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By I Taylor, M Nugus, C Gordon

Resource estimation and selective mining of structurally complex, high nugget orebodies presents a major challenge to the Mine Geologist. At the Golden Pig BIF-hosted gold deposit in Western Australia, an estimation method has been developed that replaces an assay-based resource estimate with one based on mineralisation intensity. Subjective coding of the mineralisation intensity has a more robust connection to local grade than drillhole assays. Indicator variograms of the five mineralisation codes are well structured with anisotropy directions similar to observed structural controls. The proportion of each mineralisation code is estimated and a weighted average of the average grade of each code calculated for a block. Initial validation has shown that the model is a good predictor of the mineralisation intensity, and the application of appropriate local average grade for each mineralisation code gives a reliable block grade estimate.

Jan 1, 2003

The difference between a hypothetical and a theoretical approach is considered and the advantages in using a hypothesis is discussed. Virgin horizontal stresses play an important role in stabilising strata which bridge across an excavation, and reduces the tensile stresses which develop in a beam subjected to bending. Simple formulae are deduced for the bridging of a thick massive stratum under such conditions. At shallow depths, tensile failure on the upper side of the beam is the most likely cause of fracture, but below a certain depth this gives place to compressive failure on the underside, with the possible incidence of rock bumps. The presence of strong massive beds delay the onset of subsidence and may restrict the width of the subsidence trough. If the material involved in the caving is strong, this will reduce the final subsidence, especially at shallow depths. The British regulations for the control of aquifers and their dependence on the strain developed at the seabed are discussed. As an alternative, the concept of a disturbance factor is introduced to permit the consider- ation of aquifers at depth, leading to an explanation of the make of water on the first faces to be mined in the Selby Coalfield. 'Elie paper closes with a brief consideration of the different roles played by longwall face supports in the control of readily cavable strata, and the control of strong beds which hold up in the waste.

Jan 1, 1986

By A T. Owen, F A. Benn, J D. Swift, D M. Labbett, A F. Grabsch

The AMIRA P266 æImproving Thickener TechnologyÆ series of projects has sought to provide a firm scientific basis for feedwell and thickener design, a requirement as pressures on water usage in the minerals industry increase. While advanced computational fluid dynamics modelling of feedwell processes has generated the most obvious and successful applications to improving the performance of operating units, such outcomes have drawn heavily on parallel studies into flocculation fundamentals. Central to this has been the development of a linear pipe reactor system that allows the kinetics of flocculated aggregate growth and rupture to be measured for thickener feeds under turbulent pipe flow conditions. This ensures much greater control of the intensity and duration of applied shear than is possible with conventional flocculation test procedures, offering insights into flocculation processes that would be otherwise hidden in time-averaged measurements.

Jan 1, 2009

This paper reviews the developments in understanding of the entrainment mechanism and its modelling in industrial flotation processes over the last 30 years. Both valuable and gangue minerals in the pulp zone of an industrial flotation machine can be transported through the froth zone to the concentrate launder in the water which must also be transferred from the pulp zone to maintain a stable froth zone in conventional flotation. A size dependent portion of each entrained mineral continues in normal circumstances to the concentrate launder. The size dependency arises because the larger particles are able to drain more successfully from the froth region. Gangue minerals are recovered by a number of mechanisms, entrainment being an important one in many cases. The entrainment mechanism is discussed on the basis of the pattern observed in recovery û size data for minerals. Its industrial implications are discussed and means of minimisation of the importance of the mechanism are also discussed. Various means proposed for mathematical modelling of the entrainment mechanism are also described. The effect of process variables on key parameters in these models is reviewed. Properties of both the pulp and froth zones are discussed where needed and means of taking additional measurements with devices developed over the last ten years are discussed as part of the collection of more detailed data on the flotation process in general and the entrainment mechanism in particular.

