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A universal grinding circuit model suitable for an arbitrary structure of flowsheet has been suggested. In this model classifiers and mills are described in a most general form. What puts the model in a class by itself is the automatic mass balancing in all streams of the circuit. In order to provide this a special classifier model is adopted. A previously published continuous steady state process model is used as a grinding model. Non-linearity of classifier model leads to a resultant circuit model which is equivalent to a non-linear integral equation. It complicates somewhat calculation algorithm in comparison to that of linear model, but provides a physically meaningful solution.

Jan 1, 1993

This paper examines the properties of Australian indigenous crude oil and the changes to Australian refinery process- ing required after the Gippsland crude finds in the late '60s. In addition the paper details the dif- ferent crudes available to Australian ref ineries and the relative product yields in relation to Australian crudes. Market demand for petroleum products both now and in the future is then related to the products yields. The paper also examines the impact of the OPEC induced crude price spiral and the subsequent changes in refinery engineering, current and projected market demands, and energy conservation measures both inside and outside the industry.

Jan 1, 1982

By Simes C. D

Results of experiments for dissolution of zinc by aeration of sphalerite in glass, copper, galvanised iron and stainless steel vessels of identical dimensions are reported. It was found that in a glass container dissolution of zinc reaches a maximum after 30 min aeration and then decreases whereas in the copper container dissolution remains nearly unchanged up to 30 min aeration and then increases. In the cases of galvanised iron and stainless steel containers zinc dissolution increased steadily with time up to 60 min aeration. It is suggested that the different rates of dissolution in glass and copper containers may be due to electro-chemical actions.

Jan 1, 1984

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

By I Sheppard, A Hills

This paper describes a multi-lift bench stoping method introduced recently to extract the narrow silver-lead-zinc orebodies at the Isa Lead Mine. Cut-and-fill methods were chief mining methods for the narrow orebodies at the mine over 35 years ago. Benching methods were introduced approximately two decades later, and quickly replacing the cut-and-fill methods. The benching methods had improved both the economy scale and safety of the mining operation. The multi-lift benching method combines a number of bench lifts into a single stope to further improve the operational efficiency. Three stopes in the initial multi-lift benching trials are described.

Jan 1, 2003

A methodology is described to integrate heap leaching into a CIP operation. The paper firstly describes what is meant by a 'systems approach'. A broad view of the objectives of integration of heap leaching into CIP is given, followed by the components of the system, and then a description of the methodology for integration. The seven stages of integration are given as determination of distribution of gold, sampling, metallurgical testwork, conceptual study, pilot heap operation, pit modelling and pit optimisation. The final result is a series of optimised curves which determine the maximum value of the orebody, and the optimum cut-over grade from CIP to heap leaching.

Jan 1, 1992

The development of the SECV brown coal open cut at Loy Yang will require depressurisation of aquifers both within and below the coal seam sequence in order to maintain open cut stability. Prediction of future open cut dewatering requirements at Loy Yang Open Cut and evaluation of the regional consequences of dewatering has required development of a detailed hydrogeological model of the Loy Yang area. The complex stratigraphy of the coal seam and aquifer/aquitard sequences at Loy Yang have been analysed and integrated with the hydrogeological concepts developed from regional groundwater studies to formulate a realistic hydrogeological model as a basis for finite-element flow modelling.

Jan 1, 1988

By LeJuge G. E, McKenzie C. K

Innovative mining and blasting techniques were demanded at the Richmont Mines, Francoeur Mine in Quebec, Canada, by a narrow, shallowly dipping high grade gold ore body. The ore body being mined occurs as a thin tabular deposit varying in thickness between 1.5 and 3.7 metres, and dipping at 36¦. The mine proposed experimenting with open stoping techniques using small diameter drill-holes. The hangingwall required progressive, full face rockbolting after each production blast, utilising a specially manufactured machine which provided access to the hangingwall for both scaling and bolting. Blasted material is mucked from the stope by scraper and hoisted directly to surface without benefit of primary crushing.

