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Book review Burkin, A. R. (ed.) . Leaching and reduction in hydrometallurgy. London, Institution of Mining and Metallurgy, 1975. £10. hydroxide pyritearsenopyrite NIM reports Report no. 845 A n electron-microprobe study of the nickel distribution in a serpentinite from Volspruit, Potgietersrus. (22nd Oct., 1969; re-issued Dec. 1975). Report no. 1546 Pilot-plant smelting campaign on iron ores from Tete. (22nd May, 1973; re-issued Jun. 1976). Report no. 1557 Cost estimates for the production of pig iron in the Tete district of Mocambique. (18th Jun., 1973; re-issued Jun. 1976). Report no. 1600 Dilute-acid leaching of slag from Tete ore. (20th Nov., 1973; re-issued Jun. 1976). Report no. 1602 The roasting of Tete slag for the extraction of vanadium. (20th Nov., 1973; re-issued Jun. 1976). Report no. 1635 Magnetic separation tests on Tete slag and ore. (30th Apr., 1974; re-issued Jun. 1976). Report no. 1671 Pyrometallurgical retreatment of a slag for the recovery of vanadium. (11th Oct., 1974; re-issued Jun. 1976). Report no. 1785 Some thermodynamic aspects of systems relevant to the flotation of sphalerite. Report no. 1808 Spectrophotometric determination (with pyrocatechol violet as chromogenic agent) of aluminium in zirconium metal and in the residue from anodesludges. Report no. 1813 The economic potential of some pegmatites from the Kenhardt area in relation to the trace-element content of their border zones. Report no. 1817 The rapid determination by X -ray-fluorescence spectrometry of tungsten in tungsten ores and concentrates. Report no. 1820 The thermodynamics of the formation of chlorocomplexes of iron (III), cobalt (II), iron (II), manganese (II), and copper (II) in erchlorate medium.

Jan 8, 1976

Specifile compendium' 80. Mining and engineering. (Obtainable from Specifile, P.O. Box 7870, Johannesburg 2000.) Reviewer: J. D. Austin SKF Steel. Plasmasrnelt information brochure. Hofors (Sweden), SKF Steel, 1980. Reviewer: N. A. Barcza POTENTIAL VALUE OF COLLIERY DISCARD MATERIAL By R B MacGillivray, Pr Eng, BSc(Eng) Rand, C Eng (Fellow) Preprints of perhaps the most thought-provoking of the papers delivered at the Witbank Coal Colloquium - 'Potential value of colliery discard material' by Roy MacGillivray of Rand Mines - are available on request from the South African Institute of Mining and Metallurgy. Mr MacGillivray outlines an imaginative plan to utilize the annual nine million tons of colliery discard in the WitbankBethal areas. Two SAIMM colloquia The South African Institute of Mining and Metallurgy (SAIMM) is organizing two one-day colloquia in the State Pavilion, Milner Park showgrounds, Johannesburg, to coincide with the Electra Mining Exhibition on 16th and 17th September. Over a million rands worth of equipment will be on display, the Electra Mining Exhibition being rated among the four or five largest in the world. The 1978 Electra Mining Exhibition was attended by 24 000 visitors. "Project Management in the Metallurgical Industry", "Mine Fires" APCOM International Conference by H. W. GLEN The 17th APCOM Conference (under the auspices of the Council for the Application of Computers and Mathematics in the Mineral Industries) was to have been held in Moscow during the last week in October. South Africans have always given enthusiastic support to the APCOM series of meetings, since their inception in 1961. The conference was held in the Republic in 1972.

Jan 1, 1980

By B. Mbuya, A. F. Mulaba-Bafubianda, J. M. Mvita

The paper explains the main effects of input leaching parameters, such as addition of a reducing agent, acidity, agitation, temperature, and leaching system potential, in relation to observed and predicted yields of sought-after cobalt. An artificial neural network coupled with graphical probability networks was developed wherein the abovementioned input parameters were used to predict the percentage of dissolved cobalt. Furthermore, similarities and differences between the Bayesian and neural network approaches in terms of their key outcomes are compared with respect to study of the dissolution of cobalt in sulfuric acid. Key results indicate that there is a need to use neural network results to predict conditions for dissolution of cobalt, while using Bayesian network to explain inferences about conditions of the input parameters, thereby achieving realistic predictions.

