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By Hiddlestone D. C

Effective exploration, testing and analysis is essential for good process design and optimisation of coal preparation plants. Coal processing relies on the sizing and washability characteristics of the particular coal to define the most cost effective design to meet the market requirements. Flowsheet development and equipment selection is dependent on the natural quality characteristics of the coal, its physical properties and the value of the final product in its market. The methodology of process selection and the key elements in design are discussed. Coal is consumed in two general markets: ò steaming coal - both domestic and export, and ò metallurgical coal. This paper discusses the typical economic analysis required to evaluate the potential for, and cost benefit of, providing the flexibility to switch coals between markets. A case study illustrates the methodology of process selection in a typical high value metallurgical coal.

Jan 1, 1997

LESLIE BRADFORD GOLDEN JUBILEE ORATION "Not only a metallurgist but a scientist of the highest order" Leslie Bradford and the Australian Metallurgical Industry

Jan 1, 1987

A major tool in the search for petroleum is reflection seismic mapping. The period which has seen most of the exploration in Victoria is also one which has seen major advances in this technology, from 1963 try present day. Seismic mapping can be divided into three interlinked areas - acquisition, processing, and interpretation. In acquisition the major changes have been from an explosive energy source in 1963 to gas exploders in 1968 and airguns in 1970. The number of recording channels has increased from 24 to 192, with digital recording introduced in 1966, and floating point recording in 1976.

Jan 1, 1982

By T Laurencont

The Queensland Department of Natural Resources and Mines (NR&M) accepted the environmental liability for the Mount Morgan minesite in 1991. This gold and copper mine located 38 km southwest of Rockhampton had been in operation for more than 100 years. Mining leases are still active while the feasibility of a reprocessing operation is carried out. From 1993, NR&M have operated a seepage interception pumpback system which has reduced the chronic load of acid rock drainage (ARD) to the adjacent Dee River, a tributary of the Fitzroy River system. In early-2000, it was recognised that a ten-year plan for rehabilitation of the mine, along with significant funding would be required if a long-term sustainable rehabilitation strategy was to be implemented at this minesite, ultimately making the seepage interception system redundant. A rehabilitation planning workshop coordinated by NR&M was held in May 2000. This workshop brought to the mine a range of technical expertise and key stakeholder groups. This workshop provided a technical forum for review of studies undertaken and to identify priority projects, which needed to be undertaken in the future to more clearly define contaminant sources on the mine site and to prioritise the rehabilitation program. Stakeholder consultation enabled the project team to be clear on community and other government (eg Environmental Protection Agency) expectations. It is clear that the future of the economically depressed community of Mount Morgan will be reliant on the careful management of the significant heritage values at the minesite for tourism, education and research. In the first year (2000), priority studies were initiated, which included whole of site studies on water balance, contaminant sources and a review of occupational health and safety and environment of the minesite and conservation and heritage scoping. Baseline vegetation and soil materials surveys were also initiated. The outcomes of these studies helped to shape the work program for the following year, while providing a basis for an additional funding application, which was granted. The second year of studies focused on building upon the existing baseline studies completed. In addition, studies focussed on addressing the priority issue of contingency planning for overflow from the open cut pit in accordance with best practice management of release water and river monitoring strategies were completed. Completion of these projects over the next six months will enable the optimal rehabilitation strategy to be defined in 2003. This optimal strategy may require the use of a water treatment plant for part of the ten-year program to provide space in the open cut pit for the deposition of ARD contaminant sources (eg waste dumps, tailings). It is envisaged that some sources will be rehabilitated insitu while others will be relocated to the open cut pit. Implementation of this strategy will be dependent on subsequent funding.

Jan 1, 2003

By Cudmore JF, Rowlands D

Incidents associated with spontaneous combustion of coal have resulted in the loss of many lives and considerable capital and equip- ment. Nevertheless, the factors controlling the propensity of coal to spontaneous combustion are not clearly understood and there is a need for research to study the effects of rank, petrog- raphy, moisture contents, etc. This has been attempted in a study of the propensities of selected Queensland coals to spontaneous combustion. An adiabatic calori- meter was constructed to study the self-heating of a large number of coals. Chemical and petro- graphic analyses of the coals were determined and an attempt was made to relate these propert- ies to the self-heating characteristics of the coal. The results show a strong relationship between rank and self-heating characteristics and that petrographic composition of coal may also be of importance. Some observations on the application of the laboratory results to the practical situation are made as are recommendations for future research.

