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By C E. Woolley, A Hosseini, J Foster

Northern Star’s Thunderbox Open Pit C-Zone cutback was designed to maximise extraction in a short life excavation; In fresh rock on the western wall this included 20 m to 30 m bench heights with 6.5 m to 10 m berm widths and a 90° pre-split angle. Rock mass quality in this area is generally fair to good, however, there are sections where the dominant foliation runs parallel with the designed pit wall, and more closely spaced, altered, foliation is present: these areas are difficult to predict and prone to failure. Stringent controls and monitoring were required in order to safely access below these areas, in particular the use of slope stability monitoring radar, Trigger Action Response Plans (TARPs), re-entry procedures, visual inspections, drone inspections and day-to-day personnel awareness of the hazard. Robust and comprehensively planned remediation was also required after two significant slope failure events where long reach equipment and rope access techniques were utilised to remediate the areas in question safely, but also in a timely manner, such that expected production targets were impacted as little as reasonably practicable. This combination of rigorous risk management and well planned remediation resulted in a successful and complete extraction of the C-Zone cutback with no impact to operational safety.

Jun 22, 2022

By Kristen R. Bingham

"Today, more than ever, drilling and blasting contractors are challenged to manage the ever-changing risks associated with blasting operations. New neighborhoods are encroaching upon mine sites and blasting projects are confronted with increasing scrutiny by permit issuing authorities and nearby residents disgruntled by new construction. The act of transporting explosives material to and from thejobsite is far from easy and trouble-free. At the same time, the pressure to stay in compliance with the growing number of government regulations continues to mount. While new tools and technology are appearing in the workplace to address some of these challenges, losses still occur. Can the datagenerated by this technology help drilling and blasting contractors make better decisions? While basic risk management principles are still applicable, do new tools and technology assist in the effort to prevent losses? What are the downsides? In this age of new technology, is face-to-face interaction still necessary? While technology is certainly a useful component in the drilling and blasting world, can it be helpful in defending claims?"

Jan 1, 2017

The Callie Underground Gold Mine (Callie) is owned by Newmont Asia Pacific and located 531 km north-west of Alice Springs in the Northern Territory. Historically, stopes have been mined utilising a primary and secondary stoping sequence with cemented aggregate fill and rock fill respectively. Current and near-future mining will employ long hole open stoping with rib pillars and rock fill with a paste fill system approved to allow a higher extraction ratio from mid-2011. The Callie rock mass is of good quality with little or no mining difficulties during development and stoping to a depth of 1140 m below surface. Development is currently occurring at depth of 1360 m below surface. Stress damage previously observed only in secondary stope accesses is now observed in development unaffected by stoping stresses. A change in rock mass properties is being experienced with depth, with more pronounced and frequent joint planes. Also, other structures are intersected more commonly, such as lithological boundaries and fault zones. The 'Callie rock factory' mentality that has persisted for years is challenged. This paper covers an appraisal of the stress and ground condition changes at Callie. The appraisal outlines the mine design criterion that was developed and examines the transition from a low stress environment to one where stress damage is observed. Discussion includes a judgement on the rock mass damage observed in development, the dominant geotechnical factors influencing the change in ground conditions, and if a correlation can be made between the observed rock mass damage with stress through the use of numerical modelling.

Nov 25, 2010

By Chris Twigge-Molecey, John Peacey

To meet the business objectives of a metallurgical project, there is often a need for new and untried technology or equipment, whose very novelty can present serious risks to meeting those objectives. The key risk management approach is a rigorous stepwise progression from theoretical evaluations and laboratory tests to pilot plant trials. These must be followed by demonstration-scale trials before final construction of a commercial scale plant, paying particular attention to the magnitude of the scale-up between phases. Success depends on following a well-defined program, not eliminating any steps, and ensuring adequate resources are available to the development team. Chapter 6 discusses the nature of technology risks to metallurgical plant projects, and the rigorous management practices needed to identify, analyze, evaluate, and avoid or mitigate them.

