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By S Furman, M Caccetta, A Hacket, B McDonald, M A. Wells, D Lau

In 2004, the Western Australian Department of Industry and ResourcesÆ Burrup Rock Art Management Committee commissioned a number of independent scientific studies to evaluate the condition of rock art in the Burrup Peninsula near Karratha (Western Australia). These studies are evaluating the physico-chemical aspects of the effect of environmental modification on the visible appearance of the rock art. Because of the cultural significance of the sites, the research approach has been to employ non-destructive testing strategies and work in the field has progressed with respect for the importance of the area. This paper only reports the spectral mineralogy monitoring at each of the sites to evaluate whether changes in mineralogy are observed on rock surfaces. Reflectance spectroscopy is a non-destructive, in situ materials characterisation technique that provides information about the mineralogy. The minerals detected include haematite, kaolinite, chlorite, goethite, gibbsite and manganese oxides. Current results indicate that the surface mineralogy of the rock art has not changed in the last four years.

Jan 1, 2008

By Chugh Y. P

A simplified, three-dimensional, time-dependent, mechanistic model of the overburden-coal seam-floor interaction has been developed and validated at two Illinois coal mines. The model based on the thin plate theory can involve any complex layout of mine workings, time-dependent sequence of extraction and, rheological properties of immediate floor strata. The model output data consist of spatially distributed surface subsidence and its slope and curvature, as well as load acting on pillars in one or more panels. A comparison of calculated and monitored surface subsidence or in- mine convergence measurements has proven the model's effectiveness for surface subsidence and load transfer Prediction.

Jan 1, 1992

By Butcher NM, Walker GS

Argyle Diamond Mines Pty. Limited (ADM), manager and operator of the Argyle Diamond Mines Joint Venture (ADMJV) will recruit approximately 400 employees during 1985 to operate the new large-scale, open-cut diamond mine and treatment plant being developed at Argyle, in the East Kimberley Region of Western Australia. These employees will live in Perth or environs and will commute to work at Argyle via chartered jet aircraft. On site, they will be accommodated in self-contained single person's quarters, with central messing and recreational facilities. Rostering systems have not been finalised, but it is likely employees will rotate through a cycle of 14 days at site and seven-days on leave in Perth. ADM spent three years evaluating residen- tial options before deciding to commute its workforce from Perth. Another 70 senior staff will reside in Kununurra (the nearest established town, 250 km from Argyle) and commute to the mine daily by air.

Jan 1, 1984

By Hogan C. J

The compact BWE system set up in 1984 to mine ironsand dunes and the underlying ironsand-clay has been an effective high volume produc- tion unit for New Zealand Steel Mining Ltd at the Waikato North Head ironsand mine. The system utilising two compact S400E (0 & K) Bucket Wheel Exca- vators and a single shared Beltwagon for transfer to the shiftable bench conveyors replaced a fleet of mobile elevating scrapers when the produc- tion requirement was increased by a factor of six. A key factor in favour of the BWE system was the economic advan- tages of low unit costs for both manpower and electrical energy.

Jan 1, 1989

By Jankola W. A, Delong O. J

Historically, the silica content of zinc concentrates treated at Cominco's Trail Operations has been low. Silica in the roaster calcine seldom exceeded 1.5 per cent because of the low silica content of concentrate from Cominco's Pine Point mine. With the shutdown of Pine Point, alternate sources of concentrate were required and it was anticipated that calcines containing greater than two per cent silica (with excursions above three per cent) would have to be treated. Previous experience indicated that the existing leaching circuit could not tolerate such high levels. Therefore, a research program was undertaken to identify the key factors affecting silica precipitation; to compare different process alternatives; and to make recommendations for modifications to the existing plant. A project to modify and upgrade the leaching circuit has now been completed. Calcines with higher silica contents are successfully treated, but the upper limit of the circuit is unknown. The results of the research work will be discussed and the new leaching plant will be described. Recent operating results will also be presented.

