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By E Jak

A viscosity model has been developed for both completely liquid and heterogeneous, partly crystallised slags in the Al2O3-CaO-æFeOÆ-SiO2 system in equilibrium with metallic iron. The Urbain formalism has been modified to describe the viscosities of the liquid slag phase over the complete range of compositions and a wide range of temperatures. The Roscoe equation has been used to describe the effect of presence of solid suspension (slurry effect) on the viscosity. The parameters of the viscosity model were optimised to describe large experimental data set in the low-order subsystems, as well as in the multi-component system. The computer package FACT was used for prediction of the proportion of solids and the composition of the remaining liquid phase. The model provides a good description of the experimental data (over four thousand experimental points) in liquid phase, and liquid + solid mixtures, over the complete range of compositions and a wide range of temperatures. This model can now be used for viscosity predictions in industrial slag systems. An example of the application of the new model to slag cleaning and reduction smelting processes is given in this paper.

Jan 1, 2000

By L D. Redden, M G. Nelson

Mechanical flotation machine design is typically based on hydrodynamic analysis, with scale-up calculated by geometric proportionality. End users often specify and purchase machines on the basis of retention time, characterised by the æ$/m3Æ approach; they may also consider the manufacturerÆs installed base. In some applications, end users also consider specific energy and the impact of energy consumption on operational costs. In other cases, a decision may be based on machine type (forced-air versus self-aspirating) and perceived metallurgical or operational advantages of one machine type over the other. With regard to metallurgical performance efficient bubble-particle contact is very important and is primarily influenced by two factors:the concentration and size distribution of bubbles in the machineÆs contact zone (the volume enclosed by the disperser); and the number of times that slurry is pumped through the contact zone. The second factor is a function of the machineÆs pumping rate and its retention time. Field data show that pumping efficiency is independent of aeration rate. In this paper, a new dimensionless number for the characterisation of flotation efficiency is presented. The contact frequency number (CFN) is defined as the number of times a given volume of slurry passes through a machineÆs active contact region, and is given by: CFN Qp/Qf, where:Qpis the pumping rate through the contact regionQfis the volumetric feed rate to the machine

Jan 1, 2005

By Cunningham DA

Plant based on the New Jersey refluxing process has been installed at the Cockle Creek Works of Sulphide Corporation Pty. Limited to refine portion of the zinc output from the Imperial Smelting Furnace. Refining of impure zinc is effected by distillation in two stages in vertical columns compris- ing a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage the volatile elements (zinc and cadmium) are distilled from impure metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content. The resultant zinc has a purity in excess of 99,995 per cent zinc. The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basis grades of zinc.

Jan 1, 1969

The Lake Rotokaua sulphur deposit, near Taupo, New Zealand, is a lacustrine sedimentary ore body, 220 acres in area and from 7 ft to 96 ft thick, containing, within the area drilled to date, some 20 million long tons of ore averaging 25% elemental sulphur in unconsolidated tuffaceous diatomaceous clay, overlain by about 120 ft of pumice sand and by the shallow Lake Rotokaua. An additional amount of perhaps 4 million tons of sulphur is regarded as probable in the area remaining to be drilled. Current economic studies cover the problems of mining an unconsolidated water-saturated formation with some residual thermal activity nearby; conservation and restoration after mining in a scenic recreation area; beneficiation of the ore and extraction of high- purity sulphur, principally for fertilizer manufacture. The deposit has additional importance as a pointer to possible further discoveries in the Thermal Region.\

Jan 1, 1971

By Ueki S

Underground coal gasification (UCG) is a promising process for obtai- ning energy from coal, which is either unmineable with current mining techno- logy or uneconomic to recover, using conventional methods, in the present energy market situation. There are several coal fields, which could become new coal reserves, if the UCG process were successfully applied. In the 1960's Japanese researchers made a number of basic studies and field tests into UCG, although not all of them produced favourable results. This paper reviews Japanese research on UCG. This includs basic studies into coal gasification using a small, tube reactor fed by air and oxygen, and also large scale model stu- dies(reactor size of 8.Om x 2.4m x 1.5 m). Field test results from Akabira colliery in Hokkaido and a feasibility study of power generation using UCG from a coal field in Hokkaido are also Presented.

Jan 1, 1987

The three systems of mining in use in the Southern Coalfield of New South Wales are bord and pillar with or without subsequent extrac- tion, longwall and shortwall. Bord and pillar with extraction is regarded as the conventional system. The application of continuous miners and powered roof supports (Shortwall) to coal min- ing has, grown in recent years from something of an oddity among extraction systems to an acceptable and viable approach in certain min- ing environments. The method can be applied in a high proportion of situations where normal pillar extraction is practised with advantages over the conventional approach. These advantages extend to both safety and efficiency aspects and also include better utilization of coal reserves. It holds hope for further gain in efficiency because its simplicity of layout lends itself to achieving the goal of contin- uous haulage towards which operators are always striving.