Jan 1, 2015

By B. W. Cavender

Innovative mining and metallurgical operating techniques or processes can be identified and developed by systematically analyzing change as it occurs within the mine, plant, technology, or industry. Sources of change to be monitored for innovative opportunities include unexpected successes or failures, incongruities between perceived and actual events, process needs, changes in perceptions, and the development of new knowledge. Innovation can be effectively organized, practiced, and managed. The perception of change as an opportunity rather than a threat is mandatory, as is the systematic measurement of innovative performance. Innovation is enhanced by specifically-designed policies regarding organizational structure and staffing, daily management practices, and compensation and incentives.

Jan 1, 1994

By B P. Micke

Central Norseman Gold Corporation was established in 1935 and has been mining on the Norseman field in Western Australia since then. It is Australia’s longest continuously operating gold mining operation at nearly 80 years, although it has had its periodic challenges in the intervening years.Over the last 40 years, a series of open pit mines around the Dundas Goldfield have supplied lower cost mill feed to the Phoenix Mill at Norseman from time to time but this has largely come to an end for the foreseeable future. Now that underground ore sources are once again the principal mill feed, there are several challenges to be met for an ongoing profitable operation.During the last 20 years, there have been three different owners and this has affected the manner in which the operations were managed quite significantly. These differing approaches are contrasted and examined in some detail from both the operational and financial aspects.Planning of a downsized operation to ensure sustainable profitability in the future in a mining environment where there has rarely been more than two to four years of reserves ahead of the mill for planning purposes has been a significant challenge. Several of the options examined are described, including alternatives for future mine development.CITATION:Micke, B P, 2014. Managing the margin at Norseman, Western Australia – a case study, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 119–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By J. L. Collins

"This paper deals with the quantitative analysis of mine maintenance records. Based on a case study of dozer engine records, the author suggests an easy method of deriving useful information for managerial decisions in a step-by-step manner.More specifically, the paper deals with the following topics:• determination of the most economical replacement time,• determination of reliability characteristics,• determination of the number of replacements, and• determination of the number of spares.IntroductionThe mining industry collects a lot of information about every aspect of its activities, an example of which appears in Table I. In Table I , the distribution describes the operating hours at failure of 56 different dozer engines used in severe applications. Besides calculating an average and possibly a standard derivation from the data, little else is derived, at least from a statistical point-of-view.More information can be obtained from these records that could help management in the decision-making process.To illustrate this point, the sample data appearing in Table I will be analyzed in detail by making use of well-known concepts in reliability engineering.Distribution of DataTable I represents a distribution obtained from the recorded hours cumulated from the operators' time cards. The operating hours have been divided into fourteen classes for each 1000 hours of engine running, e.g . all engines scoring an operating time of between 1001 and 2000 hours formed a class , those scoring between 2001 and 3000 hours another one, etc. Generally, the class interval should be a multiple of the equipment preventive maintenance check period.The minimum acceptable sample size should be large enough to ensure that the score in each class interval is at least one. Ideally, the score for each class interval should be at least five so that a chi-square test could be carried out if necessary.The average life of an engine can be found by adding the products of the frequency and the class mark (mid-point) values. Therefore:"

Jan 1, 1987

"The content of production reports has its origins in raw measurements taken in harsh production environments. The ensuing measurement/estimation errors always affect reproducibility such that, regardless of the fact that they are balanced through statistical data reconciliation, reported numbers are simply the most probable values of inferred probability distributions. This has important implications for how metal recoveries should be monitored and reported. Indeed, in a context where many process optimisation activities are based on small improvements in recovery, there should be no doubt that inadequate handling of measurement/estimation errors can easily exaggerate or mask actual changes in process performance. However, estimates of the reproducibility of reported metal recoveries are rarely reported to plant management. This situation persists despite the fact that a code compliant metal accounting system must inform management about business risks related to metal accounting. To this extent, this paper focuses on the continuous management of reproducibility level of metal recoveries in compliance with the best practices. Sensitivity analysis of primary and secondary metal accounting models is performed to show the resulting probability distributions for metal recoveries. Some guidelines are given for designing and managing metal accounting systems capable of achieving and sustaining predefined levels for the reproducibility of metal recoveries.INTRODUCTIONEach and every mineral processing plant produces daily, weekly and monthly production reports in which metal balances for payable and penalty elements are presented. While such production reports are usually consulted in offices, underlying raw measurements are taken in harsh production environments where mechanical vibrations, humidity, corrosion and dust, to name a few, disturb measurement procedures. It is thus no surprise that several authors (Francois-Bongarcon & Gy, 2002; Gaylard, Randolph, & Wortley, 2014; Holmes, 2010; Spangenberg & Minnitt, 2014) have reported pervasive issues related to mass/sampling measurements in the context of mineral processing."