Jan 1, 1993

By A Thornton, D Engelhardt, J Woodg

Grinding is a critical part of nearly all mineral processing operations. It is the largest consumer of energy on the mine site (and thus indirectly a producer of greenhouse gas through the generation of electrical energy at the power station). Since comminution is one of the main consumers of electrical energy worldwide, efficient control of grinding mills is of paramount importance. Mill Auto-Pilot is a control system developed for SAG mills to stabilise load and power and improve the efficiency of control and increase throughput. A dynamic, mechanistic model of the grinding circuit is used to determine circuit parameters which can not normally be measured using conventional instrumentation. The circuit model is built from models of the unit operations (such as conveyors, SAG mills, cyclones, sumps, etc), and so captures the dynamic complexities and interactions of real circuit operation. CSA Mines at Cobar NSW accepted an offer to be the reference site for Mill Auto-Pilot and the system was installed in March 2004. In this application the model is used to predict mill load mass, mill solids residence time and cyclone underflow density. These parameters are used to control mill load, power and mill discharge density. The outcomes of the introduction of Mill Auto-Pilot at the CSA Mine are discussed.

Jan 1, 2004

Gold mineralisation at the Macraes Gold Project is hosted in the Hyde-Macraes shear zone and can be traced for ~30km along strike, although economic resources are confined to a 7 km section in the vicinity of the Macraes township. The shear zone, which typically dips at a low angle (~20 o ) to the NE, is bounded by an upper hanging wall shear and a lower footwall fault. Mineralisation occurs along the hangingwall of the shear zone as well as in low angle concordant shears and stockworks. Ore types include graphitic cataclasites with variable amounts of quartz veining, ælode schistsÆ and quartz-vein stockworks. Rehabilitation at the mine has focused on creating an environmentally benign site dominated by pasture to allow continuation of the traditional pre-mine farming economy. Changing regional economics, continued urbanisation and a reduction in traditional employment opportunities has seen a rethink in the long-term rehabilitation outcomes. The community has recognised that the rehabilitated site will provide the basis of a viable tourism venture and the creation of a Heritage and Art Park (working title æGolden Point ParkÆ) is the culmination of that process.

Jan 1, 2002

By Netchaef P

A rationale is presented for the use of vegetation on mine dumps to minimise runoff and infiltration which become vehicles for potential pollution. The unique topography of mine dumps promotes high atmospheric advection which leads to extraordinary energy levels for evaporation discharge - the driving force of vegetation "pumps". This effectiveness is mainly a function of how well the vegetation will grow on a given site. Recent advances in technology allow water discharge by vegetation to be measured semi-automatically, accurately and cost effectively. As a result the basis now exists for a thorough evaluation of the optimum mine dump vegetation cover. This paper presents the current status of dump rehabilitation as seen by the mining industry. The significant prospects for use of vegetation to minimise mine water related problems with subsequent savings in capital and operational cost are also outlined. However, to examine the crucial questions of optimum hydrological ability, suitability and cost effectiveness of various types of dump vegetation a proposition is made to interested parties in the mining industry: The CSIRO needs potential study sites to evaluate the hydrological ability of vegetation under mine dump conditions.

Jan 1, 1988

By Rashleigh C

The selection and application of an effect- ive firing system first require a clear under- standing of the initiating abilities of the com- ponents in such systems. The conditions under which charges can be prematurely initiated by a detonating cord downline must be appreciated. This is a principal consideration in the design of a successful downline/'Anodet'/primer assembly. The advantages and limitations of an electric and several non-electric initiating systems are explained. The factors which in- fluenced selection of the two most suitable systems for use at Isa Mine (viz. downline/ 'Anodet'/primer assemblies and the reinforced long-lead 'Anodet'-type delay system) are dis- cussed. Blasts are detailed in which each of these has been applied. The initiating design for a hypothetical 2 x 106 tonne blast using electric short delay detonators and multi-channel exploders is presented. In this design, charges in remote blastholes are activated after the detonation of earlier firing charges by protecting the firing lines with sandbags.

