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The mining industry has a well deserved reputation earned over the years for innovation, engineering, management and the quick application to mining of emerging technology. The cumulative result is the economic exploitation of lower grade resources. The developments during the last decade have done nothing to tarnish the reputation. There are many that come easily to mind: the use of contractors for both surface and underground operations, a trend toward mine management contracts, the increasing recognition of the economic potential of ground support, and the development of physical measures to achieve it, - sophisticated measures to analyse blasting , and thus improve fragmentation, - instrumentation to assist geotechnical appraisal, - the development and application of the powerful and flexible, excavator, - the evolution of measures to improve grade control, - massive improvements in equipment productivity and reliability built largely around the application of hydraulics, - the development of powerful computer packages for orebody modelling, mine design and extraction, - simple "dense" fill systems, - maintenance management techniques including the greater use of off-site maintenance of exchange components, - the utilisation of communication systems for data transfer.

Jan 1, 1989

By E House, V Lisitsin

Recent whole-rock geochemical data from nearly 900 fresh drill core and underground samples taken from seven central Victorian gold deposits confirm the presence of distinct and identifiable primary alteration haloes surrounding the deposits. Ferroan carbonate alteration extends for up to several hundred metres away from turbidite-hosted gold mineralisation outside of contact metamorphic aureoles. A less distinct phyllic alteration zone can be identified using geochemical molar ratios or short wave infrared analysis. It generally overlaps a sulfidic halo characterised by disseminated pyrite and in close proximity to mineralised structures, arsenopyrite. The extent of the sulfidic halo can be traced using low-level analysis of pathfinder elements such as S, Au, As and Sb. Recognition of these alteration features enlarges the target for exploration and provides a tool by which drilling can be directed towards mineralised structures. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Evans A, Jones O

Surface subsidence resulting from "total extraction" of coal in the Collie Basin first occured in 1987 when Western Collieries Ltd trialled the Wongawilli mining method. Because very little quantitative subsidence data existed for the weak, Permian sediments, a research program was set up prior to the extraction of the first panel. The objective of the study was to be able to predict subsidence characteristics and effects prior to mining future total extraction panels. Attempts at predicting subsidence began using existing subsidence models from other coal mining regions, however, as more site information became available, it became clear that it was necessary to develop a separate, she specific predictive model for the Collie Coal Basin. Analysis of extensive field monitoring data for both surface and subsurface subsidence has produced a series of empirical models which can predict the shape of surface subsidence troughs and corresponding tilts, and strains for rectangular panels and describe the sequences of ground movement from the mine roof through to the ground surface.

Jan 1, 1992

Interactive data exploration is essential for visualising grade distribution and geological controls on orbodies. Quick and appropriate computer techniques for making daily 'value adding' decisions include routine imaging of numerical data suc

Jan 1, 1998

By Mathews K. E, Willstead T. V C

Initial glory holing was followed by sublevel stoping, with a small proportion of total production mined by shrink and cut-and-fill methods.The sublevel stoping method was successfully modified to cater for altering ground conditions encountered at increasing depths. At present, 94 per cent of production comes from sublevel stopes. The evolution of this mining method and current techniques and practices is outlined. A combined shrink and,sublevel benching method was also developed to increase the mining rate of narrow orebodies over the standard stoping lift of 380 ft. Pillar recovery and stope filling operations have been continuously modified to suit the relIuirements of a rapidly developing mine.INTRODUCTIONOre production commenced at Mount Isa Mines in June 1931. Since then production has increased from approximately 2,500 tons of lead ores per mine day to the current 11,000 tons of sulphide ores per mine day comprising 3,100 tons of lead ore and 7,900 tons of copper ore. The early planners selected sublevel stoping with ring drilling for ore breaking as the most efficient and economical for Mount Isa conditions: This method satisfied requirements for:1. a low cost mining method for the comparatively low grade ores,2. a stoping sequence allowing development, stope preparation, breaking and drawing of ore to proceed concurrently,3. a method of extraction in which broken ore in the stopes would be kept to a minimum because of adverse effects of oxidation on mill metallurgy and...

