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Nickel WestÆs Kalgoorlie Nickel Smelter operates three Peirce-Smith converters, each processing 110 tonnes of matte per charge. The vessels are lined with chrome-magnesia refractory with a mouth traditionally constructed from steel liner plates, protected with cast refractory. Mouth refractory is damaged by molten material and the action of cleaning solid buildup off the mouth. Once damage has accumulated, the mouth must be frequently maintained with hot refractory gunning or a mouth leak may occur. Such a leak requires a 32 hour repair period. A converter mouth redesign program was undertaken with the aim of reducing the rate of mouth damage during operation, eliminating mouth leaks and shortening mouth replacement times during vessel rebuild periods. An overview of the redesign process and operational performance is contained herein.

Jan 1, 2005

By P Jago

KCGMÆs Fimiston Open Pit, located in the centre of the historic Golden Mile, is situated above some 3000 kilometres of old underground workings. These workings, both level and vertical, present significant safety and operational problems in the pit. One of these challenges is in safely drilling void areas so that they can be charged and blasted effectively. Current drilling practices in these areas require machines that can only drill 115 mm holes on a smaller pattern than the standard blast pattern. This results in more time and cost to both drill and charge these areas. Any other method currently available to drill out these areas involves putting operators in a potentially hazardous situation by being too close to the void area being drilled. Not effectively drilling and blasting these areas leads to hazardous situations further in the mining cycle including oversize, large toe and uncollapsed voids. Ineffective blasting also causes reductions in mining productivity and mine to mill performance. In response to these issues, KCGM has commissioned the implementation of a fully remote controlled DM45 blast hole drill rig to drill out selected void areas. The remote system, installed in conjunction with Ausdrill Ltd and GM Mining Electrics, is designed to operate similarly to a tele-remote bogging system with the operator controlling the drill rig from a separate control cabin via radio signals and video feed. This allows KCGM to drill in areas of higher risk without exposing the operators to voids. The drill rig will also be able to drill standard patterns through some specially selected void areas, reducing costs and extra time associated with drilling and charging void affected areas. The remote rig is expected to provide a number of benefits, both in the drilling process and in further downstream operations. Costs of drilling in void areas are expected to decrease with standard patterns instead of smaller patterns being drilled. Safety and operator comfort are also expected to increase through removing the operator from the pit floor. Blasting is also expected to see significant improvements through increased ease of charging void areas (because of larger holes and standard patterns), more consistent patterns resulting in less secondary blasting and toe and an overall improvement in the speed and cost of charge-up practices. This more consistent blasting will also improve shovel productivity, crusher performance and overall mine-to-mill efficiency. This paper presents an overview of the development of the remote controlled system, including modifications that have occurred since commissioning. It explains some of the problems encountered and how these have been solved. Key issues for operational success will be identified and explained with a view to making future implementations easier. Factors used to assess the performance of the remote controlled rig will also be explained in further detail and used in a preliminary assessment of the rigÆs feasibility.

Jan 1, 2003

Blasting has been the most frequently used method for rock breakage since black powder was first used to fragment rocks, more than two hundred years ago. This paper is an attempt to reassess standard design techniques used in blasting by providing an alternative approach to blast design. The new approach has been termed asymmetric blasting. Based on providing real time rock recognition through the capacity of measurement while drilling (MWD) techniques, asymmetric blasting is an approach to deal with rock properties as they occur in nature, ie randomly and asymmetrically spatially distributed. It is well accepted that performance of basic mining operations, such as excavation and crushing rely on a broken rock mass which has been pre conditioned by the blast. By pre conditioned we mean well fragmented, sufficiently loose and with adequate muckpile profile. These muckpile characteristics affect loading and hauling (Scott, 1996). The influence of blasting does not end there. Under the Mine to Mill paradigm, blasting has a significant leverage on downstream operations such as crushing and milling . There is a body of evidence that blasting affects mineral liberation (Djordjevic, N, 2001). Thus, the importance of blasting has increased from simply fragmenting and loosing the rock mass, to a broader role that encompasses many aspects of mining, which affects the cost of the end product. A new approach is proposed in this paper which facilitates this trend æto treat non-homogeneous media (rock mass) in a non-homogeneous manner (an asymmetrical pattern) in order to achieve an optimal result (in terms of muck-pile size distribution)Æ. It is postulated there are no logical reasons (besides the current lack of means to infer rock mass properties in the blind zones of the bench and onsite precedents) for drilling a regular blast pattern over a rock mass that is inherently heterogeneous. Real and theoretical examples of such a method are presented.

