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By Y T. J Kwong

With the recent emphasis worldwide on environmental protection and sustainable development, finding an enriched mineral deposit no longer guarantees mining development. Only if the identified resource can be exploited in an environmentally-friendly manner is it possible that a mine may be developed. Designed primarily to aid with exploring for similar deposits of a particular type, traditional genetic ore deposit models tend to ignore the fact that all mineral deposits are characterised by type-specific environmental signatures. In fact, how an ore deposit can be mined, the commodities of interest extracted and the resultant mine wastes managed are all largely dictated by the geology and mineralogy as well as the environmental setting of the deposit. An environmental ore deposit model integrates such related information to identify the environmental challenges associated with mining an ore deposit of a particular type and facilitates the selection a suitable combination of methods to minimise environmental risks and impacts. Given that environmental management consumes a large portion of the budget for a modern mining project, making informed decisions at all stages of mining development can reduce the overall project cost. Through case examples, this paper demonstrates how environmental ore deposit models may be useful in mine permitting, active mining and in site decommissioning. It is only through an innovative and flexible approach that the mining industry can shed its tarnished image and gain the social license to mine.

Aug 22, 2011

By B L. Sommerville

"The theme of this International Mining Geology Conference is ‘Setting New Standards’. Rio Tinto’s iron ore operations include a complex integrated supply system to deliver ore from 15 mine operations through four independent terminals over 1700 km of rail line. Significant growth in the past 20 years has seen production grow from 88 Mt in 1997 to 329 Mt for the 2016 calendar year.With more than 50 years of mining in the Pilbara, Rio Tinto has extensive experience in developing standardised approaches to mine geology and the geometallurgical prediction of product quality to meet the increasing growth profile and business planning complexity.Rio Tinto’s standardised approach to mine geology can be developed and utilised on a daily basis to enable the optimisation of the supply chain in terms of tonnages and product quality. This experience demonstrates a fully standardised system can balance the needs of a systematic process across all mine sites and the flexibility for mine geologist to determine and use local properties at each mine; this is done by ensuring two key principals are in place: a single, centrally maintained, system is established and maintained, providing a common set of processes and software across all mine sites the system allows senior mine geologists to review and customise key attributes and product regressions, ensuring site specific data is used in product predictions.The benefits of formal work process and standardisation include health, safety and environment, people and skill development, cost and improved communication. Also product predictions from mine geologists are one of the key inputs into an integrated and dynamic mine to ship scheduling system, optimising the supply chain whilst still managing the product quality. The experience of Rio Tinto is that a standardised approach to mine geology is an enabler of value for the iron ore operations.CITATION:Sommerville, B L, 2017. Mine geology standardisation – providing the foundation to consistent short-term geometallurgical product predictions in a complex multimine and supply chain environment, in Proceedings Tenth International Mining Geology Conference 2017, pp 13–20 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

By M Camarda, A Pirson, F Vasconcelos, J Mesquita

ArcelorMittal Prijedor is a goethitic iron ore mine located in the north-west of Bosnia and Herzegovina, which mainly supplies ArcelorMittal’s European subsidiaries. Annual production of the asset stands at the level of 1.5–2.1 million tons of iron ore product which is sent to ArcelorMittal Zenica steelmaking plant. Two types of products with approximately 50 per cent Fe are generated in Prijedor through a process composed by crushing, screening, and magnetic separation stages. Within this process one of the tailings produced is called ‘ultrafines’. The ‘ultrafines’ product corresponds to the desliming hydrocyclones overflow in Prijedor plant, which is classified in a size fraction below 25 μm and corresponds to about 5 per cent of feed. This material is richer in iron than the coarser size fractions of the ore but do not present a good performance in concentration processes. In this way, several studies have been carried out during the last years to find solutions to use the ‘ultrafines’ material without success. In this context, the possibility of dehydroxylate the goethite contained in the material transforming the mineral into hematite and thus increasing the iron grade of the final product was investigated. During the research, several dehydroxylation tests with different temperatures and time of exposure were performed. Using dihydroxylation process at temperatures higher than 800°C it was possible to produce a material with 43 per cent Fe from the original 39 per cent Fe ‘ultrafines’ sample. In addition, the dehydroxylation tests confirmed that goethite becomes completely transformed into hematite at 400°C (with an exposure time of 60 mins) and material is completely sintered at 1200°C. A simulation study based on dehydroxylation tests results showed that it would be possible to use a ‘ultrafines’ product with Fe grade higher than 45 per cent to produce a material with 50 per cent Fe through a complete dehydroxylation process.

