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The Bau Goldfield lies in the southwestern corner of Sarawak in East Malaysia. Evidence of past mining in the form of open pits and adits can be found over an area of 250 sq kin, centred on the township of Bau. Chinese were mining gold in the district as early as 1820. The Bau Goldfield so far has produced approximately two million ounces of gold, from alluvial deposits and over 50 hard rock mines. The largest single producer was the Tai Parit mine (700 000 oz) which was operated by the Borneo Company from 1898 to 1921 and by a local Malaysian family from 1991 to early-1997. Over the past ten years, gold resources totalling around one nullion ounces have been delineated through systematic exploration using modern techniques, with the bulk of the resource hosted in two deposits (Jugan and Pejiru).Triassic to Jurassic andesitic volcanics and coeval intrusives are the oldest rocks that crop out in the Bau Goldfield. These igneous basement rocks are unconformably overlain by 500 m of late Jurassic, massive, micritic limestone which in turn is overlain by a 1500 in thick flysch sequence, composed mainly of shale. Basement rocks and limestone are exposed along the hinge of a ENE-striking anticline that passes through the Bau district (Bau Anticline). A NNE-striking belt of Miocene granodiorite porphyry stocks and dykes also passes through the Bau Goldfield. All of the known gold deposits lie within 5 km of this zone of intnisives, with a concentration of deposits at the intersection of the intrusive hell with the Rau Anticline.

Jan 1, 1997

By Savory P. J

Uranium mining operations commenced at Ranger mine site, Jabiru NT Australia in May 1980. The Ranger orebodies, totalling approximately 110 000 tonnes contained U305 had been indicated by airborne radiometric survey in 1969 and confirmed by drilling the following year. Both diamond and percussion drilling methods were used to define the mineralisation and samples were analysed using a combination of radiometric and neutron activation techniques. Ore reserve estimates were calculated from conventional and geostatistical methods, and following the mining of 15 million tonnes of ore, reconciliations with before mining estimates are well within acceptable industry standards. In-pit grade control employs radiometric techniques including a radiometric truck discriminator built in Australia to mine specification to meet production requirements and improve productivity. Environmental requirements associated with uranium mining are a daily consideration.

Jan 1, 1993

By M Scamardella

The CSA Mine is located at Cobar, New South Wales, where it was in continuous operation from 1966 to the time it went into receivership on 29 January 1998. When it closed it was under the ownership of Golden Shamrock. Glencore International, in conjunction with Mt Lyell Mining, undertook a due diligence study to determine the feasibility to re-open the mine. This envisaged operating CSA Mine as a low-cost, copper concentrate producer under the direction of Cobar Management Pty Ltd (CMPL). The new workforce would consist of contractor trades people in operating functions under the co-ordination of CMPL staff, both on the surface and underground. This was the key to establishing the new culture in the workforce. The orebodies at CSA Mine are steeply dipping with copper-lead-zinc mineralisation in zones of strong alterations in a fine-grained siltstone host sequence. The predominant economic minerals are chalcopyrite, sphalerite and galena. The major gauge minerals are pyrrhotite, pyrite, chlorite, sericite and quartz. Ore for the project is being developed and mined from two high grade copper lenses within the QTS North system. Chalcopyrite occurs in two forms. The first consists of coarse chalcopyrite grains in association with pyrrhotite or pyrite. The second form consists of chalcopyrite grains intergrown with pyrrhotite grains. This form of chalcopyrite is quite rare. It allows electrochemical interactions between grains, resulting in rapid oxidation of the chalcopyrite surface. Physically this ore looks like, and has been mistaken for æpeacock oreÆ, ie bornite, but is infact oxidised chalcopyrite.

Jan 1, 2000

By Membrey W. B, Partridge A. C

Lower transportation costs, improved handling and better utilization efficiency are some of the reasons that make low moisture coal product desirable. There has been considerable interest in the development of effective coal dewatering techniques to achieve this result. One avenue of considerable merit for enhancing dewatering processes is by modification of the surface chemistry of the coalwater slurry system by chemical means, resulting in better performance of existing equipment. This paper reports the results of an investigation of the utility of surface active agents in the enhancement of fine coal dewatering. A large variety of proprietary dewatering agents have been studied in relation to their efficiency in enhancing the dewatering of a number of Australian coals. Properties of particular coals that make them amenable to improved dewatering by particular chemical agents have been identified. Surface studies, including surface tension and zeta potential measurements as a function of surfactant concentration, as well as dewatering assessments, were used. Particular attention was paid to filtration, but the results could be applied to other dewatering systems.

