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By Q. Fu, Q. Wang, L. G. Wen, M. X. Jia, J. J. Zhao, J. W. Zhou

The BGRIMM process mineralogy analyser (BPMA) is a new automated mineralogy software platform developed in China. This system consists of the BPMA software platform, controlling a combination of commercially available scanning electron microscopy (SEM) and energy dispersive Xray spectrometry (EDS). The BPMA software controls SEM and EDS through their application programming interfaces, to form an auto-SEM and EDS system that automatically acquires BSE images and X-ray spectra, respectively, and classifies minerals by spectrum-matching. After automated measurement and mineral identification, various quantitative process mineralogical data (e.g., mineral composition, mineral abundance, mineral liberation and intergrowth relationships, mineral associations, particle and grain sizes, particle density distributions, calculated assay, elemental deportments, mineral grade recovery and elemental grade recovery, etc.) would be calculated quickly, accurately and automatically. The BPMA could be used for ore characterisation as a new advanced automated mineralogy technology. Keywords: BSE image; X-ray spectrum; automated mineral identification; quantitative mineralogical investigation; automated mineralogy

Jan 1, 2020

By R. M. Mashishi, T. Malehase, O. J. Okonkwo

The concentrations of selected trace elements (As, Cd, Hg, and Pb in run-of-mine (ROM) coal, discard, and coal product were investigated to assess the efficiency of beneficiation in reducing trace element concentrations and ascertain any implications regarding environmental compliance to regulatory frameworks. Samples were collected from a colliery in Mpumalanga Province twice a month for a period of 24 months. The samples were ashed to approximately 0.21 mm, then digested in a mixture of 70% HNO3 and 40% HF and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Except for Pb, the mean concentration of all elements decreased from the ROM stage to the coal product stage. The order in which trace elements occurred from the highest to lowest throughout the production chain was Pb>As>Hg>Cd. With the exception of Cd, the mean trace element concentrations in the discard were above the total concentration threshold (TCT) set for landfill disposal. The As, Hg, and Cd concentrations in the product were well below the thresholds for all land uses. However, Pb concentrations in the product coal were above legal limits, which is of concern with regard to environmental compliance and the performance and marketability of the product.

Dec 13, 2023

By D. Pienaar, C. O’Connor, B. McFadzean

Dithiophosphate (DTP) is classically used as a co-collector in sulphide mineral flotation, where xanthate-DTP mixtures have been shown to synergistically improve mineral flotation performance. Notwithstanding the improved recoveries observed, ethyl DTP does not appear to behave as a conventional collector, since it has been shown that it does not adsorb onto certain sulphide mineral surfaces. Recent investigations have nevertheless indicated that when ethyl DTP does not adsorb onto the sulphide mineral surface, the presence of a non-ionic frother can activate a synergistic increase in pulp phase mineral recovery, and bubble-particle attachment probability. A regular solution approach was used to determine the interactions between thiol collectors and non-ionic frothers at the air-water interface. Attractive interactions were observed between longer alkyl chain DTPs and frothers, whereas the activity of xanthates at the air-water interface were too weak to determine if an interaction was occurring. This is the first time that such interactions have been shown for the DTP-frother system and represents an important contribution to our understanding of the role of DTP reagents in the flotation process. Keywords: Collector-frother interaction, dithiophosphate, surfactant synergism

