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By D E. Langberg, D R. Swinbourne

The past century has seen the development and commercialisation of many new pyrometallurgical processes based on gas injection. The driving force behind this trend in smelting and refining technology was the increased productivity and resulting increase in capital utilisation achievable. However, measurement of system variables is not easy and their effect on the rate of the reactions involved is not well characterised. One of the critical parameters is the gas-liquid interfacial area produced by gas injection. Related variables such as bubble size and velocity, and gas hold-up fractions in aqueous systems have been measured using combinations of physical (visual, audio and electrical) and chemical techniques. Models have been developed relating interfacial area to physical properties and operating variables and attempts made to extrapolate these to high temperature, liquid metal systems. The only attempts at validation of these models have used either low temperature liquid metals, such as mercury or WoodÆs Metal, or operating plant data. This paper reviews existing knowledge of the effects of system variables on total interfacial area in gas injection systems. Interfacial area is calculated from a range of published experimental aqueous and liquid metal systems and used to assess existing models. An operating region diagram was developed to assess dynamic similarity between experimental and industrial systems. It highlights areas where further research into both measurement techniques and experimental system variables is required in order to extend knowledge and guide further technical and design advances into the 21st century.

Jan 1, 2000

Launching the Queensland Water Plan 2005 - 2010 in August 2005, Premier Peter Beattie compared the stateÆs water resources with liquid gold. QueenslandÆs peak industry body for the minerals and energy sector, the Queensland Resources Council (QRC), believes the analogy is appropriate. During early development of an industry water strategy, it has become apparent that water is like liquid gold, in that it is revered, hoarded, recycled, priced on purity, a magnet for speculators, both difficult and expensive to transport effectively, heavily regulated and fundamentally linked to issues of security. To date it has generally been economic and relatively straightforward for the resources sector to secure water. Although production has not been compromised, this must not be grounds for complacency as there is every indication that water will continue to become increasingly expensive, more tightly regulated and, relative to a growing demand for a finite water supply, increasingly scarce. During 2006, QRC has developed and is implementing a voluntary industry water strategy to address a range of challenges confronting the resource sectorÆs security of access to water. As a consequence of, at times, protracted community consultations over QueenslandÆs catchment-based water planning processes it has become clear that many community stakeholders have outdated perceptions of the stateÆs resources sector. Once established, QRCÆs water strategy will incorporate a community engagement campaign to present the industryÆs credentials as a leader in water resource management. The development of QRCÆs water strategy, and the challenges the strategy is designed to address, provides insight into the fundamental reforms that are occurring in how water is managed and regulated in Queensland. These reforms have implications for how government policies are designed and administered and also for how industry engages with communities during this transition process.

Jan 1, 2006

By G Ryan, Yu Nazimova

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. This paper aims to highlight the global exploration opportunities that exist in connection with Ural-Alaskan (UA)-type intrusions. The key economic importance of UA intrusions is the existence of metallic platinum (mainly iron-platinum alloys) associated generally with chromite mineralisation and located within a dunite core, especially its coarse-grained part. Being very dense and resistant to erosion, platinum can form rich placers as the intrusion erodes. Big multimillion ounce placer platinum deposits of this type have historically been successfully mined for many years (eg Russia, Colombia and Alaska).However, large-scale exploration and mining of platinum placers currently occurs only in the Russian Far East. Outside of Russia, there is now little or no understanding of this type of deposit and its economic importance. Using successful operations in Russia as examples, it is demonstrated that there are many opportunities for similar discoveries all around the world, especially around the Pacific Rim, where such intrusions tend to be concentrated. Examples of highly prospective areas in eastern Australia and New Zealand are given. There is also excellent potential in British Columbia (BC) Canada, South-East Asia (Philippines, Indonesia, Papua New Guinea and New Caledonia) and South America (Colombia and Ecuador).CITATION:Nazimova, Y and Ryan, G, 2015. Platinum potential of the pacific rim of Ural-Alaskan-type intrusions, in Proceedings PACRIM 2015 Congress, pp 665–670 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Jan 1, 2004

When mining of ilmenite deposits wet process of preparation is traditionally used. But this method needs large volume of water. The problem of water deficiency is characteristic of many regions of the Republic of Kazakhstan. The Satpayevskoye ilmenite deposit is situated in the East Kazakhstan, its location has problems with water, and the mineralogical composition of rock is unfavourable: rocks contain up to 40 per cent of clays. That is why designers made a decision to use dry process of preparation for processing of these ores. Offered scheme and equipment selection are presented in this paper.

