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By P. J. D. Lloyd

The Federation of Societies of Professional Engineers (FSPE) recently conducted a survey of professional engineering manpower in South Africa. This article presents the data relevant to mining and metallurgical engineering. FSPE in their survey attempted to determine the supply of engineers in South Africa both from local universities and by immigration. The immigrants gave some problems in that it is difficult to know whether a man who claims to be professionally qualified really is. However, it was estimated that the ratio of immigrants who claimed to be qualified to those who really are the equivalent of our local graduates was between 1,0 and 1,9 for mining engineers, and between 2,0 and 4,1 for metallurgical engineers.

Jan 1, 1980

By M. J. Southwood

SYNOPSIS Experiments carried out under atmospheric pressure and temperature (25°C) and sterile conditions show that the dissolution rate of nickel and copper from a pyrrhotite-pentlandite-chalcopyrite ore in a lixiviant of sulphuric acid is greatly enhanced in the presence of pyrite. At a pH value of 1,8 and in the presence of pyrite of equal mass to that of the ore, the recoveries of nickel and copper improved dramatically (21 and 80 per cent respectively). At a pH value of 4,0 the recovery of nickel was enhanced, but the chalcopyrite was refractory. A galvanic mechanism is probable, but cannot be proved from these experiments. The economic implications of the results are discussed.

Jan 1, 1985

By Z. Nzimande

The Constitution of the Republic of South Africa advocates the importance of sustainable economic development and justifiable environmental consciousness by business. The government needs to ensure that every citizen of the Republic has access to an environment that is protected, pollution free, and sustainable by enacting certain regulations. However, there are more than 5 700 derelict and unrehabilitated mines of all types in South Africa. Former asbestos operations were among the first to be targeted for clean-up under the programme instituted by the Department of Mineral Resources (DMR), owing to the proven direct impact of asbestos pollution on health. This paper seeks to investigate the challenges faced by the coal sector as far as mine rehabilitation and closure is concerned. For the purpose of this paper rehabilitation is defined as per the Chamber of Mines Rehabilitation Guidelines publication, which defines rehabilitation as putting the land impacted by mining activities back to a sustainable and usable condition. Some of the current rehabilitation challenges are technical skills (know-how), leadership focus, poor planning, cost saving initiatives, and the government's lack of capacity to enforcement rehabilitation requirements. It is imperative that mining companies identify rehabilitation as a critical strategic pillar that directly influences license to operate. The case study evidence indicates that relevant policies, appointment of accountable people, sufficient leadership support, and the correct choice of rehabilitation equipment can assist to improve the rehabilitation and land management challenge.

Jan 1, 2012

By А. V. Aksenov, S. G. Rybkin, А. Y. Senchenko

Recovered activated carbon fines result from processing of ore and concentrates via cyanide leaching and sorption of valuable metals on carbon at gold-mining plants. This intermediate product is characterised by the particles sized smaller than 0.6 mm and gold grade up to 300-500 g/t. Processing of carbon fines with recovery of valuable metals is not available at many plants due to the lack of optimal technology. The paper describes the testwork and development of an efficient technology to process carbon fines with the recovery of valuable metals into the target gold alloy. This innovative technology involves pelletising of fine activated carbon particles using an organic binder, drying and further firing of pellets in a grate fired furnace at 800-900 °С. The produced ash is subject to sintering with sodium nitrate and hydroxide at 600-700°С. The sintered ash is then leached in water. The insoluble residue containing gold and silver is removed by filtration, dried and smelted to produce gold alloy. Water solution containing sulphur and arsenic is subject to detoxification. Processing of recovered carbon fines according to the developed technology implies the use of standard full-scale equipment. The offered method to treat gold-bearing carbon fines was patented by the Eurasian Patent Office. Key words: Fine activated carbon particles, valuable metals, pelletizing, firing, ash, sintering, leaching, smelting

