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By H Ishikawa, H Zhou, M Spagnolo, R Halomoan, S Palaniandy

The Karara Mine concentrator commenced operation in November 2012 to produce high-grade magnetite concentrate. The circuit consists of three stages of comminution plus magnetic separation at each stage for early gangue rejection. High-Pressure Grinding Rolls (HPGRs) are used for fine crushing, followed by ball mills and TowerMills in secondary and fine grinding duties respectively. In recent times, the plant throughput rate has had to exceed design by 18% to maintain the targeted concentrate productivity. Meanwhile, the ore hardness has increased by 25% to 15 kWh/t, leading to changes in the circuit operation and design. These changes led to coarser and harder feed to the TowerMill circuit that affects the subsequent separation processes. Nippon Eirich (the TowerMill manufacturer) has partnered with Karara Mining Limited (Karara) to optimise the TowerMill circuit operation to achieve a circuit product with an 80% passing (P80) of 35 µm. Several activities, including a TowerMill circuit audit and performance evaluation, multi-component analysis, modelling and simulation, were carried out as part of the optimisation exercise. The circuit audit results revealed that the TowerMill circuit feed size F80 had increased and ranged from 67–75 µm. The circuit product P80 ranged between 42–55 µm. The average circuit specific energy was 3.4 kWh/t. Moreover, the differences in density between magnetite and gangue minerals had affected the hydrocyclone performance where the efficiency curve exhibits coarse end deflection indicating that low-density coarse material was bypassing to the overflow stream. A multi-component analysis was carried out to further investigate the coarse end deflection of the hydrocyclone efficiency curve. The analysis showed that the magnetite and gangue minerals had different cut sizes of 32 and 64 µm respectively. Furthermore, 33% of the magnetite (below 35 µm) was being recycled back to the mill due to the density effect. Based on these findings, several recommendations for process improvement were identified and implemented including:• converting to a bottom feeding configuration to improve the grinding efficiency in the mill• additional grinding power in the fine grinding duty to compensate for the increase in plant throughput and ore hardness• improved classification efficiency by converting to smaller size hydrocyclones. Simulation studies carried out to evaluate the impact of these implementations had indicated that a P80 close to 35 µm with a steeper size distribution could be achieved by using the bottom feed configuration with additional grinding power. The TowerMill circuit was converted to bottom feed configuration and the performance was evaluated. The operating work index, size specific energy and circulating load were 30% lower than the top feed configuration, indicating that the bottom feed configuration had a higher grinding efficiency. This paper discusses the outcome of the circuit audit, multicomponent analysis, circuit simulations, improvement strategies and quantification of the improvements. CITATION:Palaniandy, S, Spagnolo, M, Halomoan, R, Zhou, H and Ishikawa, H, 2017. Fine grinding circuit process improvement at the Karara mine concentrator, in Proceedings MetPlant 2017, pp 101–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By D R. Seaman, B Adamson, P Sharman, M McMahon

"The Telfer processing plant commissioned its pyrite regrind and flotation circuit in August 2012. The circuit was designed to regrind pyrite concentrate to a p80 of <30µm then float a gold and copper rich concentrate before tails from the flotation circuit fed the carbon-in-leach (CIL) circuit downstream. Expected benefits were: improved CIL performance that would result from the finer grind and a reduction in cyanide soluble copper to the CIL circuit, as well as a small increase in overall flotation circuit recovery. While the benefits of a finer grind were soon realised, recovery in the post-regrind flotation circuit (named the ‘pyrite recleaner circuit’) was consistently and significantly lower than that expected based on laboratory test work. Selectivity in the pyrite recleaner circuit was virtually nil and copper reporting to the CIL circuit did not change as a result of the pyrite recleaner circuit operation.A pulp chemistry survey of the plant and comparison with the lab showed that the dissolved oxygen (DO) demand in the plant was much higher than that in the lab. Lab flotation tests conducted using nitrogen gas instead of air resulted in recoveries similar to those from the plant. It was identified that the freshly ground pyrite surfaces exiting the regrind mill were consuming oxygen in the slurry and there was insufficient oxygen available for collector adsorption and pyrite depression to occur. Test work, using a pilot regrind mill, showed that a reduction in grind size resulted in an increase in DO demand.A range of oxidising agents were tested in the laboratory and using a pilot flotation rig set-up in the plant. Oxygen was found to be the most reliable and effective agent and options for increasing oxygen delivery to the plant were explored. Scale-up from the lab oxygen requirement to the plant is difficult and efforts to implement a permanent solution for meeting the DO demand in the plant are ongoing.Citation:McMahon, M, Seaman, D R, Sharman, P, Adamson, B and Seaman, B A, 2016. Optimising the Telfer Pyrite Regrind Circuit - Effect of Dissolved Oxygen Demand, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 51–58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