Jan 1, 2016

The transition from exploration to feasibility is a stage in the development of mineral resource projects that is frequently not handled well. The transition marks a point in the project development process where resource evaluation priorities change significantly from the discovery of mineralisation and the rapid assessment of the potential tenor of the mineralised system, to the detailed assessment of the deposit.   Information used in the exploration process tends to be of a qualitative or theoretical nature initially, but gradually becomes more quantitative in character as geological knowledge relating to individual prospects grows.   The transition from discovery and rapid exploration of a new deposit occurs at a relatively early stage in project development, coinciding with the first attempt to prepare a resource estimate for the deposit. Fundamental assumptions regarding both structural and grade continuity and uncertainty inherent in existing information need to be made so that they themselves may be addressed during the collection of additional data.   The effective commencement of feasibility studies involve the introduction of new accountabilities either as a result of appointment of a project manager, and through needing to be able to quantify: ò     the quality of data being collected for resource evaluation purposes; ò     confidence associated with resource estimates; and ò     the need to develop an audit trail for the project, required to make the resource evaluation decision-making process as transparent as possible.   Quality assurance is a concept to which exploration geologists have frequently had little exposure. Being able to demonstrate the quality of data used in feasibility studies is, however, a crucial component of the overall risk management and reduction.   Development of a transparent audit trail for data assists in demonstrating the quality of data which is frequently perceived to translate directly to confidence inherent in resource estimates.   Establishing procedures for geological data collection and management also provides a more reliable framework for making decisions that impact on project execution, again resulting in improved confidence in resource estimates and associated geoscientific data.   Regular, independent technical audits, in principle similar to audits conducted for the ongoing certification of standards compliant quality assurance systems, are a major, positive factor in effective project management and execution.   Information used in project evaluation, feasibility and development must be based on facts. Facts are effectively observations that are ideally made systematically, recorded in a systematic manner, and by being collected effectively are not subject to change.   Effectively managing the transition from exploration to resource evaluation, feasibility and project development involves recognising the nature of changes in the nature, detail and scope of geoscientific data required at each stage of project development. In doing so it is essential to: ò     recognise when the change occurs (as early as preparation of the initial resource estimate for a project); ò     accept that the change may not be gradual; and, ò     ensure that the project evaluation team is adequately resourced.   These objectives require recognition of the value of previous experience and the need to instill a true team approach amongst both staff and contractors associated with the project. Regular formal and informal communications between staff, contractors and other stakeholders in the project are an essential tool in ensuring personnel are aware of factors affecting their role in the project.