Jan 1, 1961

North Flinders Mines Limited (N.F.M.) is an Australian-owned mineral exploration and mining company based in South Australia. In the 1970's it researched the prospectiveness of the Tanami (central western region of the N.T.) for the identification of possible economic gold deposits. Having outlined the potential for such a deposit at The Granites (550 km. N.W. of Alice Springs), it marked out and in 1975 applied for the grant of eleven gold mining leases (G.M.L.'s) under the provisions of the then Mining Ordinance. This application was deferred by the Commonwealth Government during the time of the Aboriginal Land Rights Commission (Woodward), subsequent enactment of legislation and land claims. In 1980, the Walpiri and Kartangarurra-Kurintji land claim encompassing the G.M.L.'s, became Aboriginal land. It therefore became necessary for N.F.M. to negotiate a mining agreement with the Central Land Council (C.L.C.) represent- ing the Traditional Owners, before the G.M.L.'s could be granted. In August 1983, the C.L.C. and N.F.M. concluded an agreement to enable the grant of mining interests necessary for the devel- opment of The Granites Gold Project. In several ways this agreement is unique in That:

Jan 1, 1984

By A Kuras

Segmental tunnel linings are becoming more common in Australia. One current project employing a segmental lining is the City West Cable Tunnel (CWCT) in Sydney. The project has been commissioned by Energy Australia and is currently being constructed by Thiess Pty Ltd. The project includes 1.6 km of tunnel boring machine (TBM) driven, segmentally lined tunnel. The majority of the CWCT will be excavated through Hawkesbury Sandstone. The tunnel is required to carry a 132 kV electrical circuit under SydneyÆs central business district (CBD), between Haymarket and Energy AustraliaÆs City North Substation on Sussex Street. The segmental lining has been designed as a 3.2 m internal diameter, 200 mm thick universal ring with six trapezoidal segments. The design and detailing of this segmental lining presents some noteworthy challenges, including exposure to saline groundwater, and the exclusive use of steel fibres for flexural and tensile concrete reinforcement. This paper describes some of the key elements of the segmental lining design. These include:the case for choosing segmental linings over other forms of tunnel construction;the major design checks required of a segmental lining including ground loading, hydrostatic loading, joint bearing, joint rotation, ram loading and the early strength lifting case;the benefits of using steel fibres over conventional steel reinforcement;the design approach used for steel fibre reinforced concrete;the application of 3D computer modelling in the design;the provision for components including connector dowels and gaskets;the design for passive fire resistance; andthe design for durability of steel fibre reinforced concrete in a saline environment. Segmental lining design requires the application of specialist design approaches. Input is required by the construction team, as the methods of demoulding, handling, transportation and installation impact on the lining design. As the segmental lining is functioning as immediate ground support and also a permanent lining, high standards of manufacture and construction quality control are required to ensure that the 100-year design life is met. The requirement for a watertight tunnel means that detailing and installation of the EPDM gaskets is of importance.

Jan 1, 2008

By Wadsley MW

This paper gives an overall view of the CSIRO-SGTE computer system for thermodynamic calculations. The basis of the system is the coupling of a large self-consistent numeric data bank of thermodynamic information to a modular set of application programs. These seven programs cover management of data files, calculation of thermodynamic properties for species and reactions, plotting of predomin- ance area diagrams, equilibrium and enthalpy balances for complex processes, analysis of thermodynamic efficiency and the estimation of unknown properties. The data bank contains a wide coverage of species and data types so that the system may be applied to many areas of chemistry and metallurgy.

Jan 1, 1984

This study begins with the semivario- gram modelling of variables rutile grade and clay content from a beach sand rutile deposit. This is followed by two dimensional block kriging. The deposit was divided into blocks of 30 x 30 x 1.5 m dimensions and the kriged estimate together with the associated kriging variances for each variable within each block were determined. Finally, using the results of the krig- ing program and considering the acceptable limit of clay content together with the cutoff grade for rutile, a method for optimization of mineable thickness and hence the tonnage of ore was applied and the results were dis- Cussed.

