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By Noller B. N, Mine F. J

Modem open cut and underground mining in the tropics inevitably expose partially weathered and unweathered rocks to oxygen and water, leading to weathering and the release of solutes and often acidity as well. Historical monitoring data can demonstrate these phenomena. Three case studies from open cut mines in the north of the Northern Territory illustrate the deterioration in quality of pond water receiving drainage from waste rock dumps. The potential for deterioration of water quality was not recognised in many mine Environmental Impact Statements prepared and accepted in the 1980s. The examples documented indicate the importance of adequately planning for this near inevitable process. Retrofitting a mine water management system to 'no' or minimal release can be very difficult and expensive, and may not be feasible, leading to downstream pollution. The characterisation of acid and solute production potential of ore and waste rock, and improved dumping strategies and water management are very important to minimise the environmental impact of mining in the tropics.

Jan 1, 1994

MIM Holdings Limited (MIM) committed to a long-term future in copper in the Carpentaria Mineral Province in 1996 with the development of the Enterprise and Ernest Henry mines, and an upgrade of MIMsÆ copper smelter in Mount Isa, and copper refinery in Townsville. The upgrade of the copper smelter will enable the smelter to produce 250 000 tpa of copper with a single primary smelting unit, the copper Isasmelt furnace installed in 1992. The copper Isasmelt furnace currently smelts concentrate containing 145 000 tpa copper. To reduce the risk associated with the copper smelter upgrade, and shorten the ramp up time of the upgraded smelter, two high-rate trials were undertaken in 1997 to demonstrate that the copper Isasmelt furnace could, with an additional 525 tpd of tonnage oxygen, treat concentrates containing 250 000 tpa copper. During the trials the concentrate feed rate to the Isasmelt furnace was increased from its average rate of 100 tph of concentrate to 150 tph of concentrate. The increase in the capacity of the furnace was achieved by: supplementing the installed tonnage oxygen capacity of 595 tpd with an additional 300 tpd supply; reducing variability in the furnace feed rate from ¦25 per cent to less than ¦5 per cent; and reducing tramp air. The Isasmelt furnace smelted concentrate at a rate of 140 to 150 tph for four hours 25 minutes during Trial 1, and at a rate of 150 tph of concentrate for five hours and 30 minutes during Trial 2. The oxygen utilisation was 100 per cent during the trials with the process remaining under control. As a result of the development work for the trials the average treatment rate of the furnace under normal conditions increased by ten per cent.

Jan 1, 1998

By James D, Dawson N

The alternate mineral dressing tech-niques for the production of ilmenite roaster feed from heavy mineral concentrate and the reasons for the selection of wet high intensity magnetic separation (WHIMS) at Richards Bay Minerals are outlined.Initial flowsheet studies were under-taken using laboratory scale equipment followed by on site pilot testing. Flowsheet development culminated with an extensive test programme conducted at Readings of Lismore in 1975.

Jan 1, 1986

By T Hausler

The pitfalls, pleasures and management issues associated with international and remote projects are diverse.However, no problem is insurmountable and if an engineering team chooses (by luck or good planning) to push through the difficulties, success can mean an extremely satisfying experience for individuals and a significant, positive result for an organisation.International projects are not for the faint hearted or inflexible. Working in foreign lands with people who may or may not speak English and who may not initially respect you can become mentally and physically tiring.Sometimes the challenges are not fully explained to individuals in advance. Individuals then often learn about the challenges ù and discover solutions ù on the job. While this initially puts great pressure on individuals, matters improve eventually, especially when the locals come to understand that you are on site to make a positive difference.This paper will discuss aspects of a recent international project including meeting international clientsÆ expectations, dealing with cultural differences, social reckoning, environmental issues, and personal challenges. Specifically, it will cover aspects of working within a Russian cultural setting and overcoming social barriers.The paper also presents coping strategies for long periods of time spent away from home in remote places with extremes in weather beyond the normal experience of most Australians. For example, dealing with the effects of the spring thaw and coping with temperature ranges of -45 to +45¦C.Lastly, and possibly most importantly, there will be a focus on the role of translators. They have the power to make an engineer everyoneÆs best friend or, on your behalf, to order cold chicken liver and heart salad for lunch. If an engineering team can establish a working relationship with translators, they can become an invaluable asset and both on and off site.CITATION:Hausler, T, 2013. Achieving success in large-scale, remote area metallurgical plant projects, in Proceedings MetPlant 2013 , pp 539-552 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Kidman B. E

The Fitzpatrick area is the deepest section of the North Mine, with the orebody located between 1450 and 1800 m below the surface and some 600 m NE of the main No. 3 Shaft orebody and separated from it by the intensely sheared Globe Vauxhall Shear Zone. Development towards the Fitzpatrick area commenced in 1977 after earlier initial exploration drive development. However, it was not until 1982 that mining in the Fitzpatrick area actually began with the silling out of No. 36 level at a depth of some 1600 in. Since that time mechanised cut and fill mining from an incline ramp system with connecting stope accesses has progressed some 25 m above No. 36 level. Initial sill development on No. 37 level at 1660 m depth also commenced in July 1987 to further develop the Fitzpatrick area.