Jan 1, 2020

By J. M. Eriksen, T. Rosenqvist, H. Elstad, S. Seim, A. Hildal

The titanium industry demands high titanium feedstock for their processes. As rutile resources are limited, ilmenite has become the most important titanium source. Ilmenite smelting is an important part of upgrading ilmenite to high titanium feedstock. In the year 2005, upgrading of ilmenite by smelting, producing a slag with 80-90% Ti02, accounted for approximately 40% of the feedstock to the Ti02 pigment industry. In ilmenite smelting molten iron is produced together with a slag, which in addition to titanium oxide contains iron oxide as well as various impurity oxides of manganese, magnesium, silicon, aluminium, etc. Titanium is present mainly as Ti02 but partly also as Ti203. It is known that the concentration of Ti203 increases with decreasing concentration of FeO, but this dependency is affected by the nature of the impurity oxides. Sigurdson and Moore1 showed that slags high in CaO and MgO had a lower concentration of Ti203 than slags high in Si02 for the same amount of FeO. Pistorius2 showed in 2002 that if the impurity oxides MnO and MgO are counted, on a molar basis, as FeO, and Cr203, V203 and part of the A1203*), as Ti203, industrial slags will have a composition close to that of the M305 phase, where M denotes the elements Ti, Fe, Mn, etc, and which has the pseudobrookite structure. However, for equilibrium with liquid metallic iron he computed, by means of a computer program FACT, that the slag equilibrium composition is represented by a curved line in the ternary phase diagram FeTi03-TiO2-Ti2O3, but with a significantly higher concentration of trivalent titanium than actually observed in the industrial slags, and he discussed various mechanisms by which the slag during solidification could change its composition to a lower Ti203 content, but the possibility that the computed compositions might be wrong was not mentioned. Trane113 found in her research on titaniferous silicate slags a lower Ti3+/ Ti4+ ratio than that which is computed by the FACT program. The purpose of the present investigation was to study the equilibrium composition of Fe-Ti-O slag in equilibrium with liquid metallic iron, as well as the effects of impurities such as Si02, CaO and MgO on the slag composition. Industrial slags from TINFOS Titan and Iron KS (TTI) will also be discussed and their compositions will be plotted in the ternary phase diagram. These are slags produced from Tellnes ilmenite, quite high in magnesium and iron. Experimental In the past, equilibrium studies of the Fe-Ti-O slag system were difficult when it came to producing the slag. It was difficult to find a suitable crucible for the meltings. The highly corrosive slag would attack all known refractories, and the metal would attack metallic crucibles such as those made of platinum and molybdenum. In the present investigations the slag-metal combination was prepared in a high-frequency induction furnace with a vertically segmented water-cooled copper crucible. The crucible is shown in Figures 1 a and 1b. It was designed by the Australian Nuclear Science and Technology Organisation (ANSTO) with power from a 75 kVA high-frequency generator (750 kHz) supplied by Farfield Electronics Pty, Ltd, Australia. This enabled the slag-metal combination to be melted with turbulent stirring and is expected to be isothermal. The entire temperature gradient

Jan 1, 2007

By M. M. Hajdasinski

The internal rate of return (IRR) is one of the most popular project evaluation criteria in the mineral industry, as well as in other industrial sectors. Analysis of its assumptions reveals, however, that this criterion does not function in the way it is supposed to. The search for a new criterion that would reflect the true rate of return (TRR) of an investment project or the true borrowing rate (TBR) of a borrowing project has led to the development of several approaches, yielding, for the same project, generally different values of the interest rate in question. Two of those approaches have been selected as the most representative and practical. Each has been presented in two variants, and subsequently analysed. As a result, it is shown that the various approaches to the TRR/TBR are all consistent with the net present value (NPV) criterion, and that each can serve as an independent project evaluation instrument, provided its assumptions can be regarded in a given situation as realistic enough.

