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Ventilation characteristics of a three h -nc longwall development panel in a 1/100th tale hydraulic model using dispersion mechanics are the first applications of its Find in ventilation. Dispersion mechanics gives additional and important ventilation parameters such as degree of mixing, bypassing, -ecirculation etc. These are not obtainable the traditional pressure-volume methods. Experimentally, the model work investigates entilation characteristics of different stopping layouts, including leaky stopping,, cut-throughs and return roadway, brattice tyre ventilation and the effects of flow rate reduction on air distribution in the headings. Additionally, a model of methane generation at the face provides results used to calculate the dispersion characteristics in the return airways. It is concluded that the model resui,s -trongly suggest that dispersion mechanics could be applied to mine ventilation surveys to provide quantitative flow pattern data and details of effective dispersion '?_C!,r riro ò `b' eritilat.ing air.

Jan 1, 1983

By Waters A. G, Nightingale R. J

The quartzite added at the blast furnace for the purpose of adjusting the chemistry of the burden inputs is shown to have a disproportionate impact on both the level and the variability of the hot metal silicon (HMSi). This conclusion is supported not only by direct correlation involving data from five blast furnaces, but also by mass balances. In one case the R2 correlation coefficient was 0.96 and the mass balance was accurate to within five per cent for a wide range of quartzite additions. The results indicate that as much as 43 per cent of the silicon in the added quartzite reports directly to the hot metal. Indeed, silicon from quartzite was found to be much more likely to report to the hot metal compared to silicon from regular sources (eg coke and sinter), reflecting differences in the activity of the silicon source.

Jan 1, 1994

By J Wiklund

The impact of non-ferrous smelters on their local surroundings is well monitored and guarded by various actors: the owners looking for profitability, the villagers looking for employment, the consumers asking for ever cheaper products and services, the government collecting taxes and all cherishing the environmental impact. Recent challenges facing the industry are various new doomsday projections: that we will be running out of base metals, that the ground we dwell on will be contaminated by the use of products. Smelters, such as BolidenÆs R÷nnskSr Smelter have a long history of increasing non-ferrous resources by recycling. It is shown that extraction and recycling of metals together with energy recovery can be integrated in a modern, profitable and clean smelter. Examples of efforts to further improve the business will be discussed such as flowsheet rationalisation, environmental investments, new feed from recycling and energy utilisation.

Jan 1, 2000

By Gray J, Krouse HR, Changkakoti A, Kwak TAP

The Dachang tin field with more than one hundred million tonnes of ore at 1% tin and 3% Zn is one of the largest tin fields in the world. It comprises five carbonate replacement tin deposits, of which the Changpo deposit containing about 80 million tonnes of ore at about 1% tin is the largest deposit. The deposit, hosted by middle Devonian limestone, argillaceous limestone and black shale, is genetically related to the Longxianggei granite.The oxygen, hydrogen and carbon isotope data of minerals, rocks and fluids suggest a magmatic fluid which evolved during the crystallization of the Longxianggei granite. Mass balance calculations show that the depletions observed in 180 and 13C values of calcites from the ore bodies to the country rocks were due to continous isotopic exchange reactions between the magmatic fluid and the marine limestones at different W/R ratios and between 300 and 600¦C.

Jan 1, 1990

THE plant is one of the usual type of Mond plants, and contains no new features worthy of comment. A brief description of the process, however, with a few remarks on the working of the plant, may prove of interest.Producer gas is made by passing a mixture of air and steam through incandescent carbon contained in a furnace called a producer, which, in the Mond type, is a cylindrical casing of steel plate, lined with firebrick, and fitted at the lower end with sloping fire-bars'. Coal crushed to an even size (about 2-in. gauge) is elevated to bunkers over the producers, from which it is fed into a measuring hopper on each producer.The hopper is a cast-iron cylinder fitted with a swing cover at the top and a bell valve at the bottom, worked by a lever and balance weight. When a charge of coal is run from the bunker into the hopper, the cover is closed, and the bell valve is lowered, allowing the coal contents to drop into the producer. Thus no gas can escape from, or air be admitted to, the producer during the process of charging. The hopper discharges its coal through a steel pipe-shaped container called the bell, which projects about 9 in. through the roof of the producer. The function of the bell is to spread the coal evenly over the fire, and supply coal to any portion of the fire as it settles.

