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One major aim of the operation of Aberfoyle's matte fuming pilot plant was to assess refractories performance in the process working vessel, a SIROSMELT furnace. High wear rates were expected and whether these could be tolerated was an important question. During operations a range of refractory types was evaluated in both insulated and water cooled furnace designs. Furnace operations enabled lining wear measurements to be made. Results confirm that existing technology can solve any expected refractory problems. Design aspects that should be included in commercial furnaces are shown.

Jan 1, 1984

Over the past 5 years, Bougainville Copper Limited has undertaken a number of major plant expansions to the copper concen- trate production plant at Bougainville in the North Solomons Province of Papua New Guinea. These projects have scheduled three additional ball mills, three new banks of Outokumpu flotation cells, four additional tertiary screens, two additional tertiary crushers, and more recently four high capacity 24.5m dia. tailing thickeners. The value of the five separate projects totalled more than A$100 million. A requirement of commissioning and bringing on line of each of these projects has been to minimise both operational losses and copper concentrate production. The commissioning has been successfully implemented by detailed planning of the commissioning work in conjunction with the plant operation. Planning has been detailed for each man involved on an hourly basis, highlighting the work required on each commissioning task that is to be undertaken and the time expected to achieve activity Completion.

Jan 1, 1986

The series of events leading to the adoption of more complex flotation circuits for coal have been reviewed. In essence, it has been concluded that ac- ceptable overall flotation recovery will only be obtained when efficient distri- bution of collector over all the component feed size fractions is ensured. The achievement of this goal is most likely to be obtained by feed classification and separate flotation of appropriate size fractions. The adoption of such a phil- osophy, however, imposes a number of process problems of both a chemical and an engineering nature. Some of these problems have been identified and possible solutions discussed. A case is emerging for the development of a new generation of flotation cells designed specifically for the flotation of classified coal and for the development of a series of novel re- agents which have the propensity to float middling particles.

Jan 1, 1984

By D R. van der Meulen, P Ande, D J. Lunt

Pressure hydrometallurgy is becoming an increasingly common unit operation in the treatment of gold and base metal ores and concentrates. The design of an adequate and appropriate pilot-scale testwork program is, therefore, essential in order to minimise the risks associated with developing a project in which autoclaves form a key part of the operation. This paper identifies the approaches that have been taken in the piloting of oxidative and pressure acid leach operations. Particular emphasis is placed on the determination of scale-up ratios between the pilot and commercial plants and the pilot-plant run durations. The issues, both metallurgical and project-specific, that can impact these key parameters are reviewed.

Jan 1, 2004

By Hara Y, Arino S, Nakamura M, Tachimori M

The theoretical and experimental studies have been done to clarify the hearth flow of iron and slag. The results of dissections show that the hearth can be treated as a packed bed of coke hav- ing good permeability with a coke-free layer at the bottom of the hearth. 3-dimensional numerical calculations of hearth flow with and without a coke-free layer are carried out, and the results are assured by a water model simulation. The influences of a coke-free layer on the iron flow and the discharge route of iron and slag are examined. The 3-dimensional flow pattern can be represented simply by the travelling time, which depends on characteristically the profile of coke-free layer and the quantity of iron in the hearth. Those flow parameters could be obtained by the results of radioisotope tracer test ( Co for iron flow, and Sc for slag flow) at several furnaces. As a result, it is found that the coke-free layer repeats the cycle of appearance and disappearance at several-month intervals. This cycle corres- ponds to large temperature fluctuation at the bottom of hearth. The relation between iron flow and skull (solidified iron, coke and deposited graphite mixed layer) on the hearth brick was studied by the model experiment and the thermal analysis based on the indications of thermocouples installed in the bottom of the hearth. If a thin coke-free layer is formed on the skull, a fast iron flow is generated in the layer, and melts away the skull. The growth and melting of skull produces the fluctuation of thermal load on a bottom brick, causing brick Damage.

Jan 1, 1981

Process variables in flotation circuits are outlined with a view to producing mathematical models of circuits. The nature of the kinetics of flotation are discussed and the effect of process variables on the kinetics considered. An approach for a possible model is briefly outlined.

Jan 1, 1971

By Kelly GD

Prior to 1986, users of satellite based remotely sensed data were almost exclusively reliant on the United States Landsat series of satellites to monitor our Earth's resources. This situation changed when France, Belgium and Sweden launched SPOT-1 in 1986. The year of 1988 saw the Japanese also enter into the earth resource satellite business. The Japanese launched an earth resource monitoring satellite with an emphasis on marine resources, hence the name MOS-1 (Marine Observation Satellite). Many more remote sensing instruments are planned for launch by these nations and others in the next 10 years.

