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By Y Sha

During the last two decades, China has expanded its iron and steel industry very quickly, from less than 100 Mt/a steel production to over 700 Mt/a. It caused big increases in both domestic iron ore production and imported iron ore quantities year by year. The mode of iron ore supply has changed from almost all domestic supply to major tonnes of imported ore plus domestic ore supply. Over 200 blast furnaces with volumes larger than 1000 m3 each have been built and put into operation. Sinter machines have been enlarged quickly. There are now 135 sinter machines with =200 m2 sintering area each. Pellet production increased from 11.94 Mt in 1999 to 210 Mt in 2011, resulting from rapidly increasing domestic concentrate supply and rapid development of the grate-kiln process. The typical ferrous burden constitution is high basicity sinter plus pellets plus lump. The pellet proportion increased and the sinter proportion decreased gradually. A lot of technical improvements, like deep bed sintering, sintering with a high ratio of limonite, composite sintering, pellet process optimisation, a high ratio of hematite in pelletisation, blast furnace operation with low-grade ferrous burdens and hazardous element control, etc have been made to enhance iron burden quality and to reduce hot metal cost. Chinese iron and steel production is expected to increase slightly in the next few years. Its overcapacity should be controlled effectively. Given the variations of iron ore supply, pellet production will keep progressing in terms of production scale and pellet quality, the sintering process will be improved further by various measures to utilise different ores efficiently, and ferrous burden constitution will be optimised continuously to realise the lowest cost of hot metal production.CITATION:Sha, Y and Wang, Z, 2013. The Chinese iron and steel industry response to the challenges of iron ore supply, in Proceedings Iron Ore 2013 , pp 7-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By M Carr, K Williams, W Chen, J Plinke

The depletion of iron ore deposits at the face of the mine site dictates the necessity for the exploitation of formerly less attractive orebodies to meet the demand of the modern world. These orebodies will typically be found close to or even beneath the water table where an increasing clay and moisture content will result. Problematic iron ores, colloquially termed as ‘wet and sticky’ material (WSM), can have a significant impact in the material handling stream due to the expensive downtime of processing equipment, which is attributed to the inter-particle and boundary cohesion and adhesion forces of the bulk material.In order to gain a better understanding of the causes of poor handleability, experimental test methods to determine wall adhesion, and inter-particle adhesion within bulk materials were developed. Based on the combination of wall adhesion and inter-particle adhesion measurements, with traditional methods of assessing bulk material handleability, a new method to assess the potential of bulk materials to cause handling problems is proposed. This method reduces the multitude of factors leading to problematic behaviour to a handleability index (HI) [0,1], which is easily assessed and understood. The method is suitable for adhesive materials and applicable for a wide range of material flow, from gravity reclaim stockpiles to transfer chutes and carry back on conveyor belts.Additionally, this research presents an assessment of the HI derived by experimental testing of three iron ore samples. A clear understanding of the problematic behaviour of the iron ore samples is achieved with the use of dust extinction moisture (DEM) tests, which indicates the regions where problematic behaviour may be experienced on-site.CITATION:Carr, M, Plinke, J, Williams, K, Roberts, A and Chen, W, 2017. Determination of the handleability index of adhesive bulk materials, in Proceedings Iron Ore 2017, pp 503–510 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By U Singh

This paper presents the evolution of the studies and strategic plans to extend the life of operations at the Savage River iron ore project in north-western Tasmania. The current Life-of-Mine (LOM) plan for the Savage River operations is based on a series of open pits. Drilling has confirmed high-grade extensions of the magnetite resource at depths that exceed practical limits for open pit mining. Grange Resources Limited, the owner of the operation, is investigating underground options – not only to extend the LOM plan but also to maintain peak production at a reduced operating cost while reducing greenhouse gas emissions into the future. What makes this project unique is that it requires introducing a productive and cost-effective mining method to exploit a challenging geotechnical and geometrical orebody in an area of high rainfall. To support the study efforts, the development of an exploration decline, underground drilling programs, and an exploratory drive excavated into the orebody for geotechnical investigation was key to providing the necessary data for a pre-feasibility study (PFS). This paper describes the pragmatic approach and processes to developing the underground mining options study through data collection and then integrating these options into the open pit plans to optimise an overall strategic plan for the Savage River operations. The learnings for operators from this experience are how the technical and pragmatic approaches were aligned to develop the strategic plans, and the importance of timely investment in gathering the necessary data.

