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Iron Ore 2017 Paper Number: 92

Enhancing magnetite concentrate granulation by blending with hematite ore

M Adam1, W Skinner1 and J Addai-Mensah2

1. Future Industries Institute, University of South Australia, Adelaide, SA 5095, Australia 2. Department of Mining and Process Engineering, Namibia University of Science and Technology, Namibia

ABSTRACT

Granulation of iron ore fines into robust and highly porous granules is critical to successful sintering/pelletising and blast furnace operations in iron and steelmaking. Iron and steel makers desire iron ore granules with high compressive strength, porosity and permeability, reducibility, uniform size distribution and low energy consumption to enhance smooth blast furnace operations. Unlike hematite concentrates, magnetite concentrates do not granulate easily at low bentonite dosage or sinter at low temperature (< 1300 C). This motivates the present study to harness the complementary properties of hematite granulation to enhance granulation and sintering of magnetite concentrates via blending. The current state of the art in hematite/magnetite blend granulation is reviewed, along with granule property limitations. Preliminary experimental work, on granulation of hematite/magnetite blends for sinter production is reported.

Keywords: Blending, blast furnace, concentrate, granulation, mineralogy, pelletising, permeability, reducibility, sintering, wettability,

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Iron Ore 2017 Paper Number: 93

Process improvement at Kumba Iron Ore Sishen and Kolomela mines through the use of Geoscan on belt analysis equipment

L A Balzan, E Jacobs, A R Harris and Z Bauk

1. Technical Consultant, Scantech International 2. Process Engineer, Kumba Iron Ore AngloAmerican Sishen Mine 3. Operations Manager, Scantech International 4. Product Optimisation Manager, Scantech International

ABSTRACT

Kumba Iron Ore, part of AngloAmerican, operates the Sishen and Kolomela mines in the Northern Cape region of South Africa. The mines utilise a number of processes for handling and upgrading the ore, including direct shipping, screening, upgrade jigs (including one of the largest jig plants in the world), and dense medium separation. The processes allow Kumba Iron Ore to exploit and optimise the outcomes depending on the variation in the ore. To obtain the maximum potential for each of these processes, Kumba Iron Ore quickly recognised the value in being able to measure the grade and quality of material at various points throughout their various processes. Scantechs Geoscan on belt analysis systems have been adopted throughout Kumbas operations in the Northern Cape and have become an indispensable tool in their operations.

Kumba Iron Ore purchased their first Geoscan in 2008 and have progressively expanded to 12 Geoscans throughout their Sishen and Kolomela operations. A single Geoscan is installed at Kolomela mine to assess the grade of ore for stockpiling and shipping. Five Geoscans are installed throughout Sishen mines jig plant, including on the run-of-mine feed to the plant and on the various products belts. There are a further three Geoscans installed within the dense medium separation plant on run-of-mine, drum and cyclone feeds. Finally, three new Geoscans are to be commissioned in 2017. This paper gives a brief introduction to the equipment and how it works, and summarises how Kumba Iron Ore uses the analysis data in operations to maximise the benefit from their processes, as well as giving an overview for ongoing and future works.

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Iron Ore 2017 Paper Number: 108

The practical characterisation of ferrosilicon for dense medium applications

J Bosman1 and W Blair 2

1. PESCO 2. Ferroz

ABSTRACT

The successful application of ferrosilicon in a dense medium application is dependent upon two things i.e. medium rheology and medium losses. Medium rheology is a result of the particle size distribution, particle shape and particle density of the ferrosilicon while ferrosilicon specific medium losses are related to magnetic susceptibility and medium corrosion . Medium rheology at a given slurry density is characterised by medium stability (settling rate) and apparent medium viscosity, as ferrosilicon mediums are non-newtonian. Comparing these measurements across different grades, shapes and medium densities provides valuable insights into the rheological behaviour of the medium. Measurements of particle size distribution, density and shape are relatively straight forward and their influence on the medium rheology for a given medium density are derived. The measurement of magnetic susceptibility and corrosion rate provide further insight into the potential magnetic recovery/losses and potential for corrosion in a circuit. The characterisation of ferrosilicon using all these parameters provides valuable insights into the different parameters and their contribution to both medium rheology and medium losses as well as providing a basis for comparing different types of ferrosilicon.

