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By M E. Pierce

Recent advances in comminution and heap leach technology have resulted in the development of many large-scale, low-grade open pit mines that coincide with areas of historical underground workings. Twoand three-dimensional numerical modelling has been conducted to assess the interaction between open pit slope stability and remnant underground voids. Most design analyses for open pit slopes assume a two-dimensional problem geometry. This is not the condition encountered in practice ù particularly when remnant underground voids interact with a large-scale open pit slope. Three-dimensional numerical models have been shown to provide a more realistic representation of the interaction between overall open pit slope stability and remnant underground voids.

Jan 1, 2003

By D Purdy, K Wilkinson, P Blake, M Fitzell, J McLellan, L Feltrin, O Dixon

The northern Drummond and Bowen basins region represents one of AustraliaÆs most prospective areas for epithermal vein and stockwork style gold deposits, with both low and high sulfidation epithermal mineralisation known in the region. 3D-GIS reconstructions, numerical and probabilistic modelling (UDEC, FLAC 3D and WofE) are used here to develop a better understanding of the controls operating on the mineral systems of the region and are aimed at enhancing predictive capabilities. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Applications of chlorine metallurgy to the extraction of metals often result in the production of volatile metallic chlorides, most of which condense directly to a solid phase at one atmosphere pressure. A stirred bed condenser suitable for th

Jan 1, 1980

By Kinsella B

Titrimetric studies have been carried out on the activated carbons Kintal 1105, Norit 2520 and Kuraray 2GA. Titration curves of the carbons before and after acid and water washing and gold loading indicate that the acid-base properties of the carbons are affected by both the method of treatment and also by the loading of gold. It is considered that the pKa values of the functional groups on the carbon surface are in the regions of 11, 7 and 3 respectively.

Jan 1, 1984

By Gordon N

The in situ behaviour of claystone floors associated with the Wallarah, Great Northern and Fassifem Seams has been studied using a comprehensive suite of stress and displacement monitors. The instrumentation was supplemented by in situ and laboratory testing of the claystone materials. The instrumentation demonstrated that the presence of claystone floors is associated with floor heave, extra rib spall, and settlement of the pillar into the floor. Horizontal floor extensometers showed that the depth of extrusion of clay was limited to 1-2 in. A pore pressure transducer installed in a claystone floor demonstrated the possible existence of short-term undrained behaviour of the claystone. Long term swelling of destressed claystone was also documented. Settlement of pillars into claystone floors can be analysed using simple elastic theory. The assumption of plane strain is valid for most claystone thickness/pillar width aspect ratios. Floor heave can be analysed using bearing capacity concepts. However, it is considered that heave is the result of local bearing capacity failure in the rib spall zone. The advantage of this model is that the bearing capacity equation can be applied without resort to unrealistically high factors of safety.

Jan 1, 1992

By S Shipard

Filters are used in water treatment and hydrometallurgical process plants for objectives such as generating a dry spadable solid, pumpable high density slurry or high purity filtrate. The priority objective of every polishing filter, sometimes also termed clarifying filters is high purity filtrate and these are found in many diverse industries and even different applications within the same industry.To generate a high purity filtrate, process designers have the choice of many different polishing filter products, but in reality very few polishing filters are based on fundamentally different filtering concepts.This paper reviews the technology merits of well-known and the more recently developed polishing filter products and aims to assist metallurgists and engineers with the selection of an appropriate polishing filtration technology for pregnant liquor filtration and other process applications, plus a guide to best practice.CITATION:Shipard, S, 2013. Polishing filters for mineral processing plants, in Proceedings MetPlant 2013 , pp 118-125 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Cutler JL

At the present stage of the Rundle oil shale project planning, with depressed world oil prices, early development of the resource is unlikely. However, this postponement is being used to carry out technical studies required to evaluate alternative rehabilitation strategies and establish a sound environmental planning basis. Major technical data from the following studies are reviewed: Resource: - mine planning; material characterisation; retorting; geology; Environmental: - meteorology; surface water management; laboratory and field leachates; revegetation; waste characterisation; hydraulic and chemical modelling; dust suppression; plant/water interactions; and impact evaluation. These studies have shown that topsoil replacement, seeding mixtures, fertilizer application rates, subsoil quality and handling, waste pile slope and most importantly soil water storage are key factors in successful rehabilitation.

Jan 1, 1987

Selective open pit mining for gold has been in progress at Harbour Lights since the onset of mining in March 1985. Selective mining techniques used are similar to those in other recently opened gold mines in Western Australia. However certain practices have been introduced to accommodate the irregular distribution of mineralisation and comparatively high mill tonnage throughput. These include selective mining with large bucket excavators, sequential waste stripping - ore mining normal to the strike of the orebody and sample line preparation and ripping on bench floors. Application of these selective mining practices at Harbour Lights enables the operation to maintain delivery of approximately forty by 50-tonne truck loads of ore to the mill crusher everyday, with limited rehandling of material through ore stockpiles.

