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By I Grant

On the 1 June 1978, the Town and Country Planning Act 1953 was replaced by the revised and more comprehensive Town and Country Planning Act 1977. The new act brings in some substantial changes to the law affecting regional and district planning, and for the first time makes provision for maritime planning. The importance of the Town and Country Planning Act 1977 to the Mineral industry is primarily in the relationship between Regional Planning Schemes and District Schemes as the needs and resources identified in a Regional Planning Scheme will override the underlying District Schemes. The mineral extraction industry must be recognised as a regional responsibility which draws on the resources of a region to satisfy the demand of the communities within that region rather than a purely local operation within one District.

Jan 1, 1978

By Paley N, Cameron A, Townson P

Although blasthole deviation is a problem which can seriously affect blasting operations, there is little practical emphasis on controlling this deviation and no practical emphasis on understanding its practical behaviour. The most common way of dealing with it involves tight control over drill set up and surveying hole paths. The surveying might involve simple collar location and inclination measurement to estimate the hole's actual path. At best, some operations routinely survey hole paths after all holes in a stope have been drilled. In addition, although there is an expectation that holes will deviate, there is no planning for this behaviour in order to reduce its impact on the blast. Design decisions are invariably made with the assumption that holes are straight. If and when surveys reveal problems it is possible only to adjust charging and initiation to 'work around them'. In extreme cases the drill might be recalled to fill in gaps. The lack of planning and the lack of understanding are doubtlessly linked.A model is presented that will predict the expected path of a drill hole. By knowing how a selected few holes deviated it is possible to make a good estimate of the deviation of other holes in the same rock mass. After minimal calibration the model can be used to increase the amount of information for a given amount of surveying or the amount of surveying can be reduced while maintaining the same level of knowledge of blasthole deviation. Equally important is the ability to plan for the deviation in future drilling through altering the initial collar angles or drilling from different locations. It is the authors' hope that planning for hole deviation becomes as much a part of the design process as planning for detonator delay scatter and explosive performance variation.

Jan 1, 1992

The results of a systematic geochemical survey of rare elements are applied to elucidate genetic relations in a suite of rocks and to predict the probability of mineralization. The geology, radioactivity, major element geochemistry and classification of the main intrusives are described. The distribution of a group of rare elements, their concentration trends and the bearing these have on the emplacement sequence of the rocks are considered in some detail. The guides for exploration in the Pilanesberg that emerge are listed and some areas which substantiate predictions are described briefly. It is concluded that a study of rare element trends can make a considerable contribution as an exploration tool and for clarifying relations between the members of rock suites.

Jan 1, 1986

By W J. Shaw

Geometallurgical modelling is now a hot topic in deposit evaluation and in optimising mine performance; however, its history is long and varied. Historically metallurgical sampling has frequently suffered from a lack of data due to the cost of producing representative bulk samples. In the early 1990s geometallurgical modelling similarly suffered from a lack of data due to complex, time consuming and expensive sampling techniques. More recently, simple and relatively cheap tests for geometallurgical variables such as hardness, grindability, throughput, SAG power index, bond work index, crushing index, mineral recovery and concentrate grade have become widespread. The cheaper sampling has resulted in relatively large geometallurgical databases. However, most of the geometallurgical variables sampled are implicitly (and incorrectly) assumed to be additive when modelled by traditional geostatistical techniques, often leading to ill-informed and costly decisions. Geometallurgical variables are mostly non-additive so the current geostatistical challenge is to develop new approaches to dealing with this type of data. This paper briefly describes a historical case study of geometallurgical modelling of the George Fisher Pb-Zn mine completed in the mid 1990s, then outlines some of the current misconceptions of geometallurgical data and modelling techniques regularly applied to it, and finally discusses some recent developments in geometallurgical modelling, with examples from a number of current clients indicating the direction forward.

