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A considerable debate has arisen regarding the best route for the beneficiation of iron ore. Supporters of jigging technology claim that although the technology is old, due to recent advances in jig control and a better understanding of the separation processes within jigs, it offers significant advantages over dense medium separation, especially in terms of reduced capital and operating costs and simplicity of design. Supporters of dense medium separation claim that this technology is proven to provide the best possible separation and that the gain in efficiency over the life of the plant, compared to that of a jig, will more than offset any differences in capital or operating costs. The truth is that both viewpoints are valid and that the choice is ultimately determined by specific characteristics of the ore being treated. Factors that need to be taken into account in deciding upon the correct option include the size/density distribution of the ore to be treated, the different size fractions which must be treated (lumpy or fines), differences in yield at grade, plant layout and capital and operating costs. Each of these factors will be discussed in detail and a case study for both lumpy and fines will be presented.

Jan 1, 2007

By Morrison R. D, Davis J. J, Fraser B, Kojovic T

1991 saw the completion of a three-year $1.1 million research and development program in mineral sands beneficiation, funded in two associated projects by the Australian mineral sands industry through AMIRA, and carried out by the Julius Kruttschnitt Mineral Research Centre. It is believed to be the largest R&D project in mineral sands ever conducted by a university research group. It covered dry plant operation, and delivered several products to the industrial sponsors, including: ò A detailed characterisation of the radiation properties, mineralogy and size distribution of inhaleable dust arising in dry plants. ò New process models of magnetic and electrostatic separators. ò New on-line instruments for elemental assay (in association with AMDEL) and bulk conductivity measurements of dry process streams. ò Demonstration and evaluation of the Magstream magnetohydrostatic separation technology.

Jan 1, 1992

Industry can achieve best results via thorough planning, consultatiion with agencies and local communities and a 'hands on' approach to' environmental problem solvingThe Department of Energy and Minerals, through its Minerals Group, has regulatory responsibility for the mining and extractive industries in Victoria. The role of the group is to facilitate the environmentally responsible development of these industries for the benefit of Victorians. It has a wide range of contacts with other government agencies, local government and community groups.The paper is in three parts; firstly, an overview of the nature and contribution of the mining and extractive industries in Victoria; secondly, the industries' regulatory framework; and thirdly, the environmental issues facing the industries and the management of these issues.

Jan 1, 1992

During the intial two years (1972 - 1974) of exploration at Telfer, water require- ments were limited to supporting a 50 man camp and diamond drilling to verify thickness and grade of the stratabound ore deposit. Water bores were drilled to intersect the Middle Vale Reef down dip from its outcrop about 70 metres below surface. The MVR reef is an oxidized pyritic horizon which contains 30% - 65% sulphide below the zone of oxidation and forms a highly porous leached gossanous zone to a depth of 100 metres. Surface run-off water from the low hills associated with the Main Dome structure have led to annual re- charge of this extensive aquifer which MAP AREA Lake Waukarlyearly Permian rocks Precambrian basement - - ~;; rocks Sand d.n.s pò. _ « Drainage sg 1 qo~ (`-~.~ ? ò;+ Palaeochannel and 1 d {- subsurface drainage % GLENN BOREFIELD PASSMORE FAULT ;òTsI1. G-OId MIns BOUNDARY oChr~st as t .` Pool 4, 1 j`` Lake Dora òt ~daN 22' 0, 50 Niter KILOMETRES Fig 1. Telfer district map, Great Sandy Desert, Western Australia.