Jan 1, 1986

By Glatthar J. W, Lauder D. W, Manlapig E. V, Mackinnon I. R

The Ok Tedi copper orebody consists of porphyry and skarn orebodies. The skarn orebodies, identified by different mineralogies, are the source of high intermittent fluorine levels in the mill concentrates. This paper discusses the results of t

Jan 1, 1998

Inefficient conveyors suffer carryback, leading to the build-up of materials on idlers, and other expensive components. They spill and leak material at loading zones and transfer points, causing accumulations that can damage the belt, wear moving components, and increase both cleanup labor and maintenance expense. They wander or mistrack, spilling material and en- dangering personnel and conveyor components, including the belt itself. And through these inefficiencies, they multiply an operation's hidden costs-the dollars lost because of missed production, of increased downtime, of the expense for the replacement of prematurely worn or damaged equipment. In this paper, the author will examine the importance of belt conveyors to mines and process plants He will trace the state-of-the-art in systems for cleaning belts, and controlling the release of fugitive material from conveyor transfer points, by exploring the roots of the problems, and demonstrating solutions that have been proven to be effective. Included in these systems to improve material handling are transfer point stabilization and sealing systems, dual belt cleaning systems, and belt training idlers.

Jan 1, 1991

The middle-Devonian Dulladerry Volcanics is a complex of A-type, predominantly rhyolitic ignimbrites, lavas and breccias. They form a NNW trending belt some 90 km long and 10-20 km wide, east of Parkes, NSW. The volcanics are dominated by widespread ignimbrite units with minor basalts, sediments and rarer andesites. The volcanics were deposited in a sub-aerial, possibly continental rift setting and are similar in chemistry and age to the Eden - Comerong - Yalwal Volcanic Zone (EVZ) on the NSW south coast. The volcanics exhibit an unusual Atype chemistry (high Zr, Y, Nb, REE, Ga). This distinctive composition illustrates that the volcanics are not comagmatic with the adjacent Yeoval Granite Complex or Eugowra Granite, which show typical I-type fractionation trends. Epithermal gold veins occur in basalt and andesite in the Dulladerry Volcanics at Mt Aubrey (Hopf, 1992), near Baldry. Alteration also occurs in the Glen Isla and Red Hill areas, with epithermal sinter recognised at Glen Isla. Copper and minor gold mineralisation occurs at the contact of rhyolite and andesite at Reedy Creek, but is not of epithermal origin. The analogous EVZ also contains several epithermal gold fields and it is this style of mineralisation which provides the most prospective targets in the Dulladerry Volcanics. Although the Dulladerry Volcanics also contain high background levels of REE and metals such as Zn and Pb, the general lack of fractionation and water-undersaturated character of A-type magmas does not lend itself to the development of significant concentrations of these elements into a fluid phase and mineralisation. The prospectivity of A-type volcanics in general could not be regarded as high. However, an indicator of some fractionation in the Dulladerry Volcanics is provided by the fairly low abundance (average 230 ppm) and wide range (

Jan 1, 1995

Methane predrainage from coal seams in the Western Area of the U.K. has been practiced over the past decade. The differing reasons for the practice include the controlling of gas emission rates in coal headings required to win out coal faces and also the need to control the gas emission rates in the roadways of retreat faces in order to comply with the statutory requirements. There are some similarities with predrainage experience in the Bulli Seam NSW. The several case studies highlight the varying conditions in the Western Area coalfield where the use of predrainage was Required.

Jan 1, 1982

This paper presents an overview of the strategy adopted to bring the Ballymoney opencut lignite deposit to an advanced stage of mine design and confidence. Certain aspects of the project differentiate it from the normal Australian experience. These include the thick overlying glacial drift, the proximity to established infrastructure and the wide fluctua- tions in annual lignite demand. The incorporation of these factors in the mine plan are discussed. The deposit area is located near the town of Ballymoney, in Northern Ireland. In July 1986, after winning an internationally competitive tender, Meekatharra Minerals Ltd commenced an exploration programme designed to delineate reserves to supply a 450 MW power station. In less than eighteen months, a complete evaluation was undertaken and a price submitted in December 1987 to the relevant authorities for the supply of lignite. Subsequently, UK government consultants and significant inter- national banks have endorsed the findings. The mining study commenced with the evaluation of various develop- ment strategies, followed by selection of the most viable mining method and equipment. The equipment selected will mine four million tonnes of lignite and eleven million cubic metres of waste each year. In year 15, the waste removal requirement increases to almost seventeen million cubic metres. This results in an average strip ratio over the mine life of three cubic metres of waste per tonne of lignite. The quality of the product delivered to the run of mine conveyor transfer point, based on maximum resource recovery, will include heat content of 8813 kJ/kg (3789 Btu/Ib), ash content of 28% and moisture content of 40%.