With production at Olympic Dam scheduled to commence in June 1988, it has been necessary to install a complete underground ore handling system capable of removing two million tonnes of material annually from the mine. The system comprises mucking from stope drawpoints, truck haulage to underground storage, primary crushing, conveying and hoisting. On the surface, material is conveyed to stockpiles at the Metallurgical Plant. Mining of the numerous special excavations within the system was incorporated into the mine's ongoing development program prior to the underground construction phase. Utilisation of a decline from the surface enabled versatile construction equipment to operate at the underground sites as well as simplifying the transportation and delivery of construction Materials.

Jan 1, 1988

By M Scoble, C Hughes, M Roberts

At 14 per cent, the representation of women working in the mining industry is the lowest among primary industry categories in Canada. Despite an increase in research and industry commitment to advance and retain women in the mining industry, the gender gap in mining organisations persists.This paper is based upon a recent Canadian survey of 163 highly qualified women (HQW) working in the mining sector. For the purpose of this research, HQW were defined as women with a BachelorÆs degree or higher. This research sought to identify career progression and retention patterns of women who in theory have the educational qualifications to advance into positions of leadership in mining operations. We considered why womenÆs advancement in mining organisations has stalled; examined the career development pathways of HQW; and investigated the interactions of mining workplace culture on HQWÆs career development and retention within the Canadian mining industry. Results?indicated two distinct career pathway trends for HQW. æThe specialistÆ; a career characterised by multiple professional scientific and technical positions, and æthe corporateÆ; a career characterised by professional administrative roles and roles in mid-level management. It was found that neither æcorporatesÆ nor æspecialistsÆ systematically progressed into senior management and executive roles. These findings suggest that HQWÆs careers in mining are stalled, despite a strong indication by respondents of interest in their professional career advancement. With regards to?workplace?culture, respondents indicated that blatant forms of gender discrim-ination have been reduced in mining workplaces; however, exclusion from informal networks, implicit bias and subtler forms of workplace discrimination persist. Consistent with previous mining sector research, improving work-life balance, work flexibility and mentorship were found as key drivers for HQW to advance and remain in the industry.CITATION:Hughes, C, Scoble, M and Roberts, M, 2012. Where are the women? Highly qualified women in the mining industry, in Proceedings International Mine Management 2012, pp 23-34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By D Liu, M Edraki, L Berry

The presence of clay minerals slows down the settling rate and mitigates compact consolidation efficiency in tailings dewatering. The increasing use of saline water in many plants, affects the dewatering performance and presents the mining industry with new concerns. Efficient tailings dewatering is a great challenge due to the complexity character of tailings, especially clay mineralogy, clay content, and water chemistry. In this study, existing studies of the effect of different affecting parameters, such as pH, ionic strength and polymer flocculants, on clay aggregation behaviours are reviewed. The settling behaviours of three types of commonly observed clay minerals in tailings, kaolinite, bentonite, and illite, are also investigated in saline water with different water salinity as a case study. The settling rates of clay minerals are found to be affected by water salinity, clay type, clay content and polymer dosage levels. High salinity water hinders the settling of kaolinite but assists the settling of bentonite and illite through formation of different aggregation structures.The current work has indicated that strategies to promote more rapid dewatering could include adjusting flocculant type or level, water salinity and salt balance, and tailings solid content levels. Implementing dewatering strategies may require a more detailed knowledge of the effect of surface chemistry on the nature and strength of the clay inter-particle forces. This study discusses the research gaps on how to better manage clay-rich tailings in saline water and identifies new research directions. The development of a water management model, supported through in-line monitoring data to predict and manipulate of the surface chemistry of the clay component of the tailings could be a new direction to manage the issues associated with clay minerals in the process of dewatering and tailings management. Mine planning (water use requirements, operating costs) could benefit from more detailed studies on dewatering of clay-rich tailings in saline water. CITATION:Liu, D, Edraki, M and Berry, L, 2018. Improving the dewatering efficiency of clay-rich tailings in saline water, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 476–484 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By M Olsson, U Nyberg, K Widenberg, P Svedensten, F Ouchterlony