Mar 29, 2023

Increasing demands on quality of metallurgical grade alumina and for lower production costs led to the development of a new fluid bed calcining process. The process, jointly developed in Germany by Vereinigte Aluminium Werke A. G. and Lurgi Gesellschaften m.b.H., takes advantage of modern chemical engineering methods such as counter-current flow of combustion air and solids, direct heat-exchange between combustion air and fine solids, and near stoichiometric combustion of oil in a fluid bed. Using a two-stage Venturi-type suspension preheater for heat-recovery from combustion flue-gases, the circulating fluid bed technique with internal oil combustion at 220°F for the calcining step and a five-stage fluidized bed cooler for heat-recovery from calcines, the process gives an outstanding heat-efficiency. In a first industrial plant for 560 sh. tons/day of alumina heat consumption figures of less than 1·400 B.T.U./lb Al203 g were achieved.

Jan 1, 1972

By M Orunesu Preiata

The Odysseus Project is part of the high-grade Cosmos Nickel Complex that lies 30 km north of Leinster. The Odysseus definitive feasibility study (DFS) was approved by the Western Areas’ board in October 2018. Early works commenced in January 2019 with rehabilitation of the existing underground infrastructure. In June 2022 Western Areas was acquired by IGO Ltd. The project is now well advanced to meet its target of first concentrate. The project included the construction of a haulage shaft. The design of the hoisting equipment and the shaft barrel evolved from the initial DFS design stage to the final execution, as the data were made available from the initial investigation to the data gathered during execution (although this did not change from its initial concept). The design philosophy for the haulage shaft incorporated, from the beginning a multidisciplinary approach with inputs from three main areas involved in such projects, namely excavation techniques, geotechnical assessments, and infrastructure construction. This interaction is a fundamental component for the success of such a critical project. In fact, each of these three areas influences each other in a cyclical manner, triggering a continuous review of the project inputs and outputs, while maintaining the original project goals: the design of an infrastructure able to deliver the desired throughput. The throughput dictates the infrastructure that needs to be built, which in turn controls the size of the shaft. The key assumption applied to this is that the rock mass can accommodate the excavation void, and the excavation technique with its tolerances and limits that ultimately need to be verified back with the initial assumptions used for the infrastructure design. The aim of the paper is to present a case study of the experience gained with the Odysseus hoisting shaft and to propose a possible logic path for similar projects elsewhere.