Jan 1, 1990

By Meunier G, Davis J, Koperski G

The dry processing of mineral sands concentrates can result in the generation of significant amounts of airborne dust. The radioactive component of this dust has implications within the context of work environment health codes. The last four years have seen considerable investment in dry plant equipment enclosure and dust extraction systems, with resultant reductions in plant ambient dust levels. Simultaneously, an industry wide program was started to examine the origin, nature, mineralogy and radioactivity of the airborne dust. The major findings of this study have been: ò confirmation that monazite was the only significant source of dust radioactivity. ò recognition of two sources of dust: - agglomerates of finely divided ilmenite-rutile alteration products, which are formed by the removal of surface coatings and particles. - abraded mineral fragments, which reflect the mineralogy of the parent particles.

Jan 1, 1991

The purpose of this paper is to outline the current status of financing in the Australian Gold Mining industry and to discuss a number of developments that have occurred during 1983/84.Recognising the importance of equity financing various equity issues, including project valuation, will be discussed against the backdrop of an industry experiencing both rapid growth and a changing structure.Nothwithstanding the current tax exempt status of the industry there is a trend towards more debt financing. A number of financing issues will be covered and it will be shown howvalue can be created through astute financing planning.

Jan 1, 1984

The new generation Hlsmelt« Direct Iron Ore Smelting Process is a CRA Limited technology initiative. The process development is now focussed on commercialisation. The goal is to have the first commercial vessel operating around the year 2000. The HIsmelt« Process, based on the abundantly available iron ore fines and the more readily available non-coking coals, has the potential to fundamentally change iron ore processing through the application of high intensity techniques to replace the current sinter/coke ovens/blast furnace .technologies. The process will have great potential in the rapidly growing economies of Asia where steelmaking aspirations are based around local market focussed plants. This potential can be. realised as a supplier of premium grade iron units to electric arc furnace (EAF) steelmaking plants or as the front end to an ore based steel mill.

Jan 1, 1996

By Madgwick J. C

Leaching column techniques and microbiological methods have been described in detail in Madgwick and Ralph (1980) and Madgwick, Ralph and Sadler (1981).Sixty-nine kilograms of copper porphyry ore (0.4 per cent Cu, 2.7 per cent Fe) (particle size 2.4-11.2 mm; 60 The effect of sodium chloride (O.6M) irrigation on bacterial leaching of Bougainville copper porphyry ore was studied.Viability of suspended Thiobacillus ferrooxidants was reduced to less than 10 cells/ml in NaCI (O.6M) compared with 10' eells/ml in dilute II,SO, (0.01 M, pll 2). Salt irrigation had no significant effect on heterotrophic and sulphur oxidizing bacteria. Increascd short term recovery of copper (145 g/tonne/ 15 days) was followed by a marked decrease in tenors to less than 20 mg/litre/day compared with an acid leach, steady release, of 110 mg/litre/day. Resumption of acid leaching restored average solution copper to 46 mg/litre/day and the viability of suspended T Ierrooxidates to 10 cells/ml.Quantitative removal of sodium ehloride from ore particles was difficult and t races of NaCI remained for more than 200 days.

Jan 1, 1982

Programmes of environmental investigations to identify and minimise impacts and satisfy government and community requirements have become an integral and rate determining component in the planning and development of new mines in Australia. This paper reviews the essential features of the environmental project management Function.

Jan 1, 1983

Mineral exploration conducted over a wide area of the State during the period 1960 to 1973 has resulted in the discovery of a number of significant deposits. Base metals, particularly copper, have been of prime interest while, more recently, the search for uranium and coal have assumed import- ance. Expenditure of $27.6 million by companies during the period under re- view has located 580,000 tonnes of cop- per, 370,000 tonnes of zinc, 350,000 tonnes of lead, 24 million Kg of uran- ium oxide and 2,500 million tonnes of coal. A variety of other metals and non metallic and industrial minerals have been investigated in a diversity of geological environments.

Jan 1, 1975

The Circum-Pacific area is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands skarn deposits of different types. According to the differences of major metallic elements, the skarn deposits may be classified into seven subtypes, i.e. Fe, Cu, Pb-Zn, W, Sn, Mo and Au skarn deposits. In this paper, the distribution. and geological characteristics of above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types: magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with Fe, Cu, Au,, Sn, B, Be mineralization, calcic skarns with Fe, Cu, W, Mo, An, Be, Pb, Zn, Sn minerailization, while the alkaline skarns occur in U(Th, Nb) deposits. The skarn deposits of both East and West Pacific rims have many general characters, but have some diferences in geotectonic settings, intensities of mineralization, distribution, and metallogenic epoches. In this paper, the minerogenetic series and the mineralizing specialities of related magmatic rocks of the skarn deposits are also discussed.