Jan 1, 1918

By M D. Melville, B C. T Macdonald, T D. W

The surface waters in regions with acid sulfate soils (ASS) can contain high concentrations of acidity and dissolved metals. These soils cause problems for agriculture, construction and development. The water can be neutralised through many techniques, however a technique that is low in maintenance and low in cost is most desirable. Due to the vast spread of ASS along AustraliaÆs coastline an expensive and high maintenance solution would not be cost-effective. In this study, a passive treatment system that has been used to neutralise acid rock drainage has been applied to treat ASS water. This system is commonly referred to as an oxic limestone drain (OLD) or an anoxic limestone drain (ALD) depending on the waters dissolved oxygen concentration. The system that has been developed for ASS has a similar closed system to the OLD or ALD, that traps the carbon dioxide which forms when limestone reacts with acidic water. It has been called a closed tank reactor (CTR) and is constructed by placing limestone into an airtight tank. A common problem that will occur when acidic water with a high concentration of dissolved metals reacts with limestone is the formation of metal oxy-hydroxide precipitates. These precipitates can coat or armour the limestone and reduce its reactivity. To minimise the accumulation of precipitates in the CTR, perforated subdrains have been installed. It is anticipated that high water pressure and flow through the subdrains will remove some precipitates. A sump has also been installed at the base of the tank to collect precipitates that settle under gravity. The CTR has been tested for 70 days at a sugar cane farm located at McLeods Creek, NSW. Within this time the sump and subdrains have been used to flush the system. An orange solution was produced during flushing and it is believed to contain iron and aluminium precipitates. The initial performance of the CTR raised pH by at least one unit. Almost all dissolved aluminium was removed and more than half the dissolved iron. The total titratable acidity ranged from 17 - 92 mg/L CaCO3 in the initial month of monitoring. After passing through the CTR the acidity was reduced to zero. The performance of the CTR during the last few days of monitoring decreased. This is believed to be due to a pulse of water with higher acidity and dissolved metal content that lasted a week. In this pulse, the acidity reached 307 mg/L CaCO3 and the total dissolved aluminium reached a maximum of 24 mg/L. Higher concentrations of dissolved metals may have been the cause for lower performance due to increased precipitation and coating on the limestone.

Jan 1, 2003

By A Golev, G Corder

The concept of the circular economy has been gaining traction both in Europe and China.In Europe the Ellen Macarthur Foundation see their mission as accelerating the transition from a linear take-make-dispose economic model to a circular model that is restorative and regenerative by design, and aims to keep products, components and materials at their highest utility and value at all times. The Chinese Circular Economy initiative is effectively a sustainable consumption and production program utilising cleaner production, industrial ecology and life cycle management approaches to meet the national challenges of maintaining rapid economic growth while simultaneously enhancing environmental quality and maintaining social progress. A key characteristic of both of these circular economy initiatives is to design out, reuse or minimise the generation of waste.The mining sector, by definition, is represented by linear rather than circular activities, by supplying resources to society. However, being one of the world’s largest waste generators, the sector can adopt similar logic to that of the circular economy to improve its sustainability performance. Waste is a critical issue along the whole metals value chain, from mining waste to eventual end-of-life products, such as scrap steel from construction and demolition waste or the growing problem of electronic waste.CITATION:Corder, G and Golev, A, 2016. Can mining be part of the circular economy or is it squaring the circle?, in Proceedings Life-of-Mine 2016 Conference , pp 121–123 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By G Forbes, D J. Bradshaw, G S. Heinrich, D

Traditionally, operators on mineral flotation plants have relied on visual inspection of the froth surface when making adjustments to process set-points. Machine vision systems are being developed to relate froth surface descriptors, which can be consistently measured in real time, to flotation performance. By investigating the impact of various selected operating variables on both froth surface characteristics and metallurgical performance it is possible to develop a management strategy for the control and optimisation of the process. This paper presents the results of testwork conducted at Kennecott copper mine which investigates the relationship between the froth colour and the concentrate grade and discusses the factors which affect the froth colour. This work shows that the main factors that influence the froth colour in this system are molybdenum, copper and iron concentrate grade, pulp and concentrate per cent solids and pulp iron grade.It goes on to develop models to predict the concentrate grade based on colour information and velocity and stability information. It also shows that the most accurate prediction is made with combined colour and stability information.

Jan 1, 2005

By S Vearncombe

SpaDiSÖ is a revolutionary approach to the spatial analysis of point data using geometry to analyse geometry! SpaDiSÖ uses each and every spatial relationship and is not dependent on mathematical models. For n points there are n2 û n spatial relationships and, because of the square function, the method yields interpretable results for both small and large data sets. SpaDiSÖ is an alternative to variography for directional studies. At the regional scale, the analysis can assess distribution patterns of mineralisation and potential controlling structures. At the deposit scale, the characteristics of zones of mineralisation such as direction, spacing, high-grade ore direction and grade distribution can all be deduced.

