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By R Huntley, D Sims

Pajingo gold mine produces over 240 000 oz Au per year from underground mining using longitudinal bench stoping methods with a 15 m sublevel interval. Average mine head grade is around 12 g/t Au, contained within quartz veins between 0.5 to 16 m wide. The veins dip steeply (>60¦) and exhibit strike variations which lead to many curved and meandering drive/stope geometries. Unplanned dilution at Pajingo is predominantly controlled by fault planes that subparallel the vein and commonly lead to slabbing failure from the stope walls. Initial efforts at determining maximum spans were based on using the Stability Graph method of stope stability. However the method had a number of shortcomings that did not address mine site observations, including previous mining, interaction of different joint sets and the presence of discrete shears which resulted in poor prediction of stability. A method was developed to rate the risk of dilution for a stope based on observations made in the ore drives. The method utilises profile mapping of the ore drive, structural features observed and the orebody itself, on 10 m spaced sections along the ore drive. A matrix of factors determines the dilution risk for stoping at the time of mapping and the rating is transferred to longsection plots in the office. The dilution risk rating is used to determine the position and density of cable bolt support aimed at lessening the risk, and can be used to review blasthole designs prior to finalisation. The method has been used for more than two years and has proven to be a good indicator of potential unplanned dilution (ie waste outside of ring design). A recent review of the dilution risk mapping process has indicated it is assisting in reducing the impact of dilution at the operation and has the scope to be utilised further in the design process.

Jan 1, 2002

By Duke J. H

Advanced computer aided geological modelling techniques are now available to the geologist to allow the rapid evaluation of a gold orebody at various stages of its development. The types of grade estimation techniques used change during the various stages as the density of drilling and knowledge of the deposit increases. At the prospect evaluation stage drillhole intercept selection techniques are coupled with preliminary 2D (vein or layer) modelling or 3D block modelling techniques to arrive at a geological resource estimate. At the prefeasibility and feasibility stages more sophisticated 2D and 3D modelling techniques, such as domain controlled grade interpolation with anisotropy, are used along with interactive open pit and underground mine design, to calculate recoverable reserves. At the production stage closely spaced blasthole sample data is modelled quickly and coupled with interactive grade control facilities. Shot volumes, tonnages and grade estimates can be databased to provide reconciliation figures. These modelling techniques are embodied in MINEX-3D, an Australian software system which, with the emergence of the 386-based PC and high resolution (VGA or better) graphics, makes a whole range of advanced geological modelling techniques available to most exploration and mine geologists.

Jan 1, 1989

Jan 1, 2004

By Burrell I

This paper describes recent developments at West Cliff Colliery in environmental monitoring, using a sophisticated computer controlled system. The operations involved in environmental monitoring are described and the equipment employed is detailed. It is anticipated that the monitoring system employed at West Cliff Colliery will be expanded to allow total and instantaneous monitoring of roadway environmental Conditions.

Jan 1, 1983

By S Planeta

The use of explosives in underground mining has its drawbacks, particularly in the case of thin or narrow vein type deposits. Due to that, there is a need to develop more discriminative and safe rock-breaking technologies. Mechanical rock splitting seems to be one of the most promising avenues in this respect. This paper describes briefly principles and features of radial-axial splitters. It reviews a feasibility study done to evaluate a potential of this technology in selective mining. It was intended to compare productivity and cost of ædrill-splitÆ mining with conventional cut-and-fill method. Hypotheses and assumptions adopted, methodology used and the obtained results are presented and discussed. The study has confirmed an interesting potential of radial-axial splitters in mining thin and narrow vein deposits. In conclusion, it is stressed however, that it will take more R&D work to corroborate the results obtained. Some suggestions concerning future research in this field are also given.

Jan 1, 2003

By J Tsiklieris, O Turner

Suppliers of products and services have a pivotal role in sustainable development in the mining and minerals industry. Reputable suppliers know their products and services, and the industry, and have unique knowledge of these in relation to their customerÆs needs. Petroleum hydrocarbon suppliers, in particular, impact upon a mineÆs sustainability because of the extensive reach of petroleum hydrocarbons into the mining and minerals life-cycle. The petroleum hydrocarbon life-cycle is a useful framework to enable engagement between supplier and customer on the issue of sustainability. The life-cycle starts with supply of fuels, lubricants and services at the mine, through to plant operation and maintenance, transport of mined products, ship loading, and finally through to mineral processing and other downstream value-adding. There are barriers to leveraging supplierÆs capabilities which have to be overcome before the industry will gain the potential benefits from such supplier engagement.

Jan 1, 2004

Refractory gold concentrates and their roasted products have been examined by mineralogical and chemical methods, and the distribution of gold in the tailings after leaching has been Investigated.