Mar 29, 2023

By D Jensen, L Riffo, S Yu, F Traczyk, D Meadows

With the steady increase of molybdenum demand worldwide and the favorable molybdenum market, many technological innovations on both process and equipment have been developed and applied in many modern molybdenum plants around the world. This paper introduces the most commonly used molybdenum flotation flowsheet, together with the introduction of the flotation chemistry. Many different types of flotation cells are used in modern moly plants, and each type of flotation cell has its own unique advantages suited for particular ore and process conditions. This paper tries to provide some insight and guidelines in flowsheet development and flotation cell selection in the molybdenum plants.CITATION:Meadows, D, Jensen, D, Traczyk, F, Yu, S and Riffo, L, 2013. Molybdenum flotation circuit and flotation cells, in Proceedings MetPlant 2013 , pp 387-398 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The base metal ore from the hanging wall of White's orebody at Rum Jungle, N.T., is composed of copper and oth.er sulphides in a rock described as a phyllite,.which consists essentially of micaceous minerals with a little graphite.Fast selective flotation was obtained in acid circuit below pH 3·5. In neutral or alkaline circuit flotation was generally slow and selectivity very poor due to the ready flotation of part of the sericite. However, it was found that fast selective flotation could be obtained in neutral or alkaline circuit by either of two treatment methods following pre-conditioning in acid circuit; firstly by decanting or filtering a substantial part of the circuit liquor, and secondly by neutralizing with soda ash or lime, providing the collector was added before neutralizing. Otherwise pre-conditioning with acid brought about no improvement whatever.To explain this behaviour, three possible reasons for the flotation of part of the sericite are examined. There is evidence that some sericite floats because of thin films of either sulphides or graphite, but it seems likely such particles will float under all the conditions investigated.On the other hand, if it is assumed that part of the sericite floats because it is activated by metallic ions derived from the circuit water, a reasonable explanation can be given for the variations in flotation behaviour.INTRODUCTIONWhite's uranium orebody at Rum Jungle, N.T., sixty miles south of Darwin, is mined and treated by Territory Enterprises Pty. Ltd. (a subsidiary of Consolidated Zinc Pty. Ltd.), who are managers of the Rum Jungle project on behalf of the Australian Commonwealth Government.This ore contains a significant quantity of copper sulphides, and a flotation plant recovers a copper concentrate from the tailing remaining after the uranium has been extracted.In contact with the hanging wall of the uranium-copper orebody, a further mass of non-uraniferous sulphide ore occurs, and the present paper relates to the behaviour in flotation of this base metal ore.

Jan 1, 1959

Magnetic anomalies in the Southern Coalfields have been subdivided into two characteristic types. Each type is attributed to a separate cause, one being basement structure, and the other near-surface igneous intrusions.Detailed geological mapping of the area and the ability to sample throughout the coalmines greatly assisted in this subdivision.The Triassic sequence contributes no magnetic effect of its own except to diminish the effect of sources within the underlying formations by raising the level of observation.Detecting the presence of igneous intrusions ahead of colliery working faces by magnetic observations within the coal mines may be of value in preventing accidents caused by gas outbursts and in planning the workings so as to avoid loss of production time.

Jan 1, 1967

The Aberfoyle Tin Mine lies on a wide sloping bench about 2,000-2,500 ft. above sea level, at Rossarden, 14 miles north of Avoca, in north-eastern Tasmania. The quartz-cassiterite veins were discovered in 1916, but mining did not begin until 1926. Trenching revealed seven small tin-bearing veins within a width of 57 ft. of Palaeozoic slates and sandstones, and it was assumed that the mineralization extended beneath the adjacent cover of Permian strata, but the presence of the main vein system (the 26 Vein System) was not suspected until the Aberfoyle Fault was discovered late in 1928.The mine has now been developed on thirteen levels, to a depth of 1,350 ft. The lower limit of economic mineralization appears to lie at about the ll-level, which is 1,060 ft. vertically below the concealed outcrop of the main veins. Production of tin and tungsten concentrates began in 1932, and to date more than 550,000 tons of ore have been mined for a recovery of 8,856 tons of tin concentrates, and 3,056 tons of wolfram concentrates, valued at approximately £6,500,000.This paper reports part of an investigation undertaken by the Mineragraphic Investigations Section of C.S.I.R.O. to study the mineral composition of the ore in relation to the apparent failure of cassiterite and wolfram mineralization to extend below the present working limits of the mine, and was first issued as Mineragrapnic Report No. 639.GENERAL GEOLOGY:The deposit consists of a series of quartz veins in a northsouth trending sheeted zone, transecting folded slates and...