Jan 1, 2003

Subsidence data resulting from longwall mining in the northern part of the Newcastle Coalfield of New South Wales has been reviewed. Themain factors influencing subsidence variability in this area (apart from width/height ratio) are strong bridging strata, the effects of the first major goaf fall, mining direction and depth of cover. In 1987 the NSW Department of Mineral Resources produced a guide to subsidence prediction for the Newcastle Coalfield which is still widely used. The current study shows this guide to be no longer appropriate for this area. An alternative prediction curve, incorporating more recent data, is suggested.

Jan 1, 1998

By M Akbarpour, M Osanloo

In mining industries, materials handling costs represent a significant component of the operational cost. A variety of methods have been applied in surface mine equipment selection in order to select the suitable loading system with the lowest loading operation cost. These are queuing theory, bunching theory, linear programming and genetic algorithm. Among them, genetic algorithm is a simple method and applied for preliminary selection of the loading system. In this study, gathering information from anomaly No 2 of Gol-e-Gohar iron mine of Iran, loading system (number and its capacity) has been optimised by genetic algorithm. The study results showed that two shovels 8.25 m3 are required for the removal of 60 million tonnes of overburden. After removal overburden, these two shovels contribute to the extraction of 42 million tonnes of ore with a stripping ratio of 1:1.

Jan 1, 2007

By A R. Butcher

Gold deportment and ore characterisation studies are key tools in gaining an appropriate understanding of complex gold ores for process development and optimisation. These studies have historically involved imprecise chemical methods with slow and costly optical microscopy for gold identification. The traditional approach requires highly skilled petrographers, is prone to human error, and is not scalable, reducing the usefulness in practical analysis. The proposed methodology utilises a decision tree and knowledge base in a staged approach to gold ore characterisation, building up progressively more detailed information about the sample mineralogy, gold deportment and key mineral properties, as the process is followed. Whilst the automated QEMSCAN« system is used for mineral and gold identification, interactive and focused data analyses are used to give more efficient and accurate results. This is complemented by smart sample preparation and chemical methods to enhance and validate the data, making the staged approach methodology reliable, scalable and therefore practical and economical.

Jan 1, 2007

The international scientific and engineer-ing community is being challenged to take advantage of the opportunity offered by the U.N. International Decade for Natural Disaster Reduction (IDNDR) program to reduce rapid onset geological hazards along the Pacific Rim. Natural disasters observe no national boundaries; international cooperation offers the best opportunity to reduce the losses these catastrophic events create.

Jan 1, 1990

The history of civilisation continues to register a steady tide towards the urban life as the basis of its social organisation. The manifestation of this movement is a continuous growth and increasing density of population in our towns and cities, as the favourite space for the development of humanity. Naturally, this trend raises a certain number of problems which grow proportionally with the size of the city. The use of the underground space has an important role to play in solving such urban problems. But various issues must be taken into account when developing urban underground space.

Jan 1, 1999

By Smith T

Bacterial oxidation is often attributed with the advantage that a high level of gold recovery can be obtained at a relatively low level of sulphur oxidation. This is sometimes attributed to the bacteria "tunneling" towards gold inclusions, however it is often due to the presence of two or more sulphides of differing gold content which leach at different rates. Gold is liberated from the individual sul- phides linearly with oxidation. The distribution of gold between pyrite and arsenopyrite in two samples taken from a prospective gold resource was examined. The two samples showed differing responses to bacterial oxida tion and it was shown that this was due to differing intrinsic gold grades in the mineral phases and differing proportions of the minerals in the two samples.