Jan 1, 1992

Roasting of zinc concentrate at the Risdon Works of the Electrolytic Zinc Company of Australasia Limited, (E.Z.), is carried out in two fluid bed roasters capable of treating 450000 tonne/yr, or sufficient for the output of 220000 tonne of salable zinc. The furnaces were constructed by Lurgi, Australia, to the basic design developed by Vieille Montagne Company of Balen, Belgium. The advantages of fluid bed roasting include a higher metallurgical efficiency in sulphur oxidation from a feed which does not require any pre-grinding, mechanical reliabil- ity through the absence of any moving parts within the furnace and the capability of being scaled up to a large unit.

Jan 1, 1977

By Wilson GR

Pellets were produced from carefully sized iron ore and silica sand fractions, under controlled moisture conditions, using a sealed balling drum. The strength of these pellets was measured as a function of moisture content and particle size. The results showed that the strength of the pellets could be adequately described by a model which equates the strength of the pellets with the negative pressure developed within the porous mass, provided that the particle size distribution was narrow and the mean particle size relatively large. However this model failed to account for the observed strengths of pellets produced from systems containing even small quantities of ultrafine particles (

Jan 1, 1972

By Yesil MM, Bozdag T

This paper describes the conver- gence and load measurements carried out in inclined seams at five longwall faces, two of which were supported by hydraulic props and the other three by conventional timber supports in Karadon-Gelik mine. The minimum support capacities determined in this study are compared with the results obtained from two empirical approaches suggested by Wilson (1975) and Jacobi (1981). The characteristics of hydraulic props to be used and support patterns in the longwalls are found, conclu- sions are drawn and suggestions are made. Design nomograms are prepared for field engineers, in order to be able to approach the problem more confidently and realistically.

Jan 1, 1992

By Kershaw M. G, Maughan R. C A

A process for eliminating nickel from electrolytic zinc plant solutions by precipita- tion with dimethylglyoxime (DMG) was developed to enable the Electrolytic Zinc Company of Australasia Limited (EZ) to treat nickel-bearing zinc dust precipitates. These precipitates are leached to recover their Cd and Zn content. The final Zn bearing solutions contain relatively high Ni concentra- tions (20-100 mg/1) and are treated with DMG and then neutralized to pH 4.6-4.8. The pre- cipitate is filtered off and the solution returned to circuit. DMG consumption is about 200% of theo- retical requirement, and Ni removal is 80% complete overall.

Jan 1, 1977

By Rogers R, Kinnane T

In a typical open cast mining operation, investigation of how existing truck performance compares with the highest achievable truck performance is largely neglected. This paper addresses this issue by proposing a computerised system that will provide a systematic method for comparing existing truck operational performance to the highest performance considered achievable. Through analyses of existing versus achievable performances, various inefficiencies associated with truck operations can be identified. These inefficiencies could occur due to machine configurations, haul route design and conditions or operator skill level. Remedial action should then be taken in a timely fashion to better manage these factors and to ensure the fleet is always operating at its peak efficiency.

Jan 1, 1994

By Rowe P, Rogers D, Warren M

Pressure cyanidation of the minus 10 micron slimes fraction of the Fimiston flotation concentrates for the recovery of gold values has been evaluated as an alternative processing route to the roasting and atmospheric cyanide leaching of the calcine. Laboratory and pilot trials have demonstrated that gold extractions of greater than 94 per cent can be achieved at cyanide consumptions of 12-24 kg/t and oxygen consumptions of 0.1-0.3 Nm3/t with total pressures of 1000-2000 kPa. Economic and operational assessment of several reactor configurations suggests autoclaves may be preferred over pipe reactors at treatment rates of 10 t concentrate/h.

Jan 1, 1996

My forebears migrated to South Australia in the 1830s, 1840s and 1850s. All of them were literate but, because they moved about South Australia looking for work, family papers have become scat- tered and I am left with a few fragments. Some years ago I was intrigued to find among my fath- er's books a frontispiece in an old Anglican Book of Lessons. As can be seen Joseph, a mining smith, was also a Freemason. Thus my interest was aroused. I know some- thing of modern day mining communities in South Australia and wondered what they were like 100 or more years ago.