Jan 1, 1989

By Ormsby W, Peters M, Van Gils H, Kehprens P, De Boorder H

The northern margin of the Arunta Block is characterized by a metasedimentary and volcanic sequence of lower metamorphic grade than that of the central Arunta Block. Whereas the Harts Ranges have granulite to amphibolite metamor- phic grades, the northern margin only reached greenschist to lower amphibolite facies. Most of the high grade area of the central Arunta Block appears to be unprospective, but the lower grade marginal fringe contains most mineral pros- pects to name a few: Barrow Creek, Molyhill and the Jervois Mine. Numerous smaller prospects occur in this marginal zone. Four major lithostratigraphic units can be recognized in the Jervois Mine area: 1. Gneissic Suite consisting of granitic and rhyolitic gneisses which are characterized by a distinct intersection lineation. 2. Metasedimentary Suite of cordierite- biotite schists and chlorite-biotite schists. 3. Mine Sequence, consisting of spotted schists with andalusite and cordierite, quartz- sericite-feldspar schists with distinct rhyo- litic remnants and quartz-sericite-feldspar schists which contain the lode horizons:

Jan 1, 1984

The Curragh mine has complex operating conditions. The mine operates in four seams to produce two coal qualities and is divided into five pits which have different qualities and coal preparation characteristics. The combination of all of the necessary controls to achieve maximum resource utilisation has necessitated the development of suitable software to assist the quality control engineering function. The required software had to be able to plan the optimum yield of coking coal whilst achieving the quality parameters for the coking coal and co-produced steam coal. The program has been designed to evaluate all of the mine faces available for coking coal production. The optimisation of coking coal production is planned and co-produced middlings steam coal determined. The optimum steam coal product is determined using the middlings in combination with bypass production.The computer software to carry out these functions has been designed by using an exploration data base as the raw data source. The program accesses this data and uses a coal preparation prediction program to determine the yield vs. ash relationship for each coal face. A linear program selects the optimum -combination based upon equal incremental ash values. The final output lists feed tonnages, coal preparation conditions, product tonnages and full coal quality data.

Jan 1, 1985

By C Hertle, B Goebel, R Fabre

The mining industry maintains a ælove-hateÆ relationship with water. Dewatering, aquifer, water disposal, irrigation, process water, tailings water, run-off water, seepage, leachate and sumps are all terms that are used on a daily basis in the mining industry, highlighting the numerous water usages on site and their associated quality. According to the Australian Bureau of Statistics (2001), each year the mining industry consumes over 530 000 ML of water. The increasing recognition of water as a limited and valuable commodity, and the associated environmental concerns with the management of water disposal to the environment has led the industry into improving on-site water management. Progressively, water balance models and water reuse strategies are being developed, incorporating more sophisticated water treatment processes. By way of example, membrane technologies, once restricted to industries such as the pharmaceutical industry or the drinking water industry, are now entering the mining world with the aim of producing clean water of suitable quality for ore processing or for advanced treatment prior to release to the environment. This paper will provide a review of the threats and opportunities linked to water use and recovery/reuse in the mining industry in Australia. It will open with an overview of current water usage and associated quality for various mineral industries and continue with identifying the threats and limitations associated with the quality of available water. It will then present how newly developed water treatment technologies and assessment tools can be incorporated into the system to enhance the recovery and reuse of water on site, reduce the risks associated with securing long-term water supply and further improve production, environment and safety (health risk control).

Jan 1, 2006

The Elgas Underground Storage Facility at Port Botany, Sydney, is the first purpose-built cavern of its kind in Australia and provides large capacity, safe and environmentally benign storage of Liquefied Petroleum Gas (LPG). The facility will provide Elgas with the flexibility to source product at competitive prices and ensure long-term security of supply. Construction has provided Orica Australia, formerly ICI Explosives, with a unique opportunity to provide a bulk explosive delivery system specifically designed to meet the exacting demands of the site and of the project.

Jan 1, 1999

The Cooperative Research Centres (CRC) Program was established and is supported by the Australian Government at a total cost of $140 million per year. Six of these centres have been established to help Australia's mineral industry: three in exploration, one in mining and mineral processing and two in extractive metallurgy. Since the CRC Program has now been in operation for five years, it is a good time to ask whether the minerals industry is being served adequately by these centres. In this paper, the performance of one CRC, namely the A J Parker Cooperative Research Centre for Hydrometallurgy, will be discussed in terms of the objectives of the CRC Program. As will be shown, the Parker Centre has made considerable progress since its establishment in 1992.

Jan 1, 1996

By B R. Bittencourt, D A. B Pasin, D Pi

Three main genetic types of hematite can be recognised at Quadrilßtero Ferrffero (QF): Micaceous or schistose hematite derived by metamorphic/metasomatic process during regional metamorphism, increasing eastward, formed under temperatures ranging from 250¦C to 500¦C in CO2-rich aqueous carbonic, high- to medium-salinity fluids. Hematite in shear and mylonite zones, showing a wide variation of fluid and temperature conditions, between metamorphic and hydrothermal conditions. Deformed quartz-specular hematite veins formed during the late phases. Hydrothermal, compact and isotropic hematite developed during a brittle-ductile regime, forming the cement of the boudinage-kink breccia and jacutinga-type of gold mineralisation, under temperatures ranging from 80¦C to 140¦C in aqueous, low- to medium salinity, oxidant fluids, resulting from the interaction of meteoric and metamorphic/metasomatic fluids. Quartz-carbonate-sulfide veins were formed slightly later, through reducing fluids.