Jan 1, 1988

At moderate depths this question is of relatively small importance, but at depths over 2,000 feet it becomes a matter of some consequence. The rate of increase of temperature with the depth varies in different localities, but as a rough average we may take it to be about 1° Fahr. for every 50 feet of depth. The variation of temperature of the earth's surface from summer to winter penetrates to a comparatively shallow depth. At 50 feet the variation becomes practically insensible, and the temperature of the strata will be about the mean temperature at the given locality, from 60° to 75° F. in this country or the comfort of men working in the mines it is desirable to maintain a temperature of about 70° F. in the workings, or approximately the temperature of the strata near the surface.In order to obtain some idea of the magnitude of the undertaking involved in cooling a mine, I have examined the effect of placing in a long drive an apparatus by means of which we can abstract heat at a uniform rate from the drive, keeping, thetemperature nearly the same at all points of the drive at any given time.The lowering of temperature 70 F. at any distance feet from the centre of the drive (treated as a cylinder of the same sectional area as the actual drive), after an interval of time days from the commencement of the operation is given by the formula...

Jan 1, 1907

Western Mining Corporation (WMC), managers of the Windarra Nickel Project, installed a raise-bored haulage shaft and underground crushing system at the Mt Windarra Nickel Mine in 1982. The system is the second of its type installed by WMC, the first being at the Otter Juan Mine in Kambalda in 1976/77. Both haulage systems became necessary as a result of the increasing production limitations, and escalating costs of a deep decline mine.The Windarra haulage system required a single 3 m diameter vertical raise drill hole, 470 m deep and equipped for skip haulage. Two five tonne skips, in balance, hoist crushed ore and mullock to the surface, at a design rate of 200 tonne/hr, effectively reducing truck haulage leads by up to 50 per cent. The system is now fully operational and will enable the mine to achieve its maximum production rate.The raise-bored shaft system has been shown to be cost effective and would be used again in circumstances where raise drilling is applicable.

Jan 1, 1984

By Toomey P. T

In many open cut coal mines, rivers and large creeks can cause planning and operating difficulties, both in the terms of the more obvious location of the current watercourse, but, and sometimes more importantly, past meandering of the watercourse. Prevent and past flow regimes may have deposited large alluvial sequences within the current mining areas. The presence of groundwater within the alluvium further complicates the planning and operating practices.A situation exists at Saraji Mine in which alluvial sediments overlie a massive sandstone sequence which in turn lies at about one metre above the coal seam. The problems encountered include high levels of groundwater ingress to the pit, highwall instability, and an unacceptably high rate of blast hole collapse (prior to charging with explosives). Other aspects of the dragline stripping operation were also affected.

Jan 1, 1992

Methods of measuring the frictional properties of rock surfaces, both by direct sliding and in triaxial apparatus, are described. It was found that for some rocks the coefficient of friction remains reasonably constant as sliding is continued but for others it increases considerably.The effect of fluid pressure in the surface of sliding was found in all cases to be adequately represented by the effective stress criterion. Some observations on sliding on two conjugate planes showed that the motion on the two planes may be very different, depending on small differences in the constraints.The coefficients of friction of natural open joints in bore core were found to lie in the comparatively narrow range 0.32 to O.68 although surface coatings were very diverse.A set of diagrams on the equal area projection is given which enables a rapid determination to be made of those planes on which sliding is possible in a given three-dimensional stress field. The influence of the intermediate principal stress on this is of considerable importance.

Jan 1, 1969

By W Pytel

A special model of vertically loaded pillar behaviour is introduced to the general, multi-plate based, floor-pillar-roof system interaction analogue. This permitted analysing room-and-pillar mine systems in any geological conditions, including the effect of pillar elastic-plastic behaviour with strain softening. In the model, pillar instability is one of the important phenomenon, which may be expected to occur, and which the operator has to be prepared for. Thus the entire systemÆs safety is determined mainly by strong roof strata behaviour and therefore they have to be examined in actual stress-strain conditions utilising the appropriate strength theories. It was assumed that the so-called safety margin, representing the relation between load intensity and material strength, might serve as the basic indicator of possible roof instability development. Therefore, the safety margin may be estimated by comparing the actually computed components of stress-strain tensor with ultimate values characteristic for a given material determined in laboratory. In order to illustrate the effect of technological pillar size on roof strata stability, two different mining systems (methods of mining) in one of the æPolkowice-SieroszowiceÆ Mine districts was modelled using the finite element method formulated in three dimensions, assuming different materials within different rock mass strata, as well as a number of horizontal planes of discontinuity within the model.

