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By Dunlop JSF

A description of general mining proced- ures and tyre maintenance practice is given with particular reference to tyre mainten- ance facilities and record keeping at Groote Eylandt. Experience with tyre wear on Wabco 85C rear dump trucks is then outlined, concen- trating on wheel camber, wheel alignment, truck speed, tyre pressure, loading and haul road design. T T.1TUnilhTPTTnAT The Groote Eylandt Mining Company Pty. Limited mines and beneficiates sedimentary manganese ores from a series of orebodies occurring in the western part of the island. The island is one of a group on the western side of the Gulf of Carpentaria, about 50 kilometres from the Arnhem Land coast and about 650 kilometres from Darwin. Whilst capacity of the mine is presently 2.3 mil- lion tonnes of product per annum, current production has been reduced to just more than half this figure, due to a general mar- ket recession.

Jan 1, 1982

By Y Gu

Based on the mode of occurrence, gold is classified into three categories: microscopic gold, submicroscopic gold and surface-bound gold. Microscopic gold, or visible gold, refers to gold minerals in which Au occurs in a substantial amount, such as native gold and electrum. Submicroscopic gold, ie invisible gold, refers to gold contained in the structure of other minerals (mainly sulfides) in minor to trace amounts. Surface gold is the gold that was adsorbed onto the surface of other minerals during mineralisation and subsequent oxidation or metallurgical processing. Gold mineralogy has a significant impact on its extractive metallurgy. Gold process mineralogy helps address problems related to gold ore processing. It is widely used as a predictive and troubleshooting tool in gold ore processing, and provides useful information on process selection, flow sheet development, recovery improvement and reagent consumption optimisation. This paper will begin with the classification of gold ores, and will focus on gold mineralogy and how it impacts extractive metallurgy through case studies.

Jan 1, 2008

Classifications of Ni-Cu deposits are based on petrology, geochemistry and the geotectonic setting of host igneous bodies (Naldrett and Cabri, 1976; Besson et al, 1979; Nadrett, 1989). The four major classes in Naldrett's (1989) division rest on the geotectonic setting of the igneous complexes and the classes are further subdivided on the basis of the petrology and geochemistry of the intrusion. A more common subdivision of mafic and ultramafic igneous rocks is based on the environment of rock-forming processes, endogenic or exogenic, intrusive or extrusive, and this subdivision has been applied, in practice, to the classification of sulphide Ni-Cu deposits, too. The extrusive deposits, Class I in Naldrett's (1989) classification, are directly related to volcanic processes whereas all the others refer to the intrusive environment. This paper looks at the differences between the extrusive and intrusive groups of Ni-Cu deposits and presents generic, genetic and structural features of the intrusive group.

Jan 1, 1996

The Olympic Dam Mine is a large, mechanised, underground operation currently producing 2.2 million tonnes-per-year of copper/uranium/gold ore. The mine is accessed via one shaft and one service decline. An additional 13 raise bored ventilation shafts have been completed to-date.Ventilation requirements are stringent in order to provide adequate dilution and removal of diesel fumes, radon gas/daughters and heat generated from both engines and wall rock.Due to the nature of the orebodies, the mine workings will continue to expand laterally necessitating the addition of at least one major surface raise every year.

Jan 1, 1992

Scientific drilling and blasting techniques are currently being presented to the mining industry as an aid in the overall optimisation process. The degree of success in the development of these techniques over the last ten years has prompted statements that generally relate to blasting becoming a science rather than an art. Many of the techniques are currently operated or at least analysed by scientists. As such, their use has been restricted to project type activities while the more routine activities associated with day to day mining has continued to be carried out by engineering rather than scientific staff. Some of the scientific techniques will remain legitimately as a project or an occasional use facility. Generally speaking a cost/benefit analysis at a particular mine will decide the level of use. This should logically highlight a number of techniques with potential of regular mine site use. Regular mine site use implies mine site analysis and hence the gulf between the scientist and mine operator/engineer must be addressed. There are all sorts of solutions and they are not mutually exclusive. One alternative could be to increase specialisation at the mines. With "career paths" becoming more formalised the trend would seem to be away from mine site specialists unless, for instance, this specialisation was provided by term secondment from research establishments. Another alternative could be the scientists themselves applying their developmental skills to "humanise" and "package" the projects in such a manner that they can be routinely used at mines.