Jan 1, 2005

Exploration of a coal deposit provides the data on which a range of mine plans can be developed during project feasibility. The stages of exploration use methods and procedures which initially outline the deposit with more detailed data gathering and analysis of the specific site complexities. The in situ coal resource and reserves are calculated. The mine plan is a function of the mining method chosen and can have significant impact on the recoverable reserves. Other factors which can impact on the recovery of the reserves and the ability to maintain planned production levels are those which were either undetected during exploration or were misinterpreted. Exploration programs should be detailed enough to minimise to an acceptable standard the recognised and potential risks. Past programs which explored to achieve a minimum exploration density required to satisfy measured reserve status have generally proven to be inadequate, placing reserves and production at risk.

Jan 1, 1997

Diesel-engine exhaust emissions represent a concern to the mining industry due to the poten- tially harmful health effects of the pollutants, as well as high costs associated with providing proper ventilation to assure a healthful working environment. The control of exhaust emissions is complex since the operating mode and condi- tion of the engine, the mine environment, and the operator's skills all influence the concen- tration and composition of the emissions. It is not practical to measure each exhaust pollutant in underground mines; therefore, a monitoring methodology is required to measure the pollut- ants and assess the air quality.

Jan 1, 1988

A blast is designed to completely break competent rock such that it can be economically extracted, and efficiently handled or processed. Efficient breakage of the rock is critical to the success of an operation, and in many operations blast design is optimised to achieve fragmentation, muckpile profiles, and material that is easily excavated. There are inevitably other issues, such as damage to adjacent rock, that should be taken into account when designing a blast to achieve overall optimisation. Some of the key issues with respect to the integrity of the in situ materials adjacent to a blast are identified and briefly discussed in this paper. The potential for damage and the effects of a blast will be strongly influenced by the rock mass properties. This makes it important that site specific conditions and their response to blasting are known. Practical techniques that allow the disturbance adjacent to a blast to be measured with minimum disturbance to operations are described in the paper. Experience shows that, during the blasting process, there is considerable potential to disturb the in situ rock mass adjacent to the blast. In some circumstances a very important objective must be to minimise disturbance outside of the immediate blast area. Measured and observed disturbances caused by blasting to adjacent rock, for various common types of blasting, are discussed in this paper. Blast induced disturbances to the rock mass have been observed in both the near and far fields. These disturbances have the potential to impact on geotechnical design. The geotechnical significance of blast disturbance on a rock mass that is to remain in situ is explored and suggestions with respect to design are given.

Jan 1, 2004

By G Harbort, C Sola

The rapid development of geometallurgy in the mining industry has occurred in relatively recent times. Its importance as an independent discipline in the mineral processing world has been emphasised and recognised. To a large degree, this is the result of a growing understanding of the ore type being processed and their application to provide better metallurgical responses in different mineral processing techniques. The development has matured from early progress through to geological knowledge and into the realm of the metallurgist and mining engineer. Working together, they have developed a powerful framework that will interpret a body of mineralisation into measurable properties.The integration of geometallurgy and operations has become of increasingly important due to improvement in understanding of an orebody as a natural system formed by a number of processes and with a definite fabric of mineralisation within different geological domain. These have to be taken into account when creating techniques that will enable operations to extract the valuable components from a distinct type of ore. Incorporation of such knowledge at an early stage of development, such as the feasibility stage significantly reduces the project risk.This paper is written from the unique perspective of a process engineer embedded within a geological team. It discusses issues such cross discipline communications and misconceptions and details the numerous tricks, traps and treasures of geometallurgy encountered during defining of the Seminco and Taysan resources.CITATION:Sola, C and Harbort, G, 2012. Geometallurgy - Tricks, traps and treasures, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 187-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The Greenvale Joint Venturers, Metals Exploration Queensland Pty. Ltd. and Freeport Queensland Nickel Incorporated, use ten Herreshoff roasters, for the reduction of ground lateritic nickel and cobalt containing ores.Initially the roasting section of the plant limited production, due to high down time.The use of technology developed and adapted over a number of years has achieved significant increase in on line time and a minimization of costs.

Jan 1, 1985

One of the great attractions of academic life, for those who enjoy the opportunities of university teaching, is the continual contact with some of the most able young minds which each rising generation produces. So when I was asked to give a paper at t

Jan 1, 1994

By R Uken G P Whitmore

The coastal dune cordon of northern KwaZulu-Natal is amongst the highest in the world reaching heights in excess of 180 m and up to 2 km in width. It comprises a complex system of Quaternary stacked dunes of various geomorphologies, types and ages. The dunes contain economic heavy minerals which are currently exploited ~20 km north of Richards Bay. Although mining of these ore sands has been in operation for the last two decades, little work has been undertken on the clay-fraction (

Jan 1, 2001