Jan 1, 1989

By Trumpff H

Opencast Lignite Mining requires topwall strata of seams to be fully depleted and footwall aquifers sufficiently depressurized. To prevent a spread of the cone of depression into protected wetlands some distance away, alternatives had been investigated such as closing water works, underground slurry wall barriers and recharge by infiltration. As a result of these investigations, the infiltration method has been chosen and in a first phase during the next decade it will utilize as much as 55 x 106 m3/year. Using this approach, the survival of the wet lands is assured.

Jan 1, 1988

By Eupene GS, Cheong GE

Operations at the Mount Bonnie gold/silver project are described. The project is based on the gossan of a stratiform and stratabound polymetallic sulphide deposit. The gossan contains approx- imately 100 000 tonne of ore grading 8g/tonne Au and 230g/tonne Ag. This is mined in an open cut, and transported to a stockpile area lkm away, from which it is fed to the treat- ment plant. The ore is crushed through two stages and fed to a fine ore storage shed, from which it is reclaimed, milled and cyanide leached in draft tube agitators. The pulp is filtered using a horizontal belt filter to recover a pregnant solution. Silver sulphide is precipitated using sodium sulphide solution, and collected as a mixed sulphide/precoat concentrate on a drum filter. The solution is then passed through carbon columns where the gold is adsorbed and is subsequently recovered by methanol desorption using a process developed by Micron Research, and electrowinning. Modifications to the treatment plant circuit based on operational experience are Described.

Jan 1, 1984

By Baczynski NR, Fagan MJ

A 3050m long section of a 1.65m internal diameter tunnel is presently under construction in the Brisbane area by means of the pipe-jacking method. The soils along the alignment had been deposited in a deltaic/estaurine environment and rapid changes in soil type occur. The tunnel passes beneath several extensive bodies of surface water. Groundwater problems have been experienced with tunnelling through alluvial sands and gravels. Details of the ground conditions, the pipe-jacking method used and tunnelling experience are discussed in this Paper.

Jan 1, 1987

By J Harris, J Li, M Shi, P A. Kirsch, D Sprott

Australia has an enviable global reputation as a leader in health and safety outcomes in the hazardous industry of mining, in part due to an increased application of risk management regarding operational planning and mining practice. In 2010, the Australian Coal Association Research Program (ACARP) initiated a major project, RISKGATE, to build, capture and deliver a national body of knowledge to assist companies with the management of risk in coal mining. The online system contains information for tyres, collisions, fires, isolation, strata underground, ground control open cut, explosions, explosives underground, explosives open cut, manual tasks, slips/trips/falls, outbursts, coal bumps and bursts, human–machine interface, tailings dams, occupational hygiene and inrush. In 2014, RISKGATE is developing content for fitness for work (fatigue, drugs, alcohol, physical well-being, psychosocial well-being).This paper analyses underground mining fatalities in Australia and the United States since 2002 and introduces RISKGATE with a focus on the knowledge base for management of hazards in underground operations. Through capturing coal industry expert operational knowledge, RISKGATE provides a cumulative corporate memory at a time of high personnel turnover within the mining industry. This coal-based body of knowledge is a platform that can be evaluated and implemented for other mining domains and high-risk industries within the energy supply chain.CITATION:Kirsch, P A, Shi, M, Harris, J, Li, J and Sprott, D, 2014. RISKGATE and underground operations, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 11–18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By A Woodley, A N. Danoucaras

In 2012 the Bureau of Meteorology, under the banner of the Water Accounting Standards Board, released the Australian Water Accounting Standard 1 (AWAS 1). This standard has been in development since 2007 with key milestones being the release of the Preliminary Australian Water Accounting Standard in 2009 and the exposure draft of the Australian Water Accounting Standard in 2010. Throughout this period, the Minerals Council of AustraliaÆs Water Accounting Framework has developed concurrently with the Australian standards and the standards have informed elements of the framework. However, the framework is not identical to the standard as the objectives between the two are different. The objective of the Water Accounting Framework is to create consistency in water reporting of the minerals industry and to assist companies reporting to corporate sustainability initiatives. The objective of AWAS 1 is to provide information to water management bodies to facilitate decisions about the allocation of water resources. Companies are to report on an annual basis - not only physical flows of water but contractual requirements to supply and obtain water - regardless of whether the transaction has been fulfilled in the reporting period. In contrast, the Water Accounting Framework only reports on flows that have physically happened. The paper will provide summary information on aspects of AWAS 1 that are most relevant to the minerals industry, show the alignment and differences between AWAS 1 and the Water Accounting Framework and explain how to obtain the information for the AWAS 1 reporting statements.CITATION:Danoucaras, A N and Woodley, A, 2013. Alignment and differences between the Australian Water Accounting Standard and the Water Accounting Framework for the minerals industry, in Proceedings Water in Mining 2013 , pp 85-90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Ranklin W. J