Jan 1, 2005

By Saint-Smith J. C

The anode, tank house and wire bar plant and operations are described with particular reference to those features of design and methods which are characteristic of this refinery at its inception.Reference is also made to auxiliary equipment, transport and materials handling facilities.The work of commissioning the plant late in 1959 is discussed and comment is made on the organisation of construction and origin of the equipment.LOCATION OF PLANTThe site chosen for the copper refinery is on level ground adjacent to the junction of the Mount Isa and the main north-south railway lines at Stuart near Townsville, Queensland. Blister for refining is received by rail from Mount Isa. Refined products are taken 10 miles by road to Townsville Harbour for shipment to other Australian ports or overseas, or despatched by rail direct from the plant.Adequate room for expansion was provided to cover copper refining and any associated industry. The layout of future extensions was planned and space reserved for them before detailing the original units of the main refinery.The initial plant also provides convenient storage facilities and is laid out to derive the greatest benefit from prevailing northerly breezes during the humid tropical summer.As far as possible, the working areas are located so that the prevailing winds cool them as they traverse the buildings.These factors are of very great importance since this is believed to be the only copper refinery in the tropics operating with all white labour and in any case the Company set out to provide the best possible conditions for its operating personnel.

Jan 1, 1961

By G P. J Dijkema, M A. Reuter

From a material cycles perspective all processes are interconnected and consequently a process can never be evaluated as an isolated and independent unit. This also holds true for the evaluated co-incineration options. Environmental and sustainability issues for example, such as raw material and energy utilisation or air pollution, are a resultant of the whole system of industrial activities. It is therefore important, not to optimise a single process or industrial activity, but rather the whole system. Although engineering procedures for the design of individual industrial units are well developed, the problem of determining the best arrangement of these interconnected units is often far more difficult. Regulation that manages the arrangement of the units for waste processing is still under construction. In the evaluation of co-incineration, analogous principle from process control can be used: feedforward control. This principle includes the determination of which outlets can be used for all process outputs, hence avoidance of any æunusableÆ products or wastes possibly arising from co-incineration. To establish the extent, to which produced wastes are usable, a system overview is necessary, in addition to in-depth information on the subsystems, which produce and can consume wastes. Material cycles modelling can be used as the basis for a tool that supports the development of a suitable playing field. It should provide overview of the system and in-depth information on its subsystems. This tool then represents an attempt to bridge the gap between æholisticÆ industrial ecology and process engineering.

Jan 1, 2000

By C J. Corbett

Many underground mining methods rely on blasted rock moving under gravity to report to extraction points. Mining of orebodies dipping between 20 - 45 degrees poses a unique challenge for mining engineers in that a dip angle in this range will not allow the movement of broken ore down the footwall to the mucking horizon utilising gravity. This is more so in cases where the natural angle of repose of the rock is less than the dip of the orebody. Hence, innovative mining systems are necessary to mine this type of orebodies. In Australia, the method of uphole retreat panel stoping is commonly used to extract orebodies in the dip range of 20 - 45 degrees and thickness range of 5 - 15 m. In the Zambian Copperbelt a method called continuous retreat updip stoping is used for orebodies with similar dips and thicknesses. The mechanised form of this mining method has potential for application in the metalliferous mining industry in Australia. In this study a comparison is made between mechanised updip (MUDS) and transverse retreat stoping (TRS) methods. A hypothetical nickel sulphide orebody located in Western Australia is used as case study. The net present value for mechanised updip stoping is seven per cent higher than that of transverse retreat stoping based on the assumptions applied. Initial results of this study indicate that mechanised updip stoping can be adopted for Australian mining conditions. However, lack of significant local experience with the method is often cited as a reason for not adopting it even in situations where it is clearly the best option.

Jan 1, 2003

Thank you for the invitation to this forum today. I have a hectic schedule in the Mabo legislation process but it is important not to lose sight of the bigger picture and to attend today to talk to you about the Government's role in the development of our country.More importantly, I hope over the next couple of hours to get some feedback on developments in this area from people very much involved on a day to day basis.