Keywords: ferrosilicon, dense medium separation, rheology, corrosion and magnetic susceptibility

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Iron Ore 2017 Paper Number: 24

Separation of ultrafine particles using the reflux graviton

J Carpenter1, S M Iveson and K P Galvin

1. ARC Research Hub for Advanced Technologies for Australian Iron Ore, Newcastle Institute for Energy and

Resources, University of Newcastle, Callaghan, NSW 2308, Australia

ABSTRACT

Wet beneficiation of iron ore fines less than 1 mm typically involve a desliming stage ahead of the fine gravity separation such as spirals. The desliming is achieved using a bank of cyclones. The ultrafines emerge from the overflow streams at relatively low pulp density, containing high proportions of low value slimes, and well liberated iron ore ultrafines. Clearly, this flow stream presents a significant challenge, in removing much of the water and slimes, while concentrating the ultrafine iron ore, predominantly finer than 0.045 mm.

The Reflux Graviton consists of distinct 3D Printed modular units, based on Reflux Classifiers, which are rotated at high speed in a large centrifuge. This system has previously been investigated under semi-batch conditions, demonstrating the potential for precision separations with significant capacity. It has been shown that the throughput advantage of the inclined channels and of the G forces multiply. This is the first paper presented showing the performance of this system under continuous steady state conditions. Ultrafine silica, in the size range of 0 to 45 microns, was fed to the Graviton at different volumetric rates, fluidization rates, and pulp densities ranging from 2% to 30%, in order to develop a fundamental understanding of the system performance. Experiments were then repeated using ultrafine iron ore.

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Iron Ore 2017 Paper Number: 26

Rapid and reliable flow property testing a modified uniaxial approach

W Chen1, J Miller1, J Plinke1, K Williams1 and W Roberts1

1. Centre for Bulk Solids and Particulate Technologies, Newcastle Institute for Energy and Resources, The

University of Newcastle, Callaghan, Australia 2308 Flow properties of bulk iron ore materials define critical parameters which identify the flowability of the ore through element of the material handling plant, such as bins, hoppers, stockpile stackers and reclaimers, chutes and ship loaders. The most accepted flow property testing methods in the industry is the direct shear method. However, for quality results, this method is time expensive and requires an experienced operator for good reproducibility. This research aims to develop a modified uniaxial tester for rapid, reliable and reproducible flow property characterisation. A multi-layer compaction method was utilised to achieve uniform density across the specimen during sample preparation. Results indicated that the flow property results from the modified uniaxial test work results correlated well with the results from the direct shear test work. In addition, the uniaxial test duration is two times faster and requires a less skilled operator when compared to the direct shear test system. Consequently, the outcome of this research enables a rapid onsite flow property assessment for material handling processes.

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Iron Ore 2017 Paper Number: 125

Development and Application of Evaluation Model for Iron Ore Performances

T Chun 1*, H Long 2, P Wang 3, Z Di 4, Q Meng5 and X Zhang 6

1. PhD, Associate professor, Anhui University of Technology, Ma'anshan 243002, China 2. PhD, Professor, Anhui University of Technology, Ma'anshan 243002, China 3. Professor, Anhui University of Technology, Ma'anshan 243002, China 4. PhD, Lecturer, Anhui University of Technology, Ma'anshan 243002, China 5. Associate professor, Anhui University of Technology, Ma'anshan 243002, China 6. PhD, Professor, Anhui University of Technology, Ma'anshan 243002, China

ABSTRACT

Due to the great differences on the iron ore performances in the world, two iron ore evaluation models, simplified version and scientific version, were developed according to the properties of iron ores. Combining with the production parameters of sintering and ironmaking processes, the proportioning model of sintering and prediction model of hot metal were also developed using Visual Studio, which could provide a quantitative assessment for various iron ores rapidly including the most optimal purchasing price and its influence on the cost of hot metal. Those software is successfully applied in the ironmaking plants, such as Meishan Steel and Liuzhou Steel plants in China.

Key words: iron ore; evaluation model; sintering; application