Jan 1, 2000

By Cocks T

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By Smith J. W, Hart G. N

Compositional and isotopic analyses of coal seam gases in the Southern Coalfields have shown that these gases frequently contain abnormally high concentrations of magmatically derived carbon dioxide. The size of this carbon dioxide reservoir and the extent of permeation of the sediments by carbon dioxide are not known.Therefore caution in evaluating the natural gas potential of the region is advised.

Jan 1, 1981

By C W. Lu, Y F. Chen, M J. Lian, W W. Guo

This paper proposes a set of new approaches for the optimisation of planning and designs in mines by means of evolutionary algorithms, which include the determination of ore grade, layout of development system, selection of mining methods and production scheduling in underground mines. The applications indicate that evolutionary algorithms are particularly suitable to the complex and complicated problems in mines.

Jan 1, 2003

By Voss Smith F, Matters C. W, Slee R. T, Coldham JC, Davies HW, Wallman H. H

The Committee desires to thank the managers of the various mines along the line of lode for their hearty co-operation in its labours. It would also extend thanks to Messrs. J. O. Moulden, Howchin, Twelvetrees, and the West Australian Geological Survey for various information; to Messrs. J. G. Dreyer, S. Pope, T. Read, P. Moncrieff, R. Williams, and W. J. Rose for analyses; and to a number of local gentlemen for advice and help. Professor Skeats, of the Melbourne University, gave much valued assistance in petrology, and Mr. Herbert Lavers kindly undertook the study of the garnets.INTRODUCTIONThe famous Broken Hill lode is situated in a low range of hills, the Barrier Ranges, near the western border of New South Wales. It has been worked since 1884-first for, silver, then for silver and lead, and at present for lead, silver, and zinc. No excuse seems necessary for placing before members even an imperfect report on the geological features of this notable ore deposit, since so little work has been done on the subject as to constitute almost a national reproach. This is the more deplorablesince the evidence laid open by mining operations is destroyed almost as soon as it is exposed, and there exists the real need of a continuous and connected record of geologieal developments.

Jan 1, 1911

By N N. Viswanathan, D Kumar, S Kumar

In secondary steelmaking, calcium treatment is practised to modify the solid alumina or spinel inclusions into liquid or partially liquid calcium aluminates. It has been seen that the dissolved calcium reacts with sulfur or oxygen present in the steel to form CaS or CaO type of transient inclusions. Post-calcium treatment these transient inclusions further react with pre-existing alumina or spinel inclusions and modify them. In addition, direct modification of pre-existing inclusions is also reported in the literature. In the present study, laboratory-scale induction furnace-based experiments are carried out to melt electrolytic iron in an alumina crucible followed by deoxidation with aluminium. The CaS-based composite material, prepared in-house, is added after the aluminium deoxidation to study the stability of CaS at the steelmaking temperature. Multiple steel samples were also taken to track the dissociation of CaS by means of sulfur pick-up in steel. Additionally, inclusion analysis of these steel samples was also performed to track changes in the chemical composition of inclusions in response to CaS addition. It has been seen that the CaS dissociates leading to a gradual pick-up of sulfur in steel. The scanning electron microscope – energy dispersive X-ray spectroscopy (SEM-EDS) analysis reveals that the alumina crucible and floated alumina inclusions are modified into calcium aluminates and the extent of modification depends on the contact time of CaS with the two sources of alumina mentioned earlier. However, the modification of alumina inclusions in the bulk steel did not occur during these experiments.

Jun 19, 2024

The refractory industry in New Zealand is small, consisting of two main manufacturers - one at Huntly and the other at Kamo. Together these would have an annual refractory production of about 30 000 tonnes. The industries which use refractories include two steelworks, NewZealand Steel Limited and Pacific Steel Limited, the former is involved in continuous casting from sponge, iron and scrap steel and the latter is involved in ingot teaming from scrap steel and steel billets; One aluminium smelter, cement works, dairy companies, small foundries producing engineering requirements and many other small users. The New Zealand manufacturers produce refractories in thefire brick range, that is up to 50 per cent alumina content (ignited basis), based on indigenous raw materials and in the high alumina range up to 85 per cent alumina content (ignited basis) based on imported bauxites. All of the basic refractories high purity silica and high alumina low alkali refractories and many of the higher grade acid resisting refractories are imported.

