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By Subrahmanyam T. V, Rao V. D

GOLD, the most important and highly coveted valuable metal, is being sought and exploited in almost all the geological environ- ments by the developed, developing and underdeveloped coun- tries of the world. Brazil, one of the five largest countries of the world, has similar geological and lithological environments as of Africa, Australia and Canada and also produces this noble metal. With the recent gold rush in Serra Pelada Hill in Para State of Brazil and the consequent migration of a large number of enter- prises to the Amazon region in search of geological conditions similar to that of Serra Pelada, the status of Brazil in gold produc- tion has been considerably elevated to be among the first five of the world. The principal geological environments or the lithologies where gold can be explored are the greenstone belts, banded iron for- mations, quartz lodes and placers; and the tectonic controls like shear zones in these horizons, or the tectonic relics or the annular- structures that limit the quartz vein systems in felsic as well as volcanogenic systems and epithermal models. The greenstone, BIF associations are present in all the Archean-Proterozoic ter- rains in Central and Northern Brazil. The quartz boudins in Al rich schistose rocks and the weathered and chemically enriched

Jan 1, 1988

Orebodies in the Mt. Charlotte-Hannan's North area N. and E. of the town of Kalgoorlie provide a marked contrast to the pyritetelluride lodes of the Golden Mile, although both groups of orebodies appear to be fundamentally related.These highly siliceous telluride-free orebodies N. of the Golden Mile are closely related to strong oblique faulting. The Golden Mile lodes, while possessing an apparent overall relationship to the oblique faults also have a close relationship to E. dipping strike faults.INTRODUCTIONThe Mt. Charlotte-Hannan's North area lies N. and E. of the town of Kalgoorlie and is separated from the Golden Mile by the Golden Pike fault. The orebodies discussed lie in an area approximately 3 miles long by 1 mile wide (Fig. 1).The area includes the site of the original discovery of gold in the Kalgoorlie district in 1893. There have been numerous mining operations over the years, the bulk of the production coming from two orebodies, Mt. Charlotte and Hannan's North. These have provided approximately 900,000 tons of the 1,100,000 tons of ore mined in the area.Production to date from the principal orebodies in the area has been as follows.1. Hannan's North orebody, 582,000 tons of ore for 275,000 oz of gold2. Mt. Charlotte orebody, approximately 230,000 tons for 75,000 oz3. Pharlap and Golden Goose orebodies, each orebody approximately 8,000 tons for 2,700 oz4. Maritana Hill orebodies, approximately 170,000 tons for 70,000 oz...

Jan 1, 1965

By A Deakin

It has been almost a decade since the release of the International Council of Mining and Metals (ICMM) Health and Safety Critical Control Management: Good Practice Guide (2015a). During this time the ICMM member companies, along with many others across industry, have been busy designing, deploying and enhancing their own critical control management (CCM) programs. So, what have we learnt? This paper discusses the scope, application and learnings from the implementation of CCM within the mining industry. What’s going well? What are the common challenges? What are the opportunities to strengthen the approach? What are the threats to successful implementation? The paper draws on the author’s experience as one of the key contributors to the development of the CCM Good Practice Guide and an adviser to many mining companies, including six of the ICMM members. The paper focuses on the practical (operational) application of CCM and the cycle of identifying, defining, implementing, verifying and improving critical controls at the frontline. The paper also includes a discussion on the safety performance of the ICMM member companies over the past decade and provides a recommendation for how CCM can be incorporated into a more proactive model to measure safety performance. The paper concludes with practical recommendations that mining companies, regardless of their CCM maturity, can consider as they look ahead. They are supplemented by three additional recommendations for consideration at the industry level.

Apr 16, 2024

By M Taylor

The Project Specification and Technical Requirements documents associated with several recent large road tunnel projects within Australia have specified the application of AS/IEC 61508 – FunctionalSafety of Electrical/Electronic/Programmable Electronic Safety Related Systems at very high performance levels for the various control and fire life safety systems associated with such facilities.This paper seeks to explore the implications of referencing this standard within the road tunnel services context in terms of practicality, complexity and cost, whilst providing some examples of how a high safety integrity level (SIL) level can theoretically be achieved given current hardware availability.