Jan 1, 1978

By A Poliakov, E Donskoi, K Vining

The automated optical image analysis software Mineral4/Recognition4 (M4/R4) is capable of performing comprehensive characterisation of different materials throughout the iron ore value chain, including ore fines, lump, sinter, pellets and coke. It has been successfully used by CSIRO for industrial and research projects and has been independently licensed to several world leaders in iron ore production and ironmaking. The M4/R4 software was strongly integrated with a Zeiss microscope to make use of the company’s powerful AxioVision software. This required users to own both Zeiss microscope hardware and AxioVision software in order to be able to use M4/R4 to its full image acquisition and analysis capacity. Therefore, it was not available to the users of equipment produced by other major microscope manufacturers. In recent times however, Zeiss has indicated that the AxioVision software will no longer be supported. To overcome this limitation, CSIRO has proceeded with the next generation of this software, Mineral5/Recognition5 (M5/R5). Importantly, the M5/R5 system has been developed without any dependence on a specific microscope hardware/software platform. Furthermore, the image analysis functionality is now based on openCV open access software and has been fully rewritten using stateof- the-art software development tools to allow reading and processing of all major image formats. Although past applications have been specific to iron ore and ironmaking applications, other improvements, such as an increased number of minerals allowing better gangue segmentation, flexible mineral definitions, improved software modules behaviour and refined analysis routines enables the platform independent M5/R5 image analysis system to be used by researchers in any area of mineralogical or materials research.

Nov 8, 2021

By Miller J. D

The mechanism of adsorption of gold from alkaline cyanide solutions by carbon has been the subject of much research over the past decade. In this paper, the nature of the gold cyanide adsorption phenomenon is investigated, particularly with respect to carbon substrates and associated surface adsorp- tion sites.

Jan 1, 1991

By A R. Firth

The induration furnace for iron ore pellets was originally designed to process concentrates with high contents of magnetite. To support the use of haematite concentrates, internal fuel was added to the pellets in the form of ground coke breeze or anthracite. To ensure that the addition of coke breeze was not excessive, the ‘heat of magnetite equivalent’ or heat of magnetite equivalent (HME) relationship was developed, guaranteeing that the fi ring temperature requirements remained the same. However, this oversimplifi es the different reaction paths of magnetite and carbon in iron ore pellets. At fi ring temperatures, gas diffusion controlled reactions such as the combustion of coke, the calcination of carbonates and the reduction and oxidation of iron oxides can all occur in different parts of the pellet simultaneously. The interaction of these reactions produces a range of atmospheres across the diameter of the pellet that vary from oxidising at the pellet shell to reducing at the pellet core. Mathematical modelling and pellet fi ring experiments to preheat temperatures before quenching have shown that a higher proportion of coke relative to magnetite slows down the oxidation process, irrespective of temperature. A higher temperature, however, results in an increase in the rate of haematite reduction in the pellet core and a more reducing atmosphere, which could lead to different sintering rates in different parts of the pellet and shrinkage cracks forming. To observe these gas-solid reaction rates at a larger scale, the COREM pot grate has been updated with an additional oxygen analyser. This, along with other improvements, will allow better optimisation of straight-grate firing cycles for different pellet compositions.

Jul 11, 2011

By Canning RG, Uusna S, Goodheart BA

The paper outlines the development of"a process for removal of iron oxides from ilmenite, thereby upgrading the TiO2 content of Western Australian ilmenites, from 55 to approximately 90 per cent. In the first stage, the iron oxides are reduced with solid carbon (coal) to metallic iron. Experimental reduc- tions were carried out in crucibles,, a fluidised bed and a small pilot plant rotary kiln. The reduced'ilmenite is,then agitated in aerated water, in the presence of catalysts, so that the iron "rusts" away from the ilmenite'grains and the precipitated iron oxide is easily separable by decantation. The influence of variables on the rates. of reduction and oxidation are discussed, The oxidation rate was exam- ined for both - the' physical oxygen-transfer characteristics and electrochemically by reference to Peurbaix diagrams, which plot redox potential against solution 'PH, The upgraded ilmenite is expected to be an attractive material. for pigment -manufacture,, and the iron oxide has prospects of being a marketable by-product. The process may possibly be. applied, to .other..ores.

