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Over the last few years several important developments have taken place in the Electro- lyte Purification Plant at Copper Refineries Pty. Ltd. A fully automated system for the continuous removal of arsenic has been develop- ed. A submerged combustion process for the removal of nickel has been developed to a stage where patent coverage has been obtained in most of the copper producing countries. A plant has recently been commissioned for the production of Tetra Cupric Arsenate, which it is hoped will find a ready market in the timber preservation industry.

Jan 1, 1974

Builders have been very familiar with iron since ancient times, but because of its weathering characteristics it was relegated to use as a fastening material in unexposed places and bronze became the popular metal for exposed applications. It is of interest that iron nails buried deeply about A.D. 87 at a Roman fortress and carefully covered with clean beaten earth under conditions practically excluding oxygen were found to be almost unrusted 1870 years later. (1) Today, weathering steels, which contain less than 2% of alloying additions, can be used in exposed situations without protection and without experiencing continuous wastage. As we all know the steady access of atmospheric oxygen to the surface of plain steel causes continuous corrosion. Weathering steels, on the other hand, due to their alloying additions develop their own impervious surface layer which limits the access of atmospheric oxygen and effectively limits corrosion. Table 1 shows the chemical composition of a plain carbon steel and a typical weathering steel. Fig. 1 shows what we refer to as direct corrosion - time curves in which corrosion loss is plotted against time of exposure in an strial environment. The weathering steel has a high rate initially which then decreases steadily for about three years, as the stable rust film builds up. This is followed by a practically linear relation where the very low corrosion rate, according to one school (2), is due to a blocking of the rust pores by insoluble complex salts formed from interaction of the oxidation products of the separate alloying elements. The start of the linear region represents a total corrosion loss of only about 2 thousandths of an inch.

Jan 1, 1970

By T Wettainen, G Shekhar, M Stromsten, B Skawina

The aim of a transportation system in an underground mine is to move the rock masses from one location to another in the most preferable manner by minimising the long and short-term operational costs. A continuous improvement of material transportation systems used in mines generates a need for continuous investigation of the current and new underground transportation systems. In an underground mine, an orepass is a common system used to transfer the material to the lower levels. If this system loses the ability to transport or store the necessary material capacities, it would result in production disturbances. In this paper, discrete event simulation (DES) was utilised to analyse the material inflow and outflow of the orepass systems when subjected to the different conditions. The study presented in this paper is based on the Malmberget mine, the second largest underground sublevel caving (SLC) iron ore operation in the world.

Mar 15, 2021

By Taylor MN

The influx of an industrial environment into or adjacent to the indigenous society has in the past frequently caused the breakdown of traditional be- haviour and culture, and the generation of social and psychological impacts on the local population. Successful programmes developed by government agencies and private industry have been implemented in many areas to maintain the cultural environment and still afford the needs for industrial development. The ultimate goal of such programmes should be directed toward eventual operation and management of the established industry by the local population.

Jan 1, 1978

In preparation of this Paper, the emphasis has been laid on the commercial rather than on the technical and scientific aspects of coal evaluation. It is intended to describe and comment on the principal factors which currently determine the selection and procurement of coking coal for the steel industry, and is not based on the results of any original research by the author. Evaluation of different coals for strictly thermal uses, for gas production or other chemical applications has not been attempted, and comparisons of coal with other fuels have been excluded: the paper is concerned only with coals for the production of blast furnace coke. The discussion is strongly related to, and illustrated by, British, and to some extent, other Western European practice, but it is hoped that the general conclusions may have a wider application.

Jan 1, 1975

In Australian collieries, solutions to the outburst problem must be implemented in a highly competitive environment which has a low tolerance on negative productivity effects. Solutions are only applicable if the overall viability of the operation remains sound. Minimum time must be spent on alleviation and control measures. This is favoured by simple geology, advanced warning and efficient alleviation and control procedures. Research requirements in support of this include 1. an improved means of predicting the nature and location of outburst zones ahead of the face and, 2. an improved means of measuring the effectiveness of gas drainage. For additional safety at the face, a means of continuously monitoring outburst proneness is required. In general, greater emphasis is required on improved instrumentation.