Jan 1, 1976

By M Grinceri

The New MetroRail City Project was completed in 2007 in Perth, Western Australia. The project included construction of two underground stations, twin bored rail tunnels of 1.4 km combined length and cut-and- cover tunnels and dive structures of about 1 km total length. It is the first major underground construction project within the Perth central business district (CBD). This paper provides an introduction to the project and describes the geology and hydrogeology of the area. Ground conditions varied significantly along the alignment from soft estuarine muds in an area of reclamation to very dense cemented sands and very stiff to hard clays. Deep foundations for the project extend down into the bedrock below the CBD, a Tertiary siltstone/sandstone. Key geotechnical hazards encountered during the project are discussed. The building protection methodology on the project is described, including damage assessment, condition surveys, monitoring and protection of key structures.

Jan 1, 2008

Broken Hill is situated at an elevation of approximately 1000 ft. above sea-level, on the Barrier Ranges, in the State of New South Wales, Australia. It is approximately 700, 280 and 330 miles from the ports of Sydney, Pirie, and Adelaide, respectively.The summers are usually hot and dusty, with a recorded maximum shade temperature of 114° F. The rainfall averages approximately 9 in. per annum.

Jan 1, 1932

Coal water mixture (CWM) is a mix of finely ground coal with water and a small amount of chemicals. It is a new way of transporting and handling coal. CWM can be transported, stored and burned like fuel oil in steam generating boilers. It also has some environmental advantages over both oil and bulk coal. A group comprising Ube Industries Limited, Nissho Iwai Corporation (both from Japan) and Coal & Allied Industries Limited has been working in Japan and Australia since 1987 on a joint feasibility study into the production, transport and marketing of CWM from Australia to Japan. The group has been studying the development of a large-scale CWM plant on Kooragang Island at the mouth of the Hunter River at Newcastle, NSW. The project concepts and engineering plans for the CWM plant are well advanced and other studies related to the project are continuing.

Jan 1, 1995

By M Akhtar, E Jak, M Shevchenko

This article presents an overview of the experimental phase equilibria studies of S-containing systems (Ni-Sn-S, Cu-Sb-S, and Cu-Sn-S) and As-containing systems (Fe-Sb-As and Fe-Sn-As). These systems improve the prediction capabilities of FactSage in a 20-component ‘Cu2O’-PbO-ZnOFeO- Fe2O3-CaO-SiO2-S-(Al2O3-MgO-CrO-Cr2O3-Na2O)-(As, Sn, Sb, Bi, Ag, Au, Ni, Co) system for complex pyrometallurgical operations during both refining and recycling. Experiments involved equilibration at predetermined temperatures (300–1200°C) with or without preheating, followed by rapid quenching in a brine. Quenched samples were then directly measured using an electron probe microanalyser. For the Ni-Sn-S system, liquid phases (NiS- and SnS-rich mattes and liquid metal) and solid phases (Ni1+xSn, SnS, Ni3Sn, FCC-Ni, Ni1-xS, NiS2, Ni3Sn4, SnS2, Sn2S3 and β-Ni3S2) were observed. A new Ni3Sn2S2 phase was found to melt incongruently. For the Cu-Sb-S system, liquid metal, matte, FCC-Cu, digenite, Sb, CuSbS2, Cu3SbS3 and Cu3SbS4 phases were observed. For the Cu-Sn-S system, liquid metal, matte, digenite, SnS and Cu3Sn phases were found at liquidus.

Jun 17, 2024

By Maru Y

The use of mercury for amalgamation has been an integral part of the small-scale gold mining industry in developing countries owing to its low investment cost, simplicity of the technique and high gold recovery. However, its impact on health and environmental hazards have not been given the attention they deserve. In spite of the growing awareness and concerns over the mercury pollution problem by regul-atory authorities, precautionary measures such as bans on the use of mercury in some countries have been largely ineffective.This paper first reviews some of the mechanisms of mercury poll-ution, and mercury toxicity which varies according to its oxidation state. It then describes how mercury released to the atmosphere would go through the "Mercury Cycle". Compar-isons have also been made with previously measured mercury levels in small scale Papua New Guinean miners with their counterparts in other developing countries.