Jan 1, 1987

Alcoa of Australia's Western Australian bauxite mining operations in the Darling Ranges, south east of Perth, present major challenges in the control of air blast. The close proximity of rural communities and the face profile make the traditional methods of air blast control difficult. An extensive blast noise monitoring programme has been established. The develop- ment of a computerised blast noise prediction model and the establishment of a radiosonde weather balloon facility have reduced blast induced complaints by a factor of ten. The meteorological factors affecting blast noise transmission are discussed and examples are given of adverse weather condit- ions for the south west region of Western Australia.

Jan 1, 1982

Strip mining offers the advantages of high productivity from both human and capital resources as well as high rates of production. Experience suggests that it will be advantageous to extend strip mining to the maximum pos- sible depth in order to minimize costs and maximize the recovery of the in situ coal reserves. Highwall and spoilheap stability pose significant problems. Deep working in strip mines is likely to produce a change from methods which are based upon the elevation of material followed by dumping, to methods involving elevation and horizontal transport. There is considerable scope for optimizing the types of machines and minimizing the amount of double handling.

Jan 1, 1975

By G Chitombo, M Ruest

In surface mining, studies of the kinematics of blasted rocks using high speed film/video image analysis have allowed the estimation of the starting time, direction and magnitude of visible movement of fixed sections of the free face. Horizontal displacement versus time plots from discrete targets at the face generally report changes in slope over very small time intervals. These changes indicate step increases in velocity due to the action of explosive gases. In practice, the onset of rock mass movement, different to localised spalling, has been associated with a response time which exceeds the combined times of detonation, propagation and reflection of stress waves. This time is referred to as minimum response or burden movement time. As an engineering index, burden movement time has been used to provide guidelines for the selection of inter-hole and inter-row delay sequences in production blasting. With respect to improving breakage and fragmentation, it has been demonstrated that the delay interval between adjacent explosive charges should be less than the expected burden movement time. Similarly to reduce confinement between rows, delay intervals should exceed the expected burden movement time. The Hybrid Stress Blasting Model (HSBM) is a modelling framework that dynamically links an ideal and non-ideal explosives detonation code to a geomechanical rock model. This blast simulation tool is aimed at analysing the role played by different explosive formulations in fragmenting and/or damaging various rock types under different degrees of confinement. In the current framework, the rock behaviour under extremely high pressures and loading rates is calibrated from shock tests and the role of the explosive in fracture growth is accounted for and assumes a compressible fluid flowing through the explicit fracture network. The model is being developed as part of an international collaborative research project funded by a consortium of companies comprised of explosive and equipment suppliers and major mining houses. As part of the development and validation of the HSBM project, data from literature addressing the kinematics of the rock mass (ie burden displacement, face velocities and response times) has been collated and used to evaluate the current version of the code. A series of numerical experiments have been conducted with the view to: evaluate the response of the rock mass to changes in burden distance given by the impact of both stress waves and radial gas flow pressure;compare the modelling outcomes in terms of displacement, response time and face velocities to documented field observations; andcompare stress induced and stress/gas induced modes in terms of burden displacement outcomes. Results from these experiments have shown that in its current form the model is able to capture the trends observed and measured in practice. This is with respect to the simulation of burden displacement, response time and average face velocities for different geometries and charging conditions. The experiments have served as consistency checks which form part of an ongoing and comprehensive evaluation and validation of the HSBM code also aimed at addressing some of its current limitations.

Jan 1, 2007

By Liu H, Chen S

Natroalunite is one of colouring minerals in kaolin. In this investigation, natroalunite, on which Ca(II) was adsorbed, was flocculated by HPAM and kaolin was depressed in suspension. The adsorption of Ca(II) on the natroalunite surface was studied by zeta-potential measurement and Auger Electron Spectroscopy analysis. Ca(II) was adsorbed more on the natroalunite surface than on the kaolin surface. The mechanism of Ca(II) adsorption was considered to be chemical adsorption on natroalunite and to be physical adsorption on kaolin. It has been found that Na6P6O18 and Na2Si04 can strongly affect Ca(II) adsorption on the surface of kaolin, but weakly on the surface of natroalunite. The effects of degree of hydrolysis and the molecular weight of HPAM, the effect of pH and the effect of Ca(II) have been studied. The kaolin ore, containing SO3 1.05 per cent has been processed with this method. The products only containing S03 0.36 per cent and the weight ratio of concentrate 52.27 per cent were Obtained.

Jan 1, 1993