia.

Jan 1, 1992

By Richardson G. W, Yap L. C

Friction rock stabilisers (FRS) are steel-based, thin-walled tubular ground reinforcement widely used in underground mines in Western Australia. Following installation these stabilisers are subject to corrosion which may reduce the load carrying capacity and lead to unexpected ground falls. Although corrosion has been recognised as a common occurrence, particularly under aggressive mine water and mineral conditions present in underground mines, the knowledge of the effects of corrosion on the mechanical behaviour of FRS is limited. The Department of Minerals and Energy of Western Australia has conducted a laboratory based program of studies to investigate the effect of corrosion on the mechanical properties of FRS. The studies have focused on the effect of corrosion on tensile strength of FRS and frictional resistance along the interface between FRS and the drillhole wall. The results indicate that under certain conditions corrosion damage can significantly reduce the effectiveness of FRS.

Jan 1, 1996

By Weir D. R, Doyle B. N

The Sherritt Zinc Pressure Leaching Process is based upon the direct pressure leaching of zinc sulphide or lead-zinc bulk sulphide concentrates to produce zinc sulphate in solution and elemental sulphur in the leach residues. The zinc sulphate solution is compatible with conventional purification and electrowinning technology. The pressure leach residues can be treated for the recovery of elemental sulphur, lead and silver. With the conversion of sulphur to the elemental form, zinc pressure leaching allows zinc winning to be independent of sulphuric acid production. Direct pressure leaching of zinc sulphide concentrates was started commercially in October 1980. Continuing research and development studies have defined various pressure leaching configurations for integration with existing roast-leach operations, for grass roots plants, or for plants which are to have the roast-leach section completely replaced. These studies have included the treatment of zinc concentrates from various Australian producers and the development of process flowsheets for potential applications in Australia.

Jan 1, 1989

By Taylor RN

A simple apparatus for delivering pulverized coal as fuel to a SIROSMELT lance is described, and its performance in smelting tests is evaluated. Using the pulverized coal as fuel, the SIROSMELT furnace performed well in both oxidative copper smelting and reductive smelting (zinc fuming). In both cases the evidence suggests that part of the combustion occurred by indirect oxidation of coal particles entrained in the bath. Oxygen potential measurements made during the zinc fuming tests confirmed the general features of the the non-equilibrium mechanism for zinc fuming proposed by Richards and Brimacombe. The zinc level in the slag during continuous fuming was lower than was predicted using an equilibrium model.

Jan 1, 1987

By Groves D. I

The Norseman-Wiluna Belt (Fig.1) is a richly mineralized (production 1900 tonnes Au), Archaean greenstone belt, up to 800km long and 200km wide, which forms the major part of the Eastern Goldfields Province within the Yilgam Block. The Belt evolved ca. 2700 Ma ago as an oblique-slip mobile belt between flanking portions of an older greenstone terrane. Volcano-sedimentary successions in the Belt represent two distinct tectono-stratigraphic associations. Sequences of metamorphosed caic-alkaline intermediate to silicic volcanic rocks interlayered with tholeiitic basalts probably represent the remains of a dissected Archaean volcanic arc (or arcs), and sequences composed dominantly of ultramafic to mafic lavas and intrusions, with minor interflow tuffaceous, sulphidic or cherty sediments are interpreted as remnants of the floor of an ensialic marginal basin (Barley and Groves, 1988). Ultramafic volcanism at Kambalda has been dated at 2692 ¦ 2 Ma (Claoue-Long et al., 1986). The dominantly volcanic associations are locally overlain by coarse clastic sedimentary succes- sions. The Belt is also typified by major north- to north-northwest-striking fault systems, shear zones, and tectonic lineaments, many of which are traceable for more than 300km. As well as defining the boundaries of the belt, these structures have accomodated much of the regional strain and acted as conduits for hydrothermal fluids during deformation, metamorphism and mineralization. As a result, most of the epigenetic gold deposits in the Belt occur in subsidiary structures related to these fault systems (Eisenlohr et al., 1988). Deformation involved oblique compression resulting in a closely spaced network of low-angle faults (thrusts) as well as upright folds and oblique- to strike-slip faults (Archibald, 1987; Veamcombe et al., 1988). This was accompanied by regional metamorphism and granitoid emplacement. At Kambalda, regional deformation and metamorphism were synchronous with the emplacement of the Kambalda Granodiorite which has been dated at 2662 ¦ 4 Ma (Hill and Compston, 1986), approximately 30 Ma after volcanism.The tectonic history and style of deformation of the Norseman-Wiluna Belt are similar to those of Phanerozoic oblique- slip mobile belts at continental margins, which are also a major source of hydrothermal gold mineralization.

Jan 1, 1988