Jan 1, 1976

Applications of chlorine metallurgy to the extraction of metals often result in the production of volatile metallic chlorides, most of which condense directly to a solid phase at 1 atm pressure. A stirred-bed condenser suitable for the recovery of these materials is described.The unit, developed from the concept of a fluid bed condenser, has the advantages of versatility of operation and ability to control fog and dust formation. Test work using aluminium chloride vapour (as an example of a volatile chloride) gave recoveries approaching 100 per cent. The yield was dependent upon halide content of the vapour, flowrate, and, to a lesser extent, upon coolant temperature. Analysis of the heat transfer dataindicated condensation side coefficients in the range 10 to 30 B.T.U./hr sq. ft. 0p.

Jan 1, 1971

By Offler R, Lau J, Lea J. F

The stratiform and vein-type pyritic silver-Iead-zinc-copper sulphide deposits of Sunny Corner, NSW are hosted by acid volcanic and clastic sedimentary rocks of Middle Silurian to Early Devonian age. The rocks have been subjected to low-grade regional metamorphism (prehnite-pumpellyite facies) and three phases of folding and four faulting events are recognised. Pyrite is intensely fractured, indicating brittle deformation. Chalcopyrite and galena exhibit deformation twins and slip planes indicating ductile deformation; sphalerite and chalcopyrite show straight and curved grain boundaries and dihedral angles of 120° as evidence of annealing recryslallisation. Sulphur isotope ratios for 22 samples from five deposits range from 1.7 to 10.7 per mil and average 7.4 per mil. Sulphur isotope data are similar to those from other stratiform sulphide deposits in acid volcanic rocks of Late Silurian age in the eastern Lachlan Fold Belt, especially Woodlawn and Captains Flat and together with other features of the mineralisation, suggest a volcanic exhalative origin for the Sunny Corner deposits.

Jan 1, 1984

By M Barley, C A. RosiFre, L Lobato

The Carajßs iron ore deposits contain approximately 17.5 billion tons of ore with >64 per cent Fe and occur in the eastern part of the Amazonas Craton. They are hosted by jaspilitic banded iron-formation (BIF) of the Carajßs Formation which, together with metavolcanic rocks, comprise the ~2.75Ga Grpo Parß Group of the Itacai·nas Supergroup in the ~1000 km long, E-W trending Carajßs Synclinorium. The Carajas Formation comprises discontinuous layers and lenses of partly dolomitised BIF (17 - 43 per cent Fe and 35 - 61 per cent SiO2) and lenses of high-grade iron ore, cut by mafic sills and dykes. The high-grade iron ores occur as large tabular bodies of friable (soft) hematite with smaller lenses of hard (compact) hematite. The hard hematite ores typically occur at the contact with the underlying volcanic rocks and are surrounded by an aureole of hydrothermal carbonate alteration. BIF that has been overprinted by dolomite and magnetite crystallisation has recently been discovered at depth in the N4E Mine. With increasing amounts of carbonate, the original lamination (microbanding) and other fine primary structures in the BIF have been progressively obliterated resulting in alternating carbonate and iron oxide mesobands. The friable hematite ore that is characteristic of the Carajßs deposits results from ongoing weathering and leaching of the carbonates from this type of altered BIF. The hard hematite ores probably result from more extensive early oxidation. The association of both carbonate-altered and jaspilitic BIF with the N4 Mine is similar to that observed at the Mount Tom Price deposit in Western Australia, where carbonate-altered BIF occurs below massive hematite ore with a jaspilitic halo developed above the orebody. This indicates that as at Mount Tom Price, hydrothermal carbonate alteration and associated loss of silica from BIF may be an important step in the formation of these giant hematite deposits.

Jan 1, 2002

By Lee M. F

The Lady Loretta lead-zinc-silver mineral isation of north-west Queensland was discovered first by Placer geologists in 1968 as a result of a geochemical soil survey. The stratigraphic position, mineralisation and rock associations of the deposit are very similar to those of the Mount Isa lead-zinc-silver orebodies. Aspects of the exploration history, geo- chemistry and structural geology of the Lady Loretta deposit, are discussed. A geometric model of the Ore Horizon is given.

Jan 1, 1974

Financial markets are subject to constant change and project finance, as a product within these markets, adapts and will continue to adapt with those changes. A meaningful discussion of these adaptations requires an understanding of differences between non-, limited and full recourse project finance. The reasons sponsors seek and lenders provide project finance are also pertinent in this context. Arranging a project, financing package can be a canplex and time consuming task. An important first step is choosing the right advisor for the assignment and then structuring and tailoring the financing before approaching prospective lenders. The last thirty years has seen changes in the needs of sponsors and the ability of lenders to meet them. These shifts in preference may well be a guide to the future. Several major project financings successfully canpleted in Australia in the last few years and more recent examples are broadly discussed. Project finance will be keenly sought in the future and the form and nature it takes will continue to vary.

Jan 1, 1983