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By Lightfoot BW, Foo KA, Conochie DS

Aberfoyle Limited operated a matte fuming pilot plant, incorporating a SIROSMELT furnace in 1980/81. This plant was a significant advance in both smelting and tin extraction technology. Important design, construction and commissioning aspects are discussed and some of the key points to emerge from this phase of the work are reviewed.

Jan 1, 1984

By Budd B

this paper outlines the operating advantages gained through applying a mine processor (MISA), to various underground and surface operations. On the surface, MISA monitors and/or controls ventilation fans, crushers, fill plant and stockpiles. Underground, MISA monitors and/or controls dewatering pumps, fill reticulation and high voltage electrical distribution on most levels.

Jan 1, 1988

Australis Mining N.L. operates a continuous mode carbon-in-pulp (CIP) gold plant, processing sand and slime tailings from previous gold mining operations in the Norseman area. Plant design is that of conventional countercurrent contact between pregnant pulp and activated carbon. Gold desorption is achieved by the Zadra process using near boiling tempera- tures and atmospheric pressure. Process water is drawn from nearby Lake Cowan (saline). The plant operates at, or above, design specification of 400 dry tonnes per day. This paper describes the plant design and operating processes utilised in optimising throughput and gold recovery. TNTDnPTTnmTnM Favourable world gold prices and substantial reserves of sand and slime tailings prompted Australis Mining N.L. to construct a gold extraction plant during 1981. The projected plant throughput was set so as to complete treatment of available tailings over a three year period. Metal- lurgical tests indicated that, with a regrind facility satisfactory gold recovery could be achieved using a countercurrent CIP process. Reflecting the entry of Australis Mining N.L. into its first large scale treatment operation, the plant design emphasised simplicity but effectiveness of Operation.

Jan 1, 1982

FOR some reason there is not any extensive literature in print on the electrolytic refining of copper, although the method is in general use in America and Europe. In Australia there are but three plants in existence one small one at Wallaroo, in SouthAustralia; one at Lithgow and one at Port Kembla the last two being in New South Wales. The largest of these is the Port Kembla plant. It is also the most modern, and embodies all the latest appliances and improvements of electrolytic practice.The plant and methods about to be described is that at Lithgow, with which the writer was associated for some years, and the experience gained there may be of interest. Electrolytic refining of copper is one of the simplest operations of metallurgy, but, like all metallurgical operations, it requires constant attention and a large amount of common sense. The man in charge should be endowed with an insatiable curiosity as to why certain things are occurring, and an instinct of cleanliness, whichmy first mentor in chemistry, Mr W A Dixon, once impressed on me was better than godliness.

Jan 1, 1911

By D S. Clarke, W M. Prebble

Potential waste rock products from the mining of epithermal deposits in the Hauraki Goldfield are characterised to facilitate their management. Hydrothermally altered andesites and their weathered near surface equivalents have been examined from the Golden Cross, Karangahake and Monawai gold deposits. These materials vary in both their clay content (smectite, illite, kaolinite and chlorite) and the degree of silicification resulting from alteration and weathering. The simulated degradation (slaking tests) of waste materials cannot be explained purely by consideration of clay content, siliciflcation, or the resultant variations in porosity.   Microstructure is considered to be essential in predicting the physical degradation of waste rock. The scanning electron microscope is an effective tool in such an investigation. Increasing alteration results in clay particles becoming more randomly orientated (matrix microstructure); this causes a reduction in the surface area of contacts between components resulting in increased potential for degradation. The extent of skeletal microstructure (commonly characteristic of weathering) is an important control on effective porosity and the long term potential for degradation. Management requirements for these materials include the minimisation of moisture content variations (with the prevention of initial drying being of primary importance) and the containment of sediments produced.

Jan 1, 1991

By Peak DJ, Kearton CJ

Following a summary of the development of a BF model using aerodynamic relationship and bulk fines index a blast furnace policy model is presented complete with the development of nomograms and featuring production rate, oil rate and total fuel rate. Application of the blast furnace model is then illustrated using No. 5 Port Talbot as an example. It is also shown how the policy model assists in ore allocation in the British Steel Corporation. Further developments which have recently occurred in the correlation between the bulk fines index and the permeability coefficient are detailed and a comparison made with a number of furnaces operated elsewhere. The implications of the comparisons made are that high driving rates are possible with burden containing a high proportion of sinter only if the burden behaviour in the lower parts of the furnace permits high driving rates with a steady gas distribution and low pressure drop. It is concluded that the value of a simple set of equations resulting from the model assisted furnace operators to pin-point likely causes of failure to reach or sustain target production rates.