Jan 1, 1989

By Trudinger JP

Mt. Newman Mining Company Pty. Ltd.3 oper ates the Mt. Whaleback iron ore mine in the Ham- ersley Iron Ore Province of Western Australia. The present rate of production of high grade hematite iron ore is 33 million tonnes per year. Mining is by open cut quarrying,with 15m high benches. The present quarry operations will be extended to a large oval pit to win over 1400 million tonnes of iron ore. The pit slopes will extend up to 500m in depth and the perimet- er of the slopes will exceed 15km. Sixty per- cent of the ore is below the water table, which presently lies 45m below the general plain level Dames & Moore, rock mechanics consultants designed the pit slopes during early mine devel- opment to ensure an economic and safe operation.

Jan 1, 1975

By S Rice, A Midlin

Many of the stacking and reclaiming machines employed in the mining industry today are operating in ways that were never envisaged in the days before they were commissioned, with greater throughput, increased annualised operating hours and load cycles well in excess of their original specification requirements being the norm. In many cases these machines were supplied prior to the widespread use of finite element modelling or, in the era when such software became commercially available, those supplied designed using simplified and/or coarser meshes than would be employed today. With many of these machines being expected to operate for many years to come, it is important that their ongoing reliability be maintained and their operational limits understood. In this paper, a case study is used to outline the method required for estimating the fatigue life already consumed and the likely real life left in a machine. By reference to the machineÆs prior operating history, the use of strain gauges in the field and the development of finely meshed finite element analysis (FEA), a coherent picture of the machineÆs operational state can be generated and then investment/maintenance decisions made to ensure continuity of machine operation.

Jan 1, 2007

Powercoal Pty Ltd operates eight underground coal mines in New South Wales and produces coal for both domestic power stations and the export market. Approximately 40% of total production is from continuous miners. Over the past five years, place change mining methods have been introduced to improve productivity from continuous miners. This has involved utilising the existing coal clearance system from the continuous miner to the ratio feeder using trailing cable shuttle cars.By late 1996 average productivity at Cooranbong Colliery using this system had plateaued at 800 tonnes per eight hour shift. A number of factors were identified to increase average productivity to 1500 tonnes per eight hour shift. An improved coal clearance system was one of the factors identified.

Jan 1, 1998

Jan 1, 2004

The InLine Pressure Jig represents a breakthrough in digging technology Its design incorporates a unique combination of features previously utilised in conventional jig design. In particular, a moveable screen and circular bed are used to excellent effect. However, a major design innovation is the encapsulation of the circular bed within a vessel - allowing the equipment to operate under pressure. This innovation eliminates free water surface, improves the dynamics within the separation layer (crossflow) and provides significant cost savings in the handling of slurries. Recent research results have indicated its capacity to achieve high recoveries and upgrade ratios in the gravity separation of Minerals.

Jan 1, 1997

The long continuing controversy over the Origin of fusain, whether it is a product of primeval forest fires, or of special conditions of weathering (including bacterial decay) of the vegetal debris concerned prior to, burial, has now been extended, to include the possibility that fusain is a product of the coalifaction process subsequent to deposition, so that doubt may reach even to its time of formation.The conflicting views on this point are summarised in the following quotations from two recent publications (my italics in each quotation):1. "Recent observations made in peat and brown coal deposits in Australia, England and Germany strongly suggest that practically all fusain is formed by coalifaction after deposition and 'preliminary compression. In deposits of advanced brown coal rank, it normally takes the shape of pieces of wood compressed parallel to the bedding plane; and some fragments consisting partly of fusain and partly of vitrain exhibit the same amount of compression throughout. This would seem to indicate fusinisation after burial, as hard brittle charcoal would be crushed, or else retain its original irregular shape if strong enough to withstand pressure.In some immature deposits, however, where cover is of a hydrostatic nature rather than a vertical compressionar force, occasional pieces of fusinised wood showing very little flattening are present, but such immature deposits seldom contain the proportion of fusain found in higher rank coals. In view of this, and the possibility of introduction of charcoal into peat deposits, it is felt that a small amount of the fusain in coal may represent wood charred before burial, but most of it almost certaInly originated as a product of fusinisation after burial" (Dulhunty, 1948, p.14).

Jan 1, 1953

By Dickin FJ

Advances in the development and application of in situ imaging of mineral processing operations using electrical tomography techniques are reviewed and illustrated with case studies relating to pneumatic conveying, mixing and centrifugal separation processes. The potential for applying these methods to full three-dimensional visualisation of the dynamic behaviour of flow in pipelines and separators, and the resulting consequences for process-modelling strategies, are discussed.

Jan 1, 1993