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By P Knights, M S. Kizil

Truck/shovel operations constitute 50 - 60 per cent of the cost of open pit mining operations. Mining companies, therefore, are constantly seeking to close the gap between actual truck/shovel productive capacity and maximum potential truck/shovel capacity. This paper analyses the performance of a mixed truck/shovel fleet in an open cut coal mine in Australia. It analyses operating delays, and proposes a novel graphical means of determining truck-limited or shovel-limited operations. A goal seeking algorithm is advanced in order to maximise truck/shovel match factors (MF) and hence optimise fleet productivity.

Sep 26, 2011

By E Villaescusa

This paper summarises research work carried out at the Western Australian School of Mines on mine backfill properties in the last few years. The fill properties presented relate to cemented aggregate fill and cemented tailings fill. Emphasis of these studies has been placed on the composition of backfill materials including aggregate particle size distribution, cement dosage and influence of cement admixtures. The unique features of the backfill research carried out at WASM during the last few years are the accomplishment of a study into the properties of large cemented rockfill samples by triaxial testing and the investigation of the properties of fill material made from highly saline ground water prevailing in the Goldfields region of Western Australia. Exploring different cost-effective binding agents for mine backfill was also carried out at WASM. Special effort has been put on the development of fill materials compatible with hydraulic and paste fills. During the process, specific methods and procedures for laboratory testing of backfill material have been formalised. The on-going backfill research on sample scaling is summarised and the future direction of WASMÆs backfill research focus is outlined.

Jan 1, 2000

The developments in hydrocyclone classification in the milling circuit at Bougainville Copper Limited are discussed. A major change in cyclone size and improve- ments in operating conditions have been made. Test work has been carried out to assess the classification performance of a modified Linatex cyclone, Wemco cyclones and a two stage cycloning circuit. The use of a scalping cyclone, to remove coarse material from the present overflow product for regrind, has also been investigated.

Jan 1, 1978

By B T. Park, S D. Fundingslan, K W. Wangerud

The EPA National Risk Management Research Laboratory (NRMRL) Mine Waste Technology Program (MWTP) and the EPA Region VIII Superfund office are jointly conducting a field-scale technology demonstration of a two-step in situ treatment of the acidic Anchor Hill Pit lake at the Gilt Edge Mine Superfund site near Deadwood, South Dakota, USA. The project goal is to develop cost and performance data for the in situ treatment for potential application in long-term water treatment/management activities at the Gilt Edge site, and for potential application at other similar sites. Lime neutralisation of the pit using a Neutra-Mill was accomplished in the spring of 2001, with a resultant lime utilisation efficiency of about 71 per cent, and a typical throughput of about 1 tonne per hour using coarse, pebble quicklime and 1.4 tonnes per hour using finer, ground lime. Redox-mediated biotransformation treatment of the pit has been ongoing since May 2001. As of January 2003, denitrification is complete in the near-surface waters and about 90 per cent complete in the deeper waters. Bacterial sulfate reduction is expected to begin in the near future. This paper describes project activities, results, and lessons-learned to-date as well as future monitoring plans.

Jan 1, 2003

Geological models for the exploration and evaluation of epithermal Au and porphyry Cu-Au deposits rely upon a classification of different deposit styles and an understanding of the evolutionary processes of deposit formation. These models guide the interpretation of subsurface deposit anatomy in order to target drill testing and assist the explorationist to focus on the more prospective projects. It is important for the explorationist to distinguish between different styles of magmatic arc Au deposits as each style displays distinctive characteristics with exploration implications. Magmatic arc Au deposits are distinguished as porphyry Cu-Au formed at depths of 1 - 2 km at the apophysis to larger, buried, magmatic sources which are also the ultimate metal sources for the varying styles of shallower level epithermal Au deposits. Low sulfidation epithermal Au deposits characteristically develop from dilute circulating meteoric waters and are distinguished as the group with a closer relationship to intrusive source rocks, and slightly higher sulfide contents (still generally