Jan 1, 2003

Fluid circulation occurs in oceanic crust of all ages, at the seafloor spreading axis, on mid-ocean ridge flanks, in the ocean basins, and in subduction zones. In the first three settings the fluid originates as seawater. At the axis and on the ridge flanks, the circulating seawater produces a major chemical exchange between the oceans and the crust. Based on heat budget constraints, between 10 and 40% of the river flux of Mg can be taken up during high-temperature alteration of the basaltic crust along the mid-ocean ridge axis. Most of the hydrothermal -heat loss, however, occurs on the mid-ocean ridge flanks, where the temperatures are lower and the seawater flux correspondingly larger. The estimated heat loss on the flanks is so large that upwelling must occur over a large fraction (5-30%) of the seafloor less than 65 Ma in age, at seepage velocities on the order of 10 to 100 cm/yr. The circulating seawater need lose less than 1 to 2% of its Mg content in order to solve the Mg mass balance for the oceans. Fluids in subduction zones are commonly less saline than seawater and are rich in methane and other light hydrocarbons. These fluids may originate by dewatering of the downgoing slab. If so, they may close the geochemical cycle of H2O that began with hydration of the basaltic crust at the ridge axis.

Jan 1, 1990

This paper summarises some observations regarding the way SAG and AG mills work based on the last ten years of pilot plant operation, grinding circuit design and operational reviews for various projects in Australia and overseas. The main purpose is to promote discussion on key factors influencing breakage in a SAG mill. The focus of the paper is on two questions: How do mill lifters and liners really work and have an effect on grinding? How does the mill charge composition impact on grinding performance? The focus of the paper is on observations of mill behaviour in both pilot plant trials and plant operation, particularly on Cadia ore. DEM, by others, and JKSimMet modelling of SAG mill performance have greatly assisted in forming the ideas expressed in the paper and both are valuable tools in developing our understanding of the comminution process. Put in the æextremeÆ form the major observations and conclusions expressed in this paper are that: the main purpose of mill lifters is to reduce mill liner wear and not to promote rock breakage; the often promoted theory that balls impacting the ætoe of the chargeÆ is a dominant form of breakage is incorrect; and fines production in a SAG mill is primarily a function of the rock load mass, with a secondary dependence on ball load for any given circuit configuration.

Jan 1, 2007

Early in 1930 William S. Robinson, Managing Director of Zinc Corporation Ltd., anticipated a rise in the price of gold and a devaluation of the Australian currency. 'WS', as Robinson was known, formed a.syndicate in London, which later became incor- porated as Gold Mines of Australia Limited (GMA) to invest in gold mining properties in Australia. GMA examined many prospects and subsequently undertook the development of several mines in eastern Australia. The syndicate also held a number of options and several large reservations for gold exploration in Western Australia over which it was proposed to carry out an aerial survey and thorough scien- tific assessment. To do this Western Mining Corporation Limited (WMC) was incorporated in Melbourne on the 2nd March 1933. The founding chairman of WMC and GMA was the highly respected `Collins House' figure, Sir Colin Fraser. The aerial survey was carried out, and a group of eminent geol- ogists from Harvard University examined many prospects and identified several which warranted development. To finance these activities `WS' formed Gold Exploration and Finance Co. of Aus- tralia Ltd. (GEFCA), in London in July 1934. GEFCA ultimately held 95% of WMC and 62% of GMA. The finance came mostly from London based South African mining companies which had been subscribers to his earlier syndicate plus some American inves- tors. (The Group Structure in 1936 is shown in Appendix `B").