Jan 1, 2023

By R. Lechuti-Tlhalerwa

"Geometallurgy aims to improve mining project value by predicting the impact that ore and waste characteristics will have on mining and metallurgical processes. This requires integration of rich spatial models of orebody characteristics with validated process response models. These models have, until recently, been constrained by the spatial coverage and representativity of relevant data and the ability to validate predictions made.The revolution in the diversity and volume of data and computational power that is now becoming available for integrated geoscientific modelling of orebodies, and stochastic simulation of mining and mineral processes is accelerating. By embracing emergent integrated data analysis and simulation techniques, geoscientists and engineers can lead a transformation in the way the mining value chain, from orebody to recovery, can be conceived, evaluated, and operated by using the geometallurgical paradigm.This paper describes a methodology that is applied to an existing diamond operation. Analysis of spatial and process data is used to build an integrated geometallurgical value chain model (IGVCM). This IGVCM is used to generate geometallurgical options and evaluate their potential outcomes. The model facilitates the use of flexible, highly configurable, and potentially automated intelligent approaches to evaluate mining and mineral process configuration, and results in more robust design outcomes. The approach described here, and its successful implementation has potential to deliver step-changes in value. IntroductionGeometallurgy aims to identify treatability risks – and opportunities – that arise from the interaction of orebody characteristics with mining and treatment. Improved understanding of the rock/process relationships allows project planners and production teams to predict performance, identify potential shortfalls, and thus enable the proactive creation and evaluation of strategies to mitigate these risks. These advanced insights also create opportunities for continually improving operational performance through dynamically adapting and improving the process response to the changing properties of the ore (Figure 1)."

Apr 1, 2019

By I. B. Fernandes, M. A. Reuter, A. Abadias Llamas

Metallurgical simulation and evaluation of the resource efficiency of whole production processes are of key importance for impact assessment, in terms of environment and resources. Exergy is a measure of resource consumption, taking into account energy, raw materials, water, and chemicals; which allows for the evaluation of different technologies to find the most resource efficient and environmentally friendly process. This paper compares the sustainability for production of rare earth magnets from primary and secondary resources through an exergetic evaluation of the production process, in addition to traditional life cycle assessment (LCA). The methodology makes use of simulation tools for tracking material flow and resources used, based on thermodynamic laws, from ore exploitation to magnet production and recycling. It highlights areas with the greatest potential for improvements in terms of resource consumption and environmental impact generation, having a thermodynamic-validated flowsheet for primary and secondary production of NdFeB magnets, present in several low-carbon technologies, such as wind turbines, electric vehicles, and cooling systems. It demonstrates the minimum exergy destruction for magnet production, through an irreversibility breakdown chart, showing where irreversible material and energy losses occur. Results show that CO2-equivalent emissions for producing NdFeB permanent magnets from primary resources could be twice as high when compared to magnets produced from recycling technologies. The theoretical maximum exergetic efficiency for primary production is 57.61%, whereas for permanent magnets produced from secondary resources, the exergetic efficiency reaches up to 82.89%. Two magnet recycling technologies were evaluated, i.e. in acidic medium and via hydrogen decrepitation, and it was observed that their exergetic efficiency and environmental impact performed better than production from primary resources. Keywords: Resource efficiency, exergy analysis, permanent magnet recycling, process simulation, system design

