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By R. B. Khumalo, M. S. Nyarela, R. C. Nemathithi

Palabora Mining Company is one of the largest low-grade copper mines globally. The mine uses block caving for the extraction of the orebody. This paper enumerates the drawpoint loading strategies for the overall head grade improvements, particularly for a block that is nearing depletion. A comprehensive literature review of various considerations relating to improving productivity in block caving is presented to contextualize the draw control in caving. From this study, an optimized draw control strategy is presented, which focuses on three parameters that include grade distribution, loading compliance, and tonnage splits per sector. An empirical method based on the relational study between various parameters is used to outline the key criteria to be used in the optimization of drawpoint loading in block caving.

Nov 30, 2022

By O. Barron, C. Felix

In 2023, polymer electrolyte membrane fuel cell membrane electrode assemblies accounted for about 62% of the global fuel cell market share and this demand is expected to grow. Commercialisation requires technologies capable of cost-effective, high-volume manufacturing. The membrane electrode assembly is crucial and represents a significant cost to polymer electrolyte membrane fuel cell manufacturing. Manufacturing the electrode components for membrane electrode assemblies at high volumes can reduce production costs while delivering on the forecasted industry demands. Roll-to-roll is a mature coating technology applied in various manufacturing industries such as batteries, printed electronics, microelectronics, photovoltaics, printing, paper consumables, etc., with significant potential for polymer electrolyte membrane fuel cell manufacturing. While the high-volume production process for membrane electrode assembly manufacturing differs from laboratory-scale, the membrane electrode assembly structure remains unchanged. Roll-to-roll is a continuous coating process with speeds of 10 m/min being achieved. In this work, MicrogravureTM and slot-die coating methods have been adopted and have shown promising outcomes for producing gas diffusion electrodes for membrane electrode assemblies. An overview of the MicrogravureTM and slotdie coating methodologies is provided, and a discussion on preliminary results and challenges are presented. Work on MicrogravureTM gas diffusion electrode manufacturing has already achieved comparable performance with spray-coated gas diffusion electrodes. The influence of coating parameters and drying on the coated catalyst layer quality is discussed.

May 27, 2025

The October General Meeting of the Institute was held in Kelvin House, Johannesburg, on 15th October, 1969, at 4.30 p.m. Mr J. K. E. Douglas (President) was in the Chair. There were also present 17 Members, Messrs: M. Barcza, R. C. J. Goode, J. A. Nixon and V. C. Robinson (Council Members), M. L. Fitzgerald, D. F. H. Graves, C. G. Hinds, S. D. Hill, J. S. Hall, D. F. Malan, T. Meyer, W. pyne-Mercier, K. S. Rae, S. G. Taussig, L. W. P. van den Bosch, Dr A. Whillier, C. H. Wyndham. Four Associate Members: Messrs O. Davel, M. J. Martinson, M. P. J. Sandys, T. G. Harington. One Student: R. P. W. Henrard. Three Visitors: Messrs A. V. Pike, B. Schmitz, A. P. Raats. Secretaries: D. C. Visser and S. de. Gersigny. Total present: Twenty-eight. OBITUARY The President: "It is my said duty to announce the death of Pieter Ulrich Fischer, Member, who joined the Institute in 1961 and passed away on 24th June, 1969. As a mark of respect to the memory of the deceased and in sympathy with the bereaved I would ask you all to rise and observe a few moments' silence." MINUTES The President: "The