Jan 1, 1987

By Donald D

A number of standard tests are conventionally carried out to characterise strength properties of rock. The values of the parameters obtained are often affected by planes of weakness or defects in rock structure. For the purpose of mine design, the range in values or the class of the strength (obtained from a number of tests) is generally more important than a precise value (obtained from a single or limited number of tests). Research has been conducted to establish a relationship between an indentation index and the strength of the intact rock material from the Eastern Goldfields of Western Australia. The Tamrock Raise Boring Index (RB-i) test, which is quick and easy to perform, was selected as the indentation test. The results show that, for heterogeneous, strong to very strong rock, there is a good correlation between the indentation index and the uniaxial compressive strength and tensile strength.

Jan 1, 1996

By Eyers G. C

Long Shaft was initially developed using a rail haulage system on every working level comprising battery electric locomotives and granby trucks loaded by rail mounted rocker shovels. Production was commenced using conventional hand held cut and fill mining methods. In an effort to improve productivity and reduce operating costs a mechanised cut and fill stoping method evolved to suit the wider sections of the orebody. To further improve productivity and reduce costs the mechanised levels of the mine are progressively being redeveloped to enable the use of trackless diesel haulage equipment. An added benefit of trackless haulage equipment will be the ability to place development mullock into stopes as Fill.

Jan 1, 1988

The long term viability of a mining company is dependent on the success of its capital investments. Due to the specialised nature of the design, engineering and construction of large projects the management is often contracted to an outside organisation. This paper is a review of the phases of the relationship between Client and Contractor. A rationale is developed upon which the selection of a Contractor can be made. Subsequently, the key aspects of the Client/Contractor relationship are reviewed with reference to completing the project on time within budget. The aspects discussed include Contractor management systems, qualifications of key personnel, definition of scope of work, industrial relations, project control and Contractor remuneration.

Jan 1, 1983

By J P. R de Villiers

The Vanderbijl Park sinter plant in South Africa was investigated to determine the reason for the production of very fine sinter not acceptable as feedstock for the blast furnace. A procedure was designed to generate representative samples and to prepare the samples for chemical and mineralogical analyses. Results from a mineral analyser showed that the samples are extremely heterogeneous and therefore the sampling and sample preparation methods had to be tested in order to produce representative samples. The high production capacity at the sinter plant could also give rise to sampling errors. The method designed involved sampling of the conveyor belt at the sinter plant every four hours for the duration of three days. The samples were then milled and split into smaller sections appropriate for analysis. X-Ray diffraction (XRD) and X-Ray fluorescence (XRF) analyses were conducted on the samples. The results showed a standard deviation of less then one per cent, which indicates that the samples were representative and that the method used was therefore adequate. Systematic differences in the phase proportions between normal and fine sinter samples were detected, with the fine sinter containing more haematite than the normal sinter. The sampling method employed gives added confidence that the differences are real.

Jan 1, 2008

By R Pie, J Crusius, P Whittle, J J. McNee

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of an ongoing three-year government- and industry-funded research program. In order to assess the feasibility of various bio-remediation strategies, field-scale manipulations were conducted using enclosed mesocosms (limnocorrals). Two manipulation strategies were tested: addition of algal nutrients (phosphate and nitrate) to Main Zone Pit surface waters; and addition of algal nutrients (surface waters) and dissolved organic carbon (deep waters) to the Waterline Pit. Nutrient addition was conducted in order to stimulate algal production and enhance metal scavenging by biogenic particles, while dissolved organic carbon (ethanol) was added to increase oxygen demand and foster the development of sulfate reduction in pit bottom waters. Fertilisation resulted in rapid growth of natural phytoplankton populations in the surface waters of both pits. In the Main Zone Pit, the stimulation of algal growth resulted in the pronounced removal of both dissolved and total metals (Zn and Cu) from surface waters, with higher rates of metal removal being observed at higher nutrient additions. Metal removal could be attributed to the scavenging of dissolved metals by biogenic particles and subsequent particle settling. A similar pattern of removal from surface waters was observed in Waterline Pit (Zn and Cd). The addition of ethanol to deep waters in Waterline Pit was effective in promoting sulfate reduction in the lower layer. The development of reducing conditions resulted in near-quantitative removal of dissolved Zn and Cd, presumably as secondary metal sulfides. Iron, As and Ni profiles in Waterline Pit exhibited no evidence of removal from either surface waters or bottom waters. Collectively, the results demonstrate that the passive forms of bioremediation tested in these pit lakes may be effective for whole pit-lake remediation.