Jan 1, 1957

Greater use should be made of lineations in investigations of the engineering properties of rock masses and in structural studies guiding prospecting programmes.A prominent alignment of elongate mineral grains and stretched pebbles usually marks the primary direction in which metamorphic rocks have been extended by flow. In local adjustment zones separating masses that have extended different amounts, this lineation has been a direction of slip. Kinks and crumples resulting from this slip lie in secondary lineation directions transverse to the primary mineral lineation.During deformation relatively mobile materials move into dilatant zones caused by irregularities in primary flow directions. This secondary movement transverse to lineated, primary-flow directions is the cause of crenulations and folds with axes parallel to flow lineations.INTRODUCTIONThe arrangement of inequidimensional particles in rocks is rarely statistically random. Platy minerals tend to be parallel to bedding and foliation planes. Elongate particles and linear structures lie most frequently in certain lineation directions. The types of elongate particles in lineated rocks include needle and blade shaped mineral grains, sheared out segregations, and stretched pebbles, amygdules, and aolites.Crenulations and kinks are the most common of the linear structures involved.Faint lineations are readily overlooked. Even strong lineations have been ignored. This is unfortunate as even weak lineations may be important.Use of lineation information Well-developed lineations influence the mechanical properties of rocks. Quarry workers have long known that the mechanical properties of rock masses vary directionally...

Jan 1, 1965

By D Craw, D Wilson, D Chappell

Gold is extracted by cyanidation of a sulphide-rich concentrate at Macraes mine, and after cyanidation, the concentrate is discharged to tailings impoundments. The concentrate tailings were discharged to a dedicated concentrate impoundment from 1989 to 1993, afterwhich they were blended with the flotation tailings. Since mid-1998, concentrate tailings have been redirected to the dedicated concentrate impoundment. The concentrate tailings contain up to 1 ppm gold, and will be reprocessed in the future. However, it is a regulatory requirement that a contingency plan be in place to rehabilitate the concentrate tailings should the mine operation cease for any reason. Initial predictions suggested that the sulphide-rich tailings would oxidise and acidify, creating a potential long term environmental problem. Investigations of the state of the tailings after 4 years show that these predictions were overly conservative. Only minor oxidation has occurred in the upper 2 metres of the tailings where the pH has locally dropped from 10 (discharge condition) to between 7 and 8. Below 2 metres, the tailings are essentially unchanged from their deposition state. The low rate of change in the tailings is due to their very low permeability which in turn is a consequence of the fine grain size (ca. 15 ¦m). Dewatering is extremely slow, and incursion of oxygenated water is negligible. Calculations suggest that water movement over 30 m will take at least 100 years and possibly 1000 years. The contingency plan is to capitalise on the very low permeability and keep the tailings from drying with a semipermeable cap. A layer of limestone will be added to the top of the tailings, beneath the cap, to enhance alkalinity of any percolating water. If acidification does occur, contrary to expectations, any acid produced will be neutralised by underlying calcite-bearing schist, schist in the concentrate impoundment wall, and the flotation tailings immediately downstream. In addition, dilution by alkaline ground and surface waters would further ameliorate any acidic discharge.

Jan 1, 1998

By French D

In presenting this paper may I preface my remarks by recognizing the presence here to-day of the many delegates from the overseas mining communities throughout the world. That is to say - those delegates not representative of Companies resident in Australia. This does not mean that my comments following are directed solely to the Australian exporter - far from it. The Company which I represent is internationally based. The experiences we have had in dealing and negotiating with our good friends the mineral cargo shippers vary very little in any operational area. However for the purposes of this exercise this address is based on some of our experiences within the Australian trade scene with the emphasis on the fact that we believe it has application to all trading areas.