Jan 1, 2004

Compared with modern longwall coal mining systems, automation has not been developed very far in the underground metal minin industry. One of the main reasons for this is that present har rock mining systems do not produce ore with a controlled degre of fragmentation. The often poor fragmentation from the stopescauses large extra costs and precludes material which 1-ends itself to automationThe paper investigates the possibility c technology for automatic loading and trapconveyor belt to a shaft dump pocket. With this concept, it will be necessary to control the maximum fragment size by careful blasting design. The degree of fragmentation will have to be finer than is common to-day. The study shows that the belt conveyor mining con-cept with controlled fragmentation may be economically competitive with conventional cyclic loading and transport, even for an annual production as low as 0.5 mill. tonnes.. Fragmentation design and cost calculations have been based on a combination of the Kuznetsov relationship between blasting parameters and mean frag-ment size, and the Rosin-Rammler formula for fragment size distribution.

Jan 1, 1985

The Coke Ovens Laboratory at Australian Iron & Steel, Port Kembla has been involved in the analysis of seam gases and mine airs for approximately twenty (20) years. This period has seen many developments and changes in the techniques used to the point when the current techniques are equal to other labora- tories involved in similar analyses. The laboratory has NATA registration for the analysis of mine airs and gases. Apart from routine testing of seam gases, ventilation airs and gases emmitted from coal bore cores a number of projects have been undertaken. These have served a twofold purpose, one to provide information to the customer, generally Collieries Research and Technology and secondly in developing the skills and capabilities of the Coke Ovens Laboratory. This paper discusses the development and services available at the Coke Ovens Laboratory for the analysis of gases and airs from collieries.

Jan 1, 1983

A typical large surface mine in Scandinavia has hard rock, a cold cli- mate, poor ore, a complicated vein type orebody and high labour costs. In order to survive, these mines have to maximise their ore production, minimise waste extraction and get the most out of every man hour. This article describes two examples of how inclined blastholes drilled with hydraulic percussive drills can help to meet these requirements. Both of these Scandinavian mines, Kemira Ltd's Siilinjarvi mine in Finland and Sydvaranger A/S's Bjornevattn iron mine in Norway, use inclined blastholes of 200 mm in diameter. The Siilinjarvi quarry is using inclined holes in production drilling. The Bjornevattn iron mine is blasting the final pit walls with inclined holes. The benefits gained when using inclined instead of vertical blastholes are better selectivity, better bench drilling conditions, steeper final pit walls and increased safety.

Jan 1, 1989

By M Maulen, K van Olden, T Elkington

A large open pit is planned at the site of an existing underground mine. Strategic planning work has been undertaken to investigate the project value associated with an expansion of underground operations in conjunction with the proposed pit. Previous analysis determined that any depletion of the available pit resource that changes the optimum pushback sequence has a significant negative impact on overall project value. Therefore, to investigate the viability of an underground expansion requires a system to identify the stope resource that would add value to a combined operation if mined ahead of the pit. The key solution to this problem was to generate a resource model variable that defines the blocks, which have greater discounted value if mined by stoping rather than by the open pit. A key assumption was that the open pit is the main driver of overall project value. From the identified potential underground resource, series of mineable stope shells were generated at a range of cut-offs. This stope reserve data formed the input to a mixed integer program based software tool that was developed and used to optimise the underground mining plan, at conceptual level, for various project configurations. A dynamic programming tool was then applied to evaluate the optimum value of a combined open pit and underground operation. The overall objective of this project was to determine the strategic plan that yields the optimum value for a combined undergroundûopen pit operation. The results provided a clear focus and direction for more detailed design and planning.

Jan 1, 2009

By Sturgul J. R

The South Middleback Ranges (SMR) operation involves the develop- ment of iron ore resources at the Iron Duke mine in the South Middle- back Ranges to replace the Iron Baron mine whose reserves are nearing depletion. The Iron Duke mine will be developed by contract to the stage where it can continue operation at full production when Iron Baron is closed. As part of the mine planning of the operation a GPSS computer simulation model was written to determine equipment requirements. The model simulated the operation of the mine with trucks transporting ore and waste to the appropriate destinations and producing a blended product in the stockpiles. A loader and two trucks would transport ore from the stockpiles to the crusher for one shift per day. The simulation shut the operation down at crib, morning tea, shift change and weekends, and also on the third shift each day. It also modelled operating delays. The results gave equipment operating hours and total output of each material type. The model was modified to produce different outputs from the mine and could be used to determine the most productive shift arrangement.