Jan 1, 2003

By Battino S

ABSTRACT' The high gas emissions associated with coal extraction at some-Australian collieries have provided a need to investigate the methods used to predict these gas levels and the vent- ilation requirements for gas dilution. It is generally accepted that the introduction of longwall extraction in particular is associated with complex ventilation planning problems. These problems are made much more severe when the colliery introducing longwalls is already facing high gas emissions even during the development stages. A forecast of likely gas emissions during the longwall mining process indicated possible ventilation problems in maintaining the necessary ventilation levels to satisfy the statutory gas limitations for various production rates. Although there are sound principles used in world recognised methods of gas emission prediction a new approach developed from the findings of the Barbara Experimental Mine in Poland appears most suitable for Australian conditions. This has been applied to an Australian colliery preparing for longwall mining using statistical methods for air

Jan 1, 1983

The major slime forming minerals in coal seams are generally montmorillonite, illite and kaolinite, and due to the consistant trend to full seam mechanisation in New South Wales and Queensland these minerals remain in the feed to a coal preparation plant. After coming into contact with water their size degradation is very rapid, and therefore they mostly report to the fine coal cleaning section of the plant. Froth flotation, being the most effective method of beneficiating fine coal, is widely practised in these two major coal producing states of Australia. Plant experience and laboratory tests suggest that the presence of these slimes in the flotation circuit depresses the flotation of fine coal. Although the deleterious effects of slimes on the flotation behaviour of minerals is well known, the mode of their adsorption at the mineral surface has been a subject of controversy for some time. In this paper, on the basis of the surface properties of slime forming minerals and coal, a model has been put forward to explain the adsorption of slimes at the coal surface. The degree of slime coating has been examined by scanning electron microscopy. Laboratory tests have revealed that with the appropriate use of polyvalent phosphate electrolytes these slimes can be liberated from the coal surface. Just attrition and desliming are not enough to ensure complete liberation of slimes. Coal, after treatment with these electrolytes and then deslimed, floats readily with a common frother, such as MIBC. Modifications in the conventional flotation circuits have been suggested to ensure an efficient flotation of fine coal.

Jan 1, 1978

By Fulton E, Ring RJ, Waters DJ

Laboratory leach tests of Nabarlek uranium ore carried out by the Australian Atomic Energy Commission to compare the effectiveness of Caro's Acid1 (permonosulphuric acid) as an alternative oxident to pyrolusite indicated reduced acid consumption in leaching and lime savings in neutralisation of tailings liquors when using Caro's Acid. Interox Chemicals Pty. Ltd. arranged a plant trial for Caro's Acid at Queensland Mines Nabarlek Plant. The trial confirmed that significant savings in acid and lime can be achieved under plant conditions. Plant operations also demonstrated improved redox potential control was possible using Caro's Acid.

Jan 1, 1978

By Canning RG, Uusna S, Goodheart BA

The paper outlines the development of"a process for removal of iron oxides from ilmenite, thereby upgrading the TiO2 content of Western Australian ilmenites, from 55 to approximately 90 per cent. In the first stage, the iron oxides are reduced with solid carbon (coal) to metallic iron. Experimental reduc- tions were carried out in crucibles,, a fluidised bed and a small pilot plant rotary kiln. The reduced'ilmenite is,then agitated in aerated water, in the presence of catalysts, so that the iron "rusts" away from the ilmenite'grains and the precipitated iron oxide is easily separable by decantation. The influence of variables on the rates. of reduction and oxidation are discussed, The oxidation rate was exam- ined for both - the' physical oxygen-transfer characteristics and electrochemically by reference to Peurbaix diagrams, which plot redox potential against solution 'PH, The upgraded ilmenite is expected to be an attractive material. for pigment -manufacture,, and the iron oxide has prospects of being a marketable by-product. The process may possibly be. applied, to .other..ores.

Jan 1, 1964

Electrochemical investigations of the flotation of sulphide minerals are re- viewed. Flotation with thiol collectors is interpreted in terms of a "mixed poten- tial" model in which the process leading to hydrophobicity is the anodic oxidation of the collector at the mineral surface and this is driven by the cathodic reduc- tion of oxygen. Electrochemical studies have identified the products of anodic oxidation as chemisorbed collector, metal collector compounds, and dithiolates; the products formed in each situation depend on the collector used, the mineral under study, and the pretreatment of the mineral surface. Investigations on galena, pyrite, and chalcocite are discussed. Electrochemical and x-ray photoelectron spectroscopic studies have been used to determine the products of surface oxi- dation of sulphide minerals in order to elucidate the mechanism of collectorless flotation. The mixed potential mechanism allows consideration to be made of the ways in which flotation of sulphides with thiols can be inhibited. Examples of depressant action are presented. The relevance of electrochemical investi- gations to practical flotation is Discussed.