Sep 18, 2023

By Riley S. J

The basic aim of mine planning is to design mine layouts and schedules that achieve optimisation of operations, minimum cost and maximum resource recovery. Successful accomplishment of this aim is facilitated by timely and comprehensive rehabilitation planning commencing at the pre-feasibility stage and continuing until the end of mining. Incorporation of a final landfomt design for waste rock dumps in a mine plan requires a prediction of surface stability, which may be achieved through erosion modelling. Erosion prediction models can be placed in two broad categories: soil loss prediction models eg USLE and CREAMS, and geomorphic models such as SIBERIA. A waste rock dump landform design based on selected slope form and grade and drainage systems should be developed as part of planning. A digital terrain model (DTM) of the landfonn should then be produced which can be modelled for long-term erosional stability using pre-determined parameter values. If acceptable standards of stability are not achieved, the landform should be redesigned and remodelled until the desired result is obtained. The planning process incorporating models requires knowledge of spoil or waste rock properties and model parameter values. This information is site specific and can be obtained from drill cores or costeans at the pre-mining stage and from spoil or waste rock during the mining stage. Realistic model parameter values are critical in post-mining landfonn design and can be obtained by several methods, including rainfall simulation, monitoring, geochemical analyses and grain size analysis.

Jan 1, 1994

By S Tierney, D Cumming-Potvin, I Thin, Y Potvin, D Grant

The preliminary modifying factors for future stope design in the Southern Mine Area of Olympic Dam consisted of only a single, arbitrary value of Equivalent Linear Overbreak/Sloughing (ELOS). In order to improve this, a study was conducted which developed a more comprehensive methodology for assigning ELOS, Equivalent Linear Lost Ore (ELLO) and Equivalent Linear Fill Overbreak (ELFO) to individual stope faces based on geotechnical and mining parameters. The approach used was to look at the simple cases, which were classed as vertical stope walls in good ground (RQD 80-100%), divided into wall orientations (North, South, East, West). The stope walls were also split based on the blasting practice used (toeing, parallel or a combination of the two). The expected ELOS and ELLO from these ‘base cases’ are then modified by parameters which have historically been found to affect stope performance (Hydraulic Radius and Q’). The size of the effect found in the historical data determines the ELOS / ELLO applied. The methodology was summarised in an easy to use flow chart and was applied to all of the proposed stope shapes for the Southern Mine Area and summarised per mining block. This allowed each iteration of the mine plan to be assessed in terms of overbreak (both rock and vertical fill exposures) and underbreak.

Mar 15, 2021

By G J. Lyman

Sampling of grain for mycotoxins is challenging in that some mycotoxins, such as Ochratoxin A (OTA), have very low permitted levels and the kernels carrying the mycotoxin may be highly localised within the bulk of the grain as ‘hot spots’. Sampling for genetically modified organisms (GMOs) can be fraught with similar problems, especially if the contamination is adventitious and random. Incremental sampling under these circumstances can be shown to lead to a high variance in the sampling result.A new design of sampler for grain and other free-flowing particulates has been developed that is effective in practically eliminating the sampling variance due to distributional heterogeneity (DH).This paper introduces the design and argues that the sampler should be free of sampling variance due to DH.CITATION:Lyman, G J, 2017. A new sampler for grain and other free-flowing particulates, in Proceedings Eighth World Conference on Sampling and Blending , pp 277–280 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By P Swart, A Fletcher, P D. Erskine

Glencore Coal Assets Australia (GCAA) operates five coalmines in Queensland and has rehabilitated thousands of hectares of mined land across these sites. Accordingly, GCAA seeks to continually improve rehabilitation outcomes over time and work towards progressive rehabilitation sign-off. The ultimate test of rehabilitation success is the attainment of an agreed land-use target, whether for biodiversity conservation or some type of agricultural production, and the ability of the rehabilitated landscape to resist degradation and retain desired functions (eg biodiversity protection or grazing productivity). However, success must be based on documented evidence that can demonstrate adequate progress towards rehabilitation targets and is assessed at appropriate intervals. To assist this task, a stepwise decision guide for the GCAA monitoring program was developed to ensure consistent monitoring data is collected across the range of sites. This presentation will discuss some of the processes that were followed to allow GCAA to identify appropriate metrics to assess rehabilitation success efficiently over thousands of hectares.CITATION:Erskine, P, Fletcher, A and Swart, P, 2016. Preparing for progressive mine rehabilitation sign-off in Queensland, in Proceedings Life-of-Mine 2016 Conference, pp 148–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By T Purvis, Z Liu