Jan 1, 2020

By K. Muchima, C. Siame, L. Little, B. Kaputula, Q. Mclennan

"The variability of copper mineralization at Kansanshi mine significantly affects the efficiencies of the processes used to recover copper. Quantifying this variability is therefore essential for monitoring and optimizing the performance of the concentrator, which comprises three different flotation circuits (sulphide, mixed, and oxide) and an atmospheric leach circuit. Onsite automated scanning electron microscopy with energy-dispersive X-ray spectrometry (Auto-SEM-EDS) is used to analyse routine weekly composite samples for each circuit, providing detailed analyses of bulk mineralogy, copper deportment to different minerals, mineral liberation, and associations. Weekly mineralogical trends are used to assess changes in process performance, and characterization of the copper losses has inspired a number of projects to target the specific particle types responsible for the main losses. In this paper we describe the relationship between mineralogy and plant performance at Kansanshi, and discus IntroductionKansanshi is a copper and gold mine located in the Northwestern Province of Zambia, with an annual production in the region of 250 000 t of copper and 160 000 ounces of gold. Ore mined from the epigenetic vein-hosted deposit is classified into three ore types based on the extent of oxidation and supergene enrichment. Sulphide, oxide, and mixed ore are fed to separate mineral processing circuits tailored for recovery of the dominant copper minerals in each. After comminution to a target grind size of 80% passing 150 µm, each ore type is subjected to flotation to recover the copper sulphide minerals (chalcopyrite, bornite, chalcocite, covellite). The oxide float tails and a large proportion of the mixed float tails are then treated by atmospheric leaching to extract copper from the remaining copper-hosting minerals, which include cuprite, malachite, chrysocolla, and delafossite. Some native copper is recovered by flotation and some of it is recovered by leaching. A small portion of the combined concentrate from all circuits is subjected to high-pressure leaching and the rest is sent to the smelter. Sulphuric acid produced during smelting is used for the atmospheric leach."

Nov 1, 2018

By M. Arlandi-Rodríguez, and A. García-Berrocal, A. Alonso-Jiménez, C. Lopez-Jimeno

Spain is a major producer of dimension stone, which is one of the most important industrial sectors in the northwest of Spain. This justifies the maintenance of these industries, although the technical and environmental requirements for their continuity are increasingly demanding. The main target of this paper is to present a new methodology in order to obtain k-ratio stress values on the basis of flat jack measurements and finite element numerical back- analysis with Rocscience© RS2 software. Continuous iterations were performed to try to find a relationship between the k₀ and the measured stress in the tunnel roof and sidewalls. It focuses on technical aspects of the method for designing mine chambers in the slate industry that were previously mined by open pit methods. The size of the chambers impacts the operating cost, and the dimensioning of a correct support ensures better efficiency and safety. Correct knowledge of the k₀ therefore is critical for the design of the support. The proposed new method entails a simplification of the classical procedure for estimating the k-ratio.

Sep 1, 2022

To determine the characteristics of a mineral deposit, the usual practice is to take samples, analyse the properties of those samples and infer the characteristics of the deposit from these properties. This analysis can be done using statistical methods. In the present work we are concerned with two types of statistical approaches, classical statistics and spatial statistics. If one uses classical statistics to represent the properties of the sample values, the assumption is made that the values are realizations of a random variable. The relative positions of the samples are ignored, and it is assumed that all sample values in the mineral deposit have an equal probability of being selected. The likely presence of trends, zones of enrichment, or pay shoots in the mineralization, is ignored. The fact that two samples taken close to each other are more likely to have similar values than if taken far apart is also not taken into consideration. In contrast, spatial statistics will be used if one chooses to consider that the sample values are realizations of random functions. On this hypothesis, the value of a sample is a function of its position in the mineralization of the deposit, and the relative position of the samples is taken into consideration. The similarity between sample values is quantified as a function of the distance between samples and this relationship represents the foundation of spatial statistics. There are few situations where classical statistics can be used. The assumption that all sample values in the mineral deposit have an equal likelihood of being represented will be satisfied only if the sample values are randomly distributed, or if the sample positions are random. Sample values are in fact never randomly distributed within a mineral deposit. Further- more, geologists usually avoid taking samples at random (random sampling), as it is correctly accepted that samples located on a regular grid, or approximately on a regular grid, give more information than randomly located samples. In practice, classical statistics should be used only in the early stages of exploration, when the number of samples available is relatively small and the distances between samples are large. In these circumstances, and whenever the information available is not sufficient to permit the use of spatial statistics, application of the methods described in this chapter is justified.