Jan 1, 1987

By D. Krebs, Tero Korhonen, X. Yang, A. Kirpala, N. Heino

At present, over 85% of the world’s rare earth oxides are produced from the bastnäsite ores, found mainly in China. Meanwhile, the ion adsorption ores are the most important sources for heavy rare earth production. As the demand for rare earth materials in the world increases, other forms of rare earth deposits will become new potential resources of rare earth production in the future. In this paper, flotation performance of a steenstrupine ore from the Kvanefjeld deposit for rare earth recovery was studied through laboratory bench testwork. The effects of various factors including grinding size and collector dosage on recovery and selectivity of the selected rare earth elements, La, Ce and Y, were investigated. A rare earth concentrate with the grades of La 2.8 wt%, Ce 5.1 wt% and Y 1.0 wt% at recoveries of 80.5% La, 79.8% Ce and 55.3% Y was obtained in optimum conditions. Further potential to improve the efficiency of REE flotation was discussed. Keywords: Rare earth elements, flotation, steenstrupine, Kvanefjeld deposit

Jan 1, 2020

By T. Oberthür

The Great Dyke of Zimbabwe constitutes the world&apos;s second largest reserve of platinum group elements (PGE) after the Bushveld Complex in neighbouring South Africa. Within the Great Dyke, economic concentrations of PGE are restricted to sulphide disseminations of the Main Sulphide Zone (MSZ), which are currently mined at the Ngezi, Unki, and Mimosa mines. Near-surface oxidized MSZ ores have a large potential. Their total resources are in the range of 160-250 Mt; however, all previous attempts to extract the PGE from this ore type have proved uneconomic due to low PGE recoveries (<< 50 per cent) achieved by conventional metallurgical methods. Within the ores of pristine, sulphide-bearing MSZ, the PGE are bimodally distributed. Platinum occurs mainly in the form of discrete platinum group mineral (PGM) grains (mainly bismuthotellurides, sulphides, and arsenides), whereas approximately 80 per cent of the Pd (and some Rh) is hosted in pentlandite. Within the oxidized MSZ ores, the PGE are polymodally distributed. Whereas the arsenide- and sulphide-PGMs that make up approximately 25 per cent of the original Pt content of the ore largely remain stable (relict PGMs), the remaining PGMs are disintegrated. The base metal sulphides are destroyed, partly releasing their base metal and PGE contents, and are replaced by iron oxides or hydroxides. Unspecified amounts of the PGE are redistributed and either form secondary PGMs, are found in chemically and mineralogically ill-defined (Pt/Pd) -oxides or hydroxides, or in iron-hydroxides, Mn-Co-hydroxides, and in secondary silicates. The problematic processing of oxidized MSZ ores is attributable to their complex nature and polymodal distribution of the PGE, prohibiting a significant upgrading of the ores by conventional metallurgical methods. Therefore, only bulk leaching methods are viable for ore treatment, and novel metallurgical methods have to be developed for the processing of these ores. Our ongoing work aims at locating the PGE in their mineralogical form in order to understand the mineralogical balance of the PGE in the ores and thereby facilitate the evaluation of metallurgical options for their recovery. A short overview on options and recent advances regarding the recovery of the PGE from oxidized ores is given.

Jan 1, 2013

By A. N. Brown

The importance of the minerals industry in the economy of the country is discussed, and the tremendous changes that have taken place over the past two decades, including the widespread application of computers and the use of mechanization, are outlined. A discussion of the future of the minerals industry points out that, with the rise in the price of gold, the life of the gold-mining industry can be expected to extend beyond that previously predicted, and that the demand for uranium, which has been depressed, is uncertain. As a result of the oil crisis, the demand for coal has increased and large expansion programmes are planned. These involve coal exports and the use of coal for the generation of electric power, for the production of liquid fuels, and for the smelting of metals. Technical challenges face engineers in every avenue of the minerals industry: in deep gold mines, underground coal mines, strip coal mines, and open-pit mines. Studies indicate that only one-third of the demand for trained mining and metallurgical engineers is being met and that the position is worsening. However, there are indications that the industry is succeeding in attracting more engineering students, and the supply is expected to improve. These efforts should be co-ordinated, expanded, and intensified. There is a need to ensure that sufficient teaching staff of the right calibre and experience are attracted to universities and technikons. The first degree course is comprehensive and basic, and specialization through post-graduate study should be encouraged. The influence of national service on the education and training of engineers is discussed.