Ernest Henry mine (EHM) is an underground sublevel caving mine located in north-west Queensland with a production rate of 6.4 Mt/a. The mine has sublevels spaced with a 25 m vertical interval. The production process on each level starts with the drilling and firing of a blind uphole rise to start the slot extraction. These rises are fired as a single shot and routinely need to achieve a design height of 22 m to 30 m depending on the local mine geometry. If the rise fails to perform as designed then the production phase of the level is delayed with significant rework required to remedy the situation.This paper describes the process that the EHM team has followed to improve the first time performance of each rise. The improvement process commenced with a review of results from previous rises and resulted in the identification of a number of improvement opportunities. A revised holistic approach was established for the process, which included involvement from operators and engineers. Through continued measurement and review of rise performance, inputs to the process were improved to a point where reliable results can now be expected. The successful performance of subsequent rises has been verified through a comprehensive quality assurance quality control (QA/QC) program. Before quality control processes were implemented, the success rate of blind uphole rises was only 11 per cent (one out of nine rises) at EHM. In comparison, the success rates have been vastly improved to 25 per cent (one out of four) and 75 per cent (three out of four) respectively following two stages of improvements. This paper concludes with the ‘current’ series of best practices used at EHM and recommendations.CITATION:Purvis, T and Liu, Z, 2017. Improving the performance of blind uphole rises at Ernest Henry Mine – a case study, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 335–340 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By H Ishikawa, S Palaniandy

The gravity-induced stirred mill such as the TowerMill is an energy-efficient grinding solution used in secondary, tertiary, and regrinding duties in the mineral processing concentrator. The interest in this technology is emerging, with more than 300 mills installed globally in various grinding duties and commodities for the last 30 years. Although the technology is matured, there are still opportunities for improvement and the development of new knowledge to improve its circuit energy efficiency and reduce water consumption. Recent studies show that a combination of stress intensity, ore hardness, slurry density, and mill feed configuration can be used to evaluate the performance of the grinding circuit. A recent pilot-scale TowerMill test work at various stress intensities shows that a lower operating work index and size-specific energy were achieved at higher agitator tip speed and using medium size grinding media. These outcomes were confirmed through several site trials. A smaller 17 mm grinding media has reduced the operating work index and size-specific energy by 18 per cent and 11 per cent, respectively, compared to the 20 mm in a magnetite concentrator. Moreover, the conversion from top feed to bottom feed configuration has reduced the operating work index and size-specific energy by 13 per cent and 37 per cent, respectively. The circulating load was reduced by 34–38 per cent, leading to a reduction in the dilution water consumption in the hydrocyclone feed sump by 20 per cent. A variable frequency drive offers flexibility to change the stress intensities on the TowerMill, where a 35 per cent reduction in specific energy was achieved when the ore became soft. This paper explores the potential design and operating strategies that can be implemented to enhance the energy efficiency, reduce water consumption and reduce CO2 emissions in the circuit and finally evaluate its impact on the total cost of ownership.

Aug 24, 2022

The current economic climate and demand for iron ore has resulted in mine operators being prepared to accept aggressive slope designs and associated failures provided that they can be quantified (ie volume of failure and clean up costs, etc) and incorporated into the mining costs, at a feasibility study level. This has numerous implications for pit slope design/geomechanics. Typically when geotechnical engineers conduct slope stability modelling a single value, usually the average or mean value for model input parameters (ie structural orientations, material properties and hydrological conditions) are chosen. The implications resulting from using a single value for model input parameters will vary depending on how the modeller has chosen the value, ie should the modeller choose a mean value from a log-normal distribution of material strengths an optimistic representation of the stability may eventuate, consequently if the designer decides to conservatively downgrade the values by a nominal factor, a pessimistic representation of slope angles may occur, which would result in excessive stripping and mine development costs. A more realistic and representative way to model the inherent variability of geological/geotechnical conditions would be to do so probabilistically. Whereby the modeller can assess the variability of the geological structure as observed/recorded during the core logging process and a similar approach for the material strength properties. The final model output would be a distribution of factors of safety in relation to overall slope angles, ie probabilities of failure for individual slope angles could be determined. This output (graph) could be modified by the mining engineer to incorporate mining costs as well as clean up costs for the respective slope angles and associated failure volumes, ie probabilities of failure. The author intends to provide a detailed overview of the processes involved in deriving a geotechnical design, ie; starting from the data collection phase (core logging/face mapping), through to the data interpretation and formulation of slope parameters; determining the variability and uncertainties associated with each of the process; ensuring that it is adequately captured in the model input parameters; and how the mining engineer could utilise this information to derive final feasibility study mining costs.