Jan 1, 2004

By G M. Jones, J Rademan

Debswana, owned by the Government of the Republic of Botswana (GRB) and De Beers in a 50:50 joint venture partnership, operates the Jwaneng diamond mine in Botswana - the most valuable diamond mine in the world. The mine provides between 60 - 70 per cent of DebswanaÆs earnings, and about 30 - 40 per cent of the GRBÆs income. In 2008, the company embarked on the Cut 8 Project - an open pit waste cut-back to expose more diamond bearing ore to sustain mine life by another six to seven years. This undertaking was much larger than previous cut-backs; it increased the waste stripping ratio threefold, increasing significantly the waste handling fleet of trucks, shovels and infrastructure, and impacted a large part of the materials handling plant which required replacement with new facilities. The project coincided with the beginning of the Global Financial Crisis (GFC) and a slowdown in the economy. Its $4 billion total life cost was billed as æthe largest private investment project in BotswanaÆ which produced heightened expectations amongst stakeholders that it would redress some of the issues brought about by the GFC and leave behind a legacy of jobs, increased opportunities for citizen owned business and improved social infrastructure.Most of the big project challenges were non-technical and ranged from dealing with various stakeholders?at?all levels, a 25 per cent currency depreciation of the Botswana Pula against the South African Rand, obtaining work permits for non-citizens in a job starved environment, managing construction to world class safety standards, managing the low productivity of construction workers and producing a viable legacy program that satisfied the GRB and stakeholders. Whilst most of these risks were identified in front end studies, the magnitudes were in many instances underestimated. Managing this uncertainty on Cut 8 can provide valuable lessons to other projects in a similar environment, or at least provide the information to indicate that these factors should be adequately provided for in the financial evaluation of a project in the form of budget, schedule, contingency or risk mitigation.CITATION:Jones, G M and J Rademan, 2012. Reliability of expert judgements and uncertainty assessments, in Proceedings Project Evaluation 2012 , pp 109-116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By Carl Zapffe

THE object of the Bradley process is to free manganese oxide from its associated gangue and separate the contained iron oxide by dissolving the manganese and precipitating it from the solution. 'The fundamental features of the process are : making. both 1 a manganese ore and an iron ore; effecting a separation of manganese .and. iron by means of selective roasting; leaching- the manganese from the roasted ore by using ' ammonium sulfate; precipitating the manganese by using the ammonia gas generated during leaching; fixing the precipitate by oxidizing with air; breaking down and reforming the ammonium sulfate, so that daily very little additional ammonium sulfate beyond that originally charged into the system is required; washing the manganese precipitate and the iron-silica residue and evaporating the liquor to conserve the dissolved salts in the moistures of these two products and 'to reduce the sulfur content,; drying the precipitates; magnetic wet-concentration of the iron-silica residue; sinteriny the manganese-and .the' iron-concentrates.

Jan 1, 1929

By J. W. Jensen

EXTENSIVE research and development was performed on the manganese-copper vibration-damping alloys to determine the relationship between the properties of the alloys and variations in composition, fabrication, Mid heat treatment. Mn-Cu alloys with unusually high specific damping capacity, 20 to 25 percent at a stress of 5,000 psi, have also the following useful properties: Tensile strength, 90,000 to 110,000 psi; yield strong, 60,000 to psi; elongation, 20 to 25 percent; hardness, 90 Rockwell B; and fatigue limit at, 28,000 to 30,000 psi. Both standard and special methods of testing were employed to obtain data on strength, modulus, hardness, resistivity, dilatation, micro-structure, crystal lattice, and damping capacity. The extensive tabular and graphical data on these properties are presented for alloys containing 50 to 85 percent as quenched d solution) and after various aging treatments. Expansion coefficients for all Mn-Cu solid solutions are graphed and a dilatometer study of contraction during aging is reported. Although high damping capacity is associated with aging to precipitate a-Mn from solid solution, with a cubic-tetragonal transformation and with the occurrence of antiferromagnetic ordering in Mn-Cu alloys, a tenable theory of the damping mechanism has not been reached.