Jan 1, 1990

Much of New Zealand is comparatively young geologically in the sense that it has only recently been uplifted. In many places young marine sediments are to be found at high altitudes, as evidenced by the existence in the North Island of Pliocene shell limestones which form prominent escarpments at altitudes of about 3000 ft. inthe central part of the Island, and remnants of the same formation found on the summits of the northern Ruahin.e Range at altitudes greater than 4000 ft.

Jan 1, 1962

Basicity(aO2−) has been known to affect the physicochemical properties of molten slags in the metallurgical processes. However, because of the impossibility of direct measurement of single-ion activity, various indirect measures such as capacity, redox equilibrium of transition metal ions, activity of basic oxides, and (theoretical) optical basicity have been proposed; but these basicity measures have been restricted within slag systems and the interaction between measuring elements and slag components has affected the quantitative estimation of slag basicity. Recently, since it was reported that solubility of noble metals in molten slags could be an indirect measure of basicity, the influence of slag basicity on the solubility of platinum and silver has been reported. The reaction mechanism of platinum dissolution into basic slags has been reported, whilst that in acidic slags has not (Nakamura and Sano, 1997; Sano and Nakamura, 1997; Nakamura et al, 1998). Richardson reported that the solubility of metals such as cupper, gold, silver, and lead in the CaO-SiO2-Al2O3 slag was presumably dependent on the atomic radius and the accommodation ability of the silicate network (Richardson, 1974). Swinbourne and You measured silver solubility in the Na2O-SiO2 slag over a wide range of oxygen partial pressure and suggested that silver would be present as both Ago and Ag0.5 in the slags (Swinbourne and You, 1999). For brevity, these previous works discussed the dissolution mechanism of silver into the slags based on the existence of silver as a neutral or molecular species. However, because the almost chemical reactions occurring in the slag are affected by the basicity, the reaction formula with O2- ion is required based on the ionic characteristics of the slag such as desulphurisation and dephosphorisation reactions as given in Equations 1 and 2, respectively.

Jan 1, 2000

The recommendations of a recent American report on "Better contracting for Underground Construction" are considered in relation to Contracting practices on major Australian projects by representatives Of the "classical trilogy" - the Owner, Engineer and Contractor.

Jan 1, 1976

By Kidd CH

The excavation of a coal mine or any other mine, tunnel, or quarry, below the water table establishes a void towards which ground- water will flow. Inflows into the mine, if significant, can cause not only problems such as flooding, and/or muddy floors, in the mine, but commonly also require disposal of poor quality groundwater. The flow of groundwater towards a mine is accompanied by a decline in groundwater levels, which may extend up to several kilo- metres around the mine. This may seriously effect vegetation, stream flow and existing users of groundwater. At the pit face groundwater gradients can also cause slope stability problems and where a water table is intersected, increase blasting costs.

Jan 1, 1983

By Shunli Z, Jin X, Guanzhou Q

Flotation behaviour can be controlled, due to diminishment of granula quality and extension of specific surface area, by adding coarse particles (high- grade concentrates) to condition pulp. It has been substantiated that coarse particles can intensify fine particle flotation and its mechanisms are effects of carrier, intermedium and assistant aggregation of coarse particles. Calculation and analysis of Reynolds numbers and their variation for different size particles, under specific turbulent dynamic conditions, reveal that agglomeration among granulae is subject to specific turbulent dynamic conditions. Furthermore, sizes and adhesion strength of flocculated particles are the function of specific physical and chemical factors. Based on this research an innovative ramification carrier flotation process has been developed, which has been applied to Fankou Lead- Zinc Mine, Guang Dong province, China, etc, with satisfactory results. These results shed light on distinction between conventional flotation and fine particle flotation, meanwhile, provide a basic approach for further solution of fine particle flotation problem.

Jan 1, 1993

New Zealand's Land and Income Tax Act 1954 contains unique incentives for companies engaged in mining certain specified minerals or petroleum. Sections 152 and 153 provide for the taxable income of such companies to be based not on profits made but on dividends paid to shareholders. A significant saving in tax results, particularly where profits are not distributed: but the Act attempts to ensure that undistributed profits are used for further mineral exploration and development. To encourage investment in the mining industry, persons taking up shares in a company mining for the specified minerals or petroleum are entitled to a one-third deduction in respect of monies paid on the shares and used by the company for its purposes; and company shareholders may make loans to the company and write-off such loans for tax purposes to an amount of up to half their taxable income. Maximum utilisation of the tax incentives calls for careful consideration as to whether a mining or petroleum company should be financed by way of loan capital or share capital.

Jan 1, 1971