Jan 1, 1982

By J. Petersen, K. Shaik1, H. Kolev, Z. Cherkezova-Zheleva

Sperrylite is one of the most abundant platinum minerals globally, valued for its economic importance but also known for its highly refractory nature, making it difficult to process via the conventional route. This study explores the oxidative leaching of sperrylite using a cyanide–ferricyanide system, with a key focus on characterisation of the mineral and surface speciation under varied leaching conditions using x-ray photoelectron spectroscopy. The parameters investigated include the effect of sodium cyanide concentration, the use of potassium ferricyanide as an oxidant, copper sulphate pentahydrate as a catalyst, as well as the effects of temperature and particle size. A limited set of leaching tests was carried out to study the surface chemistry rather than optimising dissolution conditions. This approach identified mineral oxidation states and shifts in binding energies, prior to and post leaching. XPS analysis of sperrylite’s surface chemistry identified key species, comprising the bulk Pt(II)–As (≈73 eV) and As(–I)–Pt (≈41.8 eV) states, together with surface oxidation products Pt(II)–O (≈72 eV), Pt(IV)–O (≈74.5 eV), As(III)–O (≈43 eV) and As(V)–O (44.5 eV). Leaching led to the removal of pre-existing oxides on the ultra-finely ground sample, exposing the underlying bulk species. In contrast, the crystalline sample with an initial low concentration of oxides, generated higher amounts of fully oxidised species after leaching, reflecting greater surface reactivity.

Mar 6, 2026

By T. Puhakka

Simulation is a way to obtain quickly today future information on how planned systems will most likely behave in various selected situations. This information may then be used to optimize the system and its components and maximize the performance and output. Simulation is a way to fine-tune the layout, match the mobile fleet and optimize the schedule and the way of working to meet the desired production requirements. Simulation provides a glimpse of the upcoming operation, ‘future today’ and helps to predict its restrictions and sensitivity to various aspects. OptiMine™, the Sandvik Tamrock Corp. and CyberCube Oy developed simulation tool is designed to simulate underground rock flow and match suitable technology with various layout options. This tool can be used to view what-if situations and determine what kind of impact mastered changes have to production. The findings of critical points in the layout and working procedures at an early stage of a new mine can help to optimize the layout and material flow. OptiMine™is modular based simulation tool that combines the supplier machine knowledge and traffic guidance with mine operational know-how and mine environment. It is developed to work in a way that an effect of an individual incident, such as the effect of one additional turn in a continuous loading cycle to the daily capacity can be identified. The reported output can be used for economical impact evaluation of selected options. This paper discusses the use of simulation in general and the way the OptiMine™ simulation tool operates and how it may be used for operation, technology and material flow optimization.

Sep 1, 2001

By C. Pamukcu

In this paper, which is aimed to serve as a review article, first of all a breakdown of the earth?s total water reserves is given. The usage areas of water in the mining industry are mentioned and these uses are briefly outlined, together with the main pollution potential of each. According to this, most of the water (almost 80% of it) is utilized in processing. Later on, probable damages that the mining would give to groundwater as a result of acid mine drainage, heavy metal pollution, euthrophication and deoxygenation is described. Finally, the measures and controls that should be taken against water contamination in mines are presented.