Jan 1, 1981

By Mitchell D

In recent years the need to provide increased ventilation to improve environmental conditions rather than to dilute firedamp has led to increasing interest in the use of recirculation. Present UK mining law prohibits recirculation in ventilation, but it has been permitted selectively by exemption granted by Hm Inspectorate of Mines and Quarries. The conditions of use imposed by these exemptions to safeguard the safety and health of miners are examined in detail, dealing separately with primary and auxiliary recirculation systems.

Jan 1, 1988

By J Manuel, L Lu

Increasing bed depth is one of the main options sinter plants consider to increase production, since it is an incremental improvement and less expensive compared with a new plant. To maximise the benefits of increased bed depth, correct blend design and plant operation is critical. This paper discusses test work conducted to show the effects of ore type and bed depth on sintering performance and the adjustments required in both fuel rate and lime addition depending on ore type. The differences in sinter plug macro and microstructure were also examined to show the effect of bed depth on ore assimilation and matrix formation. Finally, the benefits of blending ores to achieve the best sintering performance as bed depth increases is discussed.

Jan 1, 2007

Revised throughput rates, as a result of current mining methods and tight controls on mine dilution, have dictated a change in metallurgical philosophy at Renison Limited. Emphasis on throughput capacity increases has altered to a reduction in circuit complexity and operating costs. Extensive surveys of the gravity and cassiterite flotation circuits led to several plant modifications between August 1989 and March 1990. The coarse and fine gravity retreatment roughing tables were by-passed, the coarse gravity retreatment roughing tables were re-commissioned, the cassiterite flotation rougher capacity expanded and the gravity regrind cyclones re-configured.

Jan 1, 1991

Underground space can be defined as space below natural ground level which can be used as an alternative to an above ground location. While many of our above ground structures inherently involve underground excavation for foundations and services, the term underground space specifically refers to organised development of underground openings and of the underground domain. For example, the services to a city such as power, gas, sewerage, water and communications are installed in a congested array which usually requires roads to be dug up when the services need to be accessed. An underground space installation of services would involve a well planned conduit which is easily accessed without any excavation. The concept of using this virtually untapped land resource to the advantage of our expanding cities is gaining considerable interest in Australia. Overseas, in the Scandinavian countries and some Asian countries, underground space has been used for centuries; in Great Britain, France and the United States of America over the last century and in Japan for over a decade. This paper focusses on the types of underground space usage which should be competitive with above ground use and suggests areas in which the competitive edge may be improved in favour of underground space. In particular, considerable advantage is seen by using well-planned underground space developments in major cities, where the strategic central location of the development takes advantage of proximity to potential users. However, the largest single factor affecting the acceptance of underground space is the high capital cost of construction, even though an underground space development may result in lower operating costs and reduced long-term maintenance costs. While excavation methods and associated costs are very much site-specific, the importance of applying the latest technology in rock breakage, with consideration of ground vibration, excavation rates and ground support, remains a major challenge to the development of underground space.

Jan 1, 1995

By Dunbavan M, Mallett C. W

The sequence of development and back analysis of the failure of a spoil pile in the 1B pit of the Moura Mine are given. The mode of failure was a two-wedge mechanism with a basal slip plane passing through a clay band about 2 m below the pit floor. Remedial actions for improving spoil pile stability are discussed.

Jan 1, 1981

From the ventilation aspect, there is a basic difference between advancing and ezreating longwall layouts. Particular rroblems with retreating, using differing mining methods and layouts include high gas emissions, spontaneous combustion and -radients. There is an acceptable method of crntrolling the environment at the return end a retreating longwall face without the use a multiple heading system. Incorporated in the design is the facility to practice xtensive methane drainage, thus ensuring a ntrol of the rate of methane emission into the main roadways. Case studies highlight varying mining editions under which the proposed system of Ctised.