During 2007 and 2008, the project Optimal Fragmentation in Blasting II was conducted at the Långåsen quarry of NCC Roads AB near Arlanda. The main goals were:an evaluation of the effect of using electronic delay detonators (EDDs) in quarry blastinga validation of the design curve concept introduced at the Vändle quarry.Five production blasts were monitored. After a first trial round, the remaining four rounds each had about 100 Ø89 mm holes in a 14–19 m high bench charged with site mixed emulsions. In rounds 1 and 2, a tighter pattern than normal was used in one half of the rounds, raising the specific charge there from 0.7 to 1.0 kg/m3. Non-electric initiation was used with two holes per 25 ms delay in-row and 67 ms between rows. In rounds 3 and 4, electronic delay detonators were used instead, with 10 and 5 ms in-row delays respectively.The monitoring encompassed drill hole collaring and alignment, in-hole deviations, the rock structure in the bench faces from 3D imaging, first row burdens, etc. Eleven 400 t samples were taken from the muck piles and sorted in the quarry and sieved in the laboratory (lab). The lab data made up a fines tail that was grafted onto the in-pit sorting data to form sieving curves for the test piles. These curves were then compensated for the absence of boulders to construct the sieving curves for the blasted muck pile.These have been used to derive fragmentation model formulas for the non-electric rounds, also called design formulas. They are based on blast geometry, charging data and the properties of the rock mass. The formulas may be used to estimate the effect of changing blasthole pattern, borehole diameter and stemming length for example.The use of EDDs gave several unexpected results. In comparison with non-electric initiated rounds with a somewhat lower specific charge the fragmentation was much coarser; x50 increased from 160 to 200 mm. The effect of raising the specific charge in the non-electric initiated rounds from 0.72 to 0.99 kg/m3 was a much finer fragmentation; x50 decreased from 160 to 120 mm.CITATION:Ouchterlony, F, Nyberg, U, Olsson, M, Widenberg, K and Svedensten, P, 2015. Effects of specific charge and electronic delay detonators on fragmentation in an aggregate quarry – building fragmentation model design curves, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 727–740 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

LIST OF CONTENTSAbstractIntroductionSelected Sections of the Broken Hill LodeLocality PlansPetrology1. Zinc Corporation Mine: DDH. 5.98, section 30, No. 26 level2. Zinc Corporation Mine: DDH. 838, section 30, No. 13 level3. Broken Hill Sonth Mine: 60 ft. cont01(r above 1170 ft. level4. Broken Hill South Mine : No. 7 shaft section, 1370 ft. levelOrigin of garnet sandstone5. Barrier Central Pty. Ltd.: DDH. tJ.93, Block 136. North Broken Hill Ltd.: Junction mine, DDH. 602, No. 10 level7. North Broken Hill Ltd.: Jnnction mine, DDH. 588, No. 11 level8. North Broken Hill Ltd.: North mine, DDH. through Southern ore body, 3370 ft. level9. North Broken Hill Ltd.: North mine, Northern ore body above 2300 ft. level(a) Southern end, section 27, 77 ft. above rails(b) Northern end, section 30, 6.9 ft. above rails(c) Miscellaneons samples, sections 27 and 28Relative time of ore depositionSericitizntionStructural significance of sericitizationGCLhnite OrthoclaseApatite GarnetManganese SilicatesAlteration of manganese silicatesRelation of zinc and lead to the silicatesZinc in manganese-bearing silicatesLead in potassium and lime silicates and apatite

