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While reaction to immediate demands may be required from time to time, the principal concerns of a Geological 'Survey should be proaction, with respect to the systematic production of maps, reports and data in order to meet exploration needs in the longer term, and interaction, which involves a complex matrix of relationships - firstly within the Department between disciplines and at various levels of responsibility, secondly with the exploration industry, thirdly with Commonwealth authorities particularly the Bureau of Mineral Resources (BMR), and fourthly with university researchers in related fields.

Jan 1, 1987

By Walker G. S

Infrared and Raman spectroscopy have been used to study a range of solid state and aqueous solution species which are of interest in extractive metallurgy. In the solid state new Cu(II)/CN'/NH3 complexes have been detected, iron impurities in kaolin characterised, aluminium substitution in hematite and goethite quantified, and the crystallinity and orientation of zircon determined in heterogeneous crystals. In aqueous solution metal cyanide complexes and equilibria were readily characterised, the thermal decomposition of SO2 monitored and products identified, and complexation of AI(III) by hydroxycarboxylates observed. Attempts to monitor the early stages of the gelling of silicate solutions were less successful, with only changes in the gel being detected. However, the degradation of 12-tungstosilicic acid was readily monitored as a function of both time and pH.

Jan 1, 1996

ABSTRACT' Mainland Papua New Guinea is formed of a microcontinental / island arc system (?Eocene - latest Oligocene Sepic arc) which in Middle to Late Miocene times was obducted over the northward- moving Australian plate. The sedimentary and volcanic units of this system form part of the Wogamush Group (Aure beds, Mena beds, Omaura Formation, Movi beds, Wogamush beds, Wogamush Formation. Nansananka Conglomerate and other correlates in- eluding cale-alkaline volcanics and carbonate beds). This Sepic event was followed in Pliocene-Present times by the obduction of the Finisterre-Adelbert-Oenake fore-arc or possibly oceanic plateau. Obduction of the Sepic arc produced crustal thickening

Jan 1, 1997

The Kidston Gold Mine i s located in northern Queensland some 2 Ukm northwest of Townsville. I t is the largest gold mine in Australia and produces approximately 25 percent of Australia's gold and one percent of the world's gold.Initially, traditional mining industry management approaches resulted in the rejection of what appeared to be an attractive low-grade deposit as an uneconomic proposition. Critical re-examination revealed that the rejection was based upon managerial inflexibility and traditionally over-conservative methods of mine evaluation, construction, operation, projected commodity prices and contingency factors. "Ihus it tradition was to prevail, the Kidston prospect would never have been realised.

Jan 1, 1985

By Bassett N

The Eneabba deposit, located 280 km north of Perth, Western Australia, and 30 km inland (Fig. 1) is one of the most recently developed deposits of mineral sands in the world. The area has been in production since 1974, while the Associated Minerals Consolidated Limited (AMA) operation commenced production in 1976. Total ore reserves of close to 400 million tonnes contain about 40 million tonnes of heavy minerals (proved and probable).

Jan 1, 1979

In conjunction with a study on wear of drag bits the effect of clearance angle on penetration rate was studied.Increases in clearance angle from 24 1/2 up to 30° gave an increase in penetration rate. Thereafter the rate was apparently affected by partial clogging with cuttings.Analysis of results was by a linear regression model and the t-test was applied to assess the significance of parameters in the penetration equation.

Jan 1, 1969

By H Kundapen, J J, C Rumble, S Miller

This paper describes measures taken by Ok Tedi Mining Limited (OTML) to minimise the risk of acid rock drainage (ARD) resulting from mining operations at its Mt Fubilan porphyry copper-gold mine in the remote Star Mountains of Papua New Guinea. The risk of acid generation and metal leaching as a result of oxidation of these sulfidic deposits has long been recognised by OTML. In 1998, OTML instigated the ARD Management Program to fully evaluate these risks and to formulate, if necessary, trial and implement appropriate management strategies. In implementing the ARD Management Program, OTML has adopted a risk management approach consisting of five stages: risk identification, risk analysis, risk assessment, risk treatment, and review and monitor. Significant progress has been made in relation to risk identification, analysis and assessment. The work currently underway to put in place a comprehensive risk treatment and review process will ultimately determine the success or otherwise of this approach.

Jan 1, 2003

By Quayle J. E

This paper covers period from 1973 through to 1988 and the mines of West Coast Mines, Elur Mine, North Mine and Risdon Zinc Smelter, now all part of the Pasminco Group. During this period, optimisation started with one mine (West Coast Mines) producing four Product concentrates with constant steady feed to the smelter and progressed to three mines producing eight products and a smelter varying feed inputs to maximise benefits. The initial optimisation was done manually using a desk top calculator and hand drawn graphs. This ultimately advanced to the use of PC plus linear programming software and spreadsheet generating relevant graphics. The financial benefits were achieved with no capital expenditure and increased from an initial $0.5 to $1.0 M/year (1973 $'s) to $5 to $10 M/year (1988 $'s).

