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The Kundana underground narrow vein gold mine had a recent history of large and damaging seismic events. Following a period of seismic events on 30 July 2001, in which nine miners were temporarily entrapped at depth due to falls of ground in several parts of the decline, the mine operation was required to develop a seismic management system to mitigate seismic risk to the operation. A micro seismic systems and boundary element modelling of mine sequence highlighted large-scale footwall faults and the mining of gold bearing shear veins to be focal structures for seismic energy release between depths of 300 m to the base of mining at 650 m. The integration of seismic data, identification of geological structures and mapping of zones of failed rockmass led to the successful generation of a non linear boundary element model and a seismic hazard strategy. This enabled mine sequences to be assessed daily, monthly and periodically for potential seismic hazards and therefore assigned both economic and personnel risks for the recovery of the ore reserve at the Kundana Underground Operation.

Jan 1, 2005

By Sillet R, Corin P. J, Wilson G

Zinc Corporation of Broken Hi11 had some long hole stopes coming into use which could not be mined using diesel loaders, because of ventilation restrictions. In preference to use of pneumatic loaders, and because there were no field proven electric loaders in Australia, Horwood Bagshaw Ltd., were commissioned to repower a diesel loader with an electric motor, within the confines of the existing machine

Jan 1, 1977

By M B. McKevitt, W J. Shaw

The main task of grade control on a daily basis is to define the material that should be mined to a destination under various categories. This can be determined by grade, lithology, quality and blending criteria. In the case of multi-element deposits or deposits with various blending or other processing criteria the optimum selection of ore block boundaries can be quite complex. In every case the balance between ore loss and dilution must be considered when designing the ore block boundaries and this becomes a risk-based decision when using the conditional simulation model. The use of such systems allows grade control to meet specific targets, such as budget tonnages and grades and blended product specifications. Two case studies are presented: the Prominent Hill copper/gold mine and the Rapu Rapu zinc/copper mine. Mining is based on a rational grade control strategy involving a number of factors, including strong geological control, advanced geostatistical approaches, such as conditional simulation, and optimisation of the ore blocking to meet production requirements. This provides an objective, transparent and repeatable grade control strategy.

Jan 1, 2009

In Australia 'there are hidden deposits of gold, copper, tin, lead and zinc which can be found by drilling at reasonable expense in view of the imp9rtance of the objectives. Exploration of the prospects in mind would mean about a million feet of drilling. The purpose of this paper is to outline, in a technical way, some of the geological thinking that has been given to this matter. To do this, it is necessary to unify the wider ranging thoughts into some sort of coherent perspective and also into some sort of logical sequence. This will be done by treating first the geological subject material which is in fact, at the foundation of the exploratory scheme. With this base, the argument will be continued through a sequence of prospect thinking and brought to a conclusion in regard to the practical employment of geology in the drilling planning. In this knitting together of ideas, the discussion will be given substance by welding into the argument the reasoning that has been applied to the Cobar prospect. The New Occidental Gold-Mines are operating three mines at Cobar, and the writer is indebted to the Company for allowing the reference to be made. It is intended, as opportunity permits, to furnish further examples in later publications.FOUNDATION OF EXPLORATIONThe deposits under consideration are derived from igneous rocks, chiefly granite or porphyry. In and following the emplacement of the intrusives, the rocks have been...

Jan 1, 1946

By Henderson J

Iron ore samples selected from the Deepdale, Iron Prince and Mt. Newman ore bodies have been pelletised on a pilot scale plant and subsequently reduced under laboratory conditions by hydrogen or carbon monoxide. Pellets approximately 1 cm in diameter have been reduced by hydrogen over the temperature range 5000- 900¦C and the results examined by thermogravimetric, microscopic, electron probe and x-ray techniques. After an initial time delay it was found that up to 95% reduction the rate of reduction could be described by a transport con- trolled porous model, in which the effective diffusivities of hydrogen in theòpr¦duct layer and the reaction zone are filar. Independent measurements of effective diffusivity supported the values obtained from the reduction data. ve 95% reduction the rate decreased markedly due to the formation_of retained wustite or fayalite. Comparison with reduction by carbon monoxide over the temperature range 7500 - 900¦C showed that the rate eduction by carbon monoxide was approximately five times slower than the rate by hydrogen. The rate of reduction was found to be a function of the properties of the pellets, which may account for the ely conflicting results that have been obtained in previous investigation on porous pellets.