Jan 1, 1989

A brief review is given of the history of the Colliery to date together with the reasons for the development of an additional seam.Investigations into the quality of the coal ami its suitability for the production of metallurgical coke and determination of the economic mining limits and coal reserves are discussed. The commencement of mining operations and the inter-seamarrangements necessary for the disposal of coal won are described with the stages in the opening out of the seam itself and the reasons for the installation of a 48-in. trunk conveyor belt. Choke and manning of face equipment are considered and also the work of secondary development and pillar extraction.It is concluded that with modern face equipment and conveyor belt lines, concentrated mining followed by immediate extraction of pillars is practicable and is giving excellent results at Burwood Colliery.INTRODUCTIONBurwood Colliery, the total holding of which now comprises some 3,140 acres of land and 1,450 acres of sea leases, has mined the Borehole Seam since 1883. The early work took place from Nos. 1 and 2 shafts at Glenrock Lagoon and later on at Nos. 3 and 4 shafts at Whitebridge to which the centre of operations shifted in 1893, shaft sinking at this latter area having commenced in 1888.As all the early operations were confined to the Borehole Seam, reserves of coal on this horizon had been considerably reduced by the mid 1930's, so a cross measure drift was driven to the Victoria Tunnel Seam which is about 300 ft. above the Borehole Seam, and fully mechanized coal winning commenced from the second seam in 1938. Subsequently this cross measure drift was extended to the Borehole Seam and complete mechanization of the south-west sections of this seam achieved by 1945.Four track mounted mechanical units were put into operation in the latter area and these worked in a southerly and...

Jan 1, 1958

By L Avalos, F Melo Miranda, J Misle, M Ingwersen

"Los Pelambres, majority owned by the Chilean company Antofagasta Minerals, is one of the leading producers of copper and molybdenum in the country. It is located high in Andes Mountains, over 3000 metres above sea level, 316 km from the nation's capital, Santiago.The maintenance service supplied to Los Pelambres over the past 13 years has evolved to the point that FLSmidth now provides an integrated service crucial to the management of their customer's assets. The contract initially involved specialty mechanical, electrical and instrumentation maintenance and has developed to encompass maintenance planning and plant control systems.The integrated partnership has delivered excellent results in the areas of improved availability, reliability and return on investment. The operation is now amongst the industry leaders in plant availability.The integrated maintenance service has delivered: An increase in plant availability from 93%, in the first year, to 96.5% today, generating approximately $50 million additional income per year, Quality work procedures, Process and equipment improvements, Major shutdown planning involving more than 700 personnel, 6000 parts and over 2 000 discrete activities.The ongoing success of the partnership requires a high level of understanding between both companies. A commitment to maintain a long term sustainable relationship, based on a ""win - win"" culture, is the key to this success. In this regard Los Pelambres has been a pioneer in establishing and developing such relationships.This case study will share the lessons learnt, the measures taken to improve performance and the best practices adopted during the 13 year evolution of the maintenance service partnership.CITATION:Misle, J, Melo Miranda, F, Avalos, L and Ingwersen, M, 2013. Integrated maintenance services at the Los Pelambres Mine in Chile - The lessons learnt and best practices developed from a long-term sustainable relationship, in Proceedings MetPlant 2013 , pp 296-331 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Adsorption of Alkylammoniums in the Interlayer of Montmorillonite and its Effect on the Viscosity of Organo-Montmorillonite Gels

Sep 13, 2010

Effects of High Pressure Grinding Rolls on Platinum-Bearing Ores and the Flotation Response as Compared to the Conventional Ball Mill Three major PGM ore types from the Bushveld Complex of South Africa: Merensky, UG2 and Platreef were comminuted with the use of the high pressure grinding rolls (HPGR). The influence of the feed characteristics and the various operational and design features of the HPGR on energy consumption, throughput, mineral liberation and PGM flotation recovery were investigated. The test work variables included two feed top sizes of 12 mm and 6 mm, specific grinding forces ranging between 3 - 7.5N/ mm2 and zero gaps of 1.5 mm and 3 mm. The results show that the influence of the HPGR operational and design features on energy consumption, throughput, mineral liberation and PGM recovery are ore dependent. The size reduction-specific energy relationships show that the most energy efficient utilisation of the HPGR for Platreef ore was at the lower specific grinding force of 3N/mm2 and the zero gap at 3 mm. For Merensky and UG2 ore on the other hand, the most energy efficient operation was at the higher specific grinding force of 7.5N/mm2 and the zero gap of 1.5 mm. At a specific energy input of 3 kWh/t, reduction ratios (F50/P50) of 6.5, 3.8 and 10 were obtained for Merensky, UG2 and Platreef, respectively for feed top sizes of 12mm. Further application of the HPGR as a pregrinding stage to a ball mill showed a 25 - 30 per cent increase in throughput for Merensky and UG2 ore. Batch flotation tests performed on selected samples appear to indicate that ore comminuted with the ball mill had superior grades compared with that ground with the HPGR. However, Merensky and UG2 ore comminuted at different HPGR operating conditions showed distinctions in PGM recovery. Platreef on the other hand did not appear to show any differences. Therefore, this study highlights the significance of ore type and operating variables in HPGR applications with regards to energy efficiency, throughput and PGM recovery.