Mar 8, 2011

By M Ogle

"Booster fans are relatively rare in Australian coal mines. However, as mines become progressivelydeeper it is likely that such fans will be increasingly adopted as a method to sustain or improve the ventilation of underground workings. The reasons why booster fans may be an att ractive alternative include: increased cost of sinking additional ventilation shafts with greater seam depths; environmental objections to shaft sinking projects; and increasing urbanisation and surface constraints limiting availability of potential ventilation shaft sites. As Tahmoor Colliery movedinto its northern lease the ventilation constraints became the limiting factor on production. Thelimitations of the old workings meant that the existing ventilation system would be inadequateto sustain the required production. Extensive ventilation modelling was carried out to evaluatevarious potential solutions and the recommended option was the installation of a booster fanor fans, to gain underground access to an already approved shaft site in the northern lease.Proposals were sought from recognised fan manufacturers and various alternative arrangements were tendered. Ultimately the choice was between one large centrifugal fan and a set (three or four) of smaller æauxiliary-likeÆ fans in parallel. The successful tender was for a single centrifugal, an arrangement very similar to the booster fans that have been operating eff ectively at Westcliff Colliery for a number of years. This paper describes the current ventilation network, evaluation of the ventilation options, the fan selection process, and the project status to date."

Jun 1, 2012

By S Sullivan

A recent review of resource reports lodged to statutory bodies found geological models with oversmoothed or unrealistic lithological boundaries, many of which do not represent geological appearance in the field, pit or underground drive. The underlying data is often too complex or messy to be incorporated into the resource model and is thus a simplification of reality, to the detriment of the mining operation and its shareholders. Volumes can be over- or underestimated and subsequent grade predictions can be misplaced, combining to cause over- or understatement in resource reporting to stakeholders and statutory authorities. Domain models can be improved with new modelling techniques such as machine learning. However, with poor data or improper use of machine learning techniques, the conclusions can be just as misleading as with current techniques. Machine learning rarely offers a single ‘right’ outcome, rather a range of possible outcomes from the data provided. But importantly it can take advantage of the full richness of data for more informed models. Machine learning also provides confidence in its predictions so that uncertainty in the resultant models can be quantified and passed through for risk assessment during mine planning and operation. This paper will discuss the factors accentuating complexity in deposit modelling: data diversity, structural controls, chemistry, data volumes, process workflows and external non-geological constraints. A case study illustrates the risk of reducing or ignoring complexity, which can result in an overly simplified geological model.

Mar 22, 2022

The purpose of this paper is to list by tabulation and flow sheet, the operating equipment and installations in use at Rosebery, and to refer to particular items which may be of interest for purposes of comparison, or because they possess some unusual feature. The general perspective has been taken from the viewpoint of operating and maintenance experience.The sequence begins with ore breaking and transport and proceeds through milling operations. The paper is in two sections, first, mechanical equipment, second, electrical equipment. A brief outline of a scheme for using gravel wash for stope filling, which is in course of installation, has also been given.

Jan 1, 1949

By Denholm W. T, Rankin W. J

The reduction of zinc from lead blast furnace slags using hydrogen was studied at 1300¦C as part of a laboratory investigation of zinc fuming. To perform the experiments, 300 g "spent slag" was melted in a crucible. Hydrogen was then injected into the slag through a lance and fresh blast furnace slag was added regularly in small quantities over a period of 40 minutes. Zinc added in the fresh slag was reduced and the zinc level of the bulk slag attained a steady state value of between 1 and 9% after about 10 minutes, depending on the gas injection rate. Because of the high reactivity of hydrogen, bulk supply of hydrogen to the slag was the rate limiting step at the flow rates used and it is believed that the gas-slag reactions in the system were at equilibrium. A partially/stabilized zirconia cell with a Ni/NiO reference electrode was immersed in the slags during the experiments and the steady/state oxygen potentials of the slags were measured. By using the experimental oxygen potential values and calculated values of the steady state concentrations of zinc in the offgas, the activity of ZnO in the slags was calculated from the Gibbs's free energy change for the reaction:

Jan 1, 1989

By D Bruggemann, F Sereshki

There has been an ongoing research on coal and gas outburst for the past two decades at the School of Civil, Mining and Environmental Engineering, University of Wollongong. Research study began with a humble beginning, initially conducting basic laboratory studies on the coal and gas properties, progressing into the determination of gas content of coal by sorption technique and the effect of gas pressures on coal strength. The present laboratory facilities and research interests are extended to include the study of coal permeability and shrinkage properties and their effect of gas drainage characteristics with respect to gas type, and pressures. All the changes are examined with respect to changing in-site geological conditions of the coal deposit investigated. The aim is to provide a long-term support to industry in establishing a data bank for Australian coal deposit characteristics and properties.