Jan 1, 1978

By M. Timucin

High-temperature phase relations and thermodynamics of the condensed phase region of the Pb-S-O system at 1473 K were analysed by use of the available information. The sub-regular solution models on Pb-PbS and PbO-PbSO4 continuous melts were used in conjunction to generate a consistent set of thermodynamic and phase equilibrium conditions for the Pb-S-O system. The directions and distributions of conjugation lines between melts of this system were derived with relevant activity and composition data. The calculations permitted the thermodynamic analysis of direct lead smelting and the construction of isothermal reaction diagrams for the system in terms of oxygen and sulphur partial pressures at 1473 K.

Jan 1, 1989

The 86th Annual General Meeting of the South African Institute of Mining and Metallurgy was held in Kelvin House, Johannesburg, on Wednesday, 17th August, 1983. Professor A. N. Brown (President) was in the chair, and declared the meeting open at 16h05. This account of the proceedings includes only those matters that are not reported under the heading `Annual report and accounts' elsewhere in this issue.

Jan 1, 1983

By N. V. Moraka

Mining companies are required by law to improve representation of women on their boards. However, progress in this regard has been slow. Boards of directors play an important role in formulating corporate strategy, risk assessment, and effective governance for sustained financial performance. Although some women have successfully maintained board seats, others have been unable to do so. It is difficult to ascertain whether women are being appointed as tokens to satisfy social pressures, as little is known about the experiences of women board members in mining, which may inform or refute tokenism. In-depth interviews were conducted with 20 women and 16 men across six listed mining companies. Thematic data analysis revealed evidence of tokenism where recruitment to mining boards is compliance-based and is informally driven by influential directors. Adverse boardroom experiences that further confirmed tokenism were reported by women, such as disregarding their contributions, condescending behaviour, and limited influence in decision-making, while other women sought to validate their competence and oppose social exclusion. This study recommends that a strong Board Chair and nominations committee is critical to ensure sustainable recruitment of competent and suitably qualified women; and further foster a culture of inclusivity and valuing gender-diverse boards.

Dec 13, 2023

By J. L. Porter

This paper takes a personal look, through the author?s own experiences, at the implementation of innovations in the narrow-seam, hard-rock mining environment of South Africa?s mining industry over the past 40 years. A number of examples are used to illustrate some of the successes and failures over this period. More importantly, the examples are used to illustrate that the bulk of the investment for these projects should have been applied in a manner that could have achieved more sustainable results. The use of the word ?technology? in this context is also examined, as it is the author?s contention that only measuring the performance of machinery fails to encapsulate the potential of the entire system describing the scope of the innovation being implemented. These experiences and observations are projected onto the current backdrop of upheaval in the relationship between key industry stakeholders and the sustainability challenges facing areas of the mining sector in the South African economy. The paper concludes with some opinions on where attention can be focused in order to develop new thinking that can be applied for the safe and economic extraction of the nation?s mineral wealth.

Jan 1, 2014

By E. Lutz, M. Momayez, K. W. Brown Requist

As real-time air quality monitoring becomes more prevalent in US underground mines, it is important to provide the highest data reliability with the fewest possible sensors. Real-time sensors remain costly, and these costs are not exclusively financial; the time required to install, calibrate, and maintain real-time sensors poses a large barrier to widespread implementation. Current atmospheric monitoring systems typically rely on displaying point-specific values. This requires operators to infer real-time airborne contamination distributions. Monitoring and control software utilizing mine ventilation network (MVN) solvers has been implemented in limited cases because of their ability to simulate ventilation systems quickly, but these solvers use a one-dimensional representation of the mine, limiting spatial resolution of estimated distributions. Computational fluid dynamics (CFD) has likewise been considered as a means to improve spatial resolution, but processing times prevent its use as a basis for monitoring and control. For the real-time monitoring of airborne contamination distributions, we propose a spatial interpolation method that can estimate the distribution of airborne contaminants in near-real time. This method provides a middle ground between fast processing times and increased spatial resolution. With the use of a pathfinding algorithm and optimization through absolute percentage error minimization, this method outperforms spatial interpolation with a Euclidean distance. By providing contamination distribution information to operators, this method and its derivatives stand to outperform current atmospheric monitoring systems.