Jan 1, 2001

The history of potential large scale development at Stawell in northwestern Victoria dates back to 1914, when Great Boulder Mines Limited, of Kalgoorlie, Western Australia, took up options on some of the major mines in the Stawell Goldfield. Despite this and other attempts by various groups over the next thirty years, mining activity on the field gradually dwindled to the retreatment of old mill tailings.A static price for gold and indifferent drilling results prevented a major effort towards reopening the field until the late 1970's. A renewed exploration effort led to the discovery of sufficient reserves to justify installation of a carbon-in-leach gold treatment plant.

Jan 1, 1984

By Bond W. F, Sharry P. V, Onley P. G

The use of Decision Analysis is becoming more widespread in industry as a whole, and there is considerable scope for its application in the mining industry. Wherever decisions have to be made, whenever risks have to be taken, whenever uncertainty exists or whenever judgements have to be made, then Decision Analysis can be used. In the mining industry we daily make many decisions involving risk, uncertainty and judgement. Expansion and diversity will only increase the need for balanced decision making techniques. This paper seeks to describe the history and principles of Decision Theory, and to illustrate the various modelling approaches using three fictitious yet realistic case studies. Decision Analysis logically integrates the quantifiable and seemingly non-quantifiable aspects of a decision problem into a coherent, explicit and rational solution. It also allows the decision-makers to see the full impact of each variable or uncertainty, and hence focus on the key aspects that influence the solution.

Jan 1, 1996

Christmas Island contains large deposits of phosphate minerals varying from high-grade calcium-phosphate (apatite) to lower grade iron and'aluminium phosphate (crandallite/millisite). The surface material is dominantly C-grade (Fe/Al) phosphate profiling into B-grade, a variable mixture of C- and A-grade ores, before reaching the high A-grade phosphate (apatite) which overlies a limestone Karrenfeld Base formation. A-grade ore is the basic phosphate used for the manufacture of superphosphate and phosphoric acid, whilst B-grade contains amounts of iron and aluminium which are unacceptable for these acidulation processes. Research into methods of separating the finer iron and aluminium phosphates from the coarser calcium phosphates has led to the development of wash-screen processes enabling recovery of 50 to 60%, as A-grade phosphate. Developmental stages included laboratory investigations, mineralogical studies, pilot tests leading the initial 20 tph prototype production unit and the current 100 tph production wash/screen plant, commissioned early in 1970 at Christmas Island.

Jan 1, 1971

A new national-scale geochemical survey is under way inAustralia with the aim to provide energy and mineral explorers with state-of-the-art precompetitive data and information about the continentÆs potential resources. This low-density geochemical survey will provide a national geochemical data layer using consistent sampling medium and sampling, preparation and analytical methods. Large-scale geochemical patterns thus revealed are expected to point to new areas of exploration potential. The project is funded under the Onshore Energy Security Program. It is hoped that this new national geoscience dataset will help make Australia a more attractive destination for energy and mineral exploration investments. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Baafi EY

Open cut mining in Australia is facing the greatest challenge in its history in attempting to compete not only with other operations internationally, but also with underground operations domestically. Most flat dip and shallow depth surface-mineable coal reserves have been depleted during the last two decades and new open cut operations must extract deeper coal deposits. As open cut coal mines move into deeper areas and the stripping ratios increase, the relative cost of overburden removal also increases. It therefore becomes even more important to design the mine around the optimum overburden removal scheme. The deeper mines are usually multi-seam operations with a more complex geology and with more geotechnical and hydrological problems. Deeper mines are subjected to greater problems requiring more detailed mine planning and design, such as selection of the optimum mining method and pit layout. In planning and design of such operations, the number of alternative methods which need to be considered is consequently greater.Dragline productivity and its stripping capabilities are directly affected by the selection of digging method, strip layout and pit geometry. Every mine has a unique combination of geological conditions. The operating methods that work well at one mine may not necessarily work at another site. Selection of an optimal stripping method, strip layout and pit geometry for a given dragline must be considered with respect to the geological conditions of the mine. With increasing geological complexity of Australian strip mines, it is becoming more important to use sophisticated techniques such as computerised mine planning methods to assist in optimising dragline operations.