Jan 1, 2005

By C Linklater, A Garvie, D Kentwell

Various Australian and international regulatory bodies (Environmental Protection Authority, 2015) require an early assessment of the geochemistry of waste rock. This usually includes estimates of the locations and volumes of potentially acid forming (PAF) materials and requires sampling of the waste rock zones as well as submitting the samples for a series of tests. We know that the required number of samples will vary depending on rock type, mean sulfur levels and spatial variability of sulfur as well as total volume. The key question is how do we know when we have enough samples?This extended abstract describes the application of geostatistical methods to examine how sample numbers and sample locations influence the preliminary conclusions that may be drawn for early stage waste characterisation.CITATION:Kentwell, D, Garvie, A and Linklater, C, 2016. Geostatistics and sample numbers from an acid and metalliferous drainage perspective, in Proceedings Life-of-Mine 2016 Conference , pp 12–15 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By C A. Fleming, C J. Ferron, P T. OÆ

A new process is described which allows for direct recovery of base and precious metals (Au and PGMÆs) from sulphide concentrates or other feedstocks. The process was developed initially for application to ores or concentrates that are too low-grade for economic treatment by the conventional smelting and matte leaching process (for PGMÆs). It is now believed that the process may be widely applicable to a variety of materials including PGM concentrates containing high amounts of chromium or magnesium. Operating conditions have been identified under which gold, the PGMÆs and the base metals dissolve simultaneously in a pressure leaching autoclave. The product of this leaching process can then be treated by one of several flowsheets, of which the preferred will likely involve solid/liquid separation, followed by precipitation (or adsorption on activated carbon) of gold and the PGMÆs, followed by copper solvent extraction/electrowinning. Depending on the concentrations of nickel and cobalt, the copper raffinate would either be partially recycled to the autoclave to allow Ni/Co concentrations to build up, or it would proceed directly to a Ni/Co refinery. This paper deals with the pressure leaching process and the recovery of gold and the PGMÆs from the pressure leach product.

Jan 1, 2000

By A D. Campbell, G R. Power

The increasing availability of marker data in sublevel caving operations is changing the way draw can be managed to achieve positive recovery outcomes in these mines. This paper describes how marker data has been incorporated into flow simulations to help calibrate full mine ore recovery simulations for the forecasting and optimisation of recovery.Some flow modelling techniques do not use marker data, relying instead on the outcomes of physical and numerical experiments to guide assumptions about an idealised recovery flow shape. Other mines have access to marker trial data, but find it difficult to specifically link this marker trial information to their recovery models. This can make it difficult to create a link between the marker trial information and recovery forecasting and limits the potential value of the marker trials at the mine.In the simulations shown here, the marker rings are fully incorporated into the flow model, and can be tracked in the model. The model is compared against the real underground marker recovery information to give the user an indication of how accurately the flow settings in the model are reflecting the conditions in the experimental marker rings. An example of use of this system at an operational mine is included.CITATION:Power, G R and Campbell, A D, 2016. Modelling of real-time marker data to improve operational recovery in sublevel caving mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By D Nieuwkerk, V J. Absolon

"Screw press technology is an innovative approach to tackling the growing pressure to conserve water and minimise the environmental impact of mineral tailings disposal. The principles of the technology have been known for a considerable period of time in non-mining applications such as water treatment, wastewater (municipal sludge), as well as in the paper and chemical industries for dewatering solids, particularly those containing clays.The screw press represents a viable niche technology for filtering fine and high-clay tailings, without the prior thickening stage, and is capable of producing a filtered product that is sufficiently consolidated and dry enough to provide a product suitable for conveying and dry stacking.The Ishigaki screw press was introduced in 1990 and key features are: continuous operation and excellent availability low wear to plant acceptable flocculant consumption low carbon footprint and low noise levels fully automatic.These features lead to simpler plant layouts, easier maintenance, smaller spares inventories, reduced wear, smaller footprint and overall lower capital and operating costs.The amenability of a particular tailing stream to treatment by screw press technology may be determined by test work. Two pilot plant studies are described where this technology has been applied in the mineral industry being flotation tailings from a rare earth (RE) mineral concentrator and coal tailings. In addition, preliminary details are given of an ACARP sponsored research program titled ‘The application of screw press filtration in tailings dewatering’.CITATION:Absolon, V J and Nieuwkerk, D, 2014. Innovative use of screw press filtration in tailings dewatering plant design, in Proceedings 12th AusIMM Mill Operators’ Conference 2014, pp 449–456 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 1, 2014