Jan 1, 1990

By M Noppe, I Glacken

There are many critical nodes along the mine value chain, from orebody to mineral product, and inter-disciplinary input is required to analyse the variability and uncertainty at each node in order to identify and mitigate areas of risk. Mining differs from many other industries in that the variability in the product is dictated largely by the inherent nature of the input material (the orebody). The true characteristics, including the variability of the orebody, are never known exactly and are instead based on estimates derived from sample data. A further difference is that bottom-line gains are largely controlled by world commodity prices, which can vary with time, rather than by local supply and demand issues. Methods for identifying, reporting and responding to this inherently variable raw material are discussed. These include analytical and reporting methods, equipment and software, risk analysis and reality checks (eg reconciliation). Sampling results, mineral resource and ore reserve estimates and economic assumptions are a function of the variability of the orebody. Risk quantification should be expressed as a level of confidence, which takes into account the scale or period over which the risk is being assessed (life-of-mine, annual or shorter production periods) and should convey the likelihood, severity and consequence of occurrence of a given event. The future generation of mining specialists needs to understand the entire mine value chain to better manage risks and maximise mine dollar-value.

Jan 1, 2002

By J G. Petrie, H von Blottnitz

The selection and design of process options to deliver outcomes consistent with sustainable development requires simultaneous consideration of multiple objectives, within a climate of uncertainty û including the environmental and social aspects of technology management in addition to the technical and economic aspects of such. An issue of particular relevance in primary metal production is the deportment of minor and trace components within orebodies, products and wastes and the implications of such deportment for eco-efficiency û in particular, the long-term environmental impact of solid waste management practices. The identification of opportunities to enhance recovery of valuable by-products and simultaneously improve the environmental acceptability of final waste output requires a clear understanding of the distribution of the relevant ore components, which results from the choice of processing route and unit operation efficiency. This is challenging, given that process streams generated during primary metal production are generally poorly characterised and the behaviour and deportment of trace to minor and trace components is not well understood. This paper demonstrates how current data gaps and inconsistencies can be systematically addressed through the meaningful reconciliation of empirical plant data with a fundamental understanding of the mechanisms and parameters influencing element behaviour and deportment during the formation and subsequent beneficiation of mineral ore deposits. On this basis, quantitative distribution data and a comprehensive and comprehensible inventory of unit process inputs and outputs as a function of ore compositions and processing technology options can be generated, which is consistent with early design stage information requirements, both in terms of detail and accuracy, ie is æfirst-orderÆ in nature. This predictive approach to element distribution during primary metal production provides decision-makers with key information in the early design stages of a project (in terms of developing processes within the context of sustainability), whilst simultaneously guiding further data collection and environmental impact prediction studies.

Jan 1, 2006

By Johnson D. P, Beamish B. B

The northern Bowen Basin has a very large resource of coalseam methane gas-in-place - 136 TCF(7ohnson and White, 1988). The gas is pipeline quality, being 98-99 per cent methane with traces of carbon dioxide and higher hydrocarbons. The largest resource of natural gas within the coalseams of the northern Bowen Basin is contained in the Moranbah Coal Measures (75 per cent). The next most important resource is in the combined upper Fort Cooper (16 per cent) and Rangal (nine per cent) Coal Measures. The far northern parts of the basin have low gas contents due to the combined effects of limited extent of the coal measures, shallow depth and low rank. Reserves per well are more than double that of the best coalseam methane wells in any basin in the United States. In some areas of the Moranbah Coal Measures, the gas-in-place estimates exceed 225 million cubic metres per well (80-acre spacing). A distinction is made between resource base, as determined from this basin assessment, and the deliverability potential. Parameters used to estimate gas-in-place (coal area, thickness, density, rank and depth) can be adequately extrapolated from areas of high- to low- data density. Parameters affecting methane production (permeability, gas depletion factor and critical desorption pressure) cannot be generalised. Exploration and development programs must rapidly develop a predictive capability for these factors, on a local scale, through geological modelling and confirmation drilling.

Jan 1, 1991

By R F. Johnston, I D. Sommerville

This paper presents an overview of the researches carried out in our laboratory on the application of plasma in recovery of alloy elements from waste slags and the treatment of lean ores, which are examples of advanced materials processing. After briefly reviewing the early work on the reduction of nickel, chromium, manganese, vanadium and titanium oxides, and a short investigation of the reduction of titanium oxide from the slag resulting from the blast furnace smelting of a titanomagnetite ore, the paper concentrates on the more recent studies on the reduction of an Australian scheelite. In some of these experiments, aluminium was used in addition to carbon as a reductant, in virtually all cases complete reduction was achieved within a relatively few minutes even with carbon alone during plasma processing. It therefore appears that this technique provides a possible processing route to facilitate the recovery of valuable alloying elements from non-traditional sources, or to permit process step elimination.