Jan 1, 2009

The Bureau of Mines, with a history of mining research since 1910, still seeks improvement in safety and health along with improvement and competitiveness in the mining industry. Much promise of such improvements lies in new technology, and this is particularly the case in the still growing coal mine sector, although much Bureau research is long term, high risk, aimed at new concepts.The miner's environment is a primary concern, involving technologies of contaminant monitoring and control in high production scenarios. Contaminants arising from diesel use, alternatives to high speed rotary cutting and more efficient dust removal are being addressed, and drilling efficiencies, better monitoring through unitising operations and insitu rock dust monitoring are particular features.

Jan 1, 1991

The Amacan Copper Project was constructed in the Philippines by a Finnish-Filipino Consortium during the years 1979 - 1982. The project involved a turnkey contract for a mine and a concentrator to process 25 000 tonne per day of porphy- ritic copper ore at a grade of 0.45% Cu. The orebody is located on Mindanao, the southernmost island of the Philippines, in rugged, mountainous terrain approximately 1 000 m above sea level. The adopted design principle was based on an efficient, straightforward installation utilising a minimum number of items of equipment each with high unit capacities. The consortium faced many problems which resulted in lengthy delays in construction and finally led to the client taking over responsibility for the completion of the project. The concentrator was successfully commissioned in July 1982.

Jan 1, 1986

By Gomm SA

The Mount Tom Price Concentrator, which contains a heavy medium cyclone plant for beneficiation of the -6+0.5mm fraction of low grade iron ore, is described. Testwork was carried out on an opportune basis over a period exceeding twelve months, to evaluate the separation performance of the heavy medium cyclones. Plastic density tracers were used and ore samples were taken and analysed. The effect of operating medium specific gravity (S.G.) on the separation parameters, the iron grade of the sinks product, and the mass and iron recoveries were investigated. Also examined were the differences in perform- ance between particles of different size. The implications of the findings for plant oper- ation are discussed.

Jan 1, 1987

By Brinkmann J. R

The relative effects of the two basic mechanisms contributing to rock breakage during blasting, shock and gas penetration, are neither well understood nor well characterized, and need further clarification. Blasthole liner (BHL) tests separate the two effects, and by enabling direct measurement of borehole expansion give insight into the shock/gas energy partitioning in rock confinement. The hydrodynamic code DYNA2D is used to simulate the shock effect of the detonation of emulsion in a stainless steel lined hole, and the predicted expansion is compared with experiment. Workers in the past have neglected near-blasthole phenomena and have calibrated models based on stress measurements remote from the blasthole. Extrapolation back to the blasthole has inherent limitations, and indeed, one of the deficiencies of these models is that they have not been able to predict correct borehole expansions, as observed in BHL experiments. DYNA2D has been enhanced by the ICI group with a detonation model which resolves the explosive reaction zone. As a preliminary step towards the ultimate goal of devising a practical damage model, simulations are used to predict the maximum expansion that would take place if the rock were to remain undamaged. Various material parameters are investigated and it is shown that calculated liner expansions are appreciably lower than measured values for high rock yield strengths, while greater than values for low yield strengths.

Jan 1, 1990

Small mines exist because of a restricted deposit or a small market. With the right management at the present time the small mine can have lower total costs than larger mines. Charbon is an example of a small mine with a restricted deposit and a specialised product. The development which incorporates a unique rail loading facility and flexible coal preparation plant was achieved with a modest capital outlay and in record time. To remain competitive in future with large scale mines who seek increased production the small mine must achieve increased productivity through automation, higher speed equipment and a multiskilled workforce. Deregulation of the industry, scrapping the Coal Industry Tribunal and the Joint Coal Board would benefit small mines greatly. Management of a small operation also requires multiskills which need to be supported by outside help in the form of consultants and temporary staff. In the 21st century small mines will continue to provide a service to the market.

Jan 1, 1988

By Sobek S, Lotzien RM

Although the conventional procedures for designing agitator flotation plants are well-known and reliable, little experience for designing modem pneumatic flotation plants has been gained up to now. A reliable procedure originating from graphic methods for the design of distillation columns is presented. Examples demonstrate on laboratory and semi-technical scale the application of this extremely practical method for designing a fly ash and a magnesite flotation plant.