Jan 1, 2020

By S. Budavari, F. M. C. C. Vieira

For several decades, the deep, gold-bearing reefs of the Witwatersrand basin have been mined predominantly according to layouts characterised by longwalls with strike pillars to provide regional support. During the past few years, a new generation of mining layouts has been introduced. These layouts are based on the concept of grid-type, scattered mining with dip pillars for regional support. As the extraction of the gold reefs extends to depths below 3500 m, the hazards associated with mining at these ultra-depths are expected to increase to unacceptable levels. Therefore, the question arises as to, which of the currently applied mining layouts is most acceptable for the economic and safe extraction of an ultra-deep orebody. The purpose of this paper is to describe a research investigation carried out to evaluate the degree of acceptability, from the rock engineering view point, of four currently used mining layouts for application at a depth-range of between 3500 and 5000 m. Pendant plusieurs décades, les filons d’or profonds du bassin du Witwatersrand ont été exploités d’une manière prédominante selon des dispositions caractérisées par des longues tailles avec des piliers directionnels pour donner un support local. Les dernières années ont vu la naissance d’une nouvelle génération de dispositions de mine. Ces dispositions sont basées sur le concept d’extraction type grille, éparpillée, avec des piliers au pendage pour le support local. Comme l’extraction des filons d’or va à des profondeurs en dessous de 3500m, il faut s’attendre à ce que les risques associés à l’exploitation à ces profondeurs extrêmes atteignent des niveaux inacceptables. Par conséquent, la question se pose de savoir laquelle des dispositions de mine couramment utilisées est la plus acceptable pour l’extraction rentable et sans danger d’un gisement ultra profond. Le but de l’étude présente est de décrire les recherches exécutées pour évaluer le degré d’acceptabilité, du point de vue d’ingénierie de roche, de quatre dispositions de mine couramment utilisées pour application à un rayon de profondeur entre 3500 et 5000m. Die tiefen, goldträchtigen Riffs des Witwatersrandbeckens wurden über einige Jahrzehnte hindurch vorwiegend nach jenen Layouts abgebaut, die von Langfrontstreben mit Schlagpfeilern charakterisiert waren, um regionale Unterstützung zu gewährleisten. Während der letzten Jahre wurde eine neue Generation von Grubenlayouts eingeführt. Diese Layouts basieren auf dem Konzept der Rasterfeld-Art, gestreuter Bergbau mit Neigungspfeilern für regionale Unterstützung. Es kann erwartet werden, daß auf Grund der Tatsache, daß sich die Extraktion der Goldriffs auf Tiefen unterhalb 3500 m verlagert, die Gefahren, die mit dem Bergbau an diesen Ultratiefen verbunden sind, sich auf ein nicht annehmbares Niveau erhöhen. Folglich erhebt sich die Frage, welche der gegenwärtig angewendete Abbaulayouts für die ökonomische und sichere Extraktion eines ultra-tiefen Erzkörpers am annehmbarsten ist. Zweck dieser Arbeit ist es, eine durchgeführte Untersuchung zu beschreiben, die vom Gesichtspunkt der Gesteinstechnik gesehen, vier gegenwärtig angewandte Abbaulayouts für den Einsatz in einem Tiefenbereich zwischen 3.500 und 5.000 m evaluiert.

Jan 1, 2003

By M. Shaw, H. R. Heydenrych, A. E. Lewis, E. Glass, J. Chivavava

The removal of calcium from the retentates of reverse osmosis (RO) treated minewater is desirable since it allows the recovery of both additional potable water (through RO) and higher-purity salts (in downstream processing). This, in turn, reduces the need for costly and unsustainable evaporation ponds and enhances the economics and operability of potential zero-liquid discharge downstream processes, e.g. evaporative-, cooling- and eutectic freeze-crystallisation. For this study, a multi-component retentate high in sodium content was considered, typical of those emanating from minewater reclamation plants in Mpumalanga, South Africa. Four technologies were evaluated to remove calcium: gypsum precipitation by addition of lime; calcium carbonate precipitation by addition of soda-ash; heating crystallisation of calcium sulphate anhydrite; and cooling crystallisation of gypsum. Full processes were developed and simulated using electrolyte thermodynamics. Using the results of these simulations, capital- and operating costs, as well as revenues were calculated and used in economic comparisons of the processes. Sensitivities to key purchasing and selling prices were also investigated to understand the impact of changes in these variables. For the case of a low magnesium-to-sodium ratio in the feed, gypsum precipitation through lime addition was found to have the lowest operating and total annualised costs; but, if revenue could be derived from the sale of sodium sulphate, calcium carbonate precipitation through soda-ash addition was favoured. Keywords: Calcium removal, gypsum precipitation, calcium carbonate precipitation, heating crystallsation, cooling crystallisation, economic comparison

Jan 1, 2020

The nature of metallurgical engineering?applying and optimising chemical and physical processing of ores into useful materials?is reviewed. Important trends that shape the context in which metallurgical engineers practise are identified ? increased global production of primary metals, declining prices, environmental constraints, and increased property requirements of materials. A successful department of metallurgical engineering is one which employs a team of academic leaders to develop graduate engineers who are productive across the full range of metallurgical processing. Keywords: metallurgical engineering, primary metals, commodity prices, processing