By R Halatchev

Production scheduling optimisation in open pit gold mining is a complex problem as it is driven by economic criteria reflecting particular economic interests of the concerned parties in the mining business. The contemporary organisational forms of mining, such as owner-operator and contract mining, are a good example of this relationship. These forms are complex and contradictory by nature as the contractor aims to get more waste at the beginning of mine exploitation in order to make more profit with favourable discounting effect over time, while the owner-operator aims to mine less waste at the beginning, which is a precondition for implementation of the mine planning principle of waste deferment and maximising the net present value (NPV) by accounting for the time value of money. Both forms are vital for the successful performance of the Australian mining industry as their competition is a powerful driving force of the market-oriented national economy.The present paper offers a new vision about the economic effectiveness of contract and owner-operator forms in surface gold mining through the prism of a novel production scheduling approach with a multistage stabilisation of the mining rate that implements the mine-to-market concept of modelling. The comparison of the forms is demonstrated with a case study that reveals the specific features of the new scheduling approach and the benefits of its implementation in the exploitation of Australian gold resources.CITATION:Halatchev, R, 2013. Owner-operator versus contractor production scheduling - a vision for the effective exploitation of Australian gold resources by surface mining, in Proceedings World Gold 2013 , pp 255-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By R Shaw, R Williamson

Global iron ore demand, sparked by ChinaÆs rapid industrialisation and emergence as the worldÆs newest steel market, has seen iron ore groups investing heavily in production capacity as well as infrastructure. The success of these new projects depends heavily on reliability, competitiveness and quality control in an increasingly demanding trading environment. Furthermore, the iron ore industry continues to improve its competitiveness in mining practices, technology innovation and management processes. The continued fine tuning of these sectors will be critical to the success of the industry in the years ahead, and this mining sector will continue to demand process improvements from their service suppliers to maintain competitiveness. Automation offers a real solution to these demands. A crucial quality control element in mining, beneficiation, stockpiling and shipping stages is ensuring representative samples of ore are taken along each step of the process. When these samples reach the laboratory it is imperative that the sample is representative of the entire stream and that no induced errors occur. Examples of automation start with mechanical primary and secondary samplers in the run-of-mine processes through to sample tower and laboratory crushers, dividers and collectors. Automation is widely used in many forms to provide reliable and repeatable samples for analysis whilst providing a safer working environment. Laboratory automation systems in use today vary from simple linear systems to sophisticated robotic cells. Sample automation in the iron ore industry has resulted in many benefits for both producers and their customers. The most significant benefits have come in the form of higher safety standards whilst reducing sample error, sample handling and sample contamination during collection. These benefits have been further augmented by reliability and repeatability of automating the final sample preparation and analysis stage. Today these benefits are reflected in reduced costs of sampling and improvement in both turnaround time and quality of results, whilst complying with Australian safety and ISO sampling standards.

Jan 1, 2007

Botanical exploration has identified many plant species that naturally accumulate very high concentrations of elements, particularly heavy metals. The enormous potential applications of some of these species to remove metals from soil (phytoextraction) are slowly being realised. The discovery of hyperaccumulation has resulted in considerable research into applications for removing contaminants (phytoremediation) or more importantly, in the context of this discussion, for commercially æfarmingÆ metals (phytomining) from metal-bearing soils. Currently published phytoextraction models estimate Ni yields using Berkheya coddii (a South African nickelophyte) are approximately $US 750 ha-1, excluding the cost of processing. Research indicates that B. coddii will also accumulate significant amounts of Co, resulting in a considerable increase in the value of the crop. Modification of the substrate by acidification, fertilisation and/or chelation indicate fruitful avenues for improving this yield by increasing the extractability of the target element, elevating biomass production rates and/or rendering other contained heavy metals extractable. Plant uptake of more insoluble elements, such as Au, may be induced in many plant species using chemical compounds. These chelates applied to the soil, form soluble complexes with poorly soluble metals forcing them into the soil solution. Plants may then accumulate these metal complexes through transpiration. Research has achieved foliar Au concentrations of 78 mg kg-1 in Iberis intermedia, 56 mg kg-1 in Brassica juncea and 9 mg kg-1 in B. coddii (on a dry weight basis). Therefore in theory B. coddii could phytomine a soil containing modest concentrations of Ni, Co and Au to yield 116 kg Ni, 36 kg Co and over 6 oz Au ha-1 at a current value of $US 4000. Root crops have also shown promise in chelate assisted Au accumulation (eg 6.8 mg kg-1 in Beta vulgaris and 118.5 mg kg-1 in Raphanus sativus). Phytoextraction, in its varied applications, is rapidly coming of age as a technology having considerable potential for application in environmental science and the minerals industry. Phytotechnology employs unique plant biochemical behaviours in the rhizosphere, driven by the sunÆs energy, to seek out and concentrate low levels of heavy metals at very low cost.