Jan 1, 1991

BHP Steel International's Newcastle blast. furnaces have operated since their caimissioning on cake based on local low rank coals. In the early 1960's Newcastle coke was believed to be the weakest in the world. Newcastle coke now supports a blast furnace operation with a productivity of 2.1 t/d.rn IV, a fuel rate of 490 kg/t and a coke rate of 415 kg/t. This coke is nuudv from blonds of lcxni and southern Sydney basin coals with blend Ro nex in the range 0.94 - 1.01. Blast furnace performance in periods of differing coal blends is conjured. The relationship between coal aril coke quality indices and blast. fin-mice perforrnarcc.e is discussed as well as the relevance of conventional coke tests. New BHP coke tests are referred to.

Jan 1, 1987

By Hatcher MI

Exploration undertaken at Copley diapir has located several occurrences of oxidized supergene and primary sulphide copper mineralization at the margin of the diapir or in adjacent country rocks. The mineraliza- tion is related to carbonate-rich epigenetic solutions which moved along major structural features closely associated with the intru sive diapir.

Jan 1, 1975

Investigations into the flotation behaviour of single minerals, mineral mixtures and ores at the CSIRO Division of Mineral and Process Engineering have led to the development of sophisticated laboratory flotation testing equipment. Both routine and complicated flotation investigations can be conducted in a precise and reproducible manner using procedures and equipment that have been refined over many years of conducting careful batch flotation testwork. Several important advances in flotation research can be attributed to changes in testing procedure developed as a consequence of the availability of this equipment. The flotation cell and ancillary equipment is described and associated developments and techniques discussed.

Jan 1, 1992

We live in a world in crisis. One where the tides of change run ever faster. Where the only thing we can be sure of is change itself. The challenge we face, therefore, is not how to resist the forces that move us nor even to try to predict where they will lead us, but to harness their energy and use their momentum to find new and innovative solutions to problems that can seem intractable. Indeed, crisis is often the catalyst which energises a business to change its technology and to form a partnership with a company which specialises in pioneering new technology.

Jan 1, 1993

By Corbett GJ

Comparisons between individual SW Pacific Rim gold deposits have facilit-ated proposal of a new classification of porphyry-related mesothermal gold deposit types. Carbonate base-metal gold systems form at relatively high crustal levels, peripheral to porphyry intrusions. There is a spatial assoc-iation with major structures which focus fluids from degassing porphyries at depth. Milled matrix intrusive breccias and extrusive maar volcano/ diatreme breccias form as a result of pre-mineralisation phreatomagmatic eruptions. These focus degassing magmatic fluids by the provision of fracture ground preparation, typically within competent host rocks, adjacent to the breccia bodies. Local dilational structures control the form of individual deposits which may contain bonanza gold grades at sites of fluid quenching and/or repeated mineral deposition.Early quartz veining and porphyry-related alteration is common and later gold mineralisation typically occurs in association with carbonate veining and Fe and base metal sulphides as Zn > Pb > Cu. The progressive cooling by mixing of the upwelling mineralised magmatic fluid with descending bicarbonate waters, produces characteristic zonations in carbonate compositions. These vary with distance from the porphyry source, from Ca through Mg, Mn and distal Fe types. Gold mineralisation is preferentially distributed within the Mn/Mg carbon-ates.

Jan 1, 1994

By E Heath, F McDermott, S Turner, P van Calsteren

U-Th isotope studies of recent volcanic rocks may be used to evaluate the depths and rates of melt generation beneath midocean ridges and ocean islands. Island arc rocks exhibit a similar range in Th isotopes to that seen in both MORB and om, but while those with high (230Th/232Th) tend to have excess 238U, many of those with low (230Th/232Th) are in isotope equilibrium. The excess 238U is attributed to the preferential mobilisation of U in hydrous fluids from the subducted slab within the last 100 000 years, whereas the low Th isotope ratios in the higher-K arcs are primarily due to the introduction of subducted sediment. Preliminary results from mineral separates from lavas on Soufriere on the island of St. Vincent indicate that some of the minerals crystallised up to 50 000 years prior to eruption.