Jan 1, 1988

Transport technology has produced social changes since the invention of the wheel five millenna ago when man was freed from the need to expend large amounts of energy to move goods and people. Further impetus came with the Industrial Revolution when mechanical power producing devices were applied to land and-water transport. This leap, together with the application to air transport has caused enormous social changes in our way of life. The state of technological advancement of transport modes has dictated to a large degree the develop- ment of Australia and Papua New Guinea. It is suggested that we should not make advances for technology's sake but examine the real needs of the users of transport and ensure that the un- necessary costs are not incurred. The transporting techniques for the ore, waste and slurries used by Bougainville Copper in Papua New Guinea are, in general, quite conven- tional but the scale of operations and the location has modified some modes. in particular the soft' overburden and concentrates were slurried for trans- port and the lack of experience in humid climates restricted the choice of the mine haulage truck. The near future of the transport. industry is seen as an expansion in equipment sizes but the suggestion is made that we need to examine more than the economic and technical aspects; it is necessary for the social con- sequences of our actions to bear examination by outside opinion

Jan 1, 1973

By Eldridge B. J

During recent years, Central Queensland has experienced a boom in its coal mining industry. This has involved many companies in projects requiring large capital expenditure. As with most projects of this size, many operating problems are now being experienced which were unforseen at the feasibility stage. One of these problems is the failure of pit slopes and spoil piles at some of the strip mining operations. There have been serious stability problems associated with Utah Development Company's strip mining operations in Central Queensland, in particular the Goonyella Mine. A field investigation programme was under- taken to determine the cause of highwall and spoilpile slope failures. Spoilpile failures were found to result from weakness near the spoil/floor contact zone. Highwall failures were found to result from a combination of unfavourable bedding plane dips and weakness, and the presence of joints in weak o~erburdep; Satisfactory solutions fa the staiity, problems are difficult to formulate, and-field stability experimentation is still at an early Stage.

Jan 1, 1974

The Goldfields extend from Norseman in the Eastern Goldfields to Marble Bar in the Pilbara; a distance of approximately 1,500 km. (Figure 1). Tailings dams are conspicuous on the relatively flat and featureless Goldfields' landscape. They impound wastes from mining and processing operations. Tailings dams interact dynamically with their environment and progressively consolidate as water is removed. Water recovery systems have been used over the last decade to improve water conservation, increase dam stability and to extend the service life of the dam. Without water recovery, dams would need to be significantly larger to permit the tailings to dry back sufficiently to support subsequent depositions. The paper reviews inter-relationships between the tailings dam and its environment and discusses water recovery systems, that are commonly used. The effectiveness of water management is illustrated by reference to seasonal water recoveries measured by Western Mining Corporation (W.M.C.) at their number 2 dam at Kambalda.

Jan 1, 1988

The impact of moves to introduce Abori- ginal land rights was felt in the Northern Territory as early as 1972 when the Federal Government froze the processing of all appli- cations for mining interests over vacant Crown land. The Aboriginal Land Rights (Northern Territory) Act was finally proclaimed on Aust- ralia Day 1977 and since that date the mining industry and the Territory legislature have struggled to make the Act work. Despite these efforts long delays have been experienced by those required to negotiate mining and explor- ation agreements under the Act. In fact explor- ation on Aboriginal land has been effectively stiffled since the introduction of the Abori- ginal Land Rights Act. The Northern Territory government and the mining industry have both sought amendment to the Act to remedy some of its more onerous problems. These efforts have generally been fruitless. Some of the recommendations put forward by Mr Justice Toohey following his recent review of the Act would provide relief in some important areas. However, any such improvements are more than offset by a number of Mr Justice Toohey's recommendations which would severely disadvantage the vast majority of Territorians. A recent survey of mining companies seeking exploration licences over Aboriginal land indicates that many of the existing diffi- culties could be overcome without significant amendment to the Act but rather by the adoption of a positive administrative approach by the Land Councils. It is now up to the Commonwealth and the Land Councils to demonstrate that their Act can work without crippling the Northern Territory economy and its mining industry.

