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By Brimblecombe P

Morwell Open Cut is a continuous mining operation employing 5 buck- etwheel excavators, I bucket chain excavator and 54 conveyors. The combined bunkering capacity at both client Power Stations represents less than 12 hours maximum coal demand. This creates an extremely dynamic operating environment, which is further complicated with significant variations in both excavating and transportation plant capabilities. To achieve set objectives, including- I adequate reserves, 2 coal supply reliability, 3 cyclic plant maintenance, 4 minimal cost of coal, scheduling of the operation requires constant monitoring and reappraisal.

Jan 1, 1989

By S Morrell, D Clark

æMine to MillÆ improvement involves optimising the chain of rock breakage processes from the in situ rock in the mine to the output of the concentrator. A growing number of paper studies and case histories from metalliferous mines (AusIMM, 1998; JKMRC, 1998; Clark and Scott, 2002) demonstrate that generating more breakage in the pit and the primary crusher can lead to benefits to milling that result in significant improvements to the economic performance of a mining project. However, unless the ævalueÆ of doing this (benefit over cost?) can be appropriately quantified, the approach cannot be effectively managed and the increases in blasting and monitoring costs cannot be justified.Mining operations have traditionally been organised into the separate departments of geology, mining and processing based on the specialist skills required and the different professional disciplines involved. Process optimisation across these boundaries has commonly been frustrated by management requirements to minimise the costs incurred by each department without adequate reference to the ævalueÆ being created. Companies have tended to discard positions that provide a technical over-view of the value chain, reducing the number of people with the opportunity to influence practices across these process boundaries.This paper discusses these issues and identifies measures required to quantify and manage the ævalueÆ provided by æMine to MillÆ improvement generated by the intense blasting of ore.

Jan 1, 2002

The search for an efficient and economic machine to excavate hard rock continues. Development of the Robbins Mobile Miner commenced in 1983 with the formation of a joint venture between Mount Isa Mines Limited and The Robbins Company. Construction of the machine ensued and preliminary trials to verify the cutting action were undertaken in the USA prior to transportation to and assembly at Mount I-sa where mining commenced in September 1984. Initially, the machine was used to develop the S60 Decline which serves as a combined access and conveyor drive for the Southern 1100 Orebody Ore Handling System.

Jan 1, 1988

By R G. Barker, A B. Christie

Minerals are necessary for providing almost everything we take for granted in our daily lives including food, shelter, and supplies of energy and water. Minerals are therefore essential for the maintenance and improvement of the standard of living of all New Zealanders.

Jan 1, 1998

By N R. Johnson

The overland conveyor at the Los Pelambres mine in Chile is designed to move 8700 t/h of material over 12 km at a speed of 6 m/s while descending 1400 m. The conveyor, which is divided into three segments, is equipped with a braking system that must bring it to rest without producing excessive stresses in the conveyor belt. Retardation and gently stopping a mass of 250 t requires retardation times in the order of 60 seconds. Brakes that can provide this performance require sophisticated controls as well as very high heat absorption capacity. This paper describes the thermal analysis of the braking system, which required the use of novel materials to meet the arduous duties imposed on the callipers and discs.

Jan 1, 2005

By Quayle J. E

This paper covers period from 1973 through to 1988 and the mines of West Coast Mines, Elur Mine, North Mine and Risdon Zinc Smelter, now all part of the Pasminco Group. During this period, optimisation started with one mine (West Coast Mines) producing four Product concentrates with constant steady feed to the smelter and progressed to three mines producing eight products and a smelter varying feed inputs to maximise benefits. The initial optimisation was done manually using a desk top calculator and hand drawn graphs. This ultimately advanced to the use of PC plus linear programming software and spreadsheet generating relevant graphics. The financial benefits were achieved with no capital expenditure and increased from an initial $0.5 to $1.0 M/year (1973 $'s) to $5 to $10 M/year (1988 $'s).

Jan 1, 1991

By M Kizil

Mining Engineering Degree programs have traditionally had a practical emphasis and have been highly vocational in nature. However, over the years, there has been an increasing attention to the more scientific aspects of the discipline. More recently, the professional institutions, the industry and the community at large have placed increasing emphasis on the broader aspects of the professions: management, finance, humanity, environment and social issues. Notwithstanding this, there has been a continuing emphasis on the practicalities, and most Mining Engineering programs are still strongly vocational in nature. But employers of new graduates complain about the graduatesÆ lack of practicality and readiness for employment æat the sharp endÆ on the mine site.This paper briefly describes some of the more recent developments in the Mining Engineering Degree program at the University of Queensland that attempt to address the problem. Particular attention is paid to alternative learning programs, including applications of virtual reality, practical experience at the University Experimental Mine (UQEM), and the Undergraduate Site Learning Program (USLP).