Jan 1, 1998

By B Cronin, M Gao, M F. Young

Fine grinding technology has become extremely important for Mount Isa Mines Limited in the last decade for flowsheet development for the McArthur River deposit and in rejuvenating the Lead-Zinc Concentrator at Mount Isa. Regrinding products with 80 per cent passing seven microns and 12 microns were required, respectively, for the McArthur River ore and the Lead-Zinc Concentrator at Mount Isa. Development of the ISAMILL, a horizontal stirred mill with a gross mill volume of 4000 litres (a net volume of 3000 litres), has been successful in delivering the required grinding product sizes with an energy consumption acceptable to a mining operation. The ISAMILL performance for processing both lead and zinc streams at Mount Isa is discussed in this paper, including the milling energy efficiency, the media wear and the size-by-size recovery data for one flotation process following the fine regrinding stage. The potential use of the ISAMILL technology at various phases of the mining cycle is also discussed.

Jan 1, 1998

The Drake-Rivertree area lies in the far north east of the New England district of New South Wales. Drake is some 500 miles north of Sydney by road and 36 miles west of Lismore. Rivertree is situated 24 miles north of Drake.The Drake deposits were first worked in 1878 for gold which occurred in a very fine state in ferruginous gossan but at depth copper ore became more significant. The lodes at Rivertree, discovered in 1887, were worked for silver but mixed sulphides became more prominent in deeper levels.Several mines operated at each centre and each locality smelted its own ore.The mines at both centres were operated sporadically for many years though production was not particularly substantial.A number of the larger mining companies have shown a recent interest in this mining field with special emphasis on the Drake locality.GENERAL GEOLOGYThe two mining centres are situated to the north and south respectively of a belt of Permian marine sediments and volcanics similar to, and probably representing an easterly extension of, the rocks of the Emmaville district further west.E. C. Andrews (1907) recognized two stratigraphic units within what he called the Drake Series. The Lower Division consists of rhyolite flows, tuft's, breccias and agglomerates, followed by trachytic and andesitic tuft's containing cladochonns, thanmopora willcinsoni and other Permian forms.

Jan 1, 1962

By Woodcock J. T, Rummel P. H, Sparrow G. J, MacRae C. M

An automated method, which is believed to be the fastest in the world and which can be used by mineralogically-untrained technical assistants, has been developed for the rapid location of native gold particles and other gold minerals down to 1 pm in size in ores, concentrates, and tailings using a scanning electron microscope. Searching of a 25 mm diameter polished block in 1 pm steps usually requires 3-4 h. Examples of the location of native gold and gold tellurides in drill core sections, in crushed ore samples and gravity and flotation concentrates, and in various metallurgical test products are given. The results have application in ore exploration, in guiding metallurgical test programmes, and in assessing metallurgical per- formance in testwork and in operating plants.

Jan 1, 1991

By Hoskings AD

Bolting forms a prestressed elastic layer of rock which is capable of supporting loads at right angles to the bolted surface. Investigations on rock bolting made with a number of different models give rise to empirical and theoretical prin- ciples for the formation and action of the layer. In the models, flat and arched layers of many materials were used simulating rock conditions ranging from closely interlocked blocks to fragments of various shapes. Results of observations made in the underground works of the Snowy Mountains Scheme are related to the mode of action of bolted surface layers of rock. There is abundant experimental, theoretical and practical explanation for the well-demonstrated capability of bolting as a means of rock support.