Jan 1, 1988

By O Otgonbayar, B Bayarmaa, D Batbyamba, S Amar-Amgalan, K H. Natsagdorj, J Nomin-Erdene, B Boldkhuu, T S. Sainzaya

The Argyle deposit in the Kimberley region of Western Australia was the world’s largest accumulation of natural diamonds. Following its discovery in 1979, the mining of associated alluvial diamonds commenced in 1983, followed by the pipe in late 1985. Over the life of the mine to its closure in November 2020, Argyle produced approximately 900 million carats of diamonds. Argyle diamonds are distinctive in having a predominance of brown colours and rare highly-prized pink diamonds, which are a signature of the deposit. The 3D geological model developed from mining and deep drilling shows that Argyle is a composite pipe formed by the coalescence of several steep-sided diatremes, each with their own feeder zones at depth, that were erupted along a NNE-trending fault. The ~1.2 Ga Argyle pipe is comprised of diamondiferous olivine lamproite volcaniclastic rocks and intruded by sparse olivine lamproite dykes. The volcaniclastic rocks are predominantly comprised of unconsolidated quartz-rich lapilli and coarse ash deposits formed by numerous phreatomagmatic eruptions of olivine lamproite magma through Mesoproterozoic water-rich sands and silts. Post-emplacement deformation has tilted the orebody 30° to the north and regional strike-slip faulting has offset, segmented, and elongated the orebody. Recent significant modifications of the geological model resulted from underground block cave operations, producing several critical lessons learnt. Diamond grade and quality reconciliation issues warranted a geological investigation which resulted in the recognition of new volcaniclastic olivine lamproite domains with a broad range of diamond grades, including some very high-grade units. The new lamproite domains had a significant effect on the block cave mining and resultant recovery of diamonds. The new findings enable a more coherent and detailed geological understanding of the volcanic emplacement and paragenetic sequence of the Argyle AK1 pipe. Structural modelling of the deposit also played a major role in the block cave mining tonnage recoveries and daily operations. The re-examination of the geology of the Argyle pipe and the results of this new information reinforces the need for ongoing robust geological work both in the early stages of mining a deposit and continued during the life of the mine.

Mar 22, 2022

By A Bonani, R Molina, H Constanzo

With conventional undercutting sequence the infrastructure on the production level often has a short serviceable life before major rehabilitation is necessary and is characterised by high maintenance costs. The abutment stress zone is the main cause of this situation. The application of the pre-undercut caving method variant can increase the availability and utilisation of the production level When a pre-undercut is used development and construction are carried out underneath a previously undercut area, far away from the abutment stress zone, under more favourable stress conditions. This paper describes the design principles and the relevant results from the application of the pre-undercut variant over three years to the Esmeralda sector of El Teniente mine. The aspects described are the undercut-extraction, the undercut-development and construction distances, the geometry and drawbells opening, cave extraction rates, and the rate and height of undercutting.

Jan 1, 2000

Mine evaluation methodologies are well suited to evaluating many projects in capital-intensive industries other than mining. These industries include oil, gas, power generation, transport and infrastructure projects. A case study of an open cu

Jan 1, 1998

By Diessel C. F K, Ng N

The commonly used Stopes-Heerlen coal petrographic classification and nomenclature has over the years been subject to variable interpretations. This paper discusses the problem with specific reference to the inertinite maceral group. The effect of various interpretations of the Stopes-Heerlen system on maceral analysis is discussed and illustrated by means of comparative analyses conducted by a number of laboratories in Australia. An attempt is made to define the reflectance thresholds used by the authors to subdivide the inertinite group; the genetic and technological significance of these thresholds are compared. The difficulties of distinguishing structured and non-structured macerals of the inertinite group is discussed in terms of possible improvements to the present Stopes-Heerlen system by extending the classification to include transitional maceral types.

Jan 1, 1969

By Hughes DC

Coal development in New South Wales can involve a complex series of government approvals, a requirement that results from the coincidence of many development sites with environmentally sensitive areas. The concept of network analysis is applied to the pre- development regulatory procedures leading up to the grant of a coal lease. The network facilitates a quantitative and qualitative analysis of activity schedules relating to pre- requisite statutory approvals. The sequencing of activities (with clear start and finish nodes, identification of sensitivities and time estimates for completion of each phase of the network) provides government and industry with an effective planning tool.