Jan 1, 1993

The paper describes some of the economic and human factors associated with haulroads on Mount Whaleback, a large open pit iron ore mine. These factors have combined to encourage formation of a specialised road maintenance crew which caters for haulroad construction and maintenance. Techniques used for design, construction, operation and management of haulroads are then described. Future developments are expected to effectively lower construction costs leading to an even wider application of the techniques described and consequent improvement in temp- orary roads and overall truck performance. INTRODUCTION Mount Whaleback is a large truck/shovel open pit iron ore mine located in the Pilbara region of north Western Australia. Annual production capacity exceeds 100 million tonnes per annum of waste and ore. The truck haulage fleet comprises WABCO 120 52 WABCO 3200 22 74 of which approximately 45 are operating at one time.

Jan 1, 1982

Aberfoyle sought to reduce Hellyer project development risk to a greater degree than usual. Consequently the ore reserves estimate and feasibility study were particularly comprehensive. A detailed ore reserve study was completed based on extensive drill core and underground sampling, large scale pilot plant work and a detailed feasibility study. Leading external consultants were used for advice on commercial matters which impact on ore reserves and to audit major technical conclusions, including the results from pilot plant work and the ore reserve estimate. Other project risks were diminished by negotiating a State agreement covering security of title, royalty formula and environmental management procedures, by obtaining sales contracts, and by analysing Hellyer's position on an industry cost curve. The task of financing the project was much simplified by the extent and quality of information available from the ore reserves estimate and feasibility study report.

Jan 1, 1990

By C Fountain

It is commonly known that copper smelter terms include penalties if the concentrations of elements, such as arsenic, mercury and fluorine, exceed stipulated limits. It is less commonly known that the behaviour of these elements in the smelters can depend on the processes used to treat the concentrate. The principle behind the penalties is to compensate the smelters and refineries for additional costs caused by the presence of the penalty elements, but these costs will vary depending on the process used and the location of the smelter.The issues caused by the minor elements include effects on the occupational health of smelter workers, increased environmental disposal costs, increased operating costs and reduced cathode copper quality.The effects of minor elements can be surprising. High levels of arsenic in concentrate are considered undesirable, but some smelters add arsenic to anode copper to improve the performance of the refinery.Excess concentrations of some elements will result in rejection of concentrates by smelters. China has blanket import bans on copper concentrates with concentrations of lead, arsenic cadmium, fluorine and mercury exceeding specified levels.This paper will review the behaviour of minor elements in smelters and refineries, explaining the deleterious effects of each of them, to provide a greater understanding for people and organisations wishing to market copper concentrates.CITATION:Fountain, C, 2013. The whys and wherefores of penalty elements in copper concentrates, in Proceedings MetPlant 2013 , pp 502-518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By James D, Dawson N

The alternate mineral dressing tech-niques for the production of ilmenite roaster feed from heavy mineral concentrate and the reasons for the selection of wet high intensity magnetic separation (WHIMS) at Richards Bay Minerals are outlined.Initial flowsheet studies were under-taken using laboratory scale equipment followed by on site pilot testing. Flowsheet development culminated with an extensive test programme conducted at Readings of Lismore in 1975.

Jan 1, 1986

By Conway KM

The traditional role of Australian Consultants in project development has been until recently restricted to the provision of discrete packages for survey and engineering services during the feasibility, design and construction phases of a project. Management of such projects was the province of the owner/developer or his agent. However, Australian Consultants are now being con- sidered for an expanded role on resources Projects.