Jan 1, 1982

By Sehic O. A

Geology can be the root of evil or a source of bliss; there is a choice; to ignore geology is at a mine's peril.Risk can be minimised and profitability maximised by the application of a detailed understanding of geology, alteration, structure, mineralogy, chemistry, fabric and texture.Geology is dynamic, not static.The impact of geology is pervasive.The integration of ore quality control with grade control is one strategy for improving the utilisation of both the mineable reserves and existing plant and equipment. Grade maintenance is but one constraint on the problem of how best to blend the ore. Other ore characteristics such as mineralogy, hardness for grinding, and pulp fluidity or density for slurry size classification can be included to explore alternative blending Strategies.

Jan 1, 1993

By Wood P. D, Pettifer G. R

In the upper coal surface in the Latrobe Valley, craters known locally as fireholes have developed due to prehistoric coal fires. They can be several hundred metres across and up to fifty metres deep, and are now filled with overburden materials varying from hard baked clays to very soft lacustrine clays. In addition to reducing coal reserves, continuous mining operations are seriously affected by fireholes. Large undulations in the upper coal surface result in a mixture of coal and overburden on the upper mining levels. The very soft lacustrine clays are unstable in the mine batters and the overburden dump, are difficult to handle on the bucket wheel excavator/conveyer system, and have insufficient bearing capacity for the large bucket wheel excavators. Early identification is essen- tial and both drilling and dynamic core penetrometer have been exten- sively used. However, this has not proved adequate in locating and defining the extent of all fireholes, due largely to their irregular shape. To overcome this a range of geophysical techniques has been trialled with very promising results. A trial area has been covered on a twenty metre grid using gravity and Geonics EM34 conductivity measurements and the same area has been covered at a closer spacing with high resolution magnetics. Image processing of contoured magnetic, EM34 conductivity and residual gravity data has resulted in very good correlation with drilling data.

Jan 1, 1989

By Ho D, Yang J

The ready availability of powerful desktop workstations, which combine 3D real-time graphics and processing speed better than that of supercomputers of a few years ago, now allows the cost-effective solution of real world geomechanics and underground mining strength simulations. The inclusion of geotechnical factors such as rock joints and porous flow on strength and stability are discussed together with the range of available deformation and failure models for soil, rock and concrete. This paper describes the capabilities provided by finite element graphics and analysis software for modelling and sequential investigation of both excavation and lining, or rock bolting, construction sequences. Examples of the use of finite element models in mining are also included in the paper, together with a discussion of the required people, software and computer hardware resources required to achieve timely and productive results.

Jan 1, 1995

By Gonzalez-Dominguez J. A, Dreisinger D. B

At Cominco's Zinc Refinery at Trail, British Columbia impurities are removed from zinc sulphate electrolyte by a two-stage purification process using zinc dust. Copper, cadmium and thallium are removed in the first stage whereas cobalt is removed in the second stage. Cobalt removal kinetics are affected by soluble antimony and copper additions to the electrolyte. This study was focused on the kinetics of cobalt removal by zinc powder cementation. Experimental variables included copper and antimony concentrations, pH and temperature. Common organic additives employed in zinc plants were studied to determine potential interactions with the cobalt removal process. Cementation products obtained from laboratory experiments and plant practice were studied using SEM. A number of significant results were obtained: 1. Copper and antimony ions were sustantially removed from solution during the early stages of the cementation reaction (within the first 15 minutes). Cobalt cementation kinetics are slow and follow a first order kinetic regime. 2. A drop in the cobalt removal rates can be correlated with a rise in the Eh of the slurry. 3. Ligninsulphonate, Percol 351 and animal glue at levels of 2 mg/L significantly impede cobalt cementation.

Jan 1, 1993

By Wilson R. G

The Bulli and Wongawilli Seams, the two principal sources of coking coal for the Port KKembla steelworks of Australian Iron and Steel Pty. Ltd., vary in rank and in type over the Southern and -South Western Coalfields. The Bulli Seam, ranging widely in type, produces coke varying from weak to strong. The Wongawilli Seam, more consistent in type, produces coke of more consistent strength, but considerably less strong than that from the best Bulli Seam coal. Plans of seam variation show the regional trends in rank and type for each sear. The strongest coke is derived from coal containing between 45 and 55 per cent vitrinite, m.m.f. This is obtainable from the Bulli Sean in a zone embracing Bulli and Appin Colleries.