Jan 1, 2008

Gold Fields is the world?s fourth largest gold producer with operations in South Africa, Australia, Ghana and South America. All of Gold Fields? South African Operations are located in the Witwatersrand Basin and are intermediate to deep level underground mines exploiting gold bearing, shallow dipping tabular orebodies, which have collectively produced over 50 kt (1,608 Moz) of gold over a period of more than 100 years. Although the use of Monte Carlo as a business tool was introduced in 1964, it has only been in the last 30 years that it has gained increasing acceptance within the mining industry. However, the application thereof has been mostly limited to determination of risk in project areas. This paper however, considers the possibility of using Monte Carlo simulations to asses the underlying ?Root Cause? criteria critical to the operations management of existing mining operations. Currently, working operations have a distinct advantage over project areas as they have a wealth of historical information at hand. This, in turn, can be utilized to model distributions and relationships that can be used in Monte Carlo simulations, the results of which can be analysed to determine areas of concern. Projects can then be set up to ameliorate the effects of these and in turn reduce the risk of not achieving the operational targets. It is here that it must be stated emphatically that it should be the ?root causes? and the associated relationships that need to be emplaced within the model in order to achieve results that reflect the true causal relationship. The paper outlines possible sources of ?root cause? relationships and considers the outcomes of these in a case study on a large South African Gold Mine.

Jan 1, 2009

Gerhardus Paulus Badenhorst passed away on 2nd December, 1989. Badie, as he was known to all, will be missed by his many friends and colleagues, and will be remembered by al who knew him as a warm-hearted person who was totally dedicated to the safety and health of the workers in the mining industry.

Jan 1, 1990

NOTICE The Institute has received requests for copies of Uranium in South Africa&apos;, Vols. 1 and 2, but is unable to supply, as all copies have been sold out. If any members have copies they wish to dispose of it would be appreciated if they would contact the Secretary, P.O. Box 1183, Johannesburg. Telephone 834-1271.

By J. N. Van der Merwe

Following the Coalbrook disaster in 1960, research into coal pillar strength resulted in the adoption of the concept of a safety factor for the design of stable pillars in South African coal mining. At the time when the original statistical analysis was performed by Salamon and Munro in the early 1960s, 27 cases of failed pillar workings were considered suitable for inclusion in the database of failed pillars. Pillar failure did not stop after the introduction of the safety factor formula by Salamon and Munro (1967). In the ensuing years, pillars that were created before the application of the formula deteriorated and later failed, as did ones that were created after the introduction of the formula. This means that over time, the database of failed pillar cases increased in size, allowing ever more reliable analyses to be performed. The number of failed cases in the database had grown from the original 27 in the 1960s to 86 by 2011. All the failed cases are contained in the updated database. The database of stable pillars, which is also used in the derivation of strength formulae, has now been extended from 125 to 337 cases. The new database of intact pillar cases is more complete as it bridges the time gap between the Salamon and Munro (1967) and the Van der Merwe (2006) databases. The original requirements for inclusion into the database were satisfied in the compilation of this latest collection. The characteristics of the original database of intact pillars did not change in a meaningful way. The mining depth and pillar dimensions of the new database are largely as they were in the original database. Time-related trends with regard to pillar dimensions and depth of mining could not be found, indicating that the geometrical parameters of coal mining in South Africa have not changed meaningfully in approximately a century of mining. The characteristics of cases in the updated database of failed pillars does not differ substantially from the one published by Van der Merwe (2006). The same difference between that database and the original Salamon and Munro database, namely that the average safety factor of the failed cases had increased dramatically, from 1.0 to 1.5, is still apparent. This may be due to the inclusion of more failures from specific areas that exhibit a disproportionate number of failures at higher safety factors. These areas are the Vaal Basin, Klip River, and Free State coalfields. The new database confirms yet again that there is no correlation between the safety factors of failed pillars and their time of failure. The safety factor on its own is thus not a reliable predictor of longterm stability of pillars. Keywords coal pillar, stable pillar cases, pillar collapse, pillar data base.

Nov 1, 2013

By M. Steyn

Until 2000, pricing involved profit taking and cost covering combined with limited global published information. Market information was mostly subjective in nature and large resource companies benefited exclusively from aggregated company information and data. The market constituted producers and consumers only. The nineties saw massive cost cutting drives and re-engineering initiatives and this underwrote the structural changes evident in the late 1990s? economy. This supported South African producers on the international FOB cash cost curve, and ensured profitable coal mining operations. As the debate on relative scarcity of fossil fuels ensued, producers and buyers looked to the developing terminal coal market for direction. The much needed direction was provided when the API coal indices were developed and derivative trading was embraced to include financial institutions, trading houses and hedge funds. The liquidity of coal trades increased rapidly and vastly and market information became obtainable on a daily basis. Interpretation of current and future coal prices became available to all market players and contributed to the sophistication of the market that is now able to participate in risk management of prices, capital expenditure and brownfield developments.

