Search Documents

In February 1974 a continuous synthetic polymer dosing plant was installed at Hamersley Iron Pty. Limited's Pellet Plant at Dampier. The polymer, supplied in a liquid sus- pension, is used to improve the drying characteristics of green pellets. 'Three years of test work were involved in the development of the use of polymers. Polymer is continuously dosed to the balling spray water system at a rate determined by the flow of spray water to the discs. Problems have been experienced with handling the polymer in 44 gallon drums, the increased viscosity of the spray water, disc overloads, increased bed strength and increased "stickiness" of pellet fines.

Jan 1, 1974

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

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

Economic mathematical methods have been developed and applied in the design, planning, development and managing stages in the mining industry. Economic and technological efficiency is achieved with the aid of a large range of probability models, which are used to enable decisions to be made progressively during the different stages. The entire operation is considered as a total system made up of sub- systems and the models representing these are consecutively interrelated with each other. Algorithms and programmes representing the economic mathematical models for all the stages involved were tested and were found to be applicable to the various important mines in the Donetsk basin. Currently, these models are accepted and widely used.

Jan 1, 1977

The purpose of this paper is to outline the current status of financing in the Australian Gold Mining industry and to discuss a number of developments that have occurred during 1983/84.Recognising the importance of equity financing various equity issues, including project valuation, will be discussed against the backdrop of an industry experiencing both rapid growth and a changing structure.Nothwithstanding the current tax exempt status of the industry there is a trend towards more debt financing. A number of financing issues will be covered and it will be shown howvalue can be created through astute financing planning.

Jan 1, 1984

By Valenti M

A by-product of the lead smelting operations at BHAS is a copper-lead matte typically containing 35% copper, 38% lead and 12% sulphur. A hydrometallurgical treatment process has been developed for the treatment of this matte to recover copper as cathode and results in a lead-sulphur residue which is recycled to the lead smelter. A commercial plant with a nominal capacity of 4000 tpa utilising this process was commissioned during 1984. This plant has been shown to be capable of producing copper cathode at rates approaching 4000 tpa over short periods of time.

Jan 1, 1989

By T C. Hughes, R Hughes

Ausmelt has developed and commercialised high temperature reactor technology that has been applied to waste processing in the form of a catalytic waste converter (CWC). Ausmelt Technology uses a top submerged lance system within a versatile converter containing an oxidised molten siliceous slag. Metals and other valuable products can be extracted from wastes for recycle into the community. Non-valuable components such as toxic organochlorinated compounds are destroyed and prevented from reforming. The slag produced is inert and can be safely used in building and concreting. The CWC can be applied to practically all types of wastes and examples from Ni-Cd batteries to toxic wastes are discussed. Additional benefits can be derived from large-scale operations if the surplus heat generated is exploited to produce steam and electricity.

Jan 1, 2000

By Riley TW

This paper describes a Process Simulation Package for modelling the steady-state operation of a mineral processing plant. There are two levels of input allowed into the package. The first allows simple manipulation of the process models within a defined modular format which enables a wide range of process systems to be simulated. "The second level of input is via a Command file which allows plant models to be defined and changed without reference to the code or the requirement of any recompiling of the programme sources. The Command file interface was designed for use by metallurgists and assumes a sound knowledge of the system being modelled. As such it is an effective tool for metallurgists rather than a user friendly generalised package for the layman.

Jan 1, 1985

By Kellett KR

Gold Mining at the Lancefield Mine was commenced initially in 1897 and continued intermittently through to 1956 when rising costs and mine cave-in forced closure. The mine was redeveloped in 1981 and a new-oxide treatment plant commissioned, followed by a new refractory treatment plant in late 1982. Both these treatment plants are located within the Windarra Nickel Project plant area.The refractory ore is processed by fluidised bed roasting of flotation concentrates. This is carried out in two series connected reactors to maximise arsenic and sulphur eliminations and to minimise reagent consumption. For gold recovery the zinc precipitation process was initially used, to be later replaced by carbon-in-pulp.

Jan 1, 1984

The word "mine" means different things to different people. To a professional in the mining industry, it may mean trucks and shovels, overburden dumps, headframes, mill buildings, and the other conventional nuts and bolts that constitute an operating mine. To an environmental- ist it may mean bulldozed trees and tailings dams. To a mining engineer who has spent a significant proportion of his career in mine and prospect evaluation, it can mean a hole in the ground with a liar at the top. The liar in this case is frequently not so through design but through ignorance. The purpose of this paper is to contribute in a small way to en- lightening that ignorance. In doing so, it will foster more effective deployment of the pool of risk capital available to the industry.

Jan 1, 1982

The aspect ratio (mill diameter/mill length) of autogenous and semi autogenous mills varies widely and can be as high as three or as low as 0.5. The literature on the subject of what effect aspect ratio has on grinding mill performance or energy efficiency is almost non-existent. However, at the design stage of many grinding circuits the subject is often vigorously debated amongst metallurgists. In this paper the performance characteristics of mills with different aspect ratios are examined to determine whether process performance characteristics are a function of aspect ratio and whether high aspect ratio mills are any more or less energy efficient than low aspect ratio units. Data from both pilot and full-scale mills are used for this purpose in open and closed circuit configurations.

Jan 1, 2007

By Williams DJ

Preliminary calculations suggest that spoil piles in the Bowen Basin will undergo approximately 4 m settlement as the ground water table recovers after mining is abandoned. Approximately 1 m of differential settlement is possible. Superimposed on this will be a long term creep settlement of 1-3 m/log cycle of time. Depending on the nature of the spoil material, partially submerged spoil piles could be sufficiently stable although to ensure stability during long term creep it may be necessary to flatten the final spoil pile face to approximately 25¦.