Jan 1, 1959

By J Hudson

Autogenous (AG) and Semi Autogenous (SAG) grinding mills are the conventional selection for large-scale grinding circuits. It is accepted that these forms of comminution are not the most energy efficient available. This efficiency combined with escalating energy prices, steel prices and the requirement to process larger, lower grade deposits has necessitated that better comminution techniques are found to challenge the dominant position of AG/SAG mills in the grinding circuit. Recent advances in high pressure grinding rolls (HPGR), particularly in terms of roll surface protection have meant that, depending on the application, an economic alternative is available to the large diameter AG/SAG mills. Mining companies now recognise the potential benefits of HPGR and so they need proper assessment in the design of new or upgrade of existing grinding processes. Of course, the answer to the question AG/SAG or HPGR is not straightforward and the impact of the grinding process on the whole metallurgical process needs to be evaluated. Clearly this is a complex decision to make and requires substantial metallurgical knowledge, test work, and objective analysis. The perceived downstream processing benefits will differ between different plants depending on the ore type and processing conditions. The optimal design of the comminution circuit requires that a robust methodology is followed to objectively characterise the ore, size the equipment and determine the downstream processing benefits. The paper gives a brief comparison of the capital and operating costs for both grinding systems, and then outlines the appropriate test work that is required to make an informed decision.

Jan 1, 2006

By McLennan T, Howells E, Zastawny H, Watt J. S

Nuclear techniques have been used to determine the solids weight fraction (W) and ash content of (fine) coal in slurries independent of voidage variations. The method is based on the correlation between W and the hydrogen concentration Hsl (wt/wt) of the slurry. Hsl is determined by combining measurements of neutron moderation and ?-ray transmission. Both Wand ash content are determined by combining the above measurements with the ash-sensitive measurement of X-ray backscatter compensated by a measurement of iron K X-ray intensity.The nuclear analysis system, called the SIRO coal slurry gauge, has been proved in a six-week plant trial at the BHP Steelworks washery at Newcastle, NSW. Several probes, each containing a radioisotope source and scintillation detector, were immersed directly into the coal slurry in the feed box upstream from the bank of flotation cells. For 140 samples W, ash and voidage varied in the ranges of 0 to 13 wt percent, 26 to 41 wt per cent and 0 to 4 vol. per cent, respectively. The r.m.s. difference in solids weight fraction, determined by probe measurements and conventional assay, was 0·52 wt per cent. Ash was determined with an r.m.s. difference of 2·0 wt percent in the coal. Better sampling techniques were used in the last half of the plant trial, and r.m.s. differences were 0.35 wt per cent solids and 1·5 wt per cent ash.

Jan 1, 1986

The issue of retrenchment is a topic of considerable relevance for the Papua New Guinea (PNG) mining, petroleum and gas industries. The unique environments in which Porgera Joint Venture (PJV) and other similar operations operate are likely to confront these industries with particular dilemmas that will require a range of investments to mitigate the problems associated with retrenchment and employment. This paper discusses retrenchment and employment in the PNG mining industry using the specific case study of PJV. The paper deals with the issue of employment and retrenchment of local workforces in the PNG context, which presents a serious challenge for the resources industry and the achievement of sustainable development objectives. The issue of future retrenchment of the workforce as a result of mine closure is an obvious challenge for both PJV and the Porgeran community at large, who have now come to rely upon both the employment opportunities presented through the mining. This paper examines these challenges and in doing so highlights some progress made by PJV. The paper also discusses downsizing, strategic practices and holistic approaches of retrenchment and employment. In doing so the paper highlights issues that have been overlooked in both academic and applied studies from global and local perspectives in the PNG mining sector. The latter sections articulate the relevance of the information provided by the case study in the wider context of retrenchment. The conclusion promotes a perspective that a great deal more investment will be required by all stakeholders to respond to the challenges of managing retrenchments and mine closure.

Jan 1, 2009

By M R. Drumond

The present work presents a new theoretical interpretation of the flotation process, which can also be applied to other mineral processing physical unit operations. This interpretation is part of the æModelo OperacionalÆ (Operational Model) that was developed as an attempt to establish a new theoretical basis for mineral processing unit operations. In the case of flotation, a book was edited by one of the authors in Brazil (Mass Concentration by Froth Flotation, in Portuguese and Spanish).The model establishes a link between a natural phenomenon (migration of particles from the pulp to the froth) and a real industrial phenomenon (mass concentration by operational interference). In this model, flotation is viewed as a phenomenon of macromolecular mass transport (of particles) between froth and slurry phases. Mechanisms for mass transport and particle flow between phases as a function of the hydrophobic potential in each phase are discussed. By establishing the so-called equilibrium distribution curve between phases it is possible to calculate macroscopic balances that are related to metallurgical results, which in turn are a function of the operational line that is required by the process itself. The number of cleaning stages and their efficiencies can also be determined by simple laboratory-scale experiments.