Jan 1, 1965

By Carl Zapffe

In ten years the manganiferous iron ores of the Cuyuna District have become impor-tant in the iron industry. By Dec. 31, 1923, 4,735,806 tons had been produced. Dur-ing the war, the low-phosphorus black ores were in demand; now the high-phosphorus low,-silica brown ores are favored. It is estimated that the reserves of these ores are ample for some time. A RISE in less than ten years from obscurity into great prominence economically, tersely summarizes the history and status of the Cuyuna manganiferous iron ores. The Cuyuna district produces and ships mostly high-phosphorus iron ore, but the annual production of manganiferous iron ore is increasing rapidly and productions from individual mines are becoming more regular and more dependable as to grades and tonnages. This ore bids fair to become, shortly, the principal product of the district and is responsible for the present economic prominence of this district. The iron ores of the district have been described, by the author and others, in many publications and will not be discussed here. Lately the manganiferous iron ores have been given some attention, but the range and variations of chemical composition of the ores, the principal physical characteristics of the ores and their deposits, the relative importance of the different ores and their possibilities in future developments, and the life of the respective reserves have not been discussed. It is impossible to give all of this information with the positiveness necessary for it to constitute a reliable guide for investment or even for future mine development. Each property and each party presents a special case and deserves critical consideration. We are dealing with special ores and always with a set of new conditions. Sufficient information of a general nature can be given, however, to indicate the reason for and the trend of the presently augmented developments in the district.

Jan 12, 1924

By R. C. Wallace

Since the time when Canada's East and West were joined by the railway, and communication was established into the interior, settlements grew on the southern fringe of the great Precambrian area that formed the northern protaxis of the continent during its vicissitudes of growth. They clung precariously to the fringe of that ancient land, for the Precambrian is not generous to those who wish to live by the fruits of the soil, except in those limited areas where the Pleistocene ice-sheet has been profuse in its gifts of clay to cover the hard surface of the Precambrian rock. Later settlements spread westwards over the expanse of Cretacean plains that now form the wheatfields of the Canadian West; but there still remained in northern and western Ontario, in eastern and northern Manitoba, a pioneer race, to whom agriculture had attractions only in so far that it provided the wherewithal to lay siege to the riches of the Precambrian. And they had a vision beyond their time. More than they knew, they had seized the fact that for the complete rounding out of Canadian national life, a8 well as for the establishing of the necessary contributions towards the economic stability of Canada and its provinces, an industry in mining sh01.dd be well and truly built in the hinterland of the central provinces. Failing the winning of mineral from the rocks, and timber from the forests, there would remain between the East and the West an enormous barrier of unproductive country which would not only be an incubus to the agricultural people in their struggle for economic liberty, but would effectively, and for all time, remain an un-populated void across which the aspirations of East and West would be unable to unite.

Jan 1, 1924

By P Thwaites

The mining industry uses many types of mineral and metallurgical plants to produce saleable product from ore mined. Plant design history has left current operations with a mixture of manual operation and various forms of automated process controls. Consequently, we typically see high-variability in the continuous operations together with a shortfall in the attainment of full capacity or higher utilisation of consumables.At a level of best practice, ‘operational performance excellence’ focuses on process control, using automation and control systems to deliver process optimisation. This more sophisticated delivery is a great deal more difficult than the first stage of equipment selection/installation. It includes the appropriate selection of the right instrumentation and control system, key process knowledge, individuals with a solid control engineering background/experience and the essential backing/support of the operations management team together leading to higher-value delivery. Robust solutions can be realised, considerably minimising process variation, thus leading to process optimisation. This approach results in an easier, efficient and safer process while providing considerable returns for the plant owners.How variable are your processes, and do you maintain optimised process performance with dedicated resources, modern instrumentation, ‘best practice’ control systems and performance monitoring tools? In this paper, these questions and their possible answers are discussed.I say we can do much more and be ‘more efficient’ in our efforts to remain competitive. This area remains a major opportunity for improved efficiency, minimising tailings losses and other milling costs.CITATION:Thwaites, P, 2014. Manual control, process automation or operational performance excellence – what is the difference?, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 13–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Lewis C. Karrick