Jan 1, 1989

Mining in Guyana dates back into antiquity and a brief history of gold and diamond mining and of the small-scale miner, the pork-knocker, is given. The gold and diamond deposits found on the beds and in the flats of old and present rivers and the current methods of investiga- ting these deposits are briefly described. Methods of mining these deposits including the small-scale hand methods of pitting and diving with or without helmets are also briefly described. 'The small-scale method of dredging using a suction dredge in conjunction with a diver is described in more detail, from its develop- ment to current practice, without giving too much mechanical and technical details. The organisation of the industry and the mining titles, laws and policy relating thereto are reviewed. A brief account is given of the socio- economic role of the industry. Conclusions are made regarding the need for improvements in existing equipment and financing and for incentives to stimulate production. The future outlook of the industry is con- sidered.

Jan 1, 1986

Every step on the path from the mine to the smelter invites a comparison between material inputs on one side and outputs plus accumulation on the other. Or put simply, between what you think you have produced with what you find you have at hand. The discrepancy between these sets of comparisons is the error. Following that error in a systematic and objective manner is a way to improve the mineÆs measurement systems, that in turn leads to more accurate accounting for ores, metals and concentrates. Because the control of production is so tightly coupled with the accounting of materials, any lasting improvements in materials accounting will benefit the predictions of materials movements and quality. This translates to more reliable planning and scheduling in stockpile management, logistics, shipping and marketing. The statistical tools described are direct adaptations from the long-standing methods used to maintain the quality of manufactured product in the discrete parts industries. Their use in the process industries, of which mining is one, requires some care owing to the continuous nature of ore extraction and its variable properties. The tools can be used for problem diagnostics and as early warning systems. In common practice many professional staff, in attempting to get a perfect reconciliation between expected and observed results, try to explain away the error or bury it completely. The methodology advocated here requires a different mindset because the error must be given pre-eminence for lasting improvement to be realised.

Jan 1, 2002

By S Furman, M Caccetta, A Hacket, B McDonald, M A. Wells, D Lau

In 2004, the Western Australian Department of Industry and ResourcesÆ Burrup Rock Art Management Committee commissioned a number of independent scientific studies to evaluate the condition of rock art in the Burrup Peninsula near Karratha (Western Australia). These studies are evaluating the physico-chemical aspects of the effect of environmental modification on the visible appearance of the rock art. Because of the cultural significance of the sites, the research approach has been to employ non-destructive testing strategies and work in the field has progressed with respect for the importance of the area. This paper only reports the spectral mineralogy monitoring at each of the sites to evaluate whether changes in mineralogy are observed on rock surfaces. Reflectance spectroscopy is a non-destructive, in situ materials characterisation technique that provides information about the mineralogy. The minerals detected include haematite, kaolinite, chlorite, goethite, gibbsite and manganese oxides. Current results indicate that the surface mineralogy of the rock art has not changed in the last four years.

Jan 1, 2008

By Duncan B

Shortwall continuous mining as first introduced at Burwood colliery, and currently being used at John Darling, Lambton, and Corrimal collieries, is a method of coal winning which was pioneered in the Newcastle district. The system uses individual hydraulic self-advancing chocks for roof support and the coal winning operation is by continuous miners and shuttle cars. Where physical conditions are suitable the system provides a safe, efficient and economically viable basis for pillar extraction. Shortwall operations have been conducted successfully in the Victoria and Dudley seam, near the coastal fringe of the Newcastle district and are now being tried out in the more difficult conditions of the Bulli seam in the Illawarra district.