Jan 1, 2003

By Y. Fan, D. H. Zhang, J. Y. Xu

The hydrogeological conditions in the Chambishi mine area in Zambia. were investigated. Chambishi is a very wet mine and groundwater discharge costs are high. The research goal was to identify methods to reduce the discharge costs without greatly affecting the mining process. Hydrogeological data was obtained from measurements in drill-holes and from drill cores. The differences in structural deformation in different areas determine whether a layer of rock is an aquifer. In the mine region, the Lower Roan Group ore shale and quartz-sandstone unconformably lie on the basal schist and granite aquifuge. The Upper Roan Group dolomite is continuously distributed over a large area around the orebody. This dolomite is the main target of groundwater control efforts, and its water yield is also influenced by the deformation intensity. Based on the observations, backfilling was gradually adopted to appropriately safeguard the integrity of the aquifuge above the orebody. The overlapping relationship between the aquifer and aquifuge has been utilized to increase mine drainage efficiency. This measure has not only greatly reduced the costs of mine drainage, but also improced protection of the groundwater environment. The old drill-holes that were not sealed after exploration drilling were grouted. Further, possible water-conducting fracture zones were investigated. Cover drilling towards the suspected zone was conducted to prevent the high-pressure groundwater from shallower aquifers from entering stopes in deep areas of the mine.

Jun 10, 2024

By S. J. van Wyk, A. S. H. Haagner, A. Abraha

Opencast coal mining is responsible for the greatest area of land disturbance across all of the commodity types in South Africa. Many thousands of hectares have been rehabilitated to date and, although rehabilitation performance is not always measured or reported, a significant database, spanning 24 years, has now been analysed to identify the main shortcomings holding back rehabilitation sustainability across the industry. Data from 48 different collieries with rehabilitation performance scores measured from 2000-2024 were analysed. A standardised assessment framework was implemented at all 48 collieries, focusing on aspects of land capability, soil fertility, landscape form and drainage, vegetation species composition and basal cover, implementation of maintenance programmes, and prevalence of invasive alien plants. The findings show that, although invasive species management, plant species composition, and plant basal cover are often adequate, the implementation of aftercare and maintenance programmes (influencing soil fertility) and deficiencies in overall landform design and drainage systems are most significant in preventing overall rehabilitation progression and self-sustainability. Integrating these during design and rehabilitation execution, followed by intensive maintenance (especially in the first five years post-topsoiling and seeding) will be key for the overall industry performance to improve to acceptable levels. The database is biased towards collieries that actually do undertake rehabilitation and that do measure it, hence the actual industry performance is likely worse than what is presented. Due to the substantial hectarages involved and the main post-mining land uses being grazing and crop production, the industry cannot afford to keep perpetuating deficiencies in achieving the foundational aspects of rehabilitation that would pave the way for sustained economic future use.

Apr 25, 2025

By T. Song, X. Wang, X. O. Xia, X. J. Luo, B. Chen

Interparticle breakage is the main crushing mode of an inertia cone crusher according to its working principle and feeding condition. In this paper the breakage behaviour of an inertia cone crusher is investigated, based on energy controlled compression combined with the vibration theory, rather than geometry controlled compression (form conditioned) which plays a major role in conventional eccentric cone crushers. The effect of feeding and operating conditions on breakage behaviour was described quantitatively from the perspective of energy consumption and product size distribution. The influence of feeding conditions, discharge size settings and vibration exciter speeds on the crushing process and product quality has been studied according to the results of laboratory crushing experiments. The results of the experiments show that the particle size of broken products becomes finer with the decrease of a discharge gap within the gap range selected by the experiment. The product size increases significantly when the gap approaches the upper limit of 6 mm. The variation of eccentric speed has a more prominent effect on reducing the product size compared with the change of discharge gap. The change in product size is not apparent when the eccentric speed rises to a certain level. The throughput of an inertia cone crusher is sensitive to the change of discharge gap, which increases linearly with the discharge gap and decreases with the eccentric speed. The change of feeding conditions has little influence on the crusher throughput. Keywords: Inertia cone crusher, interparticle breakage, energy consumption, product size distribution