Jan 1, 2009

By R N. Humphries

The aim of this paper is to question the need to develop bespoke monitoring and assessment methodologies and criteria, thereby ‘reinventing the wheel’, when designing and assessing the success of important natural habitat and ecosystem restoration schemes at mine sites in the UK and Australia. It draws attention to the existence and applicability of the Phase I Habitat, National Vegetation Classification (NVC) and Condition Monitoring methods in the UK and similar approaches used in Australia. These are long accepted established methodologies and have published accounts for describing, assessing and managing natural vegetation communities, habitats and ecosystems. They are often used at the environmental impact stage, but seemingly rarely, if at all, in restoration design and management at mine closure. Their application to mine restoration and closure is illustrated and discussed by reference to a surface coalmine in South Wales, UK.It is concluded that the application of a combination of the Phase I Habitat, NVC and Condition Monitoring methods is highly relevant to the expectations of the Convention on Biological Diversity (CBD) and its implementation in the UK, and probably in Australia too. The methodology and criteria described could be incorporated into the guidance and specified in the mining permits so that there is clarity as to the expectations and requirements for monitoring and assessment for bond release. Their use could be of wider application where there is a requirement to assess the success of restored CBD assets and ecosystems.CITATION:Humphries, R N, 2014. Why reinvent the wheel when there are established methodologies to aid the design and assessment of restored natural ecosystems on mined land?, in Proceedings Life-of-Mine 2014 , pp 675–692 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By K Muller, T Oosthuizen

Blast exclusion zones are instrumental in protecting equipment and personnel. When there is no constraint in footprint, the exclusion zone can be enormous, practically eliminating the hazard of flyrock. Unfortunately, this may not always be the case and in many circumstances the blast design needs to be altered to suite such scenarios. When a conservative design approach is taken, it could completely eliminate any form of ejection, whether it is from the free face or the bench itself. The degree to which typical flyrock models describe fragment motion through air with ballistic flight equations are not justified when such a high level of control is applied. This paper examines various methods of risk analysis and suggests an approach to be used for controlled blasting.The outcome of principles discussed in this paper can be seen in video form (Mavmedia, 2014).CITATION:Muller, K and Oosthuizen, T, 2015. Should the blast exclusion zone be based on a qualitative or quantitative analysis? A practical implementation conundrum, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 425–428 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By I Doye

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals responsible for highly acidic, sulfate and metals-rich drainage. Several methods of mine waste management have been developed that reduce liabilities on environment. Layered co-mingling of waste rock with compacted tailings, covers with capillary barriers effect, and co-disposal of waste rock and tailings are these new methods which are used to reduce the formation of acid mine drainage. These methods shield waste rock dumps from oxygen. These techniques could prevent oxidation reaction. In this study, alkaline industrial wastes are used with acid generating tailings to inhibit acid mine drainage. The alkaline wastes selected are cement kiln dust (CKD) and red mud bauxite (RMB). These alkaline materials are used to keep neutral conditions in the fine material layer and to inhibit the metabolic activity of Thiobacillus ferroxidans which catalyses the oxidation of sulfide minerals. A series of timed static leaching tests were performed by reacting samples of mine tailings with two, five and ten per cent alkaline material in order to characterise geochemical balance between liquid and solid phases. Column tests have been set up with oxidised tailings, waste rock, CKD, and RMB. Column tests have been carried out to simulate layered co-mingling, covers, liners, and co-disposal of waste rock and tailings. Column leach tests were conducted in order to investigate the long-term neutralisation potential of alkaline materials and the drainage water quality. Bacteria counting were performed on each sample after testing. The results obtained show that the addition of alkaline materials permit the retention of near neutral conditions in the fine material layer, thus increasing water quality and preventing bacteria development. In fact, the pH results show that the use of five per cent, ten per cent CKD or ten per cent of a mixture of CKD and RMB permit the retention of neutral pH conditions in the reactive layer. At these percent rates, the concentrations of Al, Fe, Cu, Zn, and SO4 in solution are significantly reduced compared to those obtained with the tailings only. In presence of waste rock, the relative position of the fine material layer is important. When the fine material layer overlaying reactive waste rock is composted of reactive tailings with ten per cent CKD and ten per cent (CKD:RMB), a delay was observed before achievement of near neutral pH. The neutral pH conditions remain stable over time. The mixture of CKD and RMB provides a better short-term neutralisation than the use of CKD alone. The use of alkaline materials is beneficial in order to reduce the concentrations of Fe and other metals such as Cu and Zn as well as the number of viable bacteria. The use of ten per cent RMB alone does not involve the neutralisation of reactive tailings. In the cases where the fine-grained layer are below or mixed with the waste rocks, the near neutral pH values are directly reached with ten per cent CKD. However, the pH values decrease rapidly and the number of viable bacteria increases.