Jan 1, 1964

By J Walasiak

In the climate planning of mines and tunnelling with anticipated poor climatic conditions, and especially in case of longer working shifts, the main question is whether it can be reliably prevented that certain climatic limits laid down be exceeded. Working at high temperature and/or humidity can lead to reduced human working energy û a very important economic aspect û and to a risky lack of concentration on the part of the miners or to heat collapse and extremely dangerous heat stroke. With the Deutsche Montan Technologie GmbH (DMT) climate prediction programs, both the dry and the extremely significant humid heat transfer can be calculated. This is due to the high planning reliability involved. With the help of these climate prediction programs it is already possible to determine the anticipated climatic values for the operation phase as early as the planning stage of new ore or coal fields or of tunnel construction projects and to design the optimum air cooling system for every underground project with due regard to technical and economic aspects.

Jan 1, 2005

At the outset, I guess we should define what we mean by "com- modities". In the 20 minutes or so which I have for this paper, it is impossible to tackle all commodities -one would need to con- sider not only the base metals but also the ferrous iron and steel products as well as energy commodities such as coal, oil and even uranium. For the purpose of this address however, I would prefer to refer to the principal non-ferrous commodities: copper, lead, zinc, aluminium and nickel and, I would like to consider some of the changes which have taken place in the industry over the past 20 years-and the likely reasons for these changes. I would also like to dwell a little on the future and some of the key issues which-may influence the future path and direction of the metals industry.

Jan 1, 1988

Much of the theory upon which the Sublevel Caving (SLC) method is based was developed in Scandinavia many years ago. It was based mainly on æbinÆ theory and æellipsoid of drawÆ configurations derived from sandbox models. In many cases, classical SLC layouts influenced by these early theories obtained relatively poor results. Early dilution entry, low tonnage factors and low recoveries were commonly experienced. SLC soon gained the reputation of being a high dilution, low recovery and development intensive method. This led to SLC falling into disfavour generally, other than as a pillar reclamation method used at the end of the life of mines. More recently a number of mines, notably those in Australia, have adopted SLC as a primary extraction method and have achieved good recovery results. The reason for the better results is believed to be an outcome of modifications in some of the basic design parameters and operational procedures. This has led to questions being raised regarding the original æbin theoryÆ assumptions and classical SLC layout designs. It is clear that the fragmentation and flow characteristics occurring in a choke blast situation (compaction of waste, variable size and shape of fragmentation throughout the ring) conflicts significantly with the assumptions of regular loose flow of uniform, fine grained, material in a bin. Interactive versus independent draw conditions can also materially effect the outcome of a SLC operation. The good results obtained more recently can only be explained by using ænewÆ models of behaviour, which have to a large extent been borrowed from block caving. If these models are correct, they point to a number of design and operational changes that can be applied to improve the effectiveness of SLC. This paper discusses the factors that may not have been fully considered in early SLC design and modelling. It emphasises the importance of delayed dilution entry as a primary objective of sound SLC design and provides a basis for efficient SLC design and operation.

Jan 1, 2000

By Selby J

South Australia's economic development has relied heavily on the mineral industry. In the late 1840s the rich copper deposits at Kapunda and Burra saved the Colony's economy when South Australia became a world copper producer. Copper lodes developed at Moonta-Wallaroo during the 1860s brought further prosperity when mining activities at Kapunda and Burra were in decline. In addition to those large mines there were many smaller workings scattered through the Flinders and Mount Lofty Ranges producing copper, gold, silver, lead and zinc. Most of the mines of this period were worked by Cornish immigrants who brought their own technology and mining methods with them. These people have left a cultural legacy unique in Aus- tralia. In this Jubilee 150 year (1986) the Department of Mines and Energy, working in conjunction with the Department of Environment and Planning, is helping to preserve and interpret selected historic mining sites, most of which have been neglected since their closure. This work is designed to draw people's interest to mining history by providing interpreted sites for them to visit and to demon- strate the importance of the mining industry in South Australia's cultural and economic develop- Ment.