Jan 1, 2002

By Smith M, Milton T, Pitt G

High levels of contamination (non magnetics) were present in the magnetite medium of the D.M. cyclone circuit. Attempts were made to minimise the amount of undersize (-lmm) material in the D.M. cyclone feed by improving initial desliming and examining those factors that contributed to any overall reduction in desliming efficiency. Circuit density control was improved and a system of continuous contamination monitoring implemented. A brief description is included of the major alterations to circuit control philosophy. The significant improvement in overall D.M. cyclone circuit performance is outlined.

Jan 1, 1987

By McDonald E, Clifford PJ

A mine planning system comprises all elements necessary to carry out the full range of mine planning activities from exploration to operations control. The application of computers as part of a mine planning system has great potential for increasing the efficiency and quality of mine planning and reducing its cost. The introduction of computers to mine planning in open cut coal mines has been hindered by the cost of processing the large databases associated with large coal deposits and the inherent inconvenience of performing an interactive process on a time-shared computer. A dedicated computer is ideally suited for the purpose but reasonably priced micro/ mini-computers until recently have not had the capacity to store the volume of data or the processing capability required. Recent hardware developments have cleared the way for the development of truly interactive mine planning software, covering the complete range of activities associated with open cut coal mine planning, incorporating them into a single system using a common database. The MINEMAP System is a hardware and software package tailored specifically for mine planning of open cut coal mines and is an example of such a system.

Jan 1, 1983

The problem of spontaneous combustion has long exercised the minds of Mining Engineers. The idea of inertising an area with a non combustible gas has seemed to be an attractive way to overcome the problem. Various agents have been tried but nitrogen has particular attractions and advantages. Britain adopted the idea from the German industry and found that it was particularly suitable for the conditions in British Mines. Over 8 years much development work has been done and specialist equipment has been developed as the requirements came to be better identified with experience. There is a continuing programme of innovation and the technique can be further developed in the future as a means of protecting the very heavy investments which are being made in today's large capacity, heavily capitalised faces.

Jan 1, 1988

Mount Isa Mines Ltd. annually extracts 5.6 million tonnes of copper ore from the 1100 Orebody. All production is by longhole open stoping, with an increasing emphasis on pillar recovery. Drilling and blasting prac- tices have been modified to allow more efficient pillar extraction, with the evolution of a "core and shell" approach. Blast design occurs at the stope design stage, while individual blast preparation is based on detailed ring plans. A programme of blasting research involving surface and under- ground vibration monitoring and fragmentation assessment has been car- ried out in conjunction with production personnel. Drilling and blasting practice in the orebody must continue to evolve with continued research, to suit changing conditions and take advantage of new technology.

Jan 1, 1988

By Browning E. J

The application of conventional dust control systems in British Coal mines has considerably reduced the incidence of pneumoconiosis. A number of new techniques have been developed involving extraction close to the cutting heads of mining machines which will be capable of controlling airborne dust with the greater intensity of production necessary in the present economic climate.

Jan 1, 1988

By Schommarz KH, Dunne RC, Goodall CM

Column cells are widely used today for the recovery of base metals by flotation. Their use for the flotation of iron sulphides has not been as rapid. Australia has pioneered the use of large rougher flotation columns. During the last six years, seven rougher columns have been installed on gold mines treating iron sulphides and the technical viability of this technology has been demonstrated. Laboratory column testwork on a gold bearing iron sulphide ore demonstrated the effects of both physical and chemical parameters. In general the large commercial columns operate over a broad range of conditions depending on the downstream treatment of the flotation concentrate. The addition of wash water to commercial columns is not universally applied and there appears to be a need for a better wash water System.

Jan 1, 1993

By Kaji S

The Tsugaru Tunnel, located on the Honshu island approach to the Seikan Tunnel, is 5,880 m long and has a "Shinkansen" cross section of 90 m2 area. The geological formation through which the tunnel passes consists of very soft rock most of which is unsolidified sandstone belonging to the Neogen. The permeability coefficient is in the range of 10-2 to 10-4 cm/s and being water bearing with a high ground water level, the ground is unstable and subject to soil outflow phenomenon. Kajima Corporation, undertaking the Futamata Construction Section (1,420 m long), excavated the tunnel by the upper half heading method with side pilots employing the following countermeasures to cope with these severe conditions.

Jan 1, 1987

Faced with low prices and weak demand in an oversupplied market, the Australian coal industry must seek to further reduce its costs. The paper examines minesite competitiveness of the open cut coal industry in Australia with some references to the coal operations of M.I.M. Holdings Limited. The make-up of F.O.R. mine costs is analysed in order to identify where efforts should be directed to maintain competitiveness. The scope for mine site improvements through changes to working practices, the application of new technology and cost management is examined.