Jan 1, 1991

By Price B. D, Staunton W. P

The Mineral Science Laboratory of the Government Chemical Laboratories has recently investigated various procedures for the analysis of the platinum group metals (PGMs). This investigation covered a number of methods for the extraction and preconcentration'of the PGMs from a wide range of geological materials. The nickel sulphide extraction technique proved to be overall the most applicable procedure. Flame atomic absorption spectroscopy (FAAS), electrothermal atomisation atomic absorption spectroscopy (ETA-AAS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) were examined for their suitability in analysing platinum group metals in solution. ETA-AAS and ICP-MS proved to be the instruments of choice due to their low detection limits.

Jan 1, 1987

By G Mulder, M Adams

Since the introduction of raiseboring 30 years ago there have been many operational and mechanical design improvements in the raiseboring machine, its reamers and associated cutters. These have now made the technology of raiseboring a routine and practical operation within the underground mining world. Over the last decade these advances have been aided by the introduction of robust automation packages which have allowed unattended drilling and reaming, real time performance monitoring and enhancement and the rapid diagnostic investigation of mechanical and electrical abnormalities. The constraint to higher raiseboring performance is now the drill string. However when it comes to a cost-effective solution of applying the high drill string torque and tension necessary for the next step change in performance, designers have æhit the wallÆ. Whilst carbon fiber reinforced plastic composites with abrasive resistant sheaths may offer a solution, the limit of conventional steel, drill string technology has been reached. This limit to advancement is however based on the drill string being in tension and alternative solutions may exist by literally turning the raiseboring paradigm on its head. This paper describes the story of a small Australian company engaged in the design and manufacture of mechanical excavation machines, two Australian raiseboring contractors and three Australian mines going against tradition and pushing down rather than pulling up.

Jan 1, 1998

By J E. Everett, M L. James

When iron ore is crushed and split into lump and fines components, there are systematic differences between the lump and fines grades. Generally the lump product is richer in iron and lower in the other minerals, compared to the fines product. The grade differences between lump and fines, together with the lump percentage, are referred to as the ælump algorithmÆ. Mine estimates of grade, based on exploration or blasthole drilling, relate to head grade. The ælump algorithmÆ predicts lump and fines product grades from the head grade. This knowledge is important when developing mine plans. Different ore types can be expected to have systematically different lump algorithms. Previously, lump algorithms for specific ore types have been estimated by running the crusher with a single ore type over a sample period. This method is costly, interferes with production, and yields results of limited statistical power. It has been found that weighted-least-squares (WLS) multiple regression can be used to ascribe lump algorithms to different ore types, provided sample periods have sufficiently varied ore type mixes. This study discusses the method and its application to the analysis of Mining Area C crusher production records to estimate the separate lump algorithms, which could be applied to the different ore types. The analysis has enabled the set up of lump algorithms in the production system, to improve the grade control of lump and fines product. Some other relevant applications of the WLS multiple regression approach are also considered.

Jan 1, 2005

Diversity is a key strength for Western Mining Corporation. An international corporation with assets of about $A10 billion, WMC is engaged in both mining and downstream processing of minerals including nickel, gold, alumina, copper and talc, as well as having interests in oil and gas production and agricultural fertiliser. The company is focusing on several core commodities that will maintain its strength in the years ahead. Although most current mineral assets are within Australia, it plans to have 25 per cent of its operations off-shore by the turn of the century, and be a major producer in at least six core commodities. WMC's strategic and management focus has shifted from a regional approach to a commodity focus so that it can more readily cater for different markets with differing sensitivities. This document is an ABSTRACT ONLY - no paper was published for this presentation

Jan 1, 1996

In the last 100 years, statistical sampling theory for particulate materials has developed to a stage where sampling systems can be confidently designed to provide assay results of known and controlled variance for a chosen time period. The two independent sources of sampling variance, namely intrinsic and distributional heterogeneity are defined and explained quantitatively. Intrinsic heterogeneity is characterised by the sampling constant for the material and distributional heterogeneity is quantified by the process steam variogram or covariance function. The means by which sampling systems can be designed to an accuracy specification is described.