Jan 1, 2002

By M Russ, J Gediga

This paper shows an economic feasible approach to implement greenhouse gas (GHG) reduction measures into the mining and metallurgy industry (MMI). The goal to improve energy consumption is directly linked to the reduction of GHG emissions in the MMI. A baseline scenario of the considered reference system and of the respective reference year has to be designed and analysed. In a second step an analysis of the same operation using the best available technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified gaps will be reported and the potential GHG emission reductions will be put into relation to the investment, running cost and generated carbon credits of the new process technologies to be implemented. This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap decision-making for implementing new technology into the companyÆs business operations. The GHG reduction roadmap is developed using the marginal abatement curve approach.

Jan 1, 2009

By A E. Levett, J Durbin

The environmental, social and governance (ESG) obligations of mining companies promote the consideration of water and land resources as well as the post-mining employment opportunities following the cessation of mining operations. This work aims to outline the potential for a mining operation to use their brackish mine water resources to support microalgae production, generating high-quality organic carbon sources to support their mine rehabilitation and closure outcomes. Microalgae production is an established commercial process for high-value products including vitamins, cosmetics and food supplements. On mine sites, microalgae production offers several major environmental and social opportunities: (i) carbon capture, (ii) metalliferous water treatment, (iii) acid mine drainage prevention, (iv) beneficial reuse of brackish mine water, (v) accelerated soil formation and (vi) post-mining employment (Levett et al, 2023).

Aug 2, 2023

By Honey F. R, Furnell R. G, Lyon R. J P

A Joint Venture between Union Oil Development Corporation and Geoscan Proprietary Limited carried out an Airborne Multispectral Scanner Survey over approximately 15,000 square kilometres in the Charters towers area of northeastern Queensland during late 1985 and in September, 1986. The survey, using the Geoscan Mark I scanner, consisted of 50 runs each having a swath width of 5 kilometres. Twelve or thirteen spectral bands were recorded, 5 in the VNIR, 4 in the SWIR and 3 or 4 in the TIR. The results of the survey were interpreted by interactive image processing with the aim of identifying those minerals or their weathering products which are characteristically associated with hydrothermally emplaced gold mineralisation in this part of Queensland. Spectral bands in the VNIR were used to identify and discriminate the iron hydroxides, whilst the SWIR bands were used to outline the clay and carbonate rich areas. The TIR aided in identifying areas of silicification.

Jan 1, 1989

By N Belluz, L Johnson, N Wiwoho, P Manning

The Kucing Liar skarn deposit is located in the Ertsberg mining district, which also contains other skarn deposits and the Grasberg porphyry copper û gold deposit. The Ertsberg district is located in the province of Irian Jaya, IndonesiaÆs easternmost province. Mining development began in the Ertsberg district in 1972 with the mining of the Ertsberg deposit. Daily production in the district now averages about 230 000 tonnes of ore, with the bulk of the ore coming from the Grasberg open pit and the balance from underground mining of skarn deposits. During 1998, 45 218 additional metres of drilling were conducted to delineate and understand the Kucing Liar orebody. The deposit was first intersected in drill holes in 1994 and then was intersected in underground workings located about 1000 metres from the discovery drill hole in 1995. Initially, the two intersections were thought to be different orebodies but are now realised to be different parts of the same orebody. The Kucing Liar deposit consists of magnetite û copper û gold replacement and skarn mineralisation in favorable Tertiary and Cretaceous units. The deposit is approximately 2000 metres in length and averages about 200 to 250 metres in thickness. The width varies from 400 to 600 metres. Drilling in 1998 was directed towards delineating the deposit on its NW and SE ends and to determine its down dip extension. Reserves for the deposit at the end of 1998 stand at 320 million tonnes at 1.4 per cent copper, 1.4 g/t gold, and 5.3 g/t silver. Many important questions remain to be answered concerning the relationship of the Kucing Liar orebody to the major faults in the district and to the Grasberg intrusive complex which contains the Grasberg orebody. Continued exciting developments are anticipated as work to understand the deposit by drilling and geologic study continues.

Jan 1, 1999