Jan 1, 1993

By Richardson G. W, Yap L. C

Friction rock stabilisers (FRS) are steel-based, thin-walled tubular ground reinforcement widely used in underground mines in Western Australia. Following installation these stabilisers are subject to corrosion which may reduce the load carrying capacity and lead to unexpected ground falls. Although corrosion has been recognised as a common occurrence, particularly under aggressive mine water and mineral conditions present in underground mines, the knowledge of the effects of corrosion on the mechanical behaviour of FRS is limited. The Department of Minerals and Energy of Western Australia has conducted a laboratory based program of studies to investigate the effect of corrosion on the mechanical properties of FRS. The studies have focused on the effect of corrosion on tensile strength of FRS and frictional resistance along the interface between FRS and the drillhole wall. The results indicate that under certain conditions corrosion damage can significantly reduce the effectiveness of FRS.

Jan 1, 1996

By Hayes P. C

In commercial mineral processing operations it has been found that the conditions in the drier have a considerable effect on the subsequent electrostatic separation of nttile and zircon. Laboratory scale studies simulating these heat treatment processes have shown that the electrical conductivity of nitile varies markedly with treatment temperature, time and gas composition. The zircon on the other hand is unaffected. By increasing the electrical conductivity of the rutile, significant increases in separation efficiency can be achieved. Electron microscope investigations have shown the increase in electrical conductivity to be associated with the production of planar defects in the crystal lattice.

Jan 1, 1991

The task of designing stable high walls and spoil piles in strip coal mines, and stable openings with controlled roofs and floors in underground collieries - within the constraints normally imposed by economics - depends upon a reliable assessment of rock mass strengths and rock mass reactions under a variety of stress conditions. Of the geological factors influencing internal friction and cohesion within rock masses, many may be determined qualitatively or empirically from bore-hole evidence. Rock types, descriptions and properties of intact rocks, location of boundaries, limits and degrees of weathering, potential for slaking or decomposition of rocks when exposed, bedding characteristics, the nature of rock anisotropy and the likely effects of water on rock mass properties can be assessed from bore- hole data. Discontinuities, whether they be major such as faults and dykes, or minor such as joints and fractures, present a greater problem, and in most instances the mine geologist must resort to additional techniques to describe or predict their occurrence, nature, frequency, intensity or physical properties. Information on ground water and seam gas is available from bore-holes within certain levels of reliability.

Jan 1, 1977

By B Ilich, M Brad, R Brandli, E MarT

The Wirtgen surface miner was investigated for application to the Cloud Break iron ore deposit since it can selectively mine thin seams and there is no requirement for drilling and blasting or primary crushing as the surface miner cuts and breaks the rock to secondary cone crusher feed size. A physical metallurgical study of the surface miner run-of-mine (ROM) from Cloud Break was conducted to better understand the product size distribution, amount of -31.5 +6.3 mm lump produced, lump stability and physical metallurgical quality compared to conventional drill and blast techniques. Since the Cloud Break mine was not in production, the lump product from crushing and screening of surface miner ROM was compared with product simulations using traditional premining physical metallurgical processing techniques including drop testing of PQ diamond core. Drop test conditioning is widely used in the iron ore industry to simulate blasting, crushing and screening at the mine and subsequent product degradation during handling from mine to port to predict both the amount of lump product on ship and the size distribution of the fines and lump. The size distributions of surface miner ROM for hard, medium and friable ore types show very tight size distributions with very little above 100 - 150 mm, about 60 per cent of the distribution between 75 and 6.3 mm, with less below 1 mm compared to conventional drill and blast ROM. Crushing, screening and drop test conditioning of the surface miner ROM produced more lump in equivalent ore types compared to drill and blast techniques or their breakage simulation using PQ diamond core. The higher lump yield from the surface miner was also confirmed by pilot scale crushing of some 7400 t of surface miner ROM from the Cloud Break trial pit. The lump produced from surface miner ROM was quite stable and showed similar low degradation characteristics to lump simulated from drill and blasting techniques. Product size distribution simulations using conditioned crushed lump from 1 m diameter Bauer hole samples were found to compare well with processed PQ core samples and surface miner product from trial mining at Cloud Break. The Bauer sample method is therefore considered to be a very useful close simulation to actual lump production, although the lump yield is lower.

