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By B Cope, N Hastings, D Webb

A Feasibility Study was completed in late 2002 to ascertain the risk and reward profile from the proposed deepening of operations at Perseverance Nickel Mine in Western Australia. The system and approach adopted to this brownfields extension work is outlined and the main components of the study are overviewed. In particular, emphasis is given to the integration of mine design and scheduling tools through to financial evaluation. Detailed comment is given on the ability of the system used to provide a robust project schedule complete with 3D animation. The level of importance in eliminating scheduling errors is demonstrated in relation to the reported bottom line viability of the project. It is suggested that this is an area where brownfields Feasibility Studies have lacked clarity and authenticity, leading to the creation of an unrealistic benchmark for project implementation.

Jan 1, 2003

By Waters JC

Pseudoclastic hydrothermal alteration textures occur within quenched coherent dykes forming part of a subaqueous dome complex (-4 Ma) on Ponza Island, Italy. These textures are similar to those observed in considerably older (-500 Ma) subaqueous volcanic rocks at a number of localities throughout the Mount Read Volcanics in Tasmania and elsewhere in ancient volcanic sequences of this type in Australia. This is significant because the processes of formation, hydrothermal alteration and secondary mineralisation of ancient volcanic sequences may be better understood if we can make comparisons with modern analogues. Observations at Ponza imply that these pseudoclastic alteration features form synvolcanically or immediately after dyke emplacement and lava extrusion. This is compatible with scenarios presented for their formation in ancient sequences in the Mount Read Volcanics, Tasmania.

Jan 1, 1995

By Lawson F

The leaching behaviour of BHAS copper matte in oxygenated acidic sulphate chloride solutions at 85¦C has been studied using samples containing 34% copper, 41% lead and 12% sulphur. Copper sulphide in the matte, essentially Cu2S was found to leach in two distinct stages. Similar to the behaviour of pure chalcocite, copper dissolution in the first stage was affected by the availability of oxygen in solution. The presence of chloride ions in the leachant was essential if there was to be any leaching in the second stage (which usually commenced after about 40% of the copper had been taken into solution). Lead sulphide in the matte was oxidised to lead sulphate and formed a shell around the partially leached matte particles. Electrochemical studies showed that this lead sulphate and/or sulphur produced during leaching can form a passivating layer around the copper sulphide. However, this layer was disrupted when chloride ions were present. A Plackett-Burman analysis was used to determine the species in the recycled leach solution that affect the leaching of copper. Under the experimental conditions used, in the first stage the rate of copper dissolution was influenced by the concentrations of sulphuric acid, Zn(II), Cu(II), Fe(III) and Cd(II). In the second stage, the rate was futher modified by the concentrations of Cl(I) and As(V) ions. In solutions of low acidity and high As(V) concentration, insoluble copper arsenate formed which coated the partially leached matte particles and acted as a barrier to futher reaction.

Jan 1, 1989

The transportable moisture limit of a mineral concentrate (TML) is of great importance in the shipping of that material from Australian ports. Each year Australian mining companies incur substantial costs as a consequence of delaying shipments and/or multi-handling concentrates so as to comply with transportable moisture limits. Despite this there is a general lack of in-depth knowledge concerning factors that influence the parameter. Eight major Australian mining companies supplied sizing, specific gravity and TML data for their concentrates. Zinc, lead, copper and bulk concentrates were represented in their data. Estimated surface areas of the concentrates, as calculated from their normalised sizing data, correlated strongly with the reported transportable moisture limits. This high correlation prevailed in spite of the acknowledged limitations associated with the use of multi-sourced data and the adoption of simplistic approaches in the normalisation of sizing data and the estimation of surface area. Based on the broad range of concentrates studied, concentrate sizing data were concluded to offer potential as an alternative means of reliably estimating transportable moisture limits.