Jan 1, 2020

By X. Yang, G. D. Zhai

The prop is the most important part to ensure the proper functioning of hydraulic support. When the hydraulic support is impacted by the roof, the prop is prone to extrusion deformation, expansion, and even bursting. In order to study the stress on a doubly-telescopic hydraulic support prop under impact load, an impact simulation was carried out based on the drop weight method. First, the impact model of the hydraulic system of the prop was established in AMESim software and the dynamic response curves of the bottom and middle cylinder of the prop obtained. Then, according to the conservation of energy, the pressure formulaes in the hydraulic cylinder of the prop under impact load were derived and verified by the AMESim simulation results, and the maximum pressure on the inner surface of the hydraulic cylinder of the prop obtained. Lastly, the transient dynamic simulation of a hydraulic support prop was carried out in ANSYS Workbench software, and cloud diagrams of stress and deformation of the prop obtained using Workbench simulation. The AMESim simulation process describes the change in fluid pressure in the prop, and the pressure formulae can be used to estimate the internal pressure of the prop under impact load. The finite element analysis results show that the stress of the middle hydraulic cylinder is much greater than that on the bottom hydraulic cylinder under impact load, which can provide a reference for prop design.

Jul 2, 2022

The following notes have been compiled to assist authors in the preparation of papers for presentation to the Institute and for publication in the Journal. All papers must meet the standards set by the Council of the Institute, and for this purpose all papers are referred to at least two referees appointed by the Council. Although the worldwide readership of the Journal results in a preference for papers in English, the Council treats papers in Afrikaans on an equal basis, but, to meet the needs of the majority of readers, an English summary of some 5OO to 750 words should be provided.

Jan 1, 1984

By I. Kaabachi, F. Meunier, N. Morales

In open pit mining, ore and waste are hauled outside of the excavation area by trucks that move along a system of ramps. The design of these ramps must be carefully addressed because they have to comply with geomechanical constraints to ensure the stability of the pit walls, provide access to the different levels and phases, but also maximise the value of the extracted ore and reduce the extraction of waste. Because an optimisation approach able to deal with the design of the full ramp system seems to be out of reach at the moment, this paper addresses the problem of designing one ramp providing access to a single pushback, which has been determined beforehand. The optimisation objective is therefore to find a ramp that gives access to one given potential volume, while minimising its impact on the economic value of the volume. Two versions of the problem are formalised. One version allows the extraction of ore and waste only if this extraction is necessary for the ramp system. This version somehow minimises the intrinsic value of the ramp system. In the second version, it is possible to extract more than is needed by the ramp system. For instance, this takes into account the possibility of attaining ore on the wall opposite to the ramp as soon as the ramp reaches its level. In the setting mentioned above, the contribution of this work is three-fold. First, the computational complexity of the two different versions of the problem is presented and discussed; in particular, they are shown to be NP-hard. Second, compact integer programs modelling these two versions are proposed. Third, an efficient GRASP algorithm able to cope with the large instances of the problem is proposed. To assess the proposed approaches, the models and algorithms are applied to real instances with an off-the-shelf solver, illustrating and discussing their potential and relevance for the two versions of the problem. They are also compared with other approaches from the literature in terms of value and resulting designs.

Sep 1, 2021

By A. J. S. Spearing, M. Sharifzadeh, K. V. Jessu

Empirical pillar design methods are commonly used in the mining industry. The parameters within which these methods are valid are frequently unknown to the user or ignored. In addition, empirical design may not consider essential parameters such as blasting effects, orebody dip and the presence of geological structures, which all adversely affect the stability of the pillars. This can result in potentially serious pillar design strength over-estimates. Although the commonly based tributary area method is generally conservative, as the spans are seldom that large relative to the depth, failing to consider other relevant parameters can result in errors. Problems associated with an under-designed pillar can range from a local pillar collapse to a catastrophic chain reaction collapse (or run). Over-designed pillars are generally safe but reduce the extraction of the orebody, thus adversely affecting the profitability of the mining operation. We used laboratory tests and numerical modelling to understand the effects of pillar orientation, blasting and the presence of discontinuities on pillar strength. Reduction factors were developed with these models to be implemented in conjunction with the existing empirical pillar design methods. For any pillar or mine design, once it is implemented, the actual performance of the system must be checked regularly by observation and monitoring and adjusted if needed. The pillar design approach outlined in this paper can better optimize the pillar mining method by considering other generally ignored but important parameters, thus improving safety, productivity, and economic aspects.