Jan 1, 2003

Mr Chairperson, respected leaders of the mining industry, ladies and gentlemen;   Good morning, Kiora, Nihao.   I am very honoured to give a speech to the 2005 New Zealand minerals conference. I would like to take this opportunity to express my sincere thanks to the Ministry of Economic Development to invite me to be part of this important event.   Today, I am going to talk about two themes: a brief introduction of ChinaÆs economic development, including ChinaÆs energy strategy; the good bilateral relations between China and New Zealand, its potential for further development and its relevance to our cooperation in the field of minerals and energy.   It is a well-known story that over the past 27 years, great changes have taken place in China. In 1978 when ChinaÆs reform and opening up just started, its gdp was near to only 150 billion usd dollars. By the year of 2004 it reached to 1.6 trillion usd, an average of yearly growth rate 9.4 per cent.   ChinaÆs great achievements are widely appreciated both in China and abroad. ChinaÆs development has not only improved the living standard of its own people, but also produced a huge market and brought about great opportunities for the world. Since ChinaÆs entry into WTO in 2001, China has imported near to 1.8 trillion usd dollars of goods, averaging a yearly imports of 500 billion usd dollars, creating for other countries and regions more than ten million jobs.   Our prediction is that in the next five years, ChinaÆs imports will be well over three trillion usd dollars. China will continue to serve as one of the leading growth engines for the future world economic development. Now China is on its great strive to achieve the goals of improving living standard for all the Chinese people. We are trying to reach a quadruple gdp of 2000 by the year of 2020, namely to reach gdp four trillion usd, a gdp per capita 3000 usd dollars.

Jan 1, 2005

By Oda Y, Hashiuchi M

In the smelting section, flexible fuels such as coal or coke are used in place of heavy fuel oil in order to utilize energy sources more efficiently. Heat recovered from the off gas of the furnace has been converted by the waste heat boiler into steam, which is used for self power generation and for heating or maintaining various temperatures. The amount of the recovered steam in the smelter is currently increasing due to maximum utilization of powdered cokes. The heat source required to maintain the temperature of the electrolyte in the tank house is electric power and steam. However until recent year this steam was provided by its own heavy oil combustion type boiler in the tank house since the amount of steam consumed in heating the electrolyte is large. Though experimental work over the last few years has shown the advantages of reducing steam in the tank house by fully covering the cell, the implementation of the full cover can lead to other operating problems. However various improvements, mainly the covering of the cell with a simple device, have led to greatly reduced steam consumption. As a result, steam for the tank house is now provided by the waste heat boiler only bringing more efficient energy usage.