Jan 1, 2000

By R West

The Olympic Dam smelter facility processes copper concentrate feed using direct-to-blister smelting technology to support the current site production rate of 225 000 t/a copper. The metallurgical control of the Olympic Dam smelter is largely managed from a single central control room. Control room operation and management is therefore a key function in ensuring safe and reliable operation of the smelter, including identifying and initiating control of abnormal events. As part of a consolidated smelter reliability improvement program, a team consisting of process and control system engineers was formed. The teamÆs charter was to address and resolve the alarm flooding issues being faced by the control room technicians and the lack of an up-to-date base of supporting functional documentation. The project was successfully resourced with WorleyParsons metallurgists, Citect PLC technicians and the on-site technical team. Implementation was conducted over a 12 month period with the goal of achieving best practice alarm levels. The goal was achieved through a systematic process of alarm design review that analysed every configured alarm versus best practice design standards. Innovative concepts such as group-based alarms, first-up interlock displays, graphic only alarming, alarm help and alarm shelving were developed and implemented in conjunction with improved alarm masking. Total configured alarms were reduced from 20 000 to 5000 while the alarm rates were reduced from in excess of 200 alarms per hour per controlling technician to best practice levels of less than 12 alarms per hour per controlling technician. Completion of this program has provided a firm foundation for implementing further control optimisation and was a key activity in supporting sustained smelter reliability levels.

Jan 1, 2005

By D A. Williams

The conventional method of transporting mine tailings from a process plant to a tailings storage facility (TSF) is in the form of a low to medium density1 slurry, which can be pumped using centrifugal pumps. Over the past several decades, therefore, mine operators have generally adopted this default approach. There are, however, some convincing arguments why consideration should be given to thickening the tailings slurry to a higher density paste consistency. In particular, the minimisation of environmental impacts, the reduction in water consumption and the cost savings relating to TSF closure make paste an attractive option for the life of mine tailings disposal. There are several environmental impacts that are associated with a conventional slurry TSF, such as land sterilisation, aesthetics, dust, seepage and acid mine drainage. Some of these impacts, such as dusting, may be difficult to mitigate while the TSF is in operation. Others can be influenced by adjustments made to the tailings slurry density at the plant. Unplanned fluctuations in slurry density and/or viscosity can have a significant influence on TSF performance and can exacerbate the environmental impacts relating to the facility. Relatively minor changes in the solids content of the slurry can affect tailings beaching behaviour, degree of segregation, position of the phreatic surface, amount of freeboard, consolidation behaviour, placed (settled) density (and hence TSF capacity) and in situ strength of the tailings. Paste is a non segregating slurry and many of these effects can be minimised at the TSF when the tailings slurry is thickened to a paste. These improvements are manifested by reduced seepage, flexibility in selecting an appropriate final landform, ability to rehabilitate progressively and reductions in plant water usage. It is possible to minimise environmental impacts of a TSF through the use of tailings paste. Ideally the paste production plant should be part of the initial design of the process plant. However, significant benefits can be gained by adding a paste production plant at some time later in the operational life of the mine to reduce environmental impacts and facilitate an environmentally acceptable TSF closure.

Jan 1, 2002

What is the real value of your data?Given that the cost of collecting and analysing an individual sample is always rising, it is important to understand the true value of a sample and that you are confident that you receive good value for your exploration dollar. Unfortunately too many samples are still collected today that will end up as worthless data; a liability to those who own it and a hindrance to finding that ore body.

Jan 1, 1986

About 11,000 tons of contaminated zinc flotation concentrate were available in the form of earth walls from dams used for atmospheric drying of the concentrate.Following successful laboratory tests this material was treated in a plant by crushing, grinding, and then flotation in a circuit consisting of roughing, scavenging, and two stages of cleaning. Reagents used were copper sulphate and a little butyl xanthate and frother. About 5,720 tons of zinc concentrate assaying 52· 3 per cent zinc were produced.

Jan 1, 1968

The Plant Control and Data Logging System for the Loy Yang Open Cut (LYOC) is part of a control and communications network designed to provide a high level of surveillance of open cut plant and facilitate the efficient co- ordination of operations and plant maintenance. The computer system selected utilises a central dual mini-computer and multiple microcomputer data transmission network ,linked to the plant controllers using distributed, microcomputer based remote data collectors or outstations. Several aspects of the computer system are outlined.