Jan 1, 1971

By M D. Basuki Dwi Priyono

The Toguraci low sulfidation epithermal gold vein deposits are located 2 km WSW from the Gosowong mine and form part of the Gosowong Goldfield. The goldfield lies within a Neogene magmatic arc on Halmahera Island, North Maluku Province, East Indonesia. The terrain is moderate to steep, rainforested, and poorly outcropping. Exploration and mining operations are being carried out within the PT Nusa Halmahera Minerals Contract of Work (exploration tenement) jointly owned by Newcrest Mining Ltd (82.5 per cent, operator) and PT Aneka Tambang Tbk. (17.5 per cent). First pass exploration of the Gosowong area began late 1992 resulting in the discovery of weakly developed porphyry copper mineralisation (named Bora) at Toguraci in 1993. Early in the evaluation of this porphyry an overprinting epithermal Au/Ag mineralisation event was recognised, however exploration focus remained on the Bora porphyry deposit for some time. The discovery of the nearby Gosowong epithermal gold deposit and the exploration of other prospects in the area further diverted attention and funds from Toguraci. It was not until year 2000 that Toguraci was seriously reevaluated as part of a detailed appraisal of the epithermal gold potential within a 5 km radius of the Gosowong gold mine. A fly-camp based drilling campaign using man-portable rigs was undertaken between August 2000 and March 2002. All exploration at Toguraci was then stopped pending government approvals to mine. These were finally issued in May 2003 and immediately drilling restarted and pre-mine approvals (eg the environmental impact study) were sought and granted. The first Toguraci gold bar was poured in February 2004. Exploration at Toguraci and elsewhere in the Gosowong Goldfield continues today.

Jan 1, 2004

By L M. Lobato, J C. S Seoane, F J. Baars

The Carajßs Province presents several volcano-sedimentary sequences that comprise the Itacai·nas Supergroup. The rocks represent bimodal volcanism, and clastic and chemical sedimentation in relatively unstable basins subject to recurrent structural events with subsidence and volcanism. The Grpo Parß Group represents one of these sequences with mafic volcanic rocks that enclose discontinuous jaspilite lenses, with development of large high-grade orebodies (Fe >65 per cent). This unit is named the Carajßs Formation and presents peculiar characteristics compared to other iron districts in the world, thereby departing from the classic Lake Superior or Algoma iron formation types. Owing to the dense vegetation, lack of outcrops and harsh landscape, the structural analysis of the district can only be accomplished by combination of regional field work, detailed structural work on the open pits, and remotely sensed image interpretation, in this case Landsat ETM7, JERS-1 images and the SRTM digital terrane model. The regional trend of the several sequences of the area is approximately N-S and the structure is dominated by a flattened flexural fold system with axes moderately dipping WNW, intersected by several strike-slip faults subparallel to their axial plane. The Serra dos Carajßs represents an s-shaped synform-antiform pair, herein named the Carajßs Fold. This regional structure is partially disrupted by the Carajßs Shear Zone that divides it in the northern (Serra Norte) and the southern (Serra Sul) Ranges and also probably prepared the terrane with the development of pathways for mineralising hydrothermal fluids forming large high-grade massive iron bodies. Syntectonic granitic bodies played an important role in the structural evolution of the area as well. They caused localised ductile flattening deformation and thermal contact metamorphism in surrounding terranes. The Estrela pluton, for instance, was responsible for the discontinuity of the regional trend between the Serras do Rabo and Leste. The Carajßs Province is regionally the upper crustal product of a very shallowly eroded dome-and-keel geometry of Neo-Archaean volcano- sedimentary units intruded by syntectonic calc-alkaline intrusives and overlying pre-existing infracrustal rocks. The lithostructural data suggest continental-margin back-arc basin development and closure in an oblique collision belt, with N-S shallow crustal shortening, parallel to the inferred pre-existing strike of the stratigraphy.