Jan 1, 1994

Pressures are foreseen for departments of metallurgy to make. radical changes in their undergraduate curricula. The curricula need to be made more attractive to high'school students in -order to increase the number of enrolled students. The distinctive character of extractive metallurgy needs to be emphasised to resist encroachment by chemical engineering. There should be content relevant to each of the professional functions and, particularly, to' society's broad expectations of metallurgists. Content, teaching methods, etc. need to be acceptable to women, mature-age -students, Aboriginals, and other groups, as well as young white males. Learning experiences should be negotiable by the students in response to the advent of learning packages delivered via personal computers. All of these needs could be satisfied by a radical change. in attitudes and objectives during the design; implementation and evaluation stages of . a new type of curriculum, using a wide range of problem-based learning experiences..

Jan 1, 1986

Almost all industrial products, such as buildings, cars, plastics, railways, radio and television sets, computers, and others are made from materials extracted from the Earth. Earth is main resource of energy and up to now; the energy has been derived mainly from natural resources. Mining industry has significant influence to the nature, sometimes evokes a devastation of nature. On the other hand we have got a lot of nice examples that good preparation, sensitive mining practice and consistent reclamation can minimise the negative effects. All the mentioned problems calls for effective tools for mine design, mine operation and mine reclamation. Third millennium brings next challenge given by advances in information and communication technology. The development of very sophisticated software tools provides to technical systems some features of autonomous æthinkingÆ and intelligent behaviour. We can find large effort and a lot of scientific papers reflecting last advancement in science and technology and providing inspiration for new mining technology of third millennium called Intelligent Mine. Some aspects related to creation and utilisation of æIntelligent ModelsÆ as a background of æIntelligent MineÆ are presented and discussed in this paper.

Jan 1, 2003

By Jin C, Shuyi L, Yuanbiao Z

This paper describes the structure, performance, principle and effectiveness of a new laboratory type of composed-forces field separator utilising the composition of the magnetic force, vibrating force, pulsating force, gravity and fluid-viscous force etc to separate fine feebly magnetic valuable minerals. Compared with the pulsating high gradient magnetic separator, this separator possesses unique advantages of higher enrichment ratio and higher recovery of the magnetic component.

Jan 1, 1993

In the last few years it has become legal for women to work without restriction underground in some States in Australia. Since the mid 1970's there have been women graduates in mining engineering from several Australian tertiary institutions. Women from this group are the first females to have been employed to do manual work underground this century. The questions which arise are "What are the current parameters surrounding the employment of women underground?" and "What have been the experiences of those women who have worked underground?". In order to answer these questions, contact has been made with the various mining schools in Australia, the relevant government departments, the main underground mining companies, the relevant unions and professional associations, and other women who have worked undergrond. Personal experience as both a miner and a mining engineer at the CSA Mine near Cobar in New South Wales is also used.

Jan 1, 1988

Resource developers in Papua New Guinea (PNG) are now, more than ever before, confronted with land-owner related issues that can hinder their corporate objectives.Development of PNG's custom-arily owned land since independence has brought sudden changes with mixed success. Exploitation of mineral resources has had its share of problems, and Highlands Gold Limit-ed's (HGL) endeavours in the central Highlands of PNG are no exception.

Jan 1, 1994

The principles and practical applications of the Mogensen Sizer are examined, with particular reference to the experiences at Coal Cliff Mine, New South Wales. The Mogensen Sizer has proven to be a worthwhile alternative to conventional screening. It has the flexibility and capacity to offer a useful sizing tool, particularly in areas of confined space. It is simile in design and 1 in construction.

Jan 1, 1984

By B McFadyen, Y Potvin, K Woodward

The Australian Centre for Geomechanics (ACG) held two workshops in 2019—one in Australia and one in Canada—to discuss processes and methods currently used in the mining industry for stope design and reconciliation. In practice, this work strives to optimise stope performance and aims to maximise ore recovery (minimise underbreak), while minimising dilution (overbreak). One of the key findings from the workshops was that current stope design practices, almost exclusively, rely on some versions of the empirical Stability Graph methods developed in 1980s. Although robust and useful at the feasibility study stage, there are a number of inherent shortcomings with this approach. The Stability Graph’s limitations first lie in that it cannot assess underbreak, which is a very important measure of performance. Furthermore, the method doesn’t consider a number of factors which often have a critical influence on stope stability, for example, drilling and blasting or the presence of faults. Given the current industry standard practice, there is a great opportunity to reinvent the stope design process to optimise performance. A finding of the workshops was that every mine quantifies stope performance in terms of volume reconciliation with a focus on dilution and ore losses, and reconciling metal tonnes recovered from the mill. Many mines further investigate stope performance by looking at individual stope faces and the causes for the deviations between the planned stope shape and the measured cavity. Recent research at the ACG has shown that investigating overbreak and underbreak at a higher resolution is a powerful way to identify the root causes of overbreak and underbreak. Finer scale assessment is achieved using an octree analyses, which effectively divides the relevant stope volume into cubes on the scale of a metre and produces many tens of thousands of data points. The octree data structure and subsequent analysis underpins a data-driven stope design methodology. The ACG is currently developing a design approach based on multivariate modelling methods that can account for the many variables that influence stope performance and forecast stope overbreak and underbreak results. Back-analysing stopes based on octree reconciliation results provides a rich database for training the model. Once the model can achieve reliable forecasting of overbreak and underbreak, an interactive drill-and-blast design will allow for the assessment of different firing strategies to optimise stope performance.