Jan 1, 1987

By R M. Lonsdale, M D. Goodz

"With an ever-increasing dynamic business environment, successful stakeholder engagement is becoming more fundamental to achieving desired outcomes in today’s mineral resource industries. It is imperative to be proactive in correctly identifying all stakeholders and initiating early contact. This builds trust relationships, which are essential to ensure future decision-making processes are streamlined.Often neglected is a company’s obligation to select the correct team to represent its values and mission. The company requires representation that demonstrates an understanding and commitment to its operations and people, the safety and health of the community and environment, and most importantly, represents the decision makers. Stakeholders need to believe that the engagement process is genuine and that the company representatives are aligned towards targeted outcomes that will benefit all stakeholders in some way.Among others, stakeholders include shareholders, staff, families, community, service and supply providers, regulators, land managers and the political/financial framework. Depending upon the mineral product, stakeholders may include ports, international offtake clients and those along the route. New stakeholders continually evolve during mine life, and the engagement process requires an investor–community–public relations (IR/CR/PR) team to anticipate change and actively scan perception and chatter.Successful communication is more than delivering a message; it is about engaging stakeholders and confirming the feedback loop to ensure the correct message is communicated and the relationship is strengthened.The nature of the mining company’s branding and the public’s perception of company intentions will dictate whether there is willingness to allow the company to follow its desired path. This in turn controls the company’s most scarce resource – time. Timing is fundamental to achieving targeted outcomes with minimal cost and delays, marketing in a peak cycle and acquiring critical capital for development and growth.Branding and stakeholder engagement effectively controls and extends to the company its social licence to operate.CITATION:Goodz, M D and Lonsdale, R M, 2016. Stakeholder engagement – who are you, what do you stand for and why? In Proceedings International Mine Management Conference, pp 239-248 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 22, 2016

By Booth S. A, Milton D. W

Stratabound/stratiform and remobilised mineralisation have been recognised as the two dominant styles of mineralisation which constitute the Broken Hill ore deposit. Recognition of prospective sites for accumulation of ore depends on understanding the heterogeneity of the ore environment and the distribution of the two styles of mineralisation. The internal stratigraphy of the Broken Hill ore deposit and its enveloping rocks, is described, and a generalised stratigraphic setting of the stratiform mineralisation is outlined. Fhiphasis is placed on the existence of closely-spaced sub-basins as potential sites for ore accumulation close to the Broken Hill ore deposit. Further from the immediate ore environment, recognition of the same diagnostic stratigraphic sequence

Jan 1, 1983

Dust emissions from mining, material processing and ship loading operations (fugitive dust sources) are an environmental issue of increasing concern to both government regulators and the community. The main concerns relate to potential amenity, health and environmental impacts from the emissions. Therefore it is imperative that mining/ processing operations, as part of their overall environmental management, reduce fugitive particulate emissions to as low a level as is practicably possible. This technical paper outlines the mechanisms that lead to fugitive particulate emissions, the importance of understanding the exact cause of fugitive emissions, monitoring methods that can be used to quantify the emissions from specific sources, the use of atmospheric dispersion modelling in dust management and innovative dust management strategies including predictive meteorology and proactive management.

Jan 1, 2009

By D Hume

During 2001 the Ridgeway Gold Mine, driven by company initiatives and recent NSW legislation (General Rule 2000), developed and implemented Major Hazard Management Plans to control significant hazards identified at the underground mine. The paper presents the objectives, issues, outcomes and process involved in the development and implementation of the plans at Ridgeway. The sharing of the experience gained and an overview of the intended way forward will offer a valuable insight for other mines considering embarking on a similar journey.

Jan 1, 2002

By R G. Reddy, A Yahya

The sulfur distribution ratio (Ls) is an expression of the amount of sulfur in slag to the amount of sulfur in molten metal. The sulfide capacities calculated from Reddy-Blander (RB) model were used to calculate the sulfur distribution ratio (Ls). A new Reddy model for sulfur distribution ratio (Ls) was developed for modelling Ls for ironmaking, steelmaking, and secondary steelmaking conditions. Besides calcium oxide, the major component in the ladle furnace (LF) slags is alumina. The Ls was calculated for typical LF slags as a function of temperature and composition. The model calculated Ls values are in good agreement with the experimental and industrial slags data. The extremely low oxygen potential in these furnaces after fully-killed steel is favourable for desulfurisation. For any given slag’s composition and temperature, its sulfide capacity can be calculated a priori. The equilibrium sulfur distribution ratio between this slag and liquid metal in a particular vessel can also be calculated a priori. The Ls for ladle furnace (LF) slags is about twice those for blast furnaces (BF) slags and ten times those of basic oxygen furnace (BOF) slags. The desulfurisation of pig iron in BF and desulfurisation of steel in LF during secondary steelmaking are recommended. Steel desulfurisation in steelmaking furnaces is not effective. Since the model used to calculate the sulfur distribution ratio (Ls) is a priori, it is a useful tool for the iron and steel makers in improving the product quality and optimisation of the industrial furnace operations.

Aug 21, 2024