Jan 1, 1983

By Laajalehto K

The basic condition necessary for flotation is hydrophobicity of the surface of the mineral to be floated. For sulphides, this condition usually requires treatment with a collector solution. The conditions for this treatment have until recently usually been chosen by the trial and error principle which has indeed been working relatively well under favourable conditions; ie for simple homogeneous ores. However, the present tendency to increasing use of complex and often relatively lean ores sets increasing requirements for the control of the flotation process. This development is the reason for the present rapid development of process control methods in flotation. In addition to the already well-established practices of pH and reagent feed controls, the importance of measuring and controlling the electrochemical potential of the ore particles to be floated is recognised in the case of sufficiently conductive minerals. In fact, the electrochemical potential seems to be the basic quantity determining the flotation behaviour of such relatively well-conducting minerals as sulphides. Since the hydrophobicity of the mineral and, hence, its flotation properties are ultimately determined by the composition and structure of its surface, information on these under different process conditions is important for design and operation of efficient flotation processes. The basic requirement set for the methods used for obtaining this information is high surface sensitivity of the method. The recent rapid development of surface characterisation has produced several methods which fulfil this requirement. Their application to the problem of characterising surfaces of mineral samples in contact with collector solution is, however, often complicated. The main reason for this is the vacuum environment necessary for the measurement. In the case of flotation experiments this means that in most of these methods the measurement cannot be made in situ, but the sample must be extracted from the liquid and subsequently evacuated in the vacuum chamber of the instrument. It is essential to carry out these steps so as to avoid to the extent possible changes in the sample surface. For the purpose of establishing whether this has been accomplished it is important to compare the results of methods operating in vacuum with some available in situ method. An optimal choice of methods seems therefore to be a combination of the available powerful vacuum methods with in situ measurements. The most usual combination seems to be X-ray photoelectron spectroscopy (XPS or ESCA), Fourier transform infrared spectroscopy (FTIR) and electrochemical measurements. This choice combines the unique possibilities for direct elemental and chemical characterisation offered by XPS (Cecile, 1985) with the in situ capability of FTIR and electrochemistry. In the XPS measurements, it is essential to apply a special sample handling technique to avoid loss or damage of some sensitive species of the collector-based layer on the mineral surface. In the following will be given some examples of the application of the XPS technique in combination with electrochemical methods of sample treatment to studies of the layer formed on sulphide substrates in ethyl xanthate (EX)

Jan 1, 1993

A BRIEF account of the water-power potentialities of Tasmania is given, together with possible applications of the power commercially. A short history of the Waddamana development is then given, and the main works are described.WATER POWER POTENTIALITIESTasmania is an island of approximately 24,500 sq. miles area (exclusive of small islands). An area of 12,000 sq. miles is at an elevation of over 1000 ft. above sea-level, and of 2300 sq. miles at over 3000 ft. above sea-level. Average annual rainfall varies from' over 140 in. on West Coast to 20 in. on East Coast, and for the whole island averages 48.5 in. The total water-power available, based on conservative figures for run off and efficiency, is 6,000,000 b.h.p. Only a small percentage of this total will, under present conditions, and under likely conditions in the immediate future, be capable of being developed commercially.An extensive hydro-metric and water-power survey is at present being carried out in order to collect information concerning the most promising water-power schemes. Already 400,000 b.h.p. has been located in different proposals, and there is still a large area of very likely country along the West Coast which has not been investigated yet. Tasmania thus has very vast power potentialities, which, combined with good ports and communications and wonderful mineral and timber resources, should augur well for the establishment of the great key industries, particularly chemical and metallurgical.

Jan 1, 1923

By Blaskett K. S

The physical properties of monazite and the minerals with which it is associated in east coast beach sands are studied and discussed. Possible means for improving recovery are examined. In particular, it is suggested that the practice of splitting the heavy mineral concentrate into two parts as a preliminary to treatment in separate "rutile" and "zircon" mills can be modified in a simple fashion by the addition of an extra magnetic separation stage so as to aid monazite recovery.INTRODUCTIONBeach sand deposits on the east coast of Australia are a major source of rutile and zircon, and supply 80 per cent or more of world requirements. The deposits also contain a small amount of monazite, averaging about 0.5 per cent of the total heavy minerals. Yet despite a steady price in recent years of £150-160 per ton, monazite production has remained relatively small.On the basis of rutiIe production, potential monazite production on the east coast was about 1,500 tons in 1956, but only 102 tons of high-grade concentrate was produced. The main deterrent to increased production has probably been the capital cost of the necessary equipment. Separate electrostatic and magnetic equipment and separate table concentration and drying constitute a considerable outlay for a by-product contributing 4 to 5 per cent of the revenue from rutiIe.It is the purpose of this paper to discuss monazite concentration generally and to suggest modifications to flowsheets, which may facilitate monazite production while maintaining the main objective, simple and cheap means for maximum rutile production.