Mar 15, 2021

By T Huynh, V Matanitobua, J Zheng, B N. Noller, J C. Ng, H H. Harris

A risk assessment was undertaken of the aquatic ecosystem and bioaccumulation of metals and metalloids in fish at the Leichhardt River, Mount Isa, Queensland. Residual contamination of metals and metalloids in Leichhardt River sediment was assessed and arose from mine practices using river discharge in the 1940s. The ecological risk assessment of sediments involved comparison of the concentrations of heavy metals and arsenic with those of the ANZECC/ARMCANZ (2000) Interim Sediment Quality Guidelines (ISQG). Results indicated that all sites including the background site exceeded one or both the ISQG-high and ISQG-low trigger values based on total concentrations. A lesser number of sites exceeded the ISQG-low trigger values following the 1 M hydrochloric acid extract step, which was used as an indication of bioavailability. An additional risk from particulate matter in river sediment is that acute human toxicity from the consumption of fish contaminated with metals and metalloids is unlikely. The potential risk was assessed by comparing with the maximum levels set by FSANZ (2010) for fish consumption by children and adults. In general, the liver of the fish have higher heavy metal and metalloid concentrations compared to the muscle. Frequent or regular consumption of fish from the Leichhardt River that exceed maximum levels (ML) of heavy metals and metalloids is not recommended. Risk analysis showed that an adult can consume up to 5 kg of fish fillets every day from fish caught at the man-made Lake Moondarra downstream on Leichhardt River and still be within safe consumption levels whilst a child can eat up to 1 kg daily.CITATION:Noller, B N, Ng, J C, Matanitobua, V, Harris, H H, Zheng, J and Huynh, T, ?2014. Assessment of ecotoxicology and health risk from bioaccumulation in fish of heavy metals and metalloids from historical mine practices in the Leichhardt River, Queensland, Australia, in Proceedings Life-of-Mine 2014 , pp 337–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

The safety culture in mining has progressed towards a zero tolerance of injury. This change has required that some historically inherent risks of mining are engineered out or reduced. One of the significant causes of fatality in Western Australia and Worldwide mining is through rock fall, subsidence and inrush. Efforts put into understanding the material properties of the ground we mine and the backfill we place are reflected in improved safety statistics. It is no longer acceptable to not manage these risks and mining, to be sustainable, has to be safe.   Mining historically produced waste products with little consideration of recycling or impact on the surrounding land. The rehabilitation of mining waste products such as mill tailings, heap leach and waste rock is one step towards managing the environmental impact of these waste products. A better step is towards recycling and redepositing these products to produce a more environmentally sustainable mine site.   Gold fields St Ives lease is an active network of new and historic undergrounds and open pits within the Lake Lefroy and Kambalda district. The process of creating voids underground followed by open pits mining through the old voids allows the use of backfilling to control inherent hazards and dilution. Backfill provides opportunity for the disposal and recycling of mining waste materials at the same time as meeting requirements of mine support. Materials available on the St Ives site include spent heap leach, reclaimed tailings and waste mullock. Through recycling and re-depositing these materials to St Ives and neighbouring mines, the reliance on imported material to meet their needs and impact on surrounding land is reduced.   At St Ives, paste fill and barricade design have been reworked to allow backfilling into stopes with water inflows up to six litres per second. This has required a rethink of the drainage and monitoring of water management systems previously used for hydraulic fill and apply them to paste.   The St Ives open pits have developed methods to mine through underground workings and individual stope voids up to 62,000m3. Here backfill is used to reduce the consequence of catastrophic, unexpected failure of the crown and minimise ore lost down voids and dilution through increased blast movement. This paper outlines the less common methods being adopted to use the recycled materials and ways it has been managed to suit the needs of the company.

Jun 1, 2010