Jan 1, 1986

By N C. White, L Danyushevsky, D R. Cooke

Comb-layered textures preserve the cyclic accumulation and release of volatiles inside magmas that are temporally associated with large Cu-Au-Mo-rich porphyry ore deposits. Fluid inclusions in these textures sample pristine magmatic fluid. Microanalysis of this fluid helps constrain the physical models that operate at melt-fluid interface and in the broader magma system responsible for ore deposit formation. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Mathematical economic models for assess ment of technological progress in the mining industry in the USSR are discussed. The models are based on a simple index, TT which approxi- mates the rate of growth of the people's living standards. However, for application in the mining industry it is necessary to incorporate various parameters to account for the dynamic charges in the geological, mining and other technological conditions. Derivations of the models are shown and examples of results are Included.

Jan 1, 1977

It is recognised by the current JORC (1999) code that resource classification involves the interaction of numerous qualitative and quantitative criteria such as data quality, geological continuity and grade continuity. No prescribed criteria and rules will work for all situations or even between different ore types within the same deposit. Also these criteria and rules are sometimes applied without a clear understanding of their appropriateness, accuracy or correct implementation. For these reasons case studies are useful to evaluate and compare criteria commonly used to assist in resource classification. In this paper blasthole data from a selected area of Joffre Member hosted ore of the Brockman Iron Formation at the Mt Whaleback orebody are used as the basis of a case study for the above-mentioned purposes. Iron grade, in per cent, is interpolated from a blasthole dataset into a block model using ordinary kriging. Samples are then removed from this blasthole dataset to produce a random sample grid, a semi-random sample grid and a regular sample grid. Using nearest neighbour, inverse distance squared, ordinary kriging and sequential gaussian simulation, block iron grades are estimated using these three blasthole data subsets as inputs. This provides four groups of estimates with the ordinary kriging estimate based on the complete blasthole dataset being considered to represent the true estimate of iron grades. Also generated during this process are estimates of the error for each block. These error estimates range from the simple, such as drill spacing, through to more advanced methodologies such as kriging efficiency and simulation. These estimates of grade and grade estimation error are then compared to the true estimate using graphs and statistics. In order of increasing accuracy the block grade estimation and simulation methods were nearest neighbour, inverse distance weighting, ordinary kriging and finally conditional simulation. The simulation in some instances doubled the accuracy of individual block grade estimates when compared to nearest neighbour and inverse distance weighting estimates. It was found that many methodologies for estimating the error of individual blocks performed equally well with only methods such as average drill hole spacing and classification by search ellipse pass number performing poorly. An approach on how to convert the abovementioned error estimates of individual blocks into a meaningful JORC classification is also discussed. Although advanced non-linear resource estimates are applicable, most iron ore mines are still using relatively straightforward methods. The use of blasthole data and some simple linear interpolation methods and simple linear based error estimates makes this study repeatable for most iron ore sites and their resource geologists. This style of investigation is recommended as a useful approach for the Competent Person to apply to their deposit and thus better select, implement and understand the criteria used for resource classification and provide more consistency and confidence in the resource classification process.

Jan 1, 2002

Different mineral structures can act as mineral reservoirs for the immobilisation of toxic compounds. In the paper different mineral structures will be explained and their potential for incorporation of heavy metals and anions will be shown. The following structures will be explained (P÷llmann, 2007):apatites (incorporation of heavy metals, silicate apatites);ettringites (fixation of oxo-anions);layered double hydroxides (fixation of heavy metals, fixation of anions, fixation of organics, sorption materials); andmanganese oxides. Different possibilities of solid solution and incorporation in crystal structures will be explained and advantages of stable minerals be proved using experiences with real toxic wastes. In the process of thermal treatment the formation of primary mineral reservoirs will be shown. The precursor phases (similar to well known cement minerals) react in contact with water to form secondary mineral reservoirs (cement hydration mineral products). The formation condition of primary and secondary mineral reservoirs and their stabilities and incorporation possibilities will be shown. Examples for incorporation of various elements are given. Application for water clarification will be outlined.