Jan 1, 1987

By M L. Habner, S D. Munro

In a gold CIP/CIL circuit, adding new circuit water to a final tails thickener and then directing the thickener overflow to the head of the circuit significantly reduces the cyanide concentration at the TSF discharge spigot. The new water is used to dilute the final tails. The dilution and recycle of the tails in this manner may have the added benefit of reducing reagent consumption, in some cases to the point where the reagent savings justify the expenditure and Cyanide Code compliance is achieved at no extra cost. Potential circuit configurations and water recycles can be modelled by splicing a flowsheeting and thermodynamics package, such that changes to the composition of the water can be reduced to chemical speciation with a Gibbs free energy minimisation enabling a complete understanding of the circuit water chemistry.

Jan 1, 2007

By A D. Farmer

Power ultrasound may be used in a number of ways to enhance the processing of minerals. It is both technically and commercially feasible to apply ultrasound to leaching processes in order to enhance the removal of contaminating minerals, or the rate and ultimate recovery of valuable mineral. When applied to the production of synthetic rutile from reduced ilmenite produced by the Becher process, its use proved beneficial to both the aeration and the final acid leach process. The enhanced performance is achieved through the very localised high energy release at the mineral surface from the collapse of cavitation bubbles produced by power ultrasound. This gives rise to two effects: initially, the rapid cleaning of mineral surfaces û of oxidation products and coatings of fine adhering gangue minerals û and the attenuation of the boundary layer at the mineral surface during leaching, which allows fresh leachant to contact the surface more readily.

Jan 1, 2000

Process control computers are finding ever increasing applications within the chemi-cal and mineral processing industries.To purchase a system which fulfils both the immediate and future needs of operating, technical and management groups, requires an appreciation of the capabilities of the system software and the constraints which apply to user development of application software. Early decisions are then required as to who will develop and maintain the software. Rules and conventions must be determined and adhered to if the end result is to be an orderly, well structured and properly documented system. Software development and maintenance represents a substantial, and often hidden, cost. Getting it right the first time will avoid either a major re-work, or having to live with a system which is extremely diffi-cult (at the worst, impossible) to trouble-shoot or modify.

Jan 1, 1985

By M Hino, Y Sasaki

Sustainable handling of municipal waste and sewage sludge has an important goal to recycle resources without supply of harmful substances to humans or the environment. The gasification mechanism of phosphorus from municipal waste and sewage sludge during the incineration process has been investigated to develop a phosphorus recovery system. Quadrupole mass spectrometer coupled to an electric furnace is applied to study the vaporisation behaviour of phosphorous gas phases from municipal solid waste (MSW) incinerator ash of sludge during solid-state reduction by carbon. Measurements are carried out in vacuum conditions of 2 x 10-6 Torrs and furnace temperature range 573 - 1773 K, at a heating rate of 7.22 K/minute. It has been found that most of the phosphorus is vaporised as PO2, P2 and P4, in agreement with thermodynamic estimation despite a shift in the temperature regimes.

Jan 1, 2006

Increasing attention is being focussed worldwide on the strategic environmental assessment of mining projects, including consideration of cumulative environmental effects. In New Zealand there is now an end in sight for inappropriate delays in resource consent approval of responsible mining projects. This paper investigates six case examples of recently consented mining and quarrying projects, whose applications were notified. It also explores the nature of delays that occurred, the factors that contributed to the delays, and whether the consent process delivered fair and effective public participation and desirable environmental outcomes.

Jan 1, 2005

By S Leary

Diamond drilling since early 2006 has identified an epithermal gold-silver (Au-Ag) deposit beneath 140 m to >400 m of cover. The Fruta del Norte discovery had an inferred resource estimate of 58.9 Mt grading 7.2 g/t Au in October 2007. The mineralisation is hosted by Mid-Late Jurassic andesite and andesite porphyry in a regional fault zone beneath mainly post-mineral but in part syn-mineral Late Jurassic cover. The intermediate sulfidation-style deposit formed before and in part during deposition of epiclastic cover in the fault related pull apart basin. In addition to its size and obvious economic importance, the widespread occurrences of visible gold and exquisitely preserved epithermal textures will make Fruta del Norte an important learning tool for explorationists seeking epithermal mineralisation in theAndes and elsewhere. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

This paper sets out a number of means by which professionals can reduce or eliminate the risk of professional liability whether as directors, employees, partners, independent consultants or contractors. A relationship between client and professional is commonly cited as an example of a fiduciary relationship: the professional "undertakes or agrees to act for or on behalf of or in the interests of' the client "in the exercise of a power or discretion which will affect the interests of that other person in a legal or practical sense."2 As a fiduciary, a professional must ensure that his or her exercise of power does not result in a position of ascendancy or undue influence over the client. Also, a professional must avoid situations where there is scope for even the perception of potential conflict between his or her professional duty to the client and his or her own Interest.

Jan 1, 1995

By Hughes A

Nchanga Division of ZCCM has installed and operated a trolley assist system on part of their truck fleet for some three years. This paper examines how the system came to be chosen and how the many features of construction and operation were dealt with. The economics and productivity of the system are presented as are the personnel aspects of acceptance and training. Zambia Consolidated Copper Mines is a state controlled copper mining company formed by the amalgamation of the former Nchanga Consolidated Copper Mines and Roan Copper Mines. The company operates seven copper mines the largest producer being the Nchanga division, which is scheduled to produce some forty-two percent of Zambia's copper production. The division operates four open pits and an underground mine which produce annually some 192 000 and 96 000 tonnes respectively of copper contained in ore.

Jan 1, 1986