The mechanism and rate-limiting step of carbonaceous reduction of zinc from slags was investigated in the laboratory. Disks of graphite were rotated in ZnO-containing slags at various speeds for fixed periods at 1250 to 1325¦C. The mass loss was used as a measure of the amount of ZnO reduced. Application of the Levich equation indicated that at rotation speeds at which it is valid, the reduction was chemically controlled with an activation energy of 27 kcal/mol. At zero rotation speed the reduction of ZnO by carbon appeared to be slag-phase mass transfer controlled with an activation energy of 38 kcal/mol. An increase in the FeO content of the slag increased the rate of reduction while an increase in sulphur content decreased the rate of reduction. When FeO was present in the slag, reduction appeared to occur by a combination of indirect reduction of ZnO by carbon and by reduction by FeO with reduction of Fe203 back to FeO by carbon. The effect of sulphur was consistent with a surface blockage mechanism due to the surface active nature of sulphur in slags.

Jan 1, 1993

By D T. Feinstein, M B. Gotkowitz

In Wisconsin, state laws and regulations governing metallic mine permitting stipulate that protection of groundwater quality be assured indefinitely through all phases of the mining project, including development, active mining, reclamation, and long-term closure. By rule, the Wisconsin Department of Natural Resources (WDNR) requires that permit applicants use a numerical model to assist in the assessment of compliance with this requirement for all proposed mine-waste facilities. As a part of the compliance assessment, model calculations are used to predict groundwater solute concentrations through time at designated boundaries for comparison to current groundwater quality standards. In practice, this modelling requirement has involved the application of numerical solute-transport models. Our review of a solute-transport model submitted by the developers of a proposed mine near Crandon, Wisconsin, provides us with an opportunity to assess the usefulness of transport modelling as a permitting requirement. Recent evaluations of solute-transport models by other workers suggest limitations in predictive accuracy. Our review of the model submitted for this project also identified important limitations due primarily to uncertainty in calibration of model parameters at the undeveloped site. The utility of any model to predict project compliance or non-compliance with numerical standards is limited by the range of uncertainty of key model parameters, such as dispersivity and porosity. Uncertainty in the future behaviour of the solute source(s) also reduces the predictive power. Moreover, the site characterisation provided by the model may have limited power to describe the site condition post-development. Although these inherent shortcomings accompany the use of solute transport models at undeveloped sites, the requirement for model development and the ensuing technical review has substantially assisted in our evaluation of site conditions and project design. Through this process we have identified elements of the waste facility design that are crucial to the environmental viability of the project, resulting in modifications to original project proposals. While results from this model review will be used to evaluate compliance, additional benefits come from the identification of critical design features that enhance groundwater protection.

Jan 1, 2003

During the past three years Lurgi's Circulating Fluid Bed (CFB) technology has been successfully applied to roasting of refractory gold ores and con- centrates. In comparison with the so-called Stationary Fluid Bed roasting systems, a considerable improvement of gold recovery, to around 95 per cent, has been demonstrated and achieved on many occasions in pilot CFB units and in commercial CFB roasting plants as well. The major reason for such improved gold recoveries is the excellent controllability of the roasting process in the CFB reactor system. Here, temperature, gas atmosphere and solids residence time are more precisely controllable at optimal values during roasting operation in order to achieve the highest possible gold recovery in the subsequent leaching process step. Further dominant benefits of CFB roasting systems are their flexibility with regard to feed material, throughput capacity, dry or slurry feed, almost unlimited oxygen enrichment, direct fuel addition and in situ capture of SO2 in the presence of limestone and dolomite. The system will accept 50 per cent turndown ratio, large variations in feed composition and particle size, as well as a variety of different fuel types. The commercial applications of CFB roasting systems for gold con- centrates have been realized so far at Fimiston, Kalgoorlie/Westem Australia and for whole ores at Cortez, Nevada/USA.