Jan 1, 2002

By Erceg MM

The Red Dome deposit is located about 15 kilometres by road west of Chillagoe in far north Queensland. The deposit is within a well known band of mineralisation which is adjacent to the Chillagoe - Mungana railway line. Earlier this century several mines were operating in this area, some of which were supplying feed-stock to the copper smelters which were operating in Chillagoe at that time.The area around Chillagoe has long been an interesting geological region with numerous locations exhibiting significant gold and base metal mineralisation.The Red Dome area of some time, however it was not became involved that the apparent. The upsurge in seventies added further investment.mineralisation had been known for until Noel Adam, a prospector,true potential of the area became the gold price in the late encouragement for additional

Jan 1, 1986

The aim of this paper is to broadly review the purposes of valuations and the methods used to calculate them. Examples are provided by coal and alluvial gold properties. Important factors are consistency, how to deal with uncertainty, and the selection of discount rates. The purposes of valuation are seen as: 1.  valuations for sale; within this category are sales to third parties, sales between partners, and vendor valuations for prospectuses; 2.  to provide bankable estimates for financing; and 3. to provide values for local body rating. The methods used depend on the purpose of the valuation and the amount of information to hand.

Jan 1, 1988

Silica-Kaolin Sand Wet Sizing The Bulgarian deposits of silica-kaolin sand are localised in the eastern part of the Danube plain. After wet separation the raw material yields two products - washed kaolin (different grades) and silica sand (different grades). The water washing technology includes: disintegration; spiral classification; hydrocyclone classification and dewatering of kaolin grades; hydroclassification; sizing using drum screens and dewatering of silica sand grades. Research and development program has started to improve the silica-kaolin sand separation in processing plants. Based on the raw material and tails characterisation data and the preliminary experiments using Derrick Stacksizer screening machines a silica-kaolin sand wet sizing technology was developed. The full-scale pilot flowsheet includes the following units: Derrick Stacksizer equipped with 0.43 mm opening Derrick Urethane Panel; 500 mm Flat bottom Hydrocyclone; Derrick Stacksizer equipped with 0.150 mm opening Derrick Urethane Panel; 100 mm Hydrocyclone and Derrick Dual Motor Linear Motion Machine equipped with 0.064 mm opening Derrick Pyramid Panel. The pilot-test data clearly demonstrate that the new silica-kaolin sand wet sizing technology is suitable for Bulgarian silica-kaolin raw material. There are possibilities to increase the silica sand recovery increasing the production of silica sand grade PK 0.16 and starting the production a new grade PK 0.10.

Sep 13, 2010

The management of safety has undergone a number of radical changes in the past 100 years. The most important paradigm shifts occurred through the work of Heinrich, followed by the advent of the safety systems era and, more recently, the behavioural safety approaches that have become increasingly popular around the world. Each of these æapproachesÆ to safety has left an indelible mark on the way we target safety improvements, helping decide which interventions are deployed and how they will be measured. They have also resulted in a number of æmythsÆ about safety management, each of which will be discussed, analysed and challenged in this paper. This paper highlights the complex problem of æcomplacencyÆ, that has arisen out of the increased levels of regulation and consequent perceived protection that workers enjoy in the work place. It also looks at a phenomenon called æaccident migrationÆ which results from a superficial treatment of accidents with changes to rules and procedures. The most recent approach to safety is generally known as behaviour-based safety, which flowed from the human sciences and quality management era. This approach has had a dramatic impact on the way safety is managed around the world, but still falls short in a number of key aspects, most notably the area of risk awareness and risk understanding. Many workplace accidents occur simply because the risk is unidentified, underestimated, not understood or ignored. This paper proposes a new direction for safety, called competency-based safety. It is based on cognitive psychology aimed at combating the consequence of modern protection. A case study is presented detailing the deployment of this approach throughout Placer Dome.

Jan 1, 2005