Jan 1, 1995

Precious metal mineralization at the North Arm goldfield in SE Queensland occurs in the Triassic North Arm Volcanics, a sequence of andesite to rhyolite, pyroclastic and epi- clastic rocks deposited in a continental envir- onment. This unit displays a well-defined fracture system on Landsat imagery, including several arcuate structures which may represent former calderas. Two of the latter are associ- ated with zones of hydrothermal alteration, breccias and anomalous precious and volatile metal values. At the North Arm prospect, alter- ation is zoned from outer propylitic into exten- sive sericitic, although K-feldspar alteration is prevalent in the rhyolite. A zone of advanced argillic alteration is also present at Mt. Ninderry, SSE of North Arm. Alteration involves depletion of Na, Ca and Sr, and vari- able enrichment of S, As, Au, Ag, Hg and Mo. K and Rb are strongly enriched in K-feldspar altered zones. Precious metal mineralization occurs in veins, stockworks and hydrothermal breccia zones, and pervasive low grade Au-Ag dispersion is found throughout the sericitic and K-feldspar altered rocks. Veins and brec- cia interstices contain abundant quartz (common- ly banded), minor pyrite, calcite and sericite, with traces of silver grading to electrum, frei- bergite, naumannite, allargentum, marcasite, chalcopyrite and sphalerite. Mineralogical and geochemical characteristics are consistent with that found at volcanic-hosted epithermal precious metal deposits, particularly with the low-sulphur/adularia-sericite type.

Jan 1, 1987

By Gregory L. M, Phillips G. N

Although it has long been recognised that there is a diversity of minerals associated with Victorian gold deposits, the degree to which this mineralogy is systematic or haphazard has remained uncertain. Recent work by the authors and students under their supervision permits a sharp delineation of the boundaries between different mineralogical domains, and these are interpreted in terms of recent rapid advances in Victorian tectonics, and the regional framework of Victorian gold geology described in Phillips and Hughes (1996).

Jan 1, 1997

By Sneddon A

Expansion of central production facilities at the Kutubu Petroleum Development Project in Papua New Guinea (PNG) required excavation of a steep hillside overlooking operating crude oil processing, storage and pumping facilities. Drilling and blasting were used to remove a large volume of rock which varied from hard limestone to soft sandstone, with zones of soft clay and many underground caverns. Similar ground conditions had made it very difficult to predict and control blast-ing results during previous excavation in this area.Special conditions of the project included restrictions on ground vibration levels at a high pressure oil pipeline and pump station within 100m of the blasting area, and a prohibition on any flyrock. As work progressed, some blasting was necessary with 20m of installations being constructed on the levelled project site. Thus blast design, drilling and charging were carefully controlled to avoid any incidents which could interfere with oil production or progress of the construction project.

Jan 1, 1994

By G J. Corbett

Magmatic-related low sulfidation hydrothermal ore systems at plate margins exhibit distinct spatial and temporal zonations which can be used to aid mineral exploration and development. Low sulphidation systems at all crustal levels exhibit the same paragenetic sequence of events: early breccia formation, followed by quartz - secondary feldspar sericite/illite veining, then mineralisation, and final argillic overprint. This sequence of events is interpreted to reflect the initial emplacement of melts at high crustal levels, and the progressive cooling of that melt and release of magmatic constituents into a circulating hydrothermal system.   Low sulphidation systems in the south-west Pacific region exhibit a vertical zonation in deposit types: from porphyry copper-gold at deep levels, quartz-sulfide-gold at mesothermal to deep epithermal levels, carbonate-base metal gold at mainly epithermal levels, and epithermal quartz silver-gold at shallow levels. It is interpreted that the characteristics of each of these styles of deposits is produced by mixing with circulating waters of different physio-chemical compositions.

Jan 1, 1995

The occurrence of molybdenite in a small shaft in the western margin of the Wuuluman Granite in central western New South Wales is noted. Full petrographic and mineragraphic descriptions are given of a mineralized contact zone between the granite and a basic hornfels.Mineralogical data .indicate a similarity between this mineral occurrence and other occurrences in larger mines remote from the granite.

Jan 1, 1968

By M Gao, V Lawson, W Valery

Changes in metal prices and mine output over recent years have required the Copper Concentrator of Mount Isa Mines to operate at annual tonnage rates varying from 4.0 million to 6.5 million tonnes. Several circuit combinations were operated during this period utilising up to two semi-autogenous grinding (SAG) mills and up to two ball mills. The aim was to maximise grinding efficiency and keep unit costs constant regardless of throughput rate. Measures to improve the SAG-ball mill unit operation were implemented with each circuit change. These included installation of a splitter to divert SAG Mill cyclone underflow back to the mill, increase SAG ball charge from four per cent v/v to eight per cent v/v, reduce in SAG top feed size and increase of ball mill grinding medium size. Modelling work and surveys led to a new design of the SAG liner profile from 60 rows of rail bar liners in a high-low arrangement to 40 rows of top hat liners in a high-high arrangement. An on-line SAG Mill feed sizing monitor was recently installed to improve grinding control.

Jan 1, 2000