Jan 1, 1984

Modern, high-output, continuous process plant requires heavy capital expenditure and is exroected to achieve a high rate of return upon the investment made, thus its high utilisation is an economic necessity. Downtime is extremely expensive not only in terms of idle capital but also in terms of lost production and revenue. A sound maintenance management system can alleviate the problem of unscheduled stoppages and a key document in the maintenance system is the Work Order because it both initiates work and conveys maintenance control information back to the administrator. This key document must be supported by an information base that provides technical data, job procedures, spare parts, history and costing. To be effective this information must be easily and immediately available to all concerned. Computer technology has developed extremely rapidly over the last ten years and with it a wide variety of on-line computerised maintenance systems. Selection of the most appropriate system for a given industrial plant is not a straight-forward process. Computer requirements for hardware and software must be matched to the requirements of the maintenance system and such matching must be carried out in an ordered and rational way. At Kalgoorlie Nickel Smelter, time was taken to review the existing maintenance system, select, study and test the new computerised maintenance management package and plan its implementation. As a result, the initial target of equipment recognition has been achieved on schedule and within budget.

Jan 1, 1987

Asbestos is a commercial term applied to fibrous varieties of several minerals, the properties of which are not generally appreciated by the majority of geologists. A thorough knowledge of these properties and of the uses of asbestos is of fundamental importance in the assessment of the economic value of an occurrence of asbestos. The varieties of asbestos that are used predominantly by the manufact- urers of asbestos products are chrysotile, crocidolite and amosite but chrysotile constitutes 95% of the world's usage. It is the properties of high tensile strength, 'heat resistance and large surface area that make chrysotile asbestos the most acceptable of the mineral fibres. There are no known exploration aids, other than direct visual inspec- tion of outcrops in ultrabasic environments, that could be used in the exploration of chrysotile asbestos. The surface exploration of an occurrence of chrysotile asbestos is relatively routine, though it lends itself to a unique form of bulk sampling by the use of a twelve inch diameter diamond drill core. The laboratory assessment of the prop- erties of the actual fibre requires specialized techniques and tests to assess not only the amount of fibre present but also its length distri- bution, inherent strength, filterability, dust content and other prop- erties. The way a fibre reacts to milling will determine what milling process- es must be implemented to ensure a product that is acceptable to the asbestos product manufacturing industry.

Jan 1, 1971

The mining production rate of two million tonnes per annum at Olympic Dam required greater servicing capacity than was available with the existing Whenan Shaft. To increase servicing capability a Service Decline was constructed from June 1986 to June 1987 extending 2000 m from the surface and linking up with inclining development from the existing Whenan Shaft workings. The decline was used for access of all men and materials during the construction phase of the ore handling system. During production, most mine servicing will be via the decline with hoisting of rock through Whenan Shaft.

Jan 1, 1988

By G Munro

he Melbourne City Link project will complete a missing link between two existing major freeways in the Melbourne road network, providing a much needed bypass of the Central Business District for through traffic. The project, which is being financed under a BOOT arrangement with the Victorian State Government, involves the upgrading of significant stretches of existing freeway and the construction of new sections involving viaducts and tunnels. The tunnel sections, which are the focus of this paper, are beneath residential and business areas, the Yarra River, the Royal Botanic Gardens and significant sporting facilities where surface construction would be either impossible or unacceptable (reference Figure 1). The shorter, 1.62 km west bound Domain tunnel comprises two cut and cover sections through Olympic Park then the Yarra River, the driven section of 0.68 km length and exits through a common cut and cover section with the east bound tunnel under St Kilda Road and Sturt Street. The longer 3.76 km east bound tunnel commences at the common portal, through cut and cover under St Kilda Road then 2.86 km of driven section before exiting at a cut and cover section at Burnley. The longer Burnley tunnel has an access and ventilation shaft at approximately its mid point.

Jan 1, 1999