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By Swift J. D

A key parameter affecting the performance of gravity thickeners in hydrometallurgical processing operations is the aggregation state of the feed after the addition of a flocculant. New procedures which measure the settling ratelsize relationship and the size distribution of aggregates in their process liquors have been used to quantify the aggregation state of the feedwell, overflow and underflow streams in a tailings thickener. The data obtained have been related to the thickener's operation and to a change in the flocculant dosage. A comparison is also made between the settling rate/size relationships determined with these new procedures and the mud-line settling rates from cylinder tests.

Jan 1, 1991

Prediction of large-scale underground opening stability in quite complex mining circumstances is being undertaken on a routine basis at The Zinc Corporation, Limited, (ZC) and New Broken Hill Consolidated Limited (NBHC) Broken Hill, Australia. A three- dimensional numerical modelling technique has been developed that gives good correspondence with the observed behaviour in many stopes. New insights into the rock mechanics of under- ground mining are flowing from this work. The modelling practice can be taught to engineers in a reasonable time-frame. In-house computing facilities including graphics workstations are needed. The RMS software is designed to be user-friendly and very robust.

Jan 1, 1983

In a coal mine there are many substances capable of ignition under certain circumstances, which can be placed in the following groups: ordinary combustible solids, dusts, liquids and vapours, gases, metals and plastics. There are many factors influencing ignition, including temperature, minimum ignition energy, particle size, explosion pressure level, rate of pressure rise, specific energy content and also explosive limit. Not all are applicable in every case. Frictional ignition of methane is an accident statistic of increasing concern and is considered in some detail. Practical measures that can be taken to reduce the incidence of frictional ignitions are considered, and also possible ways of ignition suppression.

Jan 1, 1981

During the post war era, the requirements of the "Third" World for modern civil works, energy and industry, coupled with an insistence that these capital installations are understood and controlled by indigenous people, have crea- ted a demand and flow of technology from those countries with well developed skills. Thus has grown a real trade in technology - an activity in which consultants play an important role. An indication of the magnitude of this trade is given, together with an outline of some of the special problems. Australia is shown to be dis- advantaged and has been slow to offer the incen- tives to consultants which other countries offer.

Jan 1, 1975

There are two main areas of application of geology in quarrying: (i) In regional planning for industrial mineral requirements.(ii) In direct quarry management. The regional planning requirement has recently become more evident because of greatly increased land demand conflicts around cities. The direct quarry involvement is a reflection of both the economy and the greatly increased sophistication of the quarry industry. Here, professional planning and development expertise by a geologist is required, to ensure continued supply of raw materials at the best price to the consumer with sufficient profit to the producer. Today, geological insurance safeguards capital investment in plant and assures economical development plans.

Jan 1, 1978

The application of new and currently practised mining techniques in new areas and at greater depths necessitates considerable and immediate research effort. This effort is aimed at identifying the factors which make a particular method suitable and economically viable in a given geological, structural and operational environment. These factors, together with greatly enhanced knowledge of a deposit at the exploration and planning stage, allow selection of the most appropriate and efficient mining method in a new area such that coal resource recovery is maximised in a cost effective manner. Current research and future requirements for research into mining methods and associated equipment and mine services are reviewed.

Jan 1, 1981

The Australian mining industry is at an interesting stage in its development. Of the large number of mining companies in Australia, some are still solely domestic in their focus. others have made their first tentative forays offshore, and others are global players of significance in the world industry. It is not long ago that the entire industry was almost exclusively domestic in its focus. Very few companies before the early 1980s had ventured offshore, and those that did so were considered quite risque. The initial moves were made mainly by large companies who could afford to lose the funds expended in getting started in a range of offshore locations.

Jan 1, 1995

The mining industry views with the utmost concern, legislative or administrative action that inherently reduces the scope for exploration activity. Is there any basis for this concern in relation to Victoria? This paper will outline the role of the Department of Minerals and Energy and the main features of legislative provisions affecting exploration effort. The practical difficulties that confront the Department and explorers alike will be examined. The importance of industry representation to influence the direction that policy and legislative review might take, will be highlighted. Above all, the paper will establish that one essential duty of government is to ensure the provision of appropriate mining titles and security of tenure.

Jan 1, 1982

The maintenance system for underground mobile equipment at Cobar Mines Pty. Ltd. has been modified from that originally planned as a result of experience gained in operating the equipment.Downtime due to breakdowns has been reduced by improvement of vehicle servicing and overhaul procedures.Frequency of breakdowns can be reduced by training operating and maintenance personnel to a high standard, ensuring adequate numbers of tradesmen and supervisors, good maintenance facilities and communications, a well designed mine layout, and a comprehensive stock of spare parts.A maintenance and downtime summary is compiled for each four-week operating period and this is useful in highlighting particular problems where corrective action must be taken.

Jan 1, 1969

By Ulvelin K, Antila K

Large scale cut and fill mining in narrow silver-lead-zinc orebodies began at Mount Isa in 1964. Initially each orebody was one stope and access was via raises from the level above. Upholing was the principal mining method, although flatbacking was employed where ground conditions were more difficult. Developments since have included access via footwall inclines and connection of all stopes with major crosscuts. Flatbacking is the principal method. The most recent cut and fill operation is now fully mechanised using drilling jumbos, rockbolting jumbos and load-haul-dump units. Improved ground support and drilling and blasting practices have enhanced safety, recovery and productivity in all cut and fill operations.