Jan 1, 1975

Over the past several years, copper prices have surged from under a dollar to over three dollars a pound. However, the long-run trend in real copper prices since at least the early 1970s has been sharply downward. While many now contend that the long-run trend in real copper prices is now upward, the result of structural changes in this market, others are sceptical. Nor is copper unique; the prices for a number of other metals, including aluminium, iron ore, lead, nickel and zinc, have followed similar patterns. This paper examines the forces behind short-run and long-run trends in metal prices. It first focuses on the short run, where it argues that shifts in demand are largely behind changes in prices. It then turns to the long run, where it concludes that production costs and supply largely govern price trends. Finally, it explores several implications of these findings, including those for diversification and market risk, for forecasting mineral prices, for assessing the growth of metal demand in China and elsewhere on metal prices, and for changes in the long-run price trends.

Jan 1, 2006

By Baker EM

The Kidston orebody is a kilometre diameter breccia pipe of Permo-Carboniferous age' assoc- iated with rhyolitic dykes and hosted by Proterozoic granodiorite and metamorphic rocks. Mineralization and alteration are associated spatially and temporally with brecciation and rhyolite intrusion. Three stages of alteration have been recognized: pre-brecciation, and early and late stage post-brecciation. Gold is known to be particularly associated with late stage post-brecciation cavity infill and sheeted veins. Fluid inclusion and stable isotope results show the importance of moderate-high temperat- ure, saline, magmatic fluids in the early stage mineralization and in the brecciation of the pipe. Later periods of alteration, accompanied by gold deposition, are associated with fluids only slightly depleted in 180 relative to mag- matic waters, unlike the strongly 180-depleted meteoric water typically found in hydrothermal Permian and Carboniferous deposits of eastern Australia. The 5180 values and low salinities in fluid inclusions suggest the fluid may have formed from vapour condensation from a magmatic fluid. Fluid inclusion data and alteration assemblages define the prevailing chemical conditions. Gold transport under these, conditions would have been primarily as a bisulfide complex.

Jan 1, 1987

Open stoping dimensions are typically controlled by a number of factors including production drilling capacity, scheduling, fill constraints, orebody dimensions and host wall rock conditions. Frequently host wall rock conditions are the key control on stope dimensions. As a new mine is brought into production, there is a steep geotechnical learning curve for those associated with the development of the mine. Initially, the experience and observations gained at other mines is used to guide the stope design. As experience is gained at the new operation, site specific techniques can be validated for use. This has been the case at BHP Cannington, where a heavy emphasis has been placed on the validation of empirical stope stability techniques for site specific conditions and experience. A range of empirical and numerical techniques can be applied during the design of open stopes. The empirical techniques are an experience based application of known performance levels during the design of open stopes. The numerical modelling and structural tools can be used to compliment the empirical techniques so that an understanding can be gained of the likely stress and structurally controlled failure mechanisms.

Jan 1, 2000

By Johnson G. D

Confidence in Yakabindie becoming a truly cost competitive nickel project has risen recently because of: ò the emergence of an economically effective contract mining climate; ò the delivery of cheaper energy via the Goldfields Gas Pipeline; and ò the development of the Yakabindie Process for production of nickel cathode and cobalt by-product directly from sulphide concentrates at site, dramatically cutting capital and operating costs compared to the conventional route. Development of the Yakabindie Process was a result of 'necessity being the mother of invention'. Yakabindie can now break out of the trap of relying on existing downstream processors to treat an intermediate, and instead the project can gain direct market access. The very attractive cost advantages demonstrate that hydrometallurgical processing of sulphide concentrates is a worthy prize. Improved cobalt recoveries, and tolerance of higher levels of magnesium and arsenic than allowable by smelters, are further advantages of this approach. Leach residues are combined with much larger quantities of naturally alkaline flotation tailings and remain at site. As a result the process is more environmentally sensitive than the conventional smelt/refine route, with no sulphur dioxide gas emissions and 'metal only out the gate'.

Jan 1, 1996

By J Wei, X Lan, F Wang

This paper presents a quantitative assessment model for the assessment of environmental load in gold production, which is based on environmental ecology, Life Cycle Assessment (LCA) and artificial neural network. In LCA evaluation indexes include resource consumption, energy consumption, gas waste, liquid waste, solid waste and so on. Each item represents an aspect in gold production while their combination reflects the relationship between gold production and environment. In this paper an utility function of evolution index on environmental load is given by linear or non-linear transformation, which changes evaluation indexes with different dimension into an equivalent value in range of [-1, 1]. This paper also provides a new approach to make decision on the weight for quantitative assessment with the help of a three-layered artificial neural network. The proposed approach in this paper has been successfully used to a real synthetic assessment for the environmental load in gold production, which include seven kinds of different operational technologies in China. The applications prove that the new approach is successful and reliable. It provides a new tool for the assessment of environmental load of the gold production.