Jan 1, 1958

By K Biegaj

The paper describes challenges the author has encountered on Australian underground gold and nickel mines over the last eight years, when recovering high-grade gold/nickel bearing mine floor material with a mobile supersucker/giant vacuum cleaner and other equipment. Whilst for a number of years the mine floor vacuuming and other mine floor clean-down technologies have been accepted/adopted and are working well in other parts of the world and on the South Australian opal mines, regrettably, they have not yet gained acceptance of mining executives and mine managers of gold and metal mines in Australia, who still elect to leave the never to be recovered gold/metal behind or to put it plainly - waste it.For reporting purposes during the mining process, the portion of gold/metal included in calculation of ore reserves prior to obtaining capital funds for their development, continues to be camouflaged in various reconciliation and call factors. This approach, ie wasting of capitally developed and already broken ore stocks should be viewed by the shareholders as totally inappropriate to say the least, especially with the current gold and other metals prices.The author attempts to provide answers as to why the technology referred to above has not yet been accepted on Australian gold and metal mines and outlines the way forward.CITATION:Biegaj, K, 2012. Why do shareholders and mining executives allow mine managers to leave behind high-grade broken ore underground?, in Proceedings Narrow Vein Mining 2012 , pp 197-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

A simple method of designing effective fill drainage systems for slurry backfill is presented. By using the proposed method, it is easy to calculate and predict the expected fill drainage rates or to provide additional drainage systems to accelerate the fill drainage. The fundamentals of hydraulic fill and an efficient method to determine its permeability is also explained. The safety in hydraulic filling and bulkhead stability depends totally on achieving effective drainage regime for the fill. This paper provides the basis for creating such efficient drainage regimes. The recent fatal fill bulkhead failures in Australia were the result of poor drainage from the respective fill masses, and therefore it is more important to provide suitable drainage arrangements to continue using hydraulic fill to the benefit of the mining industry. At present there is no procedure available to mine operators to estimate the expected bulkhead pressures to design a satisfactory bulkhead. Some mines are constructing bulkheads after their initial investigations carried out years ago. Other mines have simply borrowed the ideas from the pioneer mines and using in their areas. It is high time that we develop a rational approach to estimate the expected bulkhead pressures for the design of bulkheads. We need a simple model that could be understood and used by the mine operators on a day-to-day basis. This paper also presents a model to predict the bulkhead pressures for designing safe bulkheads.

Jan 1, 2002

In general, modern mining companies all over the world have to face the same economic circumstances as any other part of the industry: considering the tough competition, production and haulage costs must be reduced permanently whereas productivity has to increase substantially in order to remain price-competitive. However, the imposed pressure also offers the chance for consideration of alternative mining concepts, the application of which can result in substantial cost savings and improvements in the quality of the mined material. As one of these alternative mining concepts, surface mining technology offers substantial improvements in productivity. It also influences aspects of haulage, such as safety and speed, in a positive way. The capability of selective mining ties in nicely with the production of small-sized crushed material, the granulometry of which allows the elimination of the primary crusher. Mine operators profit from reduced costs for the maintenance of their haulage vehicles due to reduced wear, a decreased likelihood of accidents and higher average transport speeds. Surface Miners can also be used to cut haul roads into virgin rocks and leave a clean and level surface behind, improving the quality of these created roads. Thus, it is even possible to use ordinary road trucks for transport in mines. The current paper outlines in detail the effects of the surface mining technology on mining and haulage aspects and reports on applications where substantial cost savings could be achieved due to the application of what is also referred to as æsimple mining processÆ.

Jan 1, 2003

There are three major human resource management activities which, depending on how well they are done, impact on the performance of people and therefore the bottom line. These are: ò recruitment; ò training and development; and ò performance appraisal. Most sizeable organisations would say they are involved in all three, but there are many more that would admit that their human resource management practices are limited to recruitment. If we concentrate on the organisations that currently undertake all three, we have to ask, `Are they using different systems/benchmarks for each activity, or is there congruence between the activities?'. Our experience is that most organisations use different systems/benchmarks. The end result is: ò one set of criteria to recruit staff; ò another to identify their training needs; ò and yet another set of criteria to measure their staff's Performance.

Jan 1, 1995