Jan 1, 2005

By A Dal-Corobbo

Traditional acid and metalliferous drainage (AMD) wastewater treatment focuses on the iron co-precipitation/adsorption process as this is a very effective method of reducing heavy metals, including copper, lead, zinc, arsenic, etc, to parts per billion (ppb) levels in AMD wastewater streams. One of the drawbacks to this method however is the large volume of sludge produced and subsequent disposal costs for the mine site concerned.A proprietary metals treatment system called high density sludge (denoted HDS) which significantly reduces the quantity of waste generated is described in this paper. This process generates a dewatered sludge that contains in the order of 50 to 55 per cent solids. This sludge is denser than conventionally dewatered sludge, which typically contains only 20 to 30 per cent solids. This advanced process has a wide range of applications and can be easily retrofitted into existing AMD treatment systems. It has been successfully installed at several mine sites to treat AMD wastewaters. This paper discusses the high density sludge process, its benefits and provides data and operating results from pilot test installations.CITATION:Dal-Corobbo, A, 2013. High-density sludge process for treating metal bearing acid and metalliferous drainage wastewaters, in Proceedings Water in Mining 2013 , pp 217-220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

Corrosion affects the performance of rock support and reinforcement at various underground mines, including the George Fisher Mine, where recent studies showed that this risk to mining operations is generally not well understood. Corrosion reduces the capacity and life expectancy of ground support and generally is undetected unless the traditional destructive pull out test is employed to detect defect bolts. Where it is still acknowledged that the pull out test has still an important role to play in determining critical bond lengths for static and quasi static ground support designs, it does not provide an underground operation with any reassurance regarding its bolt's integrity, which has been compromised by in situ aggressive conditions. Non-destructive rock reinforcement calibration testing on single and twin strand cable bolts, rebar bolts and friction bolts at the George Fisher Mine enabled the testing team to detect bolts with compromised integrity in one area of the mine. The non-destructive rock reinforcement integrity testing conducted uses a complex 'Stress Wave Analysis' package based on the processing of clear seismic signals imparted into the rock reinforcement element that is being tested. The seismic signals are processed by 'Fourier Transform' into various criteria which can be used to produce models of the element such as mechanical admittance, frequency spectra and velocity which are all being used in the final modelling of the rock reinforcement element under analysis. This paper highlights the enormous potential to effectively manage the geotechnical risk that corrosion presents for an underground mining operation.

Nov 25, 2010

Jan 1, 2004

By T Kilpatrick

Managing heat stress on Australian mine sites is a complex and enduring challenge due to the combined and variable contribution of environmental conditions, physical activities, and protective equipment. Inappropriately managed, heat stress can place significant physical strain on workers, leading to serious and chronic health issues. Additionally, excessive heat stress can dramatically reduce productivity, with 30 per cent of workers reporting a loss of productivity due to occupational heat strain. In Australia, due to increased absenteeism and reduced work performance, heat strain is estimated to have an annual economic burden of over $8 billion.

May 5, 2022

By A F. Cropp, D J. Bradshaw, W R. Goodall

Mineralogy and critically the texture of both the ore and gangue phases are of paramount importance in the flotation recovery of copper from porphyry ores. Mineralogy and texture will define the theoretical grade recovery curve for a feed ore. Actual grade-recovery falling below this may be due to texture and gangue influences, whilst desired grade-recovery above this line will not be possible unless the characteristics of the feed are altered.This review discusses examples of porphyry copper deposits where process mineralogy has been used to characterise these textural and gangue influences on recovery by flotation. More specifically, the influence exerted by grain size, liberation, association and elemental distribution is explored. The implications of these on overall plant philosophy and operation are highlighted, along with the subsequent potential impact on recovery.CITATION:Cropp, A F, Goodall, W R and Bradshaw, D J, 2013. The influence of textural variation and gangue mineralogy on recovery of copper by flotation from porphyry ore - a review, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 279-292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By A Teen