Jan 1, 2003

The three papers reviewed here consider different problems of mine management. Comparison of two of the papers demonstrates a marked contrast between the old and the new, in terms of mine management and impacts. The third paper discusses post-mining rehabilitation. The paper "The impact of a derelict base metal mine on the aquatic environment", by Brooks and Mclveen contrasts strongly with the paper "Narbarlek Uranium Mine design, construction, operation monitoring and decommissioning of the water management system" by McLoughlin, Grounds and Weatherhead. Brooks and Mclveen detail the contamination emanating today from the Conrad Mine in New South Wales which was mainly operated for 15 years at the turn of the century and later for 7 years in the 1950's. The mine was apparently developed over the years on an intermittent, ad hoc basis with no regard to contamination management, resulting Ti significant contamination persisting through time. This type of mining development is the antithesis to the type of planned mining and management operation which was carried out in Arnhem Land at Narbalek, and which apparently resulted in no uncontrolled contaminant release and successful decommissioning of the mine.

Jan 1, 1988

Alliance Gold Mines was established in the early part of 1994 to acquire the assets of Diamin Resources NL at Maldon, Victoria. These comprised Exploration Licence 3422, some 20 sq km in area and enclosing the main part of the Goldfield, and a CIP plant - with a nominal capacity of 250 000 tpa - which was commissioned in 1988. Between 1988 and 1992 Diamin had mined - by open pit methods - and milled around one million tonnes of low grade gold ore, and recovered 55 000 ounces of gold. By 1992 the known shallow resources had been depleted. Historical gold production from the Maldon field is about 1.75 million ounces, at the surprising average recovered grade of 28 g/t. The last significant mine closed in 1926: since then there has been no comprehensive exploration program, though Lone Star Exploration NL tested part of the field for shallow open-pittable resources in the 1970s and Carpentaria Exploration Company Pty Ltd carried out widely-spaced drilling on the three main reefs from 1979 to 1982. Diamin (1983 - 1994) commenced a careful compilation of old mine records and newspaper clippings, and drilled several cored holes.

Jan 1, 1996

Computer programs for the storage, retrieval and use of basic thermodynamic and physical property data for chemical substances are described. Methods are presented for the collection, critical assessment and pre- processing of source data for files containing enthalpy, entropy and heat capacity data for 3000 compounds, enthalpy and excess entropy for 200 dilute solutions and critical propert- ies and vapour pressure for 600 compounds. Retrieval programs are discussed which allow the tabulation or plotting of many basic and derived thermodynamic properties for chemical substances or balanced reactions. Examples are given of the use of such data to infer the stability or corrosion resistance of materials and the feasibility, yield and heat release of reactions. A general purpose calculation program is discussed which allows the equilibrium compos- ition to be found for complex systems with many species and phases, using the method of Gibbs energy minimization. Methods of correction for non-ideal behaviour in these systems are discussed, as well as methods for fixing, maximizing or minimizing any desired property of the system. Examples are given of the simulation of various laboratory Experiments and industrial processes by this method.

Jan 1, 1977

By Gutsche O, Kapur PC

Experimental data on the production of fines as a function of specific grinding energy consumption show that in general the energy utilisation in a choke fed high-pressure roll mill is higher than in a ball mill, but lower than in the single-particle mode of comminution under slow compressive loading. There is some evidence to suggest that the presence of water in feeds improves the energy efficiency of pressurised roll milling somewhat. Within a wide range of energy input, the size distributions of the ground product are self-similar, the logarithmic median size decreases linearly with the amount of fines produced and the inverse of the median size increases linearly with the energy spent. The production of fines as a function of energy expended follows essentially the same pattern as the one frequently encountered in media mills. The kinetics of grinding in the high-pressure roll mill can be simulated satisfactorily by modifying the standard particle population balance equation in order to account for energy dissipation in the tightly compressed bed. Common characteristics and important differences in grinding by the media mill and the high-pressure roll mill are highlighted.