Jan 1, 1972

By Campain RA, Horner NJ, Limerick JM

The review covers the different concepts of automation which are appropriate to non-ferrous smelting and the degree to which the smelter, and the furnace in particular, is amenable to total automation. Due to the problems peculiar to a smelter, it is unlikely that a fully closed loop system could ever be achieved and that the smelter will continue to depend upon extended manual control supported by computer based information sorting and optimisation.Generally, loop control is performed using Taylor's Mod III process control system. For distinct plant systems involving a combination of process loops, sequencing, and data acquisition, the company has developed its own microprocessor based systems. Process optimisation using computer based analysis of operating data is well established. Utilising this data, computer modelling provides manual set point supervision for the furnace process control system.The impact of automation on the workforce and on operating costs is also examined. Predictions on future developments in the field of automation, optimisation and sequencing are propounded and related to the non-ferrous industry at large.

Jan 1, 1985

Instantaneous outbursts have occurred at Metropolitan Colliery from the pick and shovel work of early days to the modern mining techniques of today. Developments have been the introduction of an emission index to measure the proneness of the coal to outbursts, drainage and destressing by large diameter holes, attempts at higher productivity by the introduction of pulsed infusion shotfiring and improvements in ventilation. The future plans and aims for the Colliery include prediction of outbursts, seam gas pre- drainage and longwall mining.

Jan 1, 1980

Heavy media separation serves to upgrade mill feed and reduce unit operating costs, allowing ores to be mined which could other wise be uneconomic. At the Aberfoyle mine at Rossarden in north-east Tasmania, a simple heavy media operation using a converted Akins screw classifier as a separating vessel, removes barren quartz from mineralised material. At the Cleveland mine at Luina on the west coast of Tasmania a more complex ore mix requires a versatile operation combining hydro-dynamic and static separation equipment to provide an efficient beneficiation circuit. The two operations are briefly described with a background of basic heavy media separ- ation practice.

Jan 1, 1978

By Penney B. K, Baghdadi A. A

An electron probe micro-analyser, controlled by a dedicated mini-computer,has been operating at Imperial College since 1970. The data assessment capability of the computer was limited and, in order to make better use of the information produced by the analyser, extra computing facilities were needed. Following the initiation of a Laboratory Automation Project at Imperial College involving the use of a central computer linked to laboratory type computers and to further more powerful systems,it became possible to carry out much more detailed and extensive mineralogical analyses by connecting the mini -computer to the Laboratory Automation Network. The paper describes the techniques employed including hardware, software, inter- connection, analysis and operating methods.

Jan 1, 1977

Magmatism and mineralization are features of the New England Orogen in late Palaeozoic- Mesozoic time. Voluminous silicic and mafic magmatism, both orogenic and post-orogenic in association, was accompanied by abundant mineralization in the earlier phases. Later activity passed transitionally into less vol- uminous felsic to mafic intraplate basaltic volcanism, with possible migratory hot spot activity through the flanking Oxley and Sydney Basins. Only minor mineralization took place at this stage. A new inerpretation links these magmatic and mineralizing events to a major thermal cycle. A New England hot spot(?) complex evolved in latest Carboniferous/early Permian time. Its activity was partly obscured by orogenic magmatism as Australia moved slowly over magma sources in the deep lithosphere. In Triassic time Australia's movement changed direction and faster drift over the waning hot spot complex produced multiple migratory intraplateòactivity. The volume of magma and hence abundance of ancillary mineralization was related to age of the hot spot, speed of the continental movement over thermal sources and extent of accompanying orogenic activity. The New Eng- land Orogen hot spot(?) possibly existed for 165 Ma, with mineralization changing over this Period.

Jan 1, 1987

By D Kent, J Kirkpatrick

The mining industry has long wanted a single communication back bone to cover the majority of their requirements underground. The convergence of communication technologies in the office/surface environment has been identified by the mining industry as a means to achieve their long-standing goal. In particular use of Internet Protocol (IP) systems are seen as proving a basis for a mineÆs communication infrastructure. This paper presents the development philosophy and work undertaken by Inco Limited in Canada, as well as the implications of this on suppliers to enable the technology to be mine worthy and readily available.

Jan 1, 2005