An open cast mine on the West Coast of the South Island of New Zealand proposes to remove up to 30 m of overburden to access an ore body neighbouring National Reserve land. Part of the conditions of the mining permit is that no material above natural discharge levels may be released over the Mining Lease boundary onto the adjacent land. In order to meet this requirement, the client has contracted the design and installation of over 2.6 km of high energy dynamic rockfall control barriers. This paper describes how the rockfall hazards were assessed and the rockfall barriers dimensioned. The design involved 2D modelling of over 3000 simulations.   Modelling parameters were calibrated during field trials at a purpose built section of barrier. The resultant energies ranged from 500 to 3000 kJ. The construction phase of the project involved the drilling, anchoring, and installation of certified barriers up to 7 m high in a remote and inhospitable climate with limited machinery access. By exploring best practice in this specialized field of engineering, a novel rockfall hazard mitigation solution was identified.

Jan 1, 2007

By Z Tong, M Gao, X Wang

In response to the need for improved magnetic separators for beneficiation of fine grained iron ores that have been finely ground to liberate the iron minerals from the gangue, a series of high efficiency wet drum permanent magnetic separators (T-GCT) has been developed by Maanshan Tiangong Technology Co Ltd. These magnetic separators have high efficiency for separating superfine strongly magnetic minerals and the ability to produce high-grade concentrates with high recovery. They are ideal replacements for conventional drum magnetic separators, especially for treating superfine particles.

Jan 1, 2009

By M D. Taylor, G Duclaux, K Atkinson, L A. Fisher, A R. Latham, M F. Gazley, S J. de Beer, C M. Tutt

Geological logging by mine and exploration geologists involves the application of a logging code that requires a geologist to make a subjective decision to classify a particular rock unit. This will most likely result in inconsistencies in logging that will be difficult to monitor or assess over time. A potential solution to this problem is to have an objective method to determine the true nature of a given rock unit. This can be achieved using portable X-ray fluorescence technology (pXRF), as large geochemical data sets can be collected rapidly and at low cost. Plutonic Gold Mine (Plutonic), Western Australia, has a growing data set of more than 150 000 pXRF multi-element analyses from core and underground face samples, reconciled to Au fire-assay concentration, and logging codes. This study investigates and statistically validates the consistency with which the logging codes have been applied at Plutonic for the last four years, with respect to both Au distribution and other elements. In doing so, we have developed a schema that allows objective logging to occur once core has been sent for assay and analysed by pXRF. While far from replacing the geologist in the field, this is a complementary method that adds significant value to a data set.CITATION:Gazley, M F, Tutt, C M, Latham, A R, Duclaux, G, Fisher, L A, Taylor, M D, de Beer, S J and Atkinson, K, 2013. Objective geological logging using geochemical multi-element data - Plutonic Gold Mine, Western Australia, in Proceedings World Gold 2013 , pp 455-462 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By C Delwig

ThyssenKrupp specialises in the manufacture of high-grade steel-sheet products. Its main customers include the automotive, construction, household appliance, energy and packaging industries.At its works in Duisburg, Germany, ThyssenKrupp Steel Europe produces 12 Mt of crude steel annually, making Duisburg one of the world’s largest steel hubs.ThyssenKrupp have installed an online elemental analyser and limestone dosing control System on one of three Sinter strands at Duisburg in an attempt to control the sinter raw mix with better precision. Traditionally, set point changes to the raw mixture were made after sampling and laboratory analysis of the sinter product. The analyser chosen uses prompt gamma neutron activation analysis to determine the elemental content of moving material on a conveyor each minute and was supplied by Thermo Fisher Scientific. The project goal was to control the CaO/SiO2 ratio (basicity) and reduce its variability in the sinter feed.Evaluation of the system has shown that the addition of the online analyser reduces the time lag related to the former method, therefore upset conditions can be reacted more quickly by the control system, and this has resulted in a more stable sintering process. As a result, the sinter feed variability in case of the basicity has been reduced by half. While CaO/SiO2 control was the initial aim of the project, a number of other benefi ts have been realised, such as a reduction in return fi nes and a financial benefi t of 0.11 €/ton of sinter attributed to the reduction of coke breeze and limestone. ThyssenKrupp Steel Europe has identifi ed that additional information available from the analyser could be used to optimise the complete sinter process.The project was carried out with a financial grant of the research program of the ‘Research Fund for Coal and Steel’.

Jul 11, 2011