Although the Bureau of Mines has thus far made no large-scale experiments with oil shales, and the feasibility of the commercial manufacture of shale-oil products suited to present market requirements has not been demonstrated, there is ample reason to believe that these products will eventually supplement the more commonly used petroleum products and give equally good service. In 1919 the bureau, in cooperation with the Department of Metallurgical Research, University of Utah, began investigating the oil shales of the United States to obtain detailed information on their value. The States of Colorado and Indiana also cooperated through their State universities, in which research laboratories were organized to assist in carrying on the oil-shale studies planned and directed by the bureau. As a result of these studies much information is now available concerning laboratory methods of producing the greatest yields of the best products from oil shale. In order to study the principles that govern the retorting of oil shales and to test the oils produced, it has been necessary to develop and standardize reliable apparatus and methods for distilling shale, and to adapt to the testing of shale oils some of the methods the Bureau of Mines uses for testing petroleum. The methods employed by the Scottish shale-oil manufacturers were also studied, but most of them have been superseded by those described in this bulletin, which give more comprehensive and accurate results and employ more convenient apparatus. This paper is presented, therefore, as a manual of apparatus and methods that the bureau has developed for work on oil shale and found satisfactory for routine tests and for research. Explanation and discussion of the principles underlying the methods of testing are included wherever necessary for a clearer understanding.

Jan 1, 1926

By M. Ge, C. Mborah

"The acoustic emission/microseismic monitoring (AE/MS) technique has widely been used in the mining environment for the monitoring of rock mass stability. A successful implementation of the method is hinged on being able to accurately determine the P- or S-wave arrival which is then used in the determination of the source of an event. Determination of the arrival phase is usually performed visually by a human expert. However, the mining environment is characterized by high noise levels and different noise types of varying intensities. Therefore, performing manual phase picking on time series data acquired from the AE/MS monitoring system can sometimes be tedious and time consuming if not impossible. In this paper, a proposal for improving manual P-wave phase arrival picks is discussed. The method involves the filtering of the AE/MS data using a stationary discrete wavelet transform (SDWT) method. After filtering, appropriate scales/levels of the multi-level decomposition process are then selected for further processing. The first step in the picking process after filtering, requires the computation of the signal power and the root mean square (RMS) using the signal amplitudes at each scale. The preliminary P-phase arrival time is picked using the results of the calculated power and RMS values respectively. The calculated RMS values are then superimposed on the calculated power values to determine the final arrival picks. If the arrival time picks obtained by both methods coincide or are within 5 to 10 sample points, the pick is considered reliable. The accuracy of the method was verified using AE/MS data from two datasets obtained from two separate underground mines. The results of the study showed that the picking method is reliable and robust. Based on the data studied, it can be concluded that the method will help reduce the time usually spent in processing AE/MS data from mines. INTRODUCTION A successful identification and location of the source of acoustic emission/microseismic (AE/MS) events is mainly dependent on the onset time of the P-wave phase. In many seismic networks, initial picks are performed by picking algorithms followed by manual picks by human experts. If the waveform signal-to-noise ratio (SNR) is low, the P-wave onset time picks by the human expert is generally reliable and accurate [1]. However, for waveforms with high SNR, picking of the P-wave onset could be a major challenge. Also, due to the volume of data acquired daily, manual processing could be stressful and time consuming [2]. These challenges continue to provide motivation for alternative means of providing reliable and efficient ways of improving manual phase picking. The AE/MS technique has been an intergral part of safety monitoring in mines [3] due to its capacity to identify zones of instability in a monitoring area. To obtain an accurate source of an AE/MS event however depends on the quality of the data used for P-wave phase picking [4, 5]. AE/MS data from mines are generally contaminated with excessive background noise generated by the different mining operations. The AE/MS signals of interest are mostly buried in background noise which makes it difficult to pick the P-wave phase arrivals [4]. Processing AE/MS data acquired in noisy environment remains a major challenge due to the weak nature of AE/MS signals [6]. As noted by [4] most of the data recorded in the mine environment are mainly due to events not related to AE/MS events of interest. The complexity of data in this type of environment makes the detection and picking of P-wave arrival by human experts a very difficult task."