Jan 1, 1983

By Collins L

The commercial success of a mining project can be strongly influenced by the business activity which takes place away from the mine site. The project revenue is determined by marketing success which results from persistent research and full realisation of suitable products and by-products and appropriate upgrading achieved in conjunction with proper material security and insurance. Significant costs of transport can be optimised, protection of the environment carefully managed and skilled employees acquired as a valuable asset. Working capital requirements are often substantial and should be carefully established and financed, possibly by special contractual arrangements for product sales.

Jan 1, 1997

Response of a mineral to anionic and cationic flotation reagentsvaries with the nature of the mineral and the particle size. A ruleis deduced for the selection of the correct type of reagent, which leads to a simple method of testing ores to determine the possibility of separating the constituents by flotation.

Jan 1, 1963

Gold deposits in Eastern China have characteristic of belted distribution. The concentrating belts of gold mineralization are about parallel to the island are belt in Western Pacific Ocean. Gold deposits are mainly concentrated in the aged metamorphic rock series on the upwarping zones and upwarping fault zones, and obviously controlled by the deep fractures and their deriva-tive secondary faults. Gold mineralization had genetic relation to the Mesozoic (especially Yanshan period) magmatic activity. The distribution and genesis of gold deposits can be explained by the assumption of wavy structure. The formation of wavy structure is related to the process of Pacific plate and India plate.

Jan 1, 1990

By J C. de Vries

When times are tough in the mineral industry û as they have been for some time û typical responses by mining companies are to cut costs and/ or increase production. The latter is seen to spread fixed costs, thereby also reducing unit costs per tonne mined. However, most mineral deposits respond to increased production rates by lowering ore grades, so the reduction in cost per tonne of ore does not necessarily result in a reduced cost per unit of metal produced. The authorsÆ experience is that this process often leads to a mine plan that is a long way from optimal. Producing to the point where marginal cost equals marginal revenue may work well in a manufacturing operation, but it is not necessarily the best strategy for a mining company with a depleting resource. Variations in tonnage and grade with depth, ore reserve optimism and a variety of other factors conspire to produce variations in production rates and grade that often result in suboptimal outcomes and potential mine failure. Added to this is the focus of industry analysts and senior corporate management on such measures as unit costs and ounces in reserves. This is perceived to have the perverse effect of driving the share price down when strategies are adopted that actually improve the value of the mining operation, and vice versa! Many mine failures can be prevented by a close examination of the tonnage grade curve and an understanding of how margins, net cash flows and resulting business risk change with cut-off grades and rates of production. A few relatively simple analyses early in the evaluation of a project can demonstrate the tradeoffs between the main decision parameters, leading to right-sizing of the operation. Once major commitments to major capital items have been made, and reserves have been publicly reported, optimisation of the operation becomes much more difficult than if it had been done earlier. Such investigations can also identify the upside potential and downside risks associated with factors outside the companyÆs control. Many strategies that may enhance value in the good times significantly increase the downside risk in the bad times. What is often called risk analysis typically looks at superficial issues, and does not evaluate the major factors leading to the potential for financial disaster. This paper illustrates some of these major risks, and demonstrates how they may be fully evaluated so that corporate decision makers can make fully informed decisions that take account of the real risks.

Jan 1, 2003

By Whiten W. J

Data from ball mills of a wide range of sizes are analysed using detailed mathematical models and non-linear least squares fitting techniques. In this way model parameters are obtained describing the behaviour of ball mills over a wide range of mill sizes and operating conditions. These parameters define the flow and breakage of each size fraction of ore in the mill. Flow of coarse particles through the mill is found to depend on the proportion of coarse particles present. The breakage rates of coarse particles are found to decrease markedly with mill diameter for mills over 3 m in diameter.Simulation of grinding circuit throughput at constant productsizing for different mill diameters shows that throughput is proportional to theoretical mill power consumption for mills up to about 3 m in diameter. Thereafter the throughput gradually falls below that indicated by power consumption, the decrease becoming quite significant for large diameter mills. Simple qualitative physical arguments are presented to explain this behaviour. The models developed have applications to ball mill scale up. Work on their further development is continuing.

Jan 1, 1982

The distribution of p(~rphyt1 copper deposits, in time as well as place, is used to propose an occurrence model based on the genesis models of Sillitoe and Rona. A magmatic source of the metals is accepted. The characteristic metallogenic epoch and the migration of the mineralization event along an elongate metal province are explained as the result of subduction of an obliquely- oriented strip of mineral-enriched material on the oceanic plate. Two mineral-enriched trails emanate from a hot-spot source of high-intensity hydrothermal activity in an oceanic rift. Because the whole plate system moves relative to hot spots, the hydrothermal source appears to migrate along the rift, and the two trails are not parallel to transform faults, but form a broad "V" centred on the hotspot. Source loci are spaced at intervals of about 3000 km, resulting in the possible repetition of metallogenic epochs, in a subduction zone province, at about 100 m.y. intervals. The position of the mineral-enriched strip can be found graphically, given ages of a series of deposits in a province, and the plate convergence vectors. This knowledge provides an exploration tool at regional scale and, by reflection across the rift, the potential for exploration is extended across oceans. The model has implications for commodities and deposit types other than porphyry coppers.