Jan 1, 1984

Three main divisions of the. Proterozoic are recognised in the North- West of Western Australia. These are referred to, in order of decreasing age as the Mt. Bruce Supergroup, the Bresnahan Group and the Bangemall Group. The stratigraphy and distribution of each is described, their relative ages discussed and a brief geological history of the whole area is Presented.

Jan 1, 1964

By Bothe C

Froth flotation processes use different surface properties of the minerals to be sorted. In an aqueous environment the hydrophobic mineral attaches selectively to air bubbles and is lifted to the surface of a separation vessel, while the tailings settle towards its bottom. Besides the surface properties, the hydrodynamic conditions play an important role. With respect to the hydrodynamics the flotation process can be divided, for simplicity, in two sub-processes. The attachment of hydrophobic particles to air bubbles, the so-called mineralisation, demands a large number of collisions and therefore high turbulences. The phase separation however needs a deterministic movement of both the particle-bubbles-aggregates and the tailings particles and therefore a quiescent flow field. The optimisation of the overall process requires a separation of both sub-processes, especially when fine particles have to be sorted. In conventional mechanically agitated flotation cells both sub-processes take place in the same turbulent volume. For this reason they suffer from a decreasing selectivity with decreasing particle size. In flotation columns the mineralisation of air bubbles and the phase separation are performed in a quiescent environment. This results in high concentrate grades and at the same time in a very slow attachment kinetics, which must, especially for fine particles, be counterbalanced by a long residence time of the slurry.

Jan 1, 1993

LKAB operates two underground mines in Kiruna and Malmberget, Sweden. Blast furnace pellet is the main product and makes up 70 per cent of total production. The orebodies are hosted by 1910 - 1860 Ma old volcanic rocks. The host rocks and the ores were affected by the Svecokarelian orogeny for 1890 - 1860 Ma ago. The deposit belongs to the Kiruna type apatite-rich iron ore. Magnetite is the main ore mineral but haematite is the dominant ore mineral in some orebodies in the western part of the deposit. Large-scale sublevel caving is the dominant mining method. Three main haulage levels are in operation at present. The ore boundaries and quality can be detected by geophysical logging resulting in reduced waste dilution and subsequent grade reduction. The susceptibility measurements have been used in the magnetite ore since 1991 and gamma-gamma measurements in the haematite ore since 1998. The mining scale has increased during the last 20 years but diamond drilling has remained at approximately 18 000 drilling metres per year. Uncertainties in the ore constructions can lead to unexpected cost increases, ore loss and dilution. The ore boundaries are evaluated with percussion drill holes using in-hole geophysics to achieve satisfactory geological knowledge. The probes are calibrated in all currently mined orebodies. The correlation between core sample assays and measured susceptibility and gamma-gamma values is strong. The cost to determine the ore boundary by percussion drilling with in-hole geophysics is two-thirds lower, and productivity is six times higher compared to diamond drilling. The measurements are made by geotechnicians and the interpretations by a geologist. The results are transferred to a database and presented three dimensionally as holes with iron grade intervals on mine maps. The interpreted holes are used by the geologist in various ways in the geological modelling. Layout planning uses the measurements as a tool to place the drifts at the correct distance from the ore contact especially in the longitudinal sublevel caving and the production hole planning to optimise the final length of the cross-cuts and drifts for best ore recovery.

Jan 1, 2006

By Shiels O. J

The paper reviews developments in general galvanising in Australia, including a brief history of the industry and its technology. The changes in galvanising process technology are covered, as well as developments in galvanising bath design, materials handling and pre-treatment. Developments in zinc management through the use of aluminium and nickel alloys are discussed. The paper addresses the cost components of general galvanising and relates this to the competitive position of general galvanising against other coatings used for protecting steel. The environmental aspects of the general galvanising industry in Australia are outlined with respect to the utilisation of process chemicals, problems associated with their disposal and developments in filtering and regeneration of process solutions. The current status of the industry is assessed in terms of zinc usage and usage trends. Likely changes in technology which may impact on the general galvanising industry in the future are reviewed.

Jan 1, 1993