Jan 1, 2017

By A. M. Beebee

IN the present century the coal and manufactured gas industries have been eclipsed in public interest by oil, natural gas, and hydro- electric energy, which have had the benefit of rapid development and novelty. I sometimes wish that our social- order were such that hydro power had been developed first, that the use of gas from coal had never been seriously considered, and that our domestic energy requirements were supplied by other fuels. Sup- pose the manufacture of gas from coal should then come on the scene at the present time with the current plight of the railroads, coal regions, and labor generally, presenting the fact that it could increase the amount of coal mined and shipped by the railroads by some 16,000,000 tons, and increase the coal used at existing u plants five times. Imagine the great public interest that would be manifested; it would supply the cooking and water-heating requirements of a community with a superior character of service at a cost to the customer approximately half that which had obtained previously. Would not such a situation be heralded as the salvation of our country and all help be given it?

Jan 1, 1940

By W Polkowski, M Tangstad, M Wallin, J Jiao

Fe-26Si-9B (wt per cent) alloy has been identified as a potential high-temperature phase change material (PCM) due to its attractive properties, such as its high latent heat of fusion and low volumetric change during solid/liquid transition. For the successful utilisation of this alloy into thermal energy storage (TES) systems, the development of a cost-effective production method is essential. Presently, the Fe-26Si-9B alloy is produced by mixing FeSi alloys with either pure boron element or FeB alloys. However, the use of pure boron is financially prohibitive, and the carbothermic reduction results in high greenhouse gas emissions and high energy consumption in the production of FeB alloys. In this regard, our study proposes a silicothermic reduction method to produce Fe-26Si-9B PCM by using FeSi alloys and B2O3-based oxides. Accordingly, the influence of various parameters on the production process was investigated, including operating temperature, holding time, B2O3 content in the added oxides, and initial Slag/Metal (S/M) ratio. Based on the experimental results, the optimal parameters for producing FeSiB alloys with over 9 wt per cent boron were determined. Consequently, it was documented that the FeSi alloys and the added oxides enriched with 50– 65 wt per cent B2O3 should be subjected to temperatures ranging from 1550–1650°C, maintain an initial S/M ratio exceeding 1, and ensure a holding duration beyond 1 hr. Moreover, the energy consumption of this process was estimated to be ~1.86 MWh/t metal and the mass loss was lower than 7 per cent. Therefore, silicothermic reduction offers a sustainable approach for producing FeSiB alloys with a boron content above 9 wt per cent.

Jun 19, 2024

By H. R. Manouchehri

Sustainable development requires the optimal use of natural resources and recycling of the wastes. In fact recycling is the final productive use of obsoletes. ELVs, obsolete appliances and industrial wastes have become important resources for production of iron and steels, non-ferrous metals, and composites. Within shredding plants, these obsoletes are firstly shredded to the pieces and then processed to recycle different materials, especially ferrous and non-ferrous metals for metallurgy. Traditional and new developed mineral processing technologies are nowadays used for recycling different materials from waste effluents. Shredding and separating plants are currently recycle the wastes by make use of different technologies to mainly produce raw material for metallurgical application. However, other non-ferrous components are also treated for energy conservation and protecting environment. Currently, recovery in shredding and recycling plants maximises to 75% and about 25% of the feed is land-filled. However, recycling rate must be increased in due to the economical, environ-mental and social concerns. A comprehensive study for recycling, with especial focus on ferrous metal recovery, was sup-ported by Swedish Environmental Agency (MISTRA) to look at possibilities to increase the recycling rate and to reduce the amount of disposal. Part of this study was dedicated to study the shred-ding plant facilities and to look for possibilities to improve the quality and quantity of the shredding product streams. The aims were to improve the quality of ferrous scrap (apparent density > 0.9 and Cu<0.25%) for iron and steel production as well as having better quality for non-ferrous metals through the recycling schema, and finally to treat the shredder residue (SR) to recover metals and plastics to reduce the disposals. This paper summarises the results of sampling and conducting separation tests for improving the recovery of the ferrous and non-ferrous metals. The results indicated to be possible to obtain high quality ferrous scrap at recovery of 88%. However, the total recovery for metal scrap has reached 93%. Furthermore, test results on fine, P< 8mm, shredding residue (SR) showed promising prospect in recovery of metals and protecting environment by physical separation, i.e. electrical separation technique.

Jan 1, 2014