Jan 1, 1993

By R Lovel, P Fung, J Manuel, M OÆCo

The iron blast furnace is the most widely used and efficient producer of liquid iron. The integrated steel works is however under environmental pressure largely due to emissions from sintering and coking. The combustion of coke breeze during sintering contributes to greenhouse gases (eg carbon dioxide) and is the source of much of the emissions of SOx and NOx. Coke breeze, the fines produced during coking of coal, is also suffering supply issues as coke demand increases while coking capacity is constrained by environmental concerns.CSIRO Minerals has been investigating the use of wood biomass/char as a substitute for coke during sintering. Wood biomass, or char produced from it, is an attractive carbon source as carbon dioxide can be sequestered into growing biomass prior to combustion. It has great potential to reduce the emissions from integrated steelworks and improve their environmental acceptability. Harvested biomass/char is also a renewable and sustainable resource. Samples of pine wood flour, sawdust and red gum wood char were characterised and used in small-scale granulation and sintering tests. Red gum char granulated as well as coke and could be used to make acceptable sinter. Large-scale sinter pot test were conducted with char to produce sufficient sinter for ISO quality tests and calculate sintering performance parameters. Results showed that coke could be completely substituted by red gum char during sintering without loss of quality and with actual improvements in sintering performance. Furthermore, gas analyses made during sintering showed that there were significant reductions in SOx and NOx when char was substituted for coke. It is anticipated that the results reported here, although preliminary, will stimulate an increased effort into further research on the use of char in iron ore sintering.

Jan 1, 2004

By E R. Ramanaidou, M S. Piggott

Transport to and handling of iron ore at Port Hedland, Western Australia, results in the generation of airborne particulates that contribute to the atmospheric dust load, with concerns about potential local environmental impacts (eg mangrove swamps) and possible human health implications. Mineral and chemical characteristics of the Background soil samples were contaminated with particles of iron ore as martite octahedra and grains of micro-platy hematite as detected by scanning electron microscopy (SEM) in the 2.5 - 10 ¦m and 10 - 50 ¦m size fractions. Fossilized wood fragments similar to those observed in Yandicoogina fines ore were also detected in some background soil samples. With a predicted increase in demand of channel iron deposits (CID) ores and the inherently dusty Marra Mamba ores (eg West Angelas, MAC, OB29/30/35, Marandoo), in conjunction with particulate emissions from hot-briquetted iron and direct reduced iron (HBI/DRI) processing plants, there is the potential for additional sources of anthropogenic dust to contribute to background levels. Mineralogical and chemical characterisation of the entire range of particulates that could be produced is necessary for a complete understanding of their potential impact on the local environment.

Jan 1, 2002

By M F. Lee

In order to make good decisions, as to whether large diameter raise bored shafts can be constructed in blocky rock at a particular location, mine planners, management, geotechnical engineers and contractors must understand and consider a range of geotechnical issues. Firstly, mine management must ensure that adequate time and resources are available to find appropriate shaft sites. Deep weathering, adverse structures, groundwater, etc might mean that the most desirable location, with respect to other mine development, might not be suitable. Special site investigation drilling, etc may be necessary. Even then, alternative construction options might be necessary, other than just reaming through to the surface. A site investigation borehole should then be drilled to investigate specific and general ground conditions along the raise alignment. Often, only small sections of weak blocky rock dictate raise stability. While the empirical McCracken and Stacey method is typically used in Australia to assess raise stability and assess geotechnical risk, until recently it had no published performance data.An Australian database of raise performance now exists and is presented below, courtesy of an industry survey by the Eastern Australian Ground Control Group. Raise diameter and ground conditions (in terms of a lower bound Qr value) is presented for 50 cases versus raise performance.

Jan 1, 2008

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

By E Jak

A viscosity model has been developed for both completely liquid and heterogeneous, partly crystallised slags in the Al2O3-CaO-æFeOÆ-SiO2 system in equilibrium with metallic iron. The Urbain formalism has been modified to describe the viscosities of the liquid slag phase over the complete range of compositions and a wide range of temperatures. The Roscoe equation has been used to describe the effect of presence of solid suspension (slurry effect) on the viscosity. The parameters of the viscosity model were optimised to describe large experimental data set in the low-order subsystems, as well as in the multi-component system. The computer package FACT was used for prediction of the proportion of solids and the composition of the remaining liquid phase. The model provides a good description of the experimental data (over four thousand experimental points) in liquid phase, and liquid + solid mixtures, over the complete range of compositions and a wide range of temperatures. This model can now be used for viscosity predictions in industrial slag systems. An example of the application of the new model to slag cleaning and reduction smelting processes is given in this paper.