Apr 16, 2024

By N. Mutemeri, T. -L. Field, M. Chuma

The categorization of artisanal and small-scale mining has a significant impact on perception and understanding of the sector, particularly from a livelihood perspective. Several developing countries classify different types of artisanal and small-scale mining based on legal status. Given the nature such activities, the tragedy of the commons theory has been applied to understand the inevitable environmental, economic, sociocultural, safety, and health negative externalities – which are products of informality and illegality. Consequently, formalization is a panacea to sustainability. This article aims to offer a conceptual organization and foundational knowledge for characterization of artisanal and small-scale mining. It seeks to identify existing literature on the subject to avoid replication and acknowledge other scholars. Moreover, the article aims to place the study within the context of existing literature, establishing relationships with other studies and why the research is necessary. This paper pinpoints gaps left from other studies in so far as the characterization of artisanal and small-scale mining is concerned. Thus, reviewing literature abetted in finding similarities and differences on how artisanal and small-scale mining is defined from a scholarly and legal basis. The paper ascertains major claims made by earlier research on this topic, such as environmental impacts, the lack of adequate regulatory framework, and presents querying and probing questions lacking from other studies.

Jul 10, 2024

By H. M. Friede

Iron Age metal working in the Magaliesberg area by H. M. FRIEDE, Ph.D. (Visitor) Evidence of smelting and metal working in the Magaliesberg comes mainly from three sites: Broederstroom (Pretoria District). Uitkomst Cave (Krugersdorp District), and Olifantspoort/Olifantshoek \Rustenburg District). The analyses of copper ores found at or near these sites are reported. as are the analyses of twenty-six samples of slag from the Magaliesberg area and other sites in the Transvaal. Iron implements and copper ornaments found at the Magaliesberg sites are described. and the analyses of some of these specimens are reported and discussed. A metallographic report on two iron objects from Broederstroom points to similarities in the smelting and forging techniques that were practised in the Transvaal and Nigeria during the Early Iron Age.

Jan 6, 1977

By P. R. Levey, A. van Bennekom

The effects of nitrogen alloying on the corrosion properties of austenitic stainless steels were investigated by a combination of potentio-dynamic and surface analysis techniques. The results indicate that nitrogen undergoes the phenomenon of anodic segregation, affecting both general and localized corrosion resistance. Nitrogen alloying is found to be beneficial to general corrosion resistance in a de-aerated sulphuric acid solution, but to be detrimental in an aerated solution of sulphuric acid This phenomenon is explained in terms of an ammonium-ion polarization effect. Localized corrosion resistance is found to improve dramatically as a result of nitrogen alloying, the nitrogen improving the formation, maintenance, and stability of the passive film in environments that promote pitting various theories that have been proposed to account for these phenomena are discussed.

Jan 1, 1995

By A. A. Snodgaass

This paper reviews lead as a commodity, starting with a brief historical outline and dealing with the various uses of lead in some detail. It then goes on to discuss some statistics in relation to the production and reserves of lead, before sketching its mode of occurence. The topics are approached in regard both to the world and to South Africa, with the emphasis on the later. The mining and concentration of lead at Black Mountain Mine at Aggeneys in the north-western Cape Province are detailed, before a general account is given of the smelting, hydrometalurgical extraction, and refining of lead, together with the processes used in these activities. The paper concludes with a discussion of safety and health in regard to lead and a brief look at the commodity's future.