Jan 1, 1987

By Johnson M, Wooltorton B

A programme of hydraulic fracture stress measurements conducted in surface drill holes along the alignment of the King River Power Tunnel has provided information of importance to the assessment of the extent of steel lining requirements for the tunnel. A significant horizontal stress field has been detected at a location remote from the power station site, with a corresponding absolute minimum stress magnitude approximating the overburden pressure based on depth of cover. Measurements made closer to the power station site (located toward the bottom of a valley) have revealed an apparently relatively destressed region with minimum stress magnitude less than overburden pressure. The implications of these results are discussed.

Jan 1, 1987

Bendigo is AustraliaÆs second-most productive goldfield, having produced some 22 million ounces of gold between 1851 and 1954. Bendigo Mining Limited (BML), the sole lease-holder of the Bendigo Goldfield, is developing a mine that is planned to produce ore from beneath the historical workings for at least the next 25 years. The high-grade Bendigo reefs occur in the proximity of the chevron anticlines, which characterise the goldfield. Typically the reefs display relatively small cross-sectional areas and large (subhorizontal) strike dimensions. They occur in clusters due to interrelated structural controls. Most of the gold occurs as visible grains and laminae, and as such grade estimation is not amenable to ænormalÆ sampling and estimation techniques. The initial phases of exploration and development of the mine focused on understanding and resolving these sampling and estimation issues. In 2005, BML reviewed and updated the March 2004 Feasibility Study, refining the life of mine development strategy. The strategy fundamentally aims to exploit the 11 million ounce Inferred Resource and additional exploration potential by developing the current Kangaroo Flat Mine to produce ore at an initial rate of 450 000 t/yr in 2006/07, expanding to 600 000 t/yr by 2009/10; and developing the Eaglehawk Mine to produce 1 Mt/yr by 2011/12. Ore will be processed initially at the Kangaroo Flat site, and from 2011/12 also at the Eaglehawk Mine 1 Mt/yr processing plant. The two mines will connect underground in 2009. Total ore treatment capacity will be 1.6 Mt/yr, producing 600 000 oz/yr from a head grade of 12.7 g/t gold. The project is planned to operate for 25 years, processing 33.6 Mt of ore producing 13.7 Moz of gold. To achieve this production rate, the exploration and ore delineation programs will require up to 16 diamond drill rigs producing over 200 km of core per year. At the same time, approximately 8 km of on-reef development must be monitored and typically 18 stopes managed concurrently. The processing plants will be located in geographically constrained areas, which will limit the ability for selective stockpiling and campaign treatment.

Jan 1, 2006

Traditionally, the term ætotal systemÆ design applied to comminution conjures images of a design that addresses the usual business and operational drivers, including health, safety and environment (HSE), capital cost, operating cost, throughput and product size. In terms of the physical process, the mine to customer type studies also exemplifies an approach that satisfies a normal ætotal systemsÆ approach. As an industry there are drivers that are forcing a re-consideration of what we regard as our total system. This modification of drivers will require changes in approach and implementation to provide the best solutions. Some of the major changes that impact the drivers are shortage of skilled personnel, changing social attitudes to remote mine site work, greenhouse gas emissions (GHGE), quality of available orebodies and geographical location of new mine sites. One approach to the challenges presented by the changing business environment is to expand the system envelope around comminution to ensure that comminution, in its widest sense, helps to meet the new realities. Background to the new drivers and constraints is provided and some of the appropriate responses are examined in relation to the impact on the total system.

Jan 1, 2007