Jan 1, 2008

The high-shear colloidal mixer is generally recognised as the most efficient method of mixing cement based grouts. Only recently however has this technology been applied to the production of cemented rockfill (CRF) for use in underground mines in North America. Traditionally, paddle type mixers have been used to produce the cement based slurries required for the preparation of CRF. While considerable success has been achieved with these mixers, tremendous advantages are attained with the colloidal mixer. The combined effect of the highly efficient mixing action and the ability to mix low water/solids ratios, allows for reductions in the cement content for a given strength requirement. Cement can also be replaced by cheaper fillers such as flyash, resulting in further cost savings. Although large-scale dedicated CRF batching plants are typical, there is a growing need for mobile plants capable of operating anywhere underground. The compact size and rapid batching speed of high-shear colloidal mixers has allowed them to be incorporated into skid mounted systems capable of producing and discharging cement based slurries onto rockfill aggregate for the production of CRF. In many cases run-of-mine development waste can be used as CRF aggregate with these slurry plants thereby reducing the cost of waste rock removal. These relatively low cost portable plants have now allowed several mines to economically recover isolated pillars and realise positive returns on their investment.

Jan 1, 1998

By Y A. Stepanyants, J Crawford

A practical field method for determining the maximum value of the intrinsic oxidation rate, Smax , of sulfidic materials in waste rock dumps is proposed. Knowledge of the intrinsic oxidation rate of sulfidic materials distributed in a dump is necessary for predictive modelling of oxidation and pollutant generation over time. The suggested method uses the fact that drilling waste rock dumps to install probes for monitoring temperature and oxygen concentration causes large volumes of air to be injected into a dump by the drill rig. By measuring the rate of decrease of oxygen concentration along the length of a borehole immediately after installation, it is proposed that Smax can be calculated at different depths. The aims of this work were: to derive a simple, practical formula for the estimation of Smax from the oxygen concentrations measured over time, based on some simplifying assumptions; to use a two-dimensional numerical model that incorporates all the necessary physical processes to model the behaviour of an aerated dump over time for a reasonable range of dump and material parameters; and to compare the results of the two approaches to assess the validity of the simple formula as a method for estimating Smax. It has been found that the technique can provide reliable estimates of Smax when the value is of the order of 10-7 kg(O2) m-3 s-1 or greater. At the lower end of the range however the radius of the zone aerated during drilling becomes an important parameter and further work has been recommended to investigate this aspect of the method.

Jan 1, 2003

By Hargraves A. J

At 4 MPa gas pres ure and 30°C the sorptive capacity of 10 selected Australian dried coal ranges from 17 to 23 m3/tonne of CH4 and 27 to 36 m3/tonne of CO2. Values for moist coals are about 25 per cent less. At 20°C, sorptive capacities are about 18 per cent greater. No clear relationship between coal rank and sorptive capacity was established.The permeability of coal to gas is dramatically reduced by progressive hydrostatic confinement. No single 'permeability' for a coal can be established because of relative affinities of coals and the gases (Ar, CH4 and CO2) used in experiments. Bedding plane permeability is significantly greater than permeability normal to bedding. Dependent on gas/coal combinations, permeabilities without confinement ranged from 150 to 0.05 millidarcies, and with 8 MPa hydrostatic confinement from 1.0 to 0.001 md. Generally, permeability is increased by reduction in temperature, and reduced by increase in moisture as one changes from Ar through CH4 to CO2. In retrospect, it is preferable to ubject permeability sample to 8 MPa hydrostatic stress only once, because changes occur in the samples and it is difficult to use other gases successively.The initial rate of desorption, DP, does not appear to be a reliable index of proneness to instantaneou outbursts for Australian coals.The methods used for determining quantitative gas-coal properties appear suitable and reliable for testing other coals.

Jan 1, 1985

The electrochemical dissolution of gold and other noble metals in hydrochloric acid using alternating current has been investigated. The experimental results show that this technique is efficient for dissolving pure noble metals and offers prospects for their extraction from wastes and poor ores.

Jan 1, 1992

By T Hausler

The pitfalls, pleasures and management issues associated with international and remote projects are diverse.However, no problem is insurmountable and if an engineering team chooses (by luck or good planning) to push through the difficulties, success can mean an extremely satisfying experience for individuals and a significant, positive result for an organisation.International projects are not for the faint hearted or inflexible. Working in foreign lands with people who may or may not speak English and who may not initially respect you can become mentally and physically tiring.Sometimes the challenges are not fully explained to individuals in advance. Individuals then often learn about the challenges ù and discover solutions ù on the job. While this initially puts great pressure on individuals, matters improve eventually, especially when the locals come to understand that you are on site to make a positive difference.This paper will discuss aspects of a recent international project including meeting international clientsÆ expectations, dealing with cultural differences, social reckoning, environmental issues, and personal challenges. Specifically, it will cover aspects of working within a Russian cultural setting and overcoming social barriers.The paper also presents coping strategies for long periods of time spent away from home in remote places with extremes in weather beyond the normal experience of most Australians. For example, dealing with the effects of the spring thaw and coping with temperature ranges of -45 to +45¦C.Lastly, and possibly most importantly, there will be a focus on the role of translators. They have the power to make an engineer everyoneÆs best friend or, on your behalf, to order cold chicken liver and heart salad for lunch. If an engineering team can establish a working relationship with translators, they can become an invaluable asset and both on and off site.CITATION:Hausler, T, 2013. Achieving success in large-scale, remote area metallurgical plant projects, in Proceedings MetPlant 2013 , pp 539-552 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Christmas Island "C"-grade phosphate consists essentially of the minerals crandallite and millisite. Although containing over 25% P205, this material is not suitable for the manufacture of water-soluble phosphate fertilizers by conventional processes, because of its high iron and aluminium content Cover 25% total R203). In order to produce a water-soluble fertilizer from such material it is necessary to separate the iron and aluminium from the phosphate, which must report in a product acceptable as a fertilizer. Several processes were studied in detail. The first used ion exchange for dissolution and separation and yielded diammonium phosphate; processing costs were high compared with conven- tional processes based on apatite. The latter processes have basically simple flowsheets and cost of processing is low when compared with the costs of the raw materials. The need to separate iron and aluminium from the phosphate introduces additional complexity into the treatment of the C-grade material. The higher processing costs might be justified, however, if alumina could be produced as a byproduct. Two proposed processes have been developed in which: 1. hydrochloric acid is used for dissolution, and solvent extrac- tion for the separation of ferric chloride from phosphoric acid. Aluminium chloride is precipitated and hydrolysed to recover alumina and hydrochloric acid. 2. sulphuric acid is used for dissolution and aluminium is crystallized as ammonium alum. The phosphate is produced as an ammonium phosphate-sulphate fertilizer. High purity alumina can be obtained by treatment of the recrystallized alum. The technology of these processes is described, and their broad economics discussed briefly.\

Jan 1, 1971

By Hashimoto H, Arai Y, Sikong L

For utilization of solid carbonaceous materials produced in processes of cracking heavy oil, such as petroleum pitch, as powder fuel, it is necessary to develop a process for fine grinding of these materials. It is known that grinding' additives are effective for fine grinding of cohesive and heat-sensitive materials such as petroleum pitch, therefore in this study, effective methods for fine grinding of petroleum pitch with some grinding additives were investigated. Experiments were carried out by using comminution kinetics based on mass balance. From the results of the investigation by using a batch ball mill, it was found that sodium stearate, calcium stearate and carbon black were effective additives for the improvement of grinding efficiency. Optimum concentration of the grinding additives was also found to give a required particle size of products. Concerning to the action mechanism of these additives, it is considered that the additives which adhired to, or were absorbed on the surface of petroleum pitch particles not only prevented cohesion of the particles but improved dispersion of the particles as well. From the results of the investigation by using a laboratory screen mill which is a representative built-in classifiered impact crusher, carbon black was found to be an effective additive for the improvement of grinding efficiency and mill performance. It is also considered that the improvement of classification efficiency by carbon black affected the mill performance.

Jan 1, 1987