Jan 1, 1987

In recent years, the. art of electric steelmaking has received a great deal of attention, and naturally, much controversy has existed from time to time regarding the relative merits of different practices and tywes of furnaces. Nevertheless, at the present time, the basic principles of the process are reasonably well established, and by far the greatest percentage of electric steel is a product of the basic lined, direct arc type furnace. Ferro alloy manufacture has demanded the development of furnaces having very different characteristics to those used for steel. Some special alloys, however, require conditions of manufacture which are more closely approached in the steel type furnace, and thus the latter has been adapted where necessary for the production of these alloys.One such alloy, low carbon ferro-manganese, is manufactured at Whyalla, South Australia, in a basic-lined, direct arc furnace, which is used alternatively for the production of alloy steels.BRIEF HISTORY OF THE ELECTRIC FURNACEThe principle of melting by electricity was first applied to the melting of iron in 1879 by William von Siemens, whose equipment consisted of a small crucible into which were introduced two carbon electrodes. Very little practical development took place in the next 20 years, although in 1890 a Frenchman named Heroult designed a direct arc furnace for the production of ferro alloys. At the beginning of the 20th century, several types of furnaces were patented for steel melting, the most important of these being the Heroult, using a direct arc, the...

Jan 1, 1951

The history of the rail and mining industry in Queensland over the past century is inseparable. Indeed it was mining that led to the construction of the line west from Townsville and that shaped its current alignment. The discovery of gold at Charters Towers started construction of the Great Northern Railway west from Townsville in 1879, with completion to Charters Towers in 1882. The line was extended to Hughenden in 1887 and to Cloncurry in 1907 - driven by copper mines both to the south west and the north west of Cloncurry. The mining industryÆs association with funding the construction of rail lines to service their individual mines began in this area when the Hampden and Mount Elliot mine companies agreed to pay 50 per cent of the cost of the line from Cloncurry. The line to Selwyn was completed in 1910. Copper mining saw the construction of many other rail lines in the Cloncurry area in the 1910 - 20 period before copper prices slumped. Included in these lines were the Malbon to Duchess line and the line to Kajabbi and beyond.

Jan 1, 1998

By Saint-Smith J. C

The anode, tank house and wire bar plant and operations are described with particular reference to those features of design and methods which are characteristic of this refinery at its inception.Reference is also made to auxiliary equipment, transport and materials handling facilities.The work of commissioning the plant late in 1959 is discussed and comment is made on the organisation of construction and origin of the equipment.LOCATION OF PLANTThe site chosen for the copper refinery is on level ground adjacent to the junction of the Mount Isa and the main north-south railway lines at Stuart near Townsville, Queensland. Blister for refining is received by rail from Mount Isa. Refined products are taken 10 miles by road to Townsville Harbour for shipment to other Australian ports or overseas, or despatched by rail direct from the plant.Adequate room for expansion was provided to cover copper refining and any associated industry. The layout of future extensions was planned and space reserved for them before detailing the original units of the main refinery.The initial plant also provides convenient storage facilities and is laid out to derive the greatest benefit from prevailing northerly breezes during the humid tropical summer.As far as possible, the working areas are located so that the prevailing winds cool them as they traverse the buildings.These factors are of very great importance since this is believed to be the only copper refinery in the tropics operating with all white labour and in any case the Company set out to provide the best possible conditions for its operating personnel.

Jan 1, 1961

The art of flotation may be divided into two distinct branches, namely:-1. Collective flotation.2. Selective flotation.(1) Collective flotation is applied when all the valuable minerals in an ore are required in one concentrate, leaving ,only gangue minerals in the tailing. The method is applicable, for instance, to such ores as auriferous copper sulphides associated with gangue minerals only, or to silver lead ores low enough in zinc and other valuable minerals.(2) Selective flotation is applied when there are present in an ore two or more valuable sulphides, which cannot be subsequently efficiently treated unless they are separated from one another as well as from the gangue. For example, a silver-Iead-zinc ore, or a copper-gold-iron ore; where the iron is not required with the copper gold concentrate.In order to make these operations practicable chemical reagents have been developed, having power to exert definite actions on the various minerals when brought into contact with them in a water pulp.COLLECTIVE FLOTATION.In order to bring about collective flotation it is generally necessary to add to the pulp a frothing agent and an activator or activators for all the minerals which it is desired to float.SELECTIVE FLOTATION.The object of selective flotation is to activate the mineral which is to be floated, and at the same time to prevent all other minerals from floating.

Jan 1, 1936