Jan 1, 1970

By A Williamson

The New South Wales Department of Mineral Resources objective is to use data and information to undertake a detailed analysis of incidents and accidents to identify risks so that the predictable can be foreseen and avoided. The Department of Mineral Resources has established a computerised database called COMET (COmmon Mines EnvironmenT) to capture information on accidents incidents, inspections, audits and accreditation in improving safety and environment performance. This data together with data from Coal Mines Insurance and WorkCover NSW is being used to provide trend and comparison information. The NSW Injury Risk Management Research Centre at the University of NSW has been engaged by the Department to collate and prepare a detailed analysis of the data. Through this process, five areas have been identified for further research. These being: electrical energy, mechanical equipment, work environment, hours of work, and contractors involvement accident and incidents. The paper covers: the establishment of a mix of performance measures for the industry to indicate whether the safety performance is improving; the provision of data to provide useful comparisons and benchmarks against which companies can compare performance; the development of positive performance measures; the findings and outcomes of the detailed analysis of electrical energy; shocks; the provision of information to industry; an outline how the data is being used to determine departmental; operational priorities; and future plans to undertake research into the other areas identified.

Jan 1, 2003

In the face of intense global competition and other business pressures on coal miners, ongoing quality initiatives and continuous process improvements are needed to enhance business performance. By viewing a minesite in terms of key processes, rather then departments, and employing innovative technologies and better applying organisational resources, there exists enormous potential to achieve reductions in process cost and time.

Jan 1, 1998

This paper has been prepared to challenge the thinking of new leaders entering the mining industry in two areas. First, what is the worldÆs perception of mining and what does this mean to those entering the industry? Second, what is the future of learning in the mining industry and how can the industry attract and retain the best people?Then in closing, how can mining companies turn these challenges into opportunities and specifically how is BHP Billiton meeting these challenges.

Jan 1, 2004

By J J. Frausto, G R. Ballantyne, M S. Powell, R Cruz, K Runge

Hydrocyclones are the most widely used device for classification in a grinding circuit. However, even the most efficient hydrocyclone has a bypass of fines from the feed to the underflow which reduces comminution circuit performance, as well as misclassification around the cut point. Fine screens classify only according to the particle size, allowing for a reduction in the recirculation of fines back to the mill. The development of high capacity multi-screens makes fine classification in a grinding circuit a viable option. Minera Saucito recently substituted hydrocyclones with screens in its grinding circuit. The change of classifier resulted in an increase in throughput and lead recovery but a decrease in silver recovery. This case study presents the changes in comminution and flotation performance that occurred after the installation of screens and uses historical operational data collected over 12 months of operation to investigate the reasons for these observed changes. CITATION:Frausto, J J, Ballantyne, G R, Runge, K, Powell, M S and Cruz, R, 2017., in Proceedings MetPlant 2017, pp 298–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