Jan 1, 1969

By Nekitel S, Arumba J, Kopi G, Findlay RH

The Kainantu area lies within the composite Scrapland terrane which is composed of Mesozoic metamorphic and intrusive units, overlain by Cenozoic marine sediments, volcanic and intrus-ive units and Quaternary fluvial sedi-ments.Four deformations (Dl, D2, D3, D4) are recognised within the Mesozoic sequences, which consist of greenschist to amphibolite facies schist derived from felsic to intermediate pyroclastic rocks and pelitic sediments. The second, third and fourth fold events are present in the Cenozoic sequence, and these rocks are broken by thrusts related to northwest trending D3 folds. South-dipping, possibly lystric, normal faults are recognised and may be related to uplift and exposure of the metamorphic rocks as core complexes.Known mineralisation in the area consists of gold and copper skarn deposits, porphyry copper deposits, shear-hosted gold deposits, epithermal vein deposits and gold placer deposits. Over 35 hard rock and 18 gold placer deposits are known within the area. Of significance are the Kathnell shear-hosted auriferous quartz veins; such structurally controlled veins may be more widespread than proposed prev-iously and offer a new exploration target.

Jan 1, 1994

By Etheride MA

The evolution of economic precious metal and copper-gold deposits in high-level igneous terranes is dependent on very efficient fluid focussing. This is most readily achieved by contemporaneous deformation, igneous intrusion and hydrothermal activity. Mineralisation in these environments generally occurs in fault and fault-vein arrays developed in the cover sedimentary and volcanics sequences above older regional scale fault systems. Such reactivated fault systems an particularly prone to developing the complex fracture arrays, extreme local dilation and dramatic increases in permcahilit} that are necessary to efficiently focus hydrothermal fluid and produce large mineral deposits.

Jan 1, 1995

In 1972, metallurgical testwork on Renison ore indicated a significant proportion of low specific gravity, tin-barren material ideally suited to heavy medium separation (HMS). Further technical and financial studies provided adequate economic justification and in December 1974 the Renison HMS plant was cannissioned. Initial operations were interrupted by the imposition of tin production quotas for three months in 1976; they were also beset with difficulties particularly with regard to mechanical wear. During the first two operating years much develognent work was carried out including installation of a pyrrhotite flotation bank in the medium recovery circuit, investigations into various wear-resistant materials and the use of atanised rather than milled ferro-silicon. By 1977/78 financial year satisfactory performance had been achieved and since then the average floats rejection has been 18.8% of the total ore treated with an associated tin loss of 2.96%. Developnent has nevertheless continued during the last three years, principal modifications being the installation of larger aperture desliming screens and improvements to the overdense cyclone circuit.

Jan 1, 1978

The continued exploration of the major brown coal deposits of the Latrobe Valley has resulted not only in the discovery of huge additional reserves, but also in new concepts of the stratigraphy and structure of the coal seams in that area. The author sets out his interpretation of the new information which has become available over the last six years.A section of the paper is devoted to the quality of the coal. As the chemical composition of these brown coals has been discussed in some detail by previous authors, only the major constituents and the heat value of the coal are dealt with in this paper. Some of the variations in quality are related to the geological structure.The occurrence of underground water and its relation to open cuts is dealt with briefly.INTRODUCTIONThe Latrobe Valley Tertiary Basin is almost entirely covered by a layer of Post Tertiary sediments which mask the underlying rocks and their structures. As a result, the geological understanding of this area has had to await the comprehensive drilling campaign in search of brown coal, initiated by the Victorian Mines Department in 1917, and subsequently carried on by the State Electricity Commission of Victoria. The first detailed geology was published by Herman (1922), and this was followed some 25 years later by papers by Edwards, and later Thomas and Baragwanath, to which reference will be made later in this paper. Herman included a section on the geology of the Latrobe Valley in his book Brown Coal, which was published in 1952.Since that time a considerable amount of new information has become available from the continued drilling carried out by the Commission. In addition, geophysical work carried out by the Commonwealth Bureau of Mineral Resources has assisted in the defining of geological structures in the area.

Jan 1, 1960