Jan 1, 1991

Production targets are the basis for almost every decision made by operations personnel in the daily operation of a concentrator. It is the production targets that determine how the plant is operated and therefore determine its efficiency. However, to achieve maximum plant efficiency production targets must be relevant to the process and achievable.In RoseberyÆs case, for many years, production targets were taken from budget data which, with the exception of mill feed tonnes and grades were carried forward from the previous budget. The zinc concentrate grade target was fixed at 57 per cent Zn, a long-term average; it was the accepted æstandardÆ for Rosebery. Historical data showed this target was never consistently achieved and plant efficiency was highly variable.Investigations into the possible causes for the variable performance ruled out plant and mechanical issues. Despite the Rosebery concentratorÆs age the plant and equipment are more than serviceable and reliable. The mineralogy of the ore and specifically the iron content of the sphalerite was found to be the most significant determinant of zinc concentrate grade. It was found with increasing frequency that the zinc grade of the sphalerite in the ore was below the zinc concentrate grade target. Consequently on these occasions attempts to meet the required concentrate target destabilised the process resulting in plant inefficiencies.Using the correlation between iron and zinc, data modelling was able to accurately predict the maximum zinc concentrate grade achievable for any ore type. By using on stream analysis instrumentation the operations personnel are now provided with constantly updated concentrate grade targets. By knowing the mineralogical limits of the ore at the time it is being treated process stability is maintained allowing plant efficiency to be optimised. This has resulted in a step change in plant performance and a significant increase in revenue.CITATION:Harris, G R, 2012. Developing and implementing ore-specific targets for the Rosebery Concentrator, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 321-324 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Kristiansen J

A series of laboratory blasting and ball mill grinding tests have been done on four different types of hard and competent rocks. The results show that exposing these rock types to a higher level of explosive energy will enhance their grindability. True blasting optimisation should therefore look at the whole comminution process from solid rock to a marketable product.

Jan 1, 1995

By E L. Kotova

Completeness of extraction of a mineral from ore depends on many reasons. First of all it is a function of quality of disintegration of ore. It is supposed that two basic factors: character of structure and texture of the ore aggregate and a disintegration technique influence the quality of the mineral aggregate destruction, æopeningÆ of its internal boundaries. In this paper, the problem of technological mineralogy from the point of view of genesis of the mineral aggregate, its typomorphical features and methods of their quantitative description are discussed. The purpose of this research is to provide information for technologists. It should enable the development of a rational flexible scheme of disintegration of ore with full extraction of a useful component, without its losses and without unnecessary expenses of energy. For achievement of this purpose the mineralogical information should have ½number and a measure+. By the authors, the technique of the quantitative analysis of fabric of the mineral aggregate based on several models û thermodynamic, crystallographic and geometrical is offered and discussed. The leading role in the quantitative analysis of a fabric of ore belongs to internal bounders. But internal bounders of the mineral aggregate by bounders or faces of the mineral individuals or mineral grains are formed. Their geometry, orientation concerning own (mineral grain) crystallographic lattices, orientation and distribution in space of the ore aggregate are proportional to the energy accumulated at origin and the further growth. These characteristics of mineral individuals are consequences of conditions of their formation. That is why the named triad of models is used. From crystallography it is known that faces of different stability and mobility form borders of crystals. They also contain different quantity of energy. Mineral grains also are faceted by different energy borders. They form intergrowths with each other according to a principle of balance or unbalance. That is why in addition to traditional parameters of the description of a fabric of the mineral aggregate (mode and grainmetrical composition) it is necessary to add new. For example, length and the square of intergrowthing bounders of mineral individuals differentiated (in couples), crystallographic symbols of borders, their roughness and so forth. Consequently, solving a problem of the geometrical characteristic of borders, we define also its power characteristic. In this paper experience of application of our technology in studying ores of one of deposits of Urals Mountains is presented. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices, which are carrying out the analysis in a semi-automatic mode, are possessed. Structure and texture of rock or ore aggregate reflect its formation and transformation conditions. It is important to understand that disintegration energy cannot be more than aggregation energy, the energy of intergrowths formation. The square and orientation of mineral individuals borders vary at pressures or stresses of mineral aggregate evolution. These phenomena often cause selective increase in the square of borders at constant average grain size, ie the granulation. Granulation presents the increase in quantity of mineral individuals while their modal share remains constant. At the same time their average mineral grains size. Some mineral individuals increase in size at increased pressure. When lithostatic or lateral pressure drops the majority of mineral grains increases in volume at the cost of intersticial or film solutions or fine grains. These are only special examples of the ontogenesis of the mineral aggregate. They illustrate our statement that all changes in fabric of the mineral aggregate are a reaction on varying external (ie geological) conditions. It is possible to consider that structurisation of totality of mineral individuals as a whole is a process of adaptation of the mineral aggregate, which forms and exists in varying force and energy fields. Differential and integrated geometry of total internal boundaries of the mineral aggregate serves as adaptation mechanism of the mineral grains system. Boundaries form intergrowths of the mineral aggregate. Thus, it is possible to consider that the most informative parameters of the stereometric analysis for restoration of the ontogenesis of the mineral aggregate are the following. First of all, it is a quantitative estimation of the volumetric shape of the ore mineral in crystallographic coordinates, a total area of borders of all mineral grains in the aggregate, the specific square of their boundaries, the specific square of intergrowth boundaries of the ore mineral separately with grains of each minerals of the matrix of the mineral aggregate as well as traditional grainsmetric and modal composition. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices that are carrying out the analysis in a semi-automatic mode are possessed.