Jan 1, 1987

By R Puglisi, G McPhail, B D. Jilbert

The increased international focus on sustainable development and cost improvement, coupled with the unpredictability and adverse impact of droughts in Australia and globally, has highlighted the critical need for responsible management of water within the minerals industry. The Rio Tinto Technology Group recently initiated a priority program to examine how water management practices could be improved within the GroupÆs spheres of activity. Rio Tinto Technical Services (TS), the technical services consulting group of the Technology Group, has for many years been undertaking water management reviews and assisting group operations with the development of responsible water management strategies and plans. Rio Tinto therefore requested that Rio Tinto Technical Services develop a world-class approach to mine water management that will drive improvement in strategic assurance and operational efficiency of water at the companyÆs managed operations across the world. The initiative, known as æExcellence in Water ManagementÆ, includes the selection and use of state-of-the-art management, technical tools and methodologies to strive for best practice. The Rio Tinto Technical Services approach facilitates a consistent and objective assessment of performance across the entire spectrum of complex water management issues within a mining operation, from initial exploration through to decommissioning and close-out of the operation. Based on this rigorous assessment, detailed action plans can be developed, prioritised and scheduled for subsequent implementation. This paper presents the progress and experience gained to date in the æExcellence in Water ManagementÆ program, demonstrated by means of a pilot study conducted at Northparkes Mines in New South Wales.

Jan 1, 2003

By M Bannear, J-F Wilhelmy, R Jones

Mineralogical study of the interactions between fluxes and iron-oxides helps to understand how magnetite oxidises to haematite during pellet firing. Samples of OneSteel magnetite pellets tested at COREM pilot plant were collected after three firing steps and were studied mineralogically. Preheated pellets revealed no particular microstructures related to the composition of fluxes but were more affected by their bed position. After kiln firing, the impacts of lime and magnesia became more apparent. Magnetite oxidation is complete in the cooling stage. The position and the microstructure of the residual magnetite can bring useful information that could æcompleteÆ the view of the firing cycle.

Jan 1, 2007

By T Hodgkin

The WA Goldfields is a highly productive gold and nickel mining area, but is arid with highly saline groundwater. Groundwater is widely used to supply process water to mines in the region but high groundwater salinity, commonly exceeding 50 000 mg/L TDS, tends to increase processing costs, limit end uses for the water, cause problems with disposal and potentially increase impacts on a sensitive arid environment. The area has low rainfall (200 - 270 mm/year) but run-off, particularly during cyclonic events, is high. Our experience suggests that stream flow from catchments in the area can produce a divertible yield of 8 - 17 ML/km2/year. An evaluation of stream flow harvesting using AnglogoldÆs Jubilee Pit predicted that 1000 ML/year of good quality water could reliably be supplied to the Sunrise Dam Gold Mine. Because of high rainfall variability, it is likely that an alternate source of water supply will be necessary when operating a surface-water harvesting scheme in the WA Goldfields. However, a combination surface/groundwater supply could have substantial cost, operational and environmental benefits compared to traditional supply systems that utilise groundwater only.

Jan 1, 2003

In Australia 'there are hidden deposits of gold, copper, tin, lead and zinc which can be found by drilling at reasonable expense in view of the imp9rtance of the objectives. Exploration of the prospects in mind would mean about a million feet of drilling. The purpose of this paper is to outline, in a technical way, some of the geological thinking that has been given to this matter. To do this, it is necessary to unify the wider ranging thoughts into some sort of coherent perspective and also into some sort of logical sequence. This will be done by treating first the geological subject material which is in fact, at the foundation of the exploratory scheme. With this base, the argument will be continued through a sequence of prospect thinking and brought to a conclusion in regard to the practical employment of geology in the drilling planning. In this knitting together of ideas, the discussion will be given substance by welding into the argument the reasoning that has been applied to the Cobar prospect. The New Occidental Gold-Mines are operating three mines at Cobar, and the writer is indebted to the Company for allowing the reference to be made. It is intended, as opportunity permits, to furnish further examples in later publications.FOUNDATION OF EXPLORATIONThe deposits under consideration are derived from igneous rocks, chiefly granite or porphyry. In and following the emplacement of the intrusives, the rocks have been...

Jan 1, 1946

Most of the gold reef mined today in South Africa is approximately 1 m in width with slopes about 30 m long. To prevent production interruptions it is essential that the stopes should not be blasted in sections. The shortage of experienced labour and arduous working conditions at the face dictate the need for simple blasting techniques.Hence, a pyrotechnic blasting system of sequential firing is in use at present, although research work to improve this technique is in progress.

Jan 1, 1985