Jan 1, 1986

By R. R. M. Cousens, W. S. Garrett

SYNOPSIS The paper gives a background to the water hazards of the so-called West Wits Line and refers to some geological aspects of the Wonderfontein Valley in which the West Driefontein mine property lies. It describes the precautions taken against flooding during shaft sinking, development and stoping; these include cover hole drilling with cementation, provision for water storage in worked-out areas, installation of water tight bulkhead doors and pumping capacity well in excess of the mine's normal requirements. The plan of campaign adopted after the inrush took place is explained and the reorganization and expansion of pumping arrangements are discussed. When it became clear that the only means of saving the mine was to construct plugs to isolate the inrush while still maintaining all emergency pumping measures, the work was put in hand with the utmost dispatch. In considering the design of the plugs a number of major factors had to be taken into account. The most vital was the need for speed which was complicated by difficulty of access to the plug sites because of the huge volumes of water flowing in the drives. How this and other factors affecting plug design and construction, leakage problems, sequence of operations and final closure of the valves, were overcome is detailed in the paper. INTRODUCTION The inrush of water into the West Driefontein mine, the biggest gold producer in the world, which began on 26th October, 1968 and continued unabated for 23 days before the flood was stemmed, was unprecedented in the history of mining. Also unprecedented were the tremendous efforts and organization which made it possible to bring the situation under control and so save the mine from being lost for a matter of years. BACKGROUND Before going into details of how the situation was brought under control it is appropriate to consider the background to the event. The water problem on the so-called West Wits Line has been recognized for many years. As far back as 1912 the Pullinger Shaft, situated in the centre of what is now the Venterspost mine property, had to be abandoned because there were no means then available of coping with the large quantity of water encountered. To appreciate what vast quantities of water were involved, it helps to refer to some geological aspects of the Wonderfontein valley in which the West Driefontein property lies. The narrow tabular Witwatersrand gold-bearing beds, which dip at about 25 degrees towards the south, are overlain by a surface layer of dolomite which reaches a maximum thickness of some 4,000 ft at West Driefontein. A number of vertical syenitic dykes intersect the valley more or less at right angles to its course (Fig. 1). These dykes are about 150 ft thick on average and are spaced at about eight-mile intervals in the West Driefontein area. They penetrate both the dolomite and the Witwatersrand beds and as they are impervious to water they divide the valley into a series of large underground water compartments.

Jan 5, 1969

By I. M. MacGregor

This paper discusses the possible use of petrological data and proximate analyses in the prediction of cutting forces for coal. It is restricted to the development of univariate predictors based on data from thirteen collieries in five major Transvaal and Orange Free State coalfields and three coal provinces. The aim of the work was the identification and development of the best predictors of mean peak cutting force and Hardgrove grindability index from among the independent variables evaluated. The data, which were obtained by use of the penetrometer developed by the Chamber of Mines Research Organization, were processed according to the SPSS computer package. The analysis revealed reasonable correlations between the Hardgrove grindability index and (1) the volatiles and vitrinite content in the Vereeniging-Sasolburg and South Rand Coalfields, (2) the contents of vitrinite, vitrinite plus exinite, and minerals plus inertinite in the Eastern Transvaal Coalfield.

Jan 1, 1985

By N. A. Barcza

An investigation was conducted into the reactions between the slag system MnO-CaO-MgO-SiO2(AI2O3) and the alloy system Mn-Fe-Si-(C). Synthetic slags representative of plant melts and a plant alloy were reacted in alumina crucibles at temperatures of 1400°C, 1450°C, 1550°C, and 1600°C. In similar experiments, slags were used that comprised a South African manganese ore with various amounts of lime and several synthetic alloys with various silicon contents and manganese-to-iron ratios. These experiments were conducted in a vertical molybdenum-wound resistance furnace with full temperature control. Slag-to-alloy ratios were also varied during the tests. The rate of reduction of Mn.O3 and the MnO from the slag by the silicon in the alloy was extremely rapid, most of the reaction being completed within five minutes. The strongly exothermic nature of the reaction resulted in considerable generation of heat at the slag-alloy interface, causing convectional stirring of the contents of the crucible and promoting the rate of reaction. Equilibrium was usually attained after fifteen minutes. The major limitation governing the recovery of manganese is the need for the silicon content of the alloy to meet a maximum specification of 2 per cent. Higher concentrations of silicon in the final alloy of between 8 and 12 per cent favour good recoveries of manganese from the slag, but, since such an alloy is not salable, lower recoveries must apparently be tolerated. In alloys of 2 per cent silicon, low activities of the silicon are responsible for poor recoveries of manganese. The activity of MnO in the slag can be increased by moderate additions of CaO and small amounts of MgO, i.e., by an increase in the basicity of the slag.

Jan 1, 1979