Sep 13, 2010

The estimation of the shear stress distribution around an excavation is important to the design of the excavation since shear stresses can generate cracks, loosen grain boundaries or otherwise degrade the mechanical and physical properties of the rock and lead to stability problems. In this study, the distribution of shear stresses in a pillar were back-calculated from the deformation measurements made from the SPDV (Site and Preliminary Design Validation) area at the Waste Isolation Pilot Plant (WIPP) site. A plausible pattern of shear stress around an excavation has been suggested based on the Zero Strain Boundary (ZSB) calculation, computer simulation using FLAC, and back-calculation using measured deformation rates in the pillars.

Jan 1, 1998

By C Vuillier, A Roshdieh

Water is the main medium for removing impurities from iron ore during wet processing to achieve a higher quality product. However, there is a substantial increase in freshwater consumption due to an increase in demand from the following two factors: in the past 55 years the world population has doubled from 3 to 7.5 billion and crude steel production has increased five times from approximately 350 to 1662 Mt/a (IISI, 2008). Furthermore, social development in developing countries exacerbates water consumption making freshwater an increasingly valuable resource with an average distribution of 70 per cent for agriculture, 20 per cent for industry and only ten per cent for domestic consumption (Hourtolle, 2005; OECD, 2009). Rapidly changing regulations over the access and preservation of water across the world indicates the growing importance of this issue, so the mining industry must adapt to this continual change and must be committed to increasing the efficiency of water usage.Tailings dams receive most of the water used by the process plant. In arid regions where evaporation is high and availability of water low or non-existent, technical solutions other than the conventional tailings dam, such as thickened and/or filtered tailings, exist to optimise the recovery of water and reduce the need for external water consumption. However, these solutions present additional challenges, such as energy consumption and transportation from the process plant to the ultimate storage area.This paper considers a range of alternatives covering thickening and filtering, transportation and storage, water return, closure and rehabilitation. Mining projects in the future will be more affected by the rising cost in water and tighter regulations in accessing water and energy. Good tailings management can contribute significantly to reducing the dependence on these two key commodities (water and electricity), improving the resilience of iron ore projects especially in arid regions and areas with high competition for water.CITATION:Vuillier, C and A Roshdieh, A, 2017. Minimising the water loss associated with mine tailings disposal, in Proceedings Iron Ore 2017, pp 245–250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By A F. Wilson

The use of stable isotopic measurements as a technique for elucidating the origin and history of the water in hydrothermal fluids is relatively new. Recent studies have emphasised the importance of meteoric water in the formation of many hydrothermal ore deposits including many epithermal gold-base metal deposits which occur in faulted volcanic terrane. Other vein-type gold ores are believed to have formed from fluids of magmatic or metamorphic origin and exhibit characteristic d180 values. These values also give information regarding temperatures and the degree of equilibrium. Preliminary oxygen data for some important gold deposits of eastern Australia are evaluated in the context of styles of mineralisation.

Jan 1, 1980

Ladies and gentlemen, distinguished guests and fellow members of The AusIMM, good morning.   Thank you for the opportunity to address you all today, Crown Minerals are very pleased to be associated with the conference again this year, and I commend the committee on their organisation and delivery of this yearÆs event.   As you can see from the topic of my discussion, I would like to broach the subject of collaboration between ourselves û Crown Minerals û and you our clients, and convince you that we are on the right track but can each do more.

Jan 1, 2007