Jan 1, 2005

By Elford H. S

Australia has many potentially important tin deposits, particularly on the eastern shore of the continent and in Tasmania. A number of these have been worked on a meagre scale, while some of them, because of metallurgical, transport, and other difficulties, have not as yet been developed.Believing that the full development of the tin fields of the Commonwealth of Australia is in part dependent upon the adoption of the most efficient methods of milling and smelting, the Development and Migration Oommission arranged for the first-mentioned author to visit the mining fields of Cornwall, one of the oldest tin-producing districts of the world, and prepare a report for the information of the Commission.This paper, now presented to the Australasian Institute of Mining and Metallurgy with the hope that it will assist the full development of tin mining in Australia, is the joint work of both authors.For over two thousand years tin has been produced from the Cornish mines. Even the ancient Greek historians made mention of tin mining in Cornwall, and it is probable that during the earliest periods the mining was alluvial. As early as 1602 a stamp battery working in Cornwall was described, and in 1671 calcination and buddling was a recognised scheme of treating pyritic ore. In the first half of the 16th century the output of tin from Cornwall was 700 tons per annum, and, from then on, production increased to the maximum in 1914 of 6500 tons. At present (Oct., 1929) the Cambourne-Redruth area produces over 95% of the Cornish tin output. This area includes such mines as the South Crofty, East Pool, Dolcoath, Parkanchy, Polhigey, and Wheal Kitty. The remaining 5% is largely supplied by the Levant and Geevor mines at Pendeen, St. Just area, near Land's End.

Jan 1, 1930

By Shklyar FP, Babushkin NM, Bokovikov BA, Fedotov PB

A mathematical model for gas flow dynamics and heat and mass transfer processes occuring in the tuyere raceways and in the zone of the final for- mation and heating of pig iron and slag has been developed and simulated on a digital computer. It takes into account the formation and size of the raceway zones, combustion of coke and its substit- utes, oxidation of the metal, radiation from the gases to the raceway boundaries, physical heat losses and the direct reduction of the pig iron elements below the raceway zones. To evaluate the distribution of heat produced by the oxidation of metal between gases and prod- ucts of smelting, the problem of heating the mat- erials in the raceways with the sources of heat in the materials under conditions of intensive gas circulation in the raceways is solved. To determine the amount of heat transferred by radiation from the gas to the boundaries of the raceways, the problem of radiant heat transfer be- tween two grey bodies forming a closed system is solved. Using the structural parameters of the furn- ace, the inlet parameters of the combination blast and exit parameters of the melt, the model permits the calculation of the temperatures of materials entering and leaving the raceways and also the res- idual temperature of the gases, which qualitatively differs from the theoretical combustion temperature. Analysis of the operation of several different blast furnaces has shown that the overall picture of the interaction between gas flow dynamics, mass and heat transfer processes occuring in the race- ways and in the zone of final product formation, obtained with the aid of the model, now permits us to approach from a different position the deter- mination of the limiting factors in furnace operat- ion. It also allows us to explain certain phenom- ena observed in blast furnace practice and to dis- cover new relationships which may be used in analy- sis and control of the smelting process.

Jan 1, 1981

By J Vann, C Seymour

Geology is generally treated as a æfront endÆ step in mine development. After infill drilling, the majority of resource estimation, mine-planning, development, mineral processing strategies and operational procedures are planned and implemented with little geological input, particularly in open pit operations. However, significant benefits in overall costs, cash flow, and technical risk reduction can be realised when sound geology is utilised more rigorously throughout the mining process. This under-utilisation of geology in the mining process has arisen due to a combination of factors:A lack of interest in, or knowledge of the full mining process by geologists. Few geologists fully understand where their inputs make critical impacts on downstream users. As a result of this, geologists generally do not focus their inputs towards areas of greatest value added, ie addressing issues critical for other members of the mining team. Most importantly, few geologists effectively communicate their results to the downstream users of their geology models. The results are that the potential benefits of geology, and the appropriate status of geology in the mining industry, are not fully realised. It is fundamental to realise exactly what geologists do. Geologists constrain geological processes and geometry. All geoscientific tools at the geologistsÆ disposal are geared towards one of these goals. An emphasis on geological processes is present throughout the exploration process, whereas in the resource estimation and mine development process an emphasis on geometry is required. The mining process is a web of disciplines that are attempting to optimise development of a resource to provide value to shareholders. Yet few people within these disciplines have a full appreciation of this web, and where sound geology inputs can add value through various feedback loops. Geology inputs do not end at the resource estimation stage, nor are they relegated to grade control implementation. If geologists have an appreciation of the mining process and close liaison with the other disciplines such as geostatistics, geotechnical engineering, hydrogeology, and mining engineering, they can significantly benefit project costs, timelines, and constrain technical risk by addressing their issues at the earliest possible stage. Furthermore, the mining process is not a single pass timeline, but an iterative process where the exploration, resource definition, mine planning and mining loop is continually repeated over the life of a project. Therefore, the potential inputs of geology are critical throughout the mining process. Effective communication of the impacts of geology inputs on downstream users is often lacking on mining projects. The most effective way to communicate geological results is through where it impacts most û project risk. Focussing all geology inputs and communication in terms of potential material risk allows the geologist to be more effective in contributing value to the mining process, and allows the downstream users of geology inputs to better constrain the risks associated with their aspects of the mining project. Through a program of geologists:taking an interest in the entire mining process and identifying critical areas for geology inputs to downstream users (the geologistsÆ clients); focussing geology inputs to address the potentially material issues on mining projects; and communicating their inputs to the æclientsÆ in terms of technical risk, geology will be much better integrated into the mining process. As a result, the potential benefits of geology throughout the mining process will be realised, and the status of geologists within the mining process will be elevated to a more pivotal position.