Jan 1, 2007

By R Castroviejo, F Segundo, C Brea, J-C Catalina, H-J Bernhardt

Optical microscopy is a basic but still indispensable tool for examining mineral parageneses in ores. The design and concepts behind the reflected light ore microscope have obviously not been subject to spectacular technical evolutions in the last decades. However, digital imaging capabilities have opened new and stimulating perspectives for automated mineral identification. Recent works in developing multispectral image analysis (Pirard, 2004) have demonstrated its superior potential with respect to conventional colour imaging, but at the same time reconciliation with spectroscopic databases such as the Quantitative Data File III (Criddle and Stanley, 1993) still needs a more in-depth investigation as well as the possibility to extend both imaging and spectroscopy into the near infrared domain. In this paper, the authors present results gained from multispectral imaging in the range between 400 and 1000 nm together with spectrophotometric data from the QDFIII database, with an emphasis on minerals that cannot be easily distinguished in the visible spectrum.

Jan 1, 2008

By Daziel M, Corke P

Unit cycles in mining have not changed for many years. Productivity increases over the past three decades have mainly been achieved by using larger and heavier machines. This investment in size has probably reached the point of diminishing returns and increased productivity in the future will have to be generated by other means. One way of achieving this is through automation of selected unit operations, eg dragline overburden removal, truck haulage, ground support installation and secondary breakage. Although, in the past few years, there has been significant progress in this direction, we are still a long way away from even partial automation - especially in hard rock mines. This paper addresses the technical obstacles facing mining automation; suggests ways by which these obstacles may be overcome and identifies the role of industry groups and research providers in this process.

Jan 1, 1997

Experience in evaluating grade control at operating mines has shown that a number of similar errors re-occur in diverse settings. These can be broadly classed as technical errors, and procedural or grade contra management errors. Examples of typical errors are presented a; generalised case studies. A brief explanation of why the recommender solution worked is also presented for each case.

Jan 1, 1993

There are many variables in a flotation concentrator, some of which are outside the actual flotation stage, which affect metallurgical performance. The number of such variables which can now be measured on a continuous basis has increased significantly over the past 20 years. They can be broadly classified under the headings of physical, chemical, and elemental. In this paper reference is made to a number of such variables, and comment is made on the state of the art in their measurement. Although not confined to development in Australia, particular reference is made to the considerable Australian contribution in this area of Technology.

Jan 1, 1984

The geographical and geological situations of the two mineral sand deposits currently being mined by Western Titanium Limited and the mining methods in use are briefly described. Production scheduling involving the ability to vary the proportions of the major minerals produced, together with maintaining a constant feed grade to the wet concentrator has been assuming greater importance to the company in recent years as the relative value of these minerals, due mainly to technological advances and environmental considerations, is subject to significant and rapid change. Manual calculation, even using a programmable calculator, became a trade-off between man hours and data usage. Schedules were updated infrequently and only a fraction of the avail- able data was used. In July 1975 a Data General NOVA 2/10 minicomputer with a 24K word core and three cassette drives was purchased. A suite of programmes was developed using BASIC to assist in production scheduling and these were opera- tional early in 1976.

Jan 1, 1977

By Hall S, Upton D

WMC Resources Ltd nickel operations have expanded significantly over the last three years. Production capacity has increased at mine/concentrate, smelting and refinery processes to such an extent that WMC now ranks within the top three or four producers of nickel metal in all forms. The stainless steel industry remains the dominant user of nickel. WMC's forecast is for stainless steel production to grow at 2.8 per cent per annum off of the 1995 peak, with much slower growth in the short-term as the stainless steel inventory overhang unwinds, followed by a return to higher trend growth rates. WMC's forecast for the long-term growth in demand for primary nickel is three per cent per annum off the 1995 peak; again, slower growth in the short-term before a return to higher long-term trend rates. This projection is towards the optimistic end of the range of industry experts. It equates to a requirement for new primary nickel of 25 000 to 30 000 tonnes of annual capacity each year.

Jan 1, 1996