Jan 1, 2000

By Qisu W

The ground vibration produced by the bench blasts of a single hole and a row of two or three holes is recorded in an iron mine. Using the seismic signal generated by a single-hole shot as the source function, we have developed a computer program of a simulating ground vibration by bench blast. The reasonable delay time of blast in the iron mine has been discussed tentatively with the Fourmap invented by Anderson, D.A. The seismograms measured from the single-row blasts of two or three holes have shown the method of simulating vibration is feasible on the whole. For large scale production blasts, a combination of the vibration simulation and the high-speed photograph is used to choose the delay Time.

Jan 1, 1990

By I Thin, I Sheppard

Resin encapsulated rock bolting practices have been adopted by Mount Isa Mines since the early-1980s. Fully encapsulated rock bolt systems meet designated requirements for long-term ground support in the mines. A variety of rock bolts, resins and installation methods have been utilised over this period in underground mining. As a parallel to this evolving application, Mount Isa Mines have tested various resin encapsulated rock bolt systems. Testing has included routine underground pull testing and the development and implementation of the push test for the entire encapsulated bolt length. The latter test enables a greater understanding and representation to be had of the overall mixing, level of encapsulation and capacity of the system. Rock mechanics at Mount Isa Mines undertake evaluation of new bolt systems that become available, in addition to the maintenance of compliance with quality control measures for the existing systems. Improved methods of installation and systems are also investigated to further the cost-effective nature and minimise risks associated with resin rock bolt practices.

Jan 1, 2002

We are all no doubt aware that with today's high costs it is more important than ever to get the maximum possible return on capital invested in the mining industry. Screening is an important and often costly process in the size classification of industrial minerals and for this reason alone it is essential for both managers and operators to fully understand what type of screening equipment is best suited for a particular application and why. The advent of elastic materials such as rubber and polyurethane have added a new dimension to the process of screening. It is important to understand why the physical properties of these materials can be of benefit in the screening process, and recognise which type of screening applications best take advantage of these orooerties.

Jan 1, 1984

The smelting operation associated with the production of aluminium has a voracious appetite for high grade carbon materials. Within the technical parameters of the Hall-Heroult process, the reduction of alumina to one tonne of aluminium results in the consumption of nearly 0.5 tonne of carbon at the anode of an electrolytic cell. This paper reviews the role of carbon and the basic quality requirements of carbon products in the production of aluminium, discusses the effects of certain physical and chemical specifications on smelting and related operations, and examines recent trends in the quality of these raw materials.

Jan 1, 1977

By C Philander

The West Coast of South Africa is well known for its placer gem quality diamond deposits and also associated with these hosts of Cenozoic unconsolidated marine and aeolian sand and gravel are significant concentrations of heavy minerals. Exploration for economic concentrations of zircon, ilmenite and rutile along the coast started in the mid-1980s. This resulted in the discovery of an inferred 1.6 billion tonne resource with a grade of ten per cent total heavy minerals (THM), which developed into the Namakwa Sands Mine, a world-class producer of heavy minerals. Several other resources, including satellite deposits proximal and distal to the mine area, extensive diamond mine dumps and present day beach placers, demonstrate the vast heavy mineral potential along the West Coast. The favourable gangue to economic mineral ratio, a higher zircon content compared to other similar deposits, relatively lower U+TH content of zircon, low slimes content and effectively pristine low chromium-manganese ilmenite of these deposits, render them attractive exploration targets. Negative factors that will affect conventional mineral beneficiation and liberation include secondary mineral coatings and the regional coastal development of several layers of superimposed duricrust. The economically attractive heavy mineral assemblage along the West Coast is the result of erosion of the proximal, gneissic Namaqualand Metamorphic Province and mature Table Mountain Group sandstone, concentration by marine and aeolian processes and preservation under arid climatological conditions over a period of more than 100 Ma.