XstrataÆs Mount Isa Copper Operations (MICO) is a world-class mining operation producing in excess of six million tonnes of copper ore per annum from its underground mining operations. The Mount Isa Copper Mines have been producing from the underground operations since 1952. Current copper reserves are 87 million tonnes at 2.8 per cent Cu, extending the mineÆs life beyond 2018. The underground orebodies in the copper mines are divided into nine distinct areas and are mined by sublevel open stoping techniques. One of the nine areas is the hanging wall lens, which consists of two sections; a northern lens (NHWL) and a southern lens (SHWL). The SHWL has a proven reserve of 2.2 million tonnes with an average grade of 2.9 per cent copper. Stopes in the SHWL have an average size of approximately 245 000 tonnes and will be extracted in a primary-secondary mining sequence, producing ore until 2009. This paper discusses various aspects of stope design applied in the southern hanging wall lens, including sequencing options and the rationale for the selected sequence. Design features are also discussed and how they have evolved as more is learnt about the SHWL orebody. These include mass firing techniques, focusing on minimising ground vibrations, using seed wave form analysis and prediction. Rock mechanics issues will also be discussed, in particular the reinforcement of stope hanging walls and the use of instrumentation to monitor behaviour within the hanging wall.

Jan 1, 2006

The coal under the ridgeline is the most valuable part of the known reserve at Solid EnergyÆs Stockton Opencast Mine. Some ridgeline mining had been attempted in the past with mixed results. Solid Energy recognised that significant project planning was required in order to overcome the formidable technical issues associated with mining the area. It also recognised that the local community also had concerns about the potential impacts of this work including the visual impact of changing the topography of the ridgeline and the nearness of the Department of Conservation estate.   This paper outlines some of the risks and challenges that were faced and the management approaches that were adopted to address them.

Jan 1, 2007

Polarization phenomena associated with the use of an agitated bed of particles as an electrode for metal deposition were studied. The concentration polarization at this type of electrode is much smaller than that occurring at a fixed or moving electrode surface. Agitated particle electrodes can be used to electro-reduce copper from solutions over a wide range of concentration and at cur·rent densities up to 2000 AIsq. ft. of bed cross section.

Jan 1, 1971

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

There was a time, in the memory of some here tonight, when the annual meeting of The Institute was a nostalgic occasion. Often, in the 1920s, there was comment on the decline of Australian mining and on the lack of new mineral discoveries. When some of our Presidents prayed then for a new Bendigo, and instead were given a Mount Isa, they were justifiably disappointed because of the vastly different capital requirements.In 1967 the mining picture is very different. The recent mining developments in Australia are certainly as important as several Bendigos and several Kalgoorlies. The mining industry in Australia has never been more dynamic than today (Table 1). And if we ask why it is so dynamic, the answer lies in the role which overseas capital is playing in the industry. The contribution of overseas capital should concern us not only because we are members of the mining and metallurgical profession, but also because we have a duty to make our profession contribute as much as possible to the well-being of Australians. It is not sufficient to argue that overseas capital is good for the mining industry; we must also examine whether it is good for the economy and the nation. In this context the current criticism of the inflow of overseas capital into Australian mining is useful, for it gives us an opportunity to see what has resulted from the inflow.In discussing this question I do not suggest that we emulate Captain Hancock, that legendary Moonta mine manager who, according to Oswald Pryor's cartoon, used to say to his miners: "When I say a thing is, it is, even if it isn't". The question can only be discussed on a factual basis; and I would submit that many of the important facts relating to overseas capital in our mining industry are often overlooked or ignored. I would further submit, on the basis of these facts, that Australia's present day mining industry has been largely built on overseas capital and that the overall benefits of that capital to Australia have been enormous.

Jan 1, 1967

Australis Mining N.L. operates a continuous mode carbon-in-pulp (CIP) gold plant, processing sand and slime tailings from previous gold mining operations in the Norseman area. Plant design is that of conventional countercurrent contact between pregnant pulp and activated carbon. Gold desorption is achieved by the Zadra process using near boiling tempera- tures and atmospheric pressure. Process water is drawn from nearby Lake Cowan (saline). The plant operates at, or above, design specification of 400 dry tonnes per day. This paper describes the plant design and operating processes utilised in optimising throughput and gold recovery. TNTDnPTTnmTnM Favourable world gold prices and substantial reserves of sand and slime tailings prompted Australis Mining N.L. to construct a gold extraction plant during 1981. The projected plant throughput was set so as to complete treatment of available tailings over a three year period. Metal- lurgical tests indicated that, with a regrind facility satisfactory gold recovery could be achieved using a countercurrent CIP process. Reflecting the entry of Australis Mining N.L. into its first large scale treatment operation, the plant design emphasised simplicity but effectiveness of Operation.