Jan 1, 2010

By P. N. Harris

The Colloquium on &apos;Recent Mining and Metallurgical Developments in the Orange Free State&apos; was held at the Civic Centre in Welkom on the 4th and 5th May, 1983. The Chairman of the Orange Free StatejKlerksdorp Branch of the Institute and Acting General Manager of Unisel Gold Mining Company, Mr D. A. Parfitt, opened the proceedings, and Professor A. N. Brown gave the welcoming address. Mechanization of mining The South African Institute of Mining and Metallurgy is to hold a one-day colloquium on &apos;Developments in the Mechanization of Mining Operations&apos; during September 1984. Surfac,e mining and quarrying The Second International Surface Mining and Quarrying Symposium is being organized by The Institution of Mining and Metallurgy in association with the Institute of Quarrying.

Jan 1, 1983

By John Freer

A colloquium on solid-liquid separation was held by The South African Institute of Mining and Metallurgy on 23rd September, 1982, at the State Pavilion Auditorium, Milner Park, Johannesburg, to co-incide with the Electra Mining Exhibition. It was attended by about 150 delegates. Eight papers were presented covering: Geostatistics The School of Earth Sciences of Stanford University, the Centre de Geostatistique ofthe Paris School of Mines, and the Department de Genie Mineral of the Ecole Polytechnique of Montreal are cosponsoring the organization of a 2nd NATO ASI (North Atlantic Treaty Organization Advanced Study Institute), under the name of &apos;GEOSTAT TAHOE 1983&apos;, to be held at South Lake Tahoe, California, on 4th to 17th September, 1983.

Jan 1, 1982

By S. Kauchali, J. van Dyk, J. Feris, S. Pershad, M. van der Riet, D. Love, J. Brand, C. A. Strydom

"This paper offers an introduction to and strategic context for the other papers included in this special UCG edition of the Journal of the Southern African Institute of Mining and Metallurgy. South Africa is facing long-term energy security challenges, brought about by a myriad of factors that are somewhat unique or exacerbated in the global context. Underground coal gasification (UCG) is a process used to produce synthesis gas from coal in situ, that is, in the coal seam. UCG is an emerging, advanced clean coal technology that offers a potential solution for these challenges, as it can cost-effectively and cleanly liberate vast coal resources in the country that currently cannot be economically exploited using traditional mining technologies. One of the tasks of the South African Underground Coal Gasification Association (SAUCGA) is to advance the development of UCG in South Africa by compiling a technology roadmap. This paper presents the initial findings of the SAUCGA Roadmap (Draft), and contextualizes the technology opportunities and challenges, stakeholders, and provides a basis from which to progress further plans for technology development. Firm development plans and deadlines are not yet possible due to the reliance of the UCG Roadmap on the higher level South African energy policy and regulatory framework. However, the draft roadmap has taken the first step of identifying these policies and stakeholders, and should be seen as the seed from which this embryonic technology and industry can be further developed. IntroductionSouth Africa’s long-term energy security challenges include energy access and affordability, dwindling reserves of accessible bulk primary energy, mounting environmental concerns with all forms of energy generation (especially coal and nuclear), balancing the electricity grid by incorporating an increasing proportion of non-despatchable renewable energy sources, mounting environmental liabilities regarding defunct mining operations, and lastly but by no means less important, fluctuating exchange rates and energy commodity prices.Correctly managed underground coal gasification (UCG) is an emerging, advanced clean coal technology that offers a potential solution for these challenges, as it has been shown to have the potential to cost-effectively and cleanly liberate vast coal resources in the country that currently cannot be economically exploited using traditional mining technologies."

Jan 1, 2019