Oct 1, 2022

By D. W. Dean, J. A. Ryder

"A computer system designed to assist in maintenance scheduling and costing, and in monitoring the performance of equipment, is described. The emphasis is on the information retrieval and implementation aspects of the system.INTRODUCTIONThe cost of the maintenance of equipment can account for a substantial proportion of the total costs of any large industry. These costs are made up of the following elements:(i) capital expenditure,(ii) maintenance labour,(iii) maintenance spares,(iv) maintenance overheads,(v) production losses.Control of these cost elements cannot be achieved without a system which maintains and retrieves the necessary infor¬mation efficiently.The system should provide engineering management with the information necessary to:(i) establish the cost of maintaining items of equipment,(ii)establish the economic life of equipment,(iii) determine breakdown patterns for the establishment of optimum inspection, service and overhaul frequencies,(iv) establish work schedules for those responsible for the maintenance of equipment,(v) establish the optimum maintenance labour complement,(vi) establish the optimum stockholding of maintenance stores items,(vii) improve the performance of equipment,(viii) justify the selection of a particular type and make of equipment,(ix) establish the reasons for any abnormal usage of materials and labour, and to(x)reduce the dependence on the human element for the control of equipment maintenance activities.Many industries have comprehensive and numerous equipment maintenance records but they experience great difficulty in retrieving the required information in the time available and with the labour available. Many industries do not bother to maintain meaningful records, because of this difficulty."

Jan 1, 2014

By O. S. Tinkler, K. C. Sole

"Although the first large-scale application of copper recovery by solvent extraction took place in Zambia in the early 1970s, it is only in the last decade that this technology has become widely employed in this part of the world and is now a mainstay unit operation in copper hydrometallurgical flow sheets. The mineralogy of the ores of the African Copperbelt, and hence the characteristics of African leach liquors, differs significantly from those in Chile and the southwestern USA, where copper solvent extraction has had a long and successful history. These differences provide operators, metallurgists, reagent vendors, and engineers with many challenges: new approaches are needed to adapt solvent-extraction technology for successful implementation in this region. This paper examines typical operating practice in the African Copperbelt, discusses differences compared with other parts of the world, and looks at some of the challenges and opportunities presented by these flow sheets. IntroductionFollowing the success of the Rancher’s Bluebird and Bagdad solvent extraction and electrowinning (SX–EW) operations in Arizona in the late 1960s, the Tailings Leach Plant at Chingola, Zambia, became the first large-scale copper SX plant in the world, commissioned in 1974. Despite the equipment design now being outdated, this plant still continues to operate successfully, indicating the versatility and adaptability of this technology. Today, there are some 75 copper SX operations worldwide with cathode production above 10 kt/a. The top ten producers currently account for about 40% of the global 4.3 Mt/a SX–EW copper production. South America (predominantly Chile and Peru) is the largest copper cathodeproducing region, with annual production of some 2 Mt. The Central African Copperbelt (Zambia and the Democratic Republic of Congo (DRC)) is second, with cathode production of 1.2 Mt/a, and North America (USA and Mexico) third, producing close to 0.8 Mt/a Cu (Solvay Cytec data, 2014). The remaining 0.35 Mt/a comes from all other regions combined (referred to as ‘Rest-of-World’)."

Jan 1, 2016

By C. Karageorgos, J. Sakala, A. Prinsloo, B. Ngambi

The sulphide flotation circuit at First Quantum Minerals’ Kansanshi mine in Zambia produced over 100,000 t of copper in 2019. For this circuit, mineralogical analysis has shown that the majority of the copper lost is hosted in fine liberated chalcopyrite, which is a paramagnetic mineral. The objective of this work was therefore to improve fine chalcopyrite recovery in the sulphide flotation circuit at Kansanshi, using a magnetic conditioning technology to agglomerate fine paramagnetic minerals. This theoretically increases the probability of attachment during collision and therefore improves recovery. A four-month paired ‘t’ test plant trial was carried out and comprised of consecutive ON-OFF periods with and without magnetic conditioning in the rougher flotation bank of the sulphide circuit. The experimental design involved assessment of recovery by size based on daily and weekly composite samples of feed and tails, sized using both wet-screening and cyclosizer. Both the daily plant data and the sized samples showed an increase in Cu recovery with magnetic conditioning ON. A 0.56% copper recovery improvement was measured with magnetic conditioning at a 99.4% confidence level. Keywords: Flotation, fine mineral, chalcopyrite, magnetic aggregation

Jan 1, 2020

By M. Weir, J. R. Cutland, L A. J. Pronk van Hoogeveen

"A computer system for the design of open pits to mine stratiform orebodies has been developed for use at Nchanga Consolidated Copper Mines, Ltd. The particular requirements of such a system, for example, the accuracy of representation of geological detail and the ability to follow footwalls, arc described in this paper, together with the methods that have been adopted to satisfy them.A modified version of the Open Pit Design Program of Rio Tinto Zinc Consultants, Ltd. is incorporated in the system and the geological data are converted into a form usable by the computer by means of a pencil follower. Some of the uses which have been made of the system are described, with reference to the long- and medium-term planning of the Nchanga Open Pit, the major producing pit at Chingola Division."