Jan 1, 2008

The process of evaluating orebodies at the feasibility study stage is extremely important. In recent times many groups have indicated that they would like ore reserve estimation to be numeric and objective. Whilst sampling, geological, mining and mathematical principles may be used to analyse the data, all ore reserve methods require the use of experience factors and as such are value j ddgment statements.

Jan 1, 1990

By A S. Kurilko

For mines located in the cryolitic zone, thermal conditions are an important factor for all kinds of mining works, especially for ventilation of workings. In the present paper, some models of mine air heat transfer considering air distribution in a net of mine workings are developed. A combined solution is suggested for heat transfer and air distribution problems in mine workings and other underground structures located in the cryolitic zone. A software package is also presented for calculating temperature conditions in an underground refrigeration plant and for optimisation of ventilation conditions. This software uses a special 3D mathematical model to describe heat transfer in a freezing chamber between surrounding rock massif and stored product as well as between atmospheric air and the daylight surface of rock massif. A problem requiring strengthening of a backfill material and its thermal interaction with surrounding rocks during underground deposit mining by horizontal layers in conditions of the cryolitic zone is also discussed. The developed program takes into account cement consumption, geometrical dimensions of workings filled and a sequence of deposit mining.

Jan 1, 2005

A relationship is predicted between oxidic nickel in slag, oxygen in matte and Ni/Fe ratio in matte after the examination of thirty sets of contiguous matte and slag samples taken from industrial nickel smelters. Oxidic nickel in slag is found to increase with increase in oxygen content of matte of constant Ni/Fe ratio, and it is proposed that the relationship may be used to predict nickel solubility in slag from a knowledge of matte composition alone.

Jan 1, 1979

By B Poborowski, A Chen

"For some time, the Australian and Chinese underground coal mining industries have evolvedindependently with minimal infl uence on each other. Despite the fact that in recent years severaltechnologies and solutions have become common to both industries, this trend has seeminglycontinued to the point that there are still many important diff erences in legislation and hazardmanagement systems in both countries. Austar Coal Mine as an Australian based and Chineseowned enterprise has a unique opportunity to benefi t from the technology and knowledge ofboth nations. This paper compares the Australian and Chinese approach towards spontaneouscombustion hazard management in order to exchange experience, identify possible improvements and learn from each other."

Jun 1, 2012

By Y Wei, P Soole

This paper gives a brief description of VirtuoBlast technology ù a new, automated and highly interactive stereo vision technology which has been developed in CSIRO Exploration and Mining. VirtuoBlast technology is an integration of three advanced technologies - close-range digital terrestrial photogrammetry, oblique stereo imaging or high-speed stereo imaging, and temporal-spatial image matching technique. VirtuoBlast has been developed for the automated 3D measurement of blasting through rapid collection, processing, analysis and visualisation of 3D data related to blasting. A major field trial has been undertaken in August 1998 at the KCGM super pit. The field trial involved three applications of the technology, namely, pre-blast 3D surface mapping; post-blast 3D performance measurement; and temporal-spatial modelling of dynamic blasting process. This paper presents some results from this trial with emphasis on the application of VirtuoBlast technology to pre-blast 3D surface mapping and post-blast 3D performance measurement. Application to the temporal-spatial 3D modelling of dynamic blasting process will be presented in a separate paper. Pre- and post-blast surface models derived using both VirtuoBlast technology and conventional field survey method are presented. The differences in results using the two mapping methods clearly show that the digital photogrammetric technique has many advantages over conventional survey methods. Results of pre- and post-blast from the field trial have demonstrated the potential of VirtuoBlast technology to efficiently perform pre-blast 3D surface mapping and post-blast 3D performance measurement of production blasts. Demonstrated applications of VirtuoBlast technology to automated 3D measurement of blasting are showing an exciting future in advancing blasting science and modern blast design. The basic technologies are in place, however, continued improvements to the functionality, robustness and outputs are needed. The challenge is to build on the current state-of-the-art, by developing techniques and hardware which can be easily transferred to and implemented by the mining community. Current and future research and development will see improvements in imaging systems, automatic image processing and 3D data analysis.

Jan 1, 1999