Jan 1, 1988

The interaction of man with the environment has a double character. From one side, mankind can not exist without co- nsuming the natural resources and, from the other side, we actively alter and exert influence upon nature. Analysis reveals that the ecological problem is, to a great extent, a geological one. The paper deals with the application of grouting techniques to construct impermeable barriers for the protection of ground water and soils from depletion and industrial wastes pollution. A number of case histories in the field of mine construction is given to illustrate the solution of geotechnical problems in concert with environ- mental protection measures.

Jan 1, 1988

New and more cost-effective methods of haulage and hoisting will be needed to develop the underground mines of the future. A review of the development of technology since the 1950s shows that once mechanised equipment became available it took 25 years for appropriate mining methods to be developed and the equipment made reliable, then a further 25 years to reach todayÆs level of automation and reliability. Suggestions are made about possible areas for ongoing research with the observation that there is little research worldwide into disruptive technologies. A call is made for better organisation and presentation of the opportunities and potential benefits of new underground mining technologies.

Jan 1, 2005

The smaller mining company with full ownership of, or participation in, a mining project is generally unable to obtain funding as easily as the major mining house. While the equity market remains the main funding source for small projects, debt fund- ing options are becoming more available. Many international banks possess in-house mine fin- ancing expertise which can assist the smaller company in financing its share of project development. A clear understanding is necessary of both the benefits and limitations of bank funding, to ensure that all potential sources of funds are properly considered and integ- rated into the financial plans of the smaller mining companies.

Jan 1, 1984

Economies in cemented fill demand the utilisation of the full potential of the portland cement component of the mix. If declined tailings are used, it is desirable to establish the optimum particle size distribution. Pozzolic materials and slags are. very useful additions to increase the amount of cementitious material through reaction with calcium hydroxide produced by hydration of the cement. It is also essential to check out the presence of substances which may seriously affect the setting and hardening of the cement or the durability of the cement bond. The importance of quality control in the preparation of cemented fill cannot be over Emphasised.

Jan 1, 1973

Wrenching between basement blocks is considered to be the mechanism whereby a well developed set of en echelon folds and an associated fracture system are developed in the Fitzroy Depression, Western Australia. The regular geometry of these structures accords with a right lateral regional coupling between high-standing, basement blocks bounding a trough filled with a thick pile of stratified Phanerozoic sediments. The structures developed during or after the Mesozoic Era, but the couple is inferred to have been applied to blocks outlined by old lineaments, which may reflect strains or ruptures in basement that developed during the Precambrian, and which were regenerated during Palaeozoic and Mesozoic time.

Jan 1, 1967

Efficient performance of pulp lifters to discharge ground rock is critical to the effective performance of SAG and AG mills. The paper covers developments in the design of pulp lifters and associated grates, of both conventional straight-radial and curved types, and of the inner discharge cone. Issues covered include the discharge performance of both the slurry and rock components of the discharge, reverse flow back into the mill through open grates and backflow down the pulp lifters of material that fails to discharge from the mill. The design experience is interpreted in the light of developments in particle flow modelling of the flow of charge in pulp lifters.

Jan 1, 2004

By Johnston G, Revy T

Dominion Mining Ltd. and the JKMRC have conducted a detailed investigation of the performance of two of Dominion Mining's gold treatment plants (Haveluck and Paddy's Flat). In terms of design each plant is considerably different. The Paddy's Flat plant uses a single stage SAG mill with recycle crusher, followed by single stage ball milling. The Haveluck plant uses the more traditional approach of multi-stage crushing and ball milling. The performance of these two plant designs in terms of energy efficiency and cost of comminution equipment, developed at the JKMRC, to accurately predict both power draw and size reduction characteristics at these plants is evaluated.

Jan 1, 1991

By Milner E. F

Thallium is largely volatilized during sintering in the conventional sinter/blast furnace production of lead. The new direct oxygen smelting processes will force the thallium into the bullion, necessitating a means of removal to avoid contamination of the refined lead. Pilot plant testwork demonstrated that thallium was efficiently removed from lead bullion by treatment with molten zinc chloride. The spent zinc chloride salt was treated in the laboratory to recover lead sulphate, a zinc chloride solution, and a thallous chloride salt containing over 80% thallium. Cominco is installing this thallium process as part of its Trail Lead Smelter Modernization Program which will commission a QSL bath smelter in late 1989.

Jan 1, 1989

To counter depressed world nickel prices, a continuing effort is being made at Kalgoorlie Nickel Smelter to reduce unit production costs. One major area in which production costs can be reduced is the substitution of coal for fuel oil. Two areas where this has been achieved to bring about a saving are, the addition of coal to flash furnace flux to reduce supplementary fuel oil requirements in flash smelting and the replacement of two oil-fired air preheaters with a coal-fired unit. These actions have resulted in coal replacing 67% of the current fuel oil requirement in flash smelting at the Kalgoorlie .Lckel Smelter.

Jan 1, 1987

By S Servant

In the mine of this study, cemented hydraulic backfill is placed under the form of a slurry at a percentage of solid by weight varying from 50 to 65 per cent. This slurry settles and cures in the stope. During this process an important amount of water must be drained from the stope. Field observations in the case studied here show that the geometry of the drains system has a significant impact on the drainage of the stopes. The mode of filling produces a backfill showing an evident stratification typical of a sedimentation process. In situ observations on this material show that this stratification translates into a very strong heterogeneity in the physical properties of the cemented backfill. This heterogeneity should affect the hydraulic conductivity of the backfill in the stope. In order to study this aspect, finite element simulations were performed. This paper presents the results of these simulations, where the impact of this stratification on hydraulic conductivity is related to the performance of the backfill drainage system for various geometry. This preliminary study is aimed at providing a better understanding of the role of the drains in the dewatering process of the backfilled stope in the case of this mine.

Jan 1, 1998