Jan 1, 2014

By S. Khan, M. Auret

Due to the modernisation of mines, traditional training methods may be supplemented to support the upskilling of supervisors in mines. A project was initiated by the SAMERDI SATCAP programme to demonstrate the “art of possibility” through a modern training methodology. Two exemplar digital supervisory leadership development modules for underground gold and platinum-group metal conventional and modernising mines, were developed for potential uptake by the mining industry. These exemplar modules were exhibited on a digital platform, towards leading and driving mining modernisation. The research adopted a mixed method approach that included a literature review, a review of an existing supervisory leadership development programme, data gathering, a pilot study, and stakeholder validation workshops. The research supported the development of exemplar digitised modules. The two digitised modules were showcased to the industry for potential adoption. Training slides, a facilitator guide, and a training video were developed for ease of use by industry. The training modules are generic and not specific to a particular mine. They may be used by multi-commodity mines, including gold and platinum-group metals, as ‘stand-alone’ modules. They are customisable, through consultation with relevant service providers for specific working environments. The findings indicated that both the traditional classroom training and the new digitised online learning solution offer advantages for supervisory leadership development. Digital learning is not a new concept for supervisors at mines and modern training methods are well-supported by supervisors in the industry. A ‘modernised’ training solution may consider a ‘blended’ learning approach that combines traditional training with digital methods.

Jun 27, 2025

By V. K. Risinggård, M. Sparta

We report on the development of a finite-element method model for a pilot furnace for the production of manganese alloys. The model is a multiphysics model that addresses material flow, electrical conditions, heat transfer, and physical and chemical transformations. It is capable of studying both quasi-steady and transient states in time-dependent simulations. The model includes common charge materials and fluxes and can simulate production of both ferromanganese and silicomanganese alloys with acid and basic slags, as well as changing charge compositions. The model output provides access to the material distribution in the furnace during furnace runs, temperature profiles, current paths, energy balances, and alloy and slag production rates and compositions.

Apr 16, 2024

"Chairman: Professor J. de V. Lambrechts Rapporteur: Mr R. HempPapers:Computer-aided design of a flash smelting installation by M. A. T. Cocquerel, R. T. Gates and L. A. GreenPlanning of mine ventilation by E. U. Reuther and A. DohrnenCoal mine ventilation systems in the U.S.A. by R. Stefanko and R. V. Ramani Heat flow models in ventilation planning by A. J. Dickson and A. M. StarfieldThe first of the papers in the session dealt with a flash smelter installation, while the remaining three papers dealt with mine ventilation. In view of this the Chairman proposed that the paper on flash smelting be introduced and discussed first, after which the remaining three papers would be introduced followed by discussion on all three.Dr Cocquerel, who presented the first paper, used some typical flow diagrams to illustrate the process and stated that the program considered only steady-state operations and did not take into account the dynamical changes. Subjective judgment was necessary for the preparation of input data and some degree of user appreciation was required.Dr Cocquerel said that no work bad yet been done on an optimization program, but that this was being considered. Such a program would require a large amount of physical and chemical data which were not yet available. The variables to be optimized were the energy and material consumptions and the loss of metal in the slag.The Chairman opened the discussion by asking Dr Cocquerel if he could give a brief description of the flash smelting process for the benefit of those not familiar with the subject. Dr Coquerel replied that in the Outokumpu process con¬centrates were injected directly into the furnace, and that the process was somewhat analogous to flash distillation or evaporation processes, but was perhaps closer to the burning of pulverized fuel.The process had two distinct advantages. First, the heat evolved in the smelting reaction was used to heat the furnace, which resulted in less fuel consumption, and, second, the effluent gases were cheaper to treat than the effluent gases from other pyrometallurgical processes. This was important particularly in view of the current interest in pollution problems.Mr P. Marais thought that the authors had done themselves an injustice by not including details of the very complex processes taking place in the furnace."

Jan 1, 2014