Jan 1, 1982

By D M. Aranha, A R. Cabral

Theories on the origin of the Itabira iron formation (itabirite) in Quadrilßtero Ferrffero (QF), as elsewhere in the world, are restricted by the apparent lack of adjoining volcanic units, severe syndeformational metamorphism and deep weathering. Besides the three types of iron formations at QF (siliceous, dolomitic and amphibolitic; Dorr, 1969) we include a fourth type initially described as ocherous, goethitic, limonitic or even yellow iron formation. Considering its high magnetite content, it has been described as yellow magnetite itabirite (Pires, 1979). It was reported as formed by the alteration of the dolomitic itabirite (Dorr, 1969) although the anomalous Al2O3 contents are high for normal weathered itabirite. The yellowish magnetitic itabirite occurs at the bottom of the Itabira Iron formation, along the contact with the Batatal schists, and at the top units of the Itabira, within the Gandarela Formation. Within the magnetitic itabirite at the Tamanduß iron ore mine there are metric zones, concordant to the bedding of pillow-like structures, exhibiting a porous core, surrounded by an intermediate, more granular zone with numerous, minute rounded cavities grading to an external, fine-grained zone with much less minute cavities. In the external portions of some pillows a breadcrust type structure, derived by quenching with the water can be observed. In some other zones, such as the Barreiro hill, an outer, vesicular, whitish yellow, 5 - 10 mm thick, band grades to an aphanitic, isotropic band. The vesicles are slightly flattened against the band surfaces. The existence of fragmental layers showing flowage and fragment alignment, kaolinitic laminas and vesicles filled with kaolinite at Barreiro Hill and Capitpo do Mato Mine represent mesoscopic structures, indicators of a possible volcanic origin. Chemical compositions of the magnetitic itabirite from a wide area in QF revealed a relatively high Al2O3 content, consistent with a volcanic origin.

Jan 1, 2005

By J Shooter

Pezzimenti Laserbore designed, fabricated and commissioned the first microtunnelling machine in Australia in 1986. The System was initially a very basic one, developed in isolation to the overseas explosion in microtunnelling growth headed by Japan and Germany. Market needs in Australia have demanded increasing flexibility in microtunnelling capacity-longer distances, variable ground conditions and larger diameters. The one constant throughout the development process is in maintaining high accuracy û the attribute which most readily differentiates microtunnelling from other limited steering techniques.This paper will highlight the features of microtunnelling by drawing on case studies of completed projects.

Jan 1, 1999

By Houchin MR, Jenkins DH

This paper examines the importance of processing to the properties and performance of high purity zirconia ceramics. Many of the principles discussed, however, apply to ceramic processing in general. For fabricated ceramic articles to display their wide range of high performance properties, they must be made fully dense. The precursor powder and postpowder processing requirements necessary to achieve full density in the fabricated body are discussed. Brittleness, the anathema of ceramics, can be overcome in zirconia by incorporation of toughening mechanisms. Transformation toughening and microcrack toughening and their origins in partially stabilized zirconia are reviewed.

Jan 1, 1989

Robe River Mining manages a large open pit iron ore mine in the Pilbara region of the North-West of Australia. The mine is managed for various joint venture participants.In July 1986, Robe River Mining made various changes to its management philosophy, which were heavily publicised in the media at the time.As a result of those changes to its management philosophy, Robe River Mining has been able to dramatically increase its production output, productivity, and safety performance without having to resort to major capital outlays and without the benefit of restructuring of applicable industrial awards.

Jan 1, 1992

By Oboso A, Nakahiro Y, Takenaka Y, Wakamatsu T

As part of the fundamental studies on the recovery of Au by solvent extraction, the synergism of combined extractants on the extraction of An from the sulphuric acid solution containing thiourea was investigated. Extractants tested were di-(2-ethylhexyl)phosphoric acid (D2EHPA), tri-n-octylamine (TOA), tri-n-butyl phosphate (TBP), and trioctyl phosphine oxide (TOPO). Four kinds of extractant combinations, D2EHPA/TBP, D2EHPA/TOPO, TOA/I'BP, and TOAITOPO, were tested to clarify the synergism on the extraction of Au in terms of various concentration ratios, diluents, the concentration of sulphuric acid, and the concentration of thiourea.

Jan 1, 1993

By J E. Everett, M L. James

When iron ore is crushed and split into lump and fines components, there are systematic differences between the lump and fines grades. Generally the lump product is richer in iron and lower in the other minerals, compared to the fines product. The grade differences between lump and fines, together with the lump percentage, are referred to as the ælump algorithmÆ. Mine estimates of grade, based on exploration or blasthole drilling, relate to head grade. The ælump algorithmÆ predicts lump and fines product grades from the head grade. This knowledge is important when developing mine plans. Different ore types can be expected to have systematically different lump algorithms. Previously, lump algorithms for specific ore types have been estimated by running the crusher with a single ore type over a sample period. This method is costly, interferes with production, and yields results of limited statistical power. It has been found that weighted-least-squares (WLS) multiple regression can be used to ascribe lump algorithms to different ore types, provided sample periods have sufficiently varied ore type mixes. This study discusses the method and its application to the analysis of Mining Area C crusher production records to estimate the separate lump algorithms, which could be applied to the different ore types. The analysis has enabled the set up of lump algorithms in the production system, to improve the grade control of lump and fines product. Some other relevant applications of the WLS multiple regression approach are also considered.

Jan 1, 2005