Jan 1, 1993

By R Heath, P Rose, L Coetser

A sustained eight-year major research effort has been undertaken in South Africa to develop integrated passive water treatment systems for the sustainable removal of sulfates, while simultaneously addressing the removal of metals and acidity. The research effort addressed the problem both at a fundamental science level and at the more empirical pilot plant level. Whereas there are numerous anaerobic sulfate reducing reactors in operation on mine waters that remove some sulfate together with metals and acidity, these are typically plagued by low sulfate removal efficiency and gradual reductions in overall reactor efficiency with time. The South African research effort has focused on understanding the fundamental microbiological and biochemical reactions that occur in anaerobic reactors filled with lignocellulosic material and subjected to high sulfate water. Hypotheses have been developed that differentiate the reactions occurring in such a reactor into groups that should be individually optimised and these hypotheses have been verified through rigorous laboratory and pilot scale studies. The results of this research are incorporated into a patented multi-stage integrated passive treatment system that is capable of sustained high rate removal of sulfates, metals and acidity.

Jan 1, 2003

The following is an outline of the main metallurgical process developments which have occurred at Port Pirie during more than 100 years of smelting. Emphasis is placed on those process developments which evolved from research and development at Port Pirie, rather than those based upon purchased or established technology and straightforward plant engineering. Most processes involved have undergone major change and improvement through the efforts of Port Pirie staff. A culture of metallurgical research and development evolved strongly during the years when G K Williams made such a great impact, and continued for half a century. This culture involved strong links with external research bodies, particularly universities. A near complete bibliography of these developments is provided, together with a listing of patents. Research and development by The Broken Hill Associated Smelters Pty Ltd commenced in 1918 at South Melbourne, and after transfer to Port Pirie in 1921, continued there until 1989. Three periods of highly successful innovation resulted ù that of G K Williams into the 1930s, the post-war period until about 1962 and the period with developments led by Denby H Ward from about 1970 to 1985.

Jan 1, 2000

Agglomeration Drum Selection and Design A model has been developed by for drum agglomeration which allows selection of geometry and power input. Specific aspects considered are: calculation of total operating volume, solids residence time based on drum geometry and operating parameters, selection of the drum aspect ratio, selection of proportion of critical speed, calculation of rotating power requirements. The model uses solids total residence time to calculate the required operating volume. The burden density is calculated from the solids bulk density, agglomerate packing and the fluid density. Power is calculated using a modified Liddell and Moys correlation for burden position and shape, and the operating drum speed. A further power allowance is made to allow for accretion drop off during drum rotation. Results from the model (especially power and per cent operating fill) have been verified from industrial installations of significant size. Predicted and observed power draws are within five per cent when burden slip and bypassing are not significant. When these are significant (at fills above 15 per cent) the actual power draw will be less than the model prediction. Under these circumstances the quality of the agglomerates will be poor.

Sep 13, 2010

By Szymanski J

The problems associated with underground mining continue to grow in size and complexity. As a result mine management is becoming aware of the benefits that can be achieved through the use of computer-oriented tools for system analysis. When such tools are employed in conjunction with benchmarking practices, the drivers of the system that lead to superior performance can more easily be determined. This paper discusses the use of the Simulation Language for Alternative Modelling (SLAM II) in the determination of the drivers of an underground room-and-pillar mining system. The mining operations included in the model consist of extracting, loading and hauling of the coal using continuous mining equipment in a room and pillar system. Equipment specifications and mining techniques used in the model are based upon current methods employed at the existing underground coal mines worldwide. The model developed is capable of adequately predicting the operational performance of the real world system from a statistical point of view. The results from the study show that computer simulation is an excellent tool for evaluating various mine configurations and for gaining a better understanding of the mining systems.

Jan 1, 1995

By Govett G. J S, Currie D. A, Cohen D. R

Analysis of mechanical size fractions of soils around the Paddington deposit (W.A.) and the Charters Towers Goldfields (Queensland) shows a bimodal gold distribution, with enrichment in the coarsest and finest fractions; this is probably a common feature of soils in arid terrains. To establish the true distribution of Au within the soil fractions, the effect of bulk Au content and percent weight variations in size fractions can be reduced by a normali- zing procedure. The greatest extent of lateral dispersion of Au recorded in the -125 ¦m fraction at Paddington and the -63 ¦m in the Charters Towers area as compared to the coarser fractions, and increas- ed levels of sample representivity in the finer fractions, favours their use in exploration. If orientation studies indicate the preferen- tial use of coarse or intermediate fractions, only wet sieving can quantitatively dis- aggregate the clays and remove finer contamina- ting material. The collection of extremely fine fractions such as the -63 ¦m is also accelerated by wet sieving. The additional costs of wet sieving may be offset by better interpretation of results through increased analytical sample representivity, anomaly contrast and continuity.

Jan 1, 1988