Jan 1, 1982

The interaction of flotation collectors with sulphide minerals takes place at the solid - solution interface. The electrochemistry of the processes which affect this interface are discussed. The interaction of xanthates with sulphides is an electrochemical process, xanthates being electro-oxidized to chemisorbed xanthate and dixanthogen. The role of oxygen is to provide a cathodic process to allow the anodic oxidation to occur. The hydrophobic condition of the mineral surface is brought about by the presence of the oxidized xanthate species. The action of reagents which can activate or depress the flotation of sulphides is discussed briefly.

Jan 1, 1980

By D Jones

The development, piloting and engineering design of an innovative water treatment system for process water produced by a uranium mine mill are described. The process incorporates lime/carbonate softening (Stage 1), reverse osmosis (Stage 2) and biopolishing (Stage 3) to produce water of quality suitable for release to the receiving environment. Comprehensive performance data are presented for each stage. The unique features of the proposed process are: recycle of the lime/CO2 softening sludge to the uranium mill as a neutralant; potential use of power station off-gas for carbonation; and the potential recovery and recycle of ammonia from the RO reject stream.

Jan 1, 2003

The comminution process indicates that the most energy-efficient comminution system would be one where the particles leave the breakage field as soon as they reach product size. Contrary to the free falling gravitational (vertical) flow in crushers, the grinding millÆs energy efficiency essentially depends on ore characteristics and the discharge rate of broken particles, which in turn depends on how efficiently the discharge pump (grate and pulp lifters) operates. The essential function of a pulp lifter is to transport the broken material and slurry from the discharge grate out of the mill. Hence, the design optimisation of pulp lifters affects not only the energy efficiency and throughput of autogenous grinding/semi-autogenous (AG/SAG) grinding mills, but also contributes other process benefits such as improved wear life and operator-friendly steady and smooth mill operation. Following its introduction in 2006, OutotecÆs patented Turbo Pulp Lifter (TPLÖ) design has been retrofitted at existing sites and also installed in some new ones around the world. This paper will provide operational experience and data on how the TPLÖ design has allowed AG and SAG mills to operate efficiently.

Jan 1, 2009

By Moorrees C

The end uses of magnesia are determined by both its chemical and its physical proper- ties. There is seen to be an increasing need for products of high chemical purity. Prod- ucts containing 90-95 per cent MgO can be routinely produced by physical beneficiation and calcination of most magnesite ores, the dominant source of magnesia. However, pro- duction of grades containing more than 98 per cent MgO with low impurity levels is not readily achieved physically. Such products can only be readily produced by chemical processing techniques. This presentation outlines the types of impurities present in magnesite deposits and the general concepts that are involved in chemically upgrading them. Of the potential leachants, only hydrochloric acid and aqueous carbon dioxide appear to be commercially attractive.

Jan 1, 1987

By Mishra S. N, Mishra R, Sen P. K

Control of silicon in produced through the submerged-arc furnace can result in reduced power and coke consumption in addition to improving the quality of the hot metal. A thermo-chemical analysis of the production of ferro-chromium was carried out to devise strategies to control the recovery of silicon during the manufacture of ferro-chromium. The presence of three thermochemical zones in the furnace with respect to the reduction of silica was recognised from this analysis. Any strategy for the control of silicon recovery has to take cognizance of these thermochemical zones. The effect of various strategies on the silicon level in the hot metal have been evaluated. Possible strategies, such as the reduction of coke level in the charge; the replacement of quartz; pre-reduction of the ore and the control of the temperature profile are discussed in this paper.

Jan 1, 1999