Jan 1, 2000

Atlas Copco is one of the worldÆs leading providers of industrial productivity solutions (Atlas Copco, 2009). Furthermore, the company spans 160 markets and held 34 000 employees at the end of 2008. The company is organised under three ætechniquesÆ whereby the Construction and Mining TechniqueÆs business division is located within +rebro, Sweden. This paper is aimed at briefly facilitating information on how the company and more specifically, the Construction and Mining Technique is run. Also, by sharing my experiences, this paper is intended to encourage and motivate students currently studying for a degree relevant to the minerals industry, to apply for this extremely beneficial scholarship. Through a number of presentations relating to the various divisions, products and aftermarket services of the company, I came to realise that Atlas Copco extends beyond simply selling equipment suitable for the mining and civil industries. This tour through Sweden also contained highlights of visiting the Underground Rock Excavation factory, Surface Drilling Equipment factory and Secoroc divisions. I was also fortunate enough to participate in a tour of the LKAB mine in Kiruna. In addition, time was allocated to less industry related activities, and I was able to go dog sledging, sip vodka cocktails out of ice glasses at the Ice Hotel and enjoy traditional Swedish foods of moose and reindeer. Most important and memorable to me; however, was the ability for employees of Atlas Copco to speak of the company and their products with such passion and enthusiasm, which truly made this a motivational and unforgettable experience.

Jan 1, 2009

By P Hollings, J Holliday

Porphyry copper, gold and molybdenum deposits form in subduction-related settings in association with calc-alkalic or alkalic magmatism. Hydrothermal alteration assemblages are zoned, with potassic cores and propylitic haloes overlain by extensive domains of clay alteration and silicification (lithocaps). Copper sulfides, gold and molybdenite typically occur in veins or hydrothermal breccias, and less significantly as wall rock replacements. Epithermal deposits may form above or to the side of porphyry systems, and may be juxtaposed into the core of a porphyry deposit if rapid uplift and exhumation occur through the life of the magmatic-hydrothermal system. Volcanichydrothermal breccia pipes (ædiatremesÆ) commonly form late in the life of a porphyry system. They may contain clasts of porphyry-style mineralisation, and can host significant epithermal gold resources. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Edwards A. B

Yampi Sound is a small channel in the Buccaneer Archapelago (latitude 16° 10' S.; longitude 123° 40' E.), on the northern coast of Western Australia (Fig. 1), about 90 miles north of Derby, and 200 miles north-east of Broome.The iron ore deposits of Yampi Sound occur on an approximately S.E.-N.W. trending belt of islands which form the northern boundary of the Sound (Fig. 2). From east to west they are Koolan Island, Tarrant Island, Usborne Island, Cockatoo Island, Irvine Island, Kathleen Island, Flora Island, and Bathurst Island. To the south of the Sound lie Margaret Island, which is separated from the mainland by a channel only 60 ft. wide, Dorothy Island, and Gibbings Island. Some of the channels between the...

Jan 1, 1938