Jan 1, 2008

The preconcentration of uranium ore by radiometric ore sorting at Mary Kathleen Uranium Ltd. is described. The operation of the ore sorting machines is discussed in detail and performance results obtained with the existing system are presented.

Jan 1, 1978

By J M. Palin

Hydrothermal scheelite precipitated in fault-veins at Paradise, Bonnie Jean, Davidson's and Glenorchy mines display chemical variability involving REE patterns that are transitional between two end-member types. Type I is a MREE-enriched pattern with no or a small positive Eu anomaly. Type II is a flat to MREE-depleted pattern with a strong positive Eu anomaly. The chemical inhomogeneity of these scheelites can be explained by a model of fractional precipitation of REE, with preferential removal of MREE from the fluid during precipitation of scheelite. Irrespective of the mechanism responsible for scheelite precipitation, the source of dissolved constituents is different for scheelites from the Paradise Mine. Bonnie Jean, Davidson's and Glenorchy scheelites formed from LREE-enriched fluids whereas Paradise scheelites precipitated from fluids that were lower in LREE. These inferred fluid characteristics cannot be linked unambiguously to specific source rocks in the region, but could suggest that scheelite deposited in the Paradise fault-vein reflects a more mafic source of REE possibly greenschists, whereas the REE in scheelite from the other mines suggest a more felsic source.

Jan 1, 2003

By Terlich R. E, Finlayson J. M

A combination of high virgin rock temperatures, deep workings and extensive utilisation of heavy diesel equipment has presented North Mine (A Division of North Broken Hill Limited) with challenging ventilation problems. These problems have been addressed in a variety of ways which include in the order of 6000 kM of underground refrigeration. The future of North Mine depends on the successful development and extraction of ore in excess of 1100 m below the shaft collar using mechanised cut and fill mining. The success of this will depend on the installation of a complex chilled water reticulation circuit in this area. This will involve planning and constriction of a number of large dams, installation of pups and turbines, and the successful commissioning of several large water to air heat exchangers.

Jan 1, 1988

Recent operating experience from West Australian open pit gold mines has shown that geotechnical input into initial design is rare. As a result, ground stability is poor - almost half the pits designed in this way suffer major failure.West Australian experience shows that geotechnical studies for individual mines are site specific, and therefore empirical experience cannot be transported from site to site. Geotechnical studies performed prior to design have resulted in significantly improved pit stability.

Jan 1, 1990

By P Grouhel

In the recent years several new blasting technologies have come into use in surface mines. Electronic initiation, low-density emulsion explosives and modelling software are in regular use throughout the world. In Australia, these new technologies have achieved significant application, largely in open cut coal mines where more than 20 per cent of blasting is now conducted with electronic initiation systems. These new techniques have contributed to the vast improvement in blasting outcomes evidenced by increased recovery of saleable product and faster excavation rates. In large surface mines, OricaÆs unique combination of electronic initiation systems, bulk emulsion explosives and modelling software can be harnessed to target critical value outcomes. This includes targeting better fragmentation, increased ore uncovery rates and better wall stability û all adding to improved mining operation profitability. Orica Mining Services have combined these technologies into a set of offerings called Blast Based Services (BBSÖ). The paper describes applications of these new technologies and possible benefits in large surface mines.

Jan 1, 2007

By G Ride

The provision of a water supply is a major consideration in planning mining developments particularly in remote areas. The evaluation and development of adequate water supplies in arid areas of Australia is often as important as the discovery of the orebody. The copper orebody at Warrego near Tennant Creek could not be mined economically if cheap treatment water was not available near the mine. This paper describes the difficulties in obtaining water in the Tennant Creek area and the water supply investigations carried out near the Warrego Mine which resulted in the successful discovery and evaluation of a reliable large scale water supply. It is contended that the establishment of a water supply must be approached on a systematic and scientific basis similar to the approach with the exploration and establishment of actual ore reserves. Mining companies with similar water supply problems may benefit by approaching their problem on this basis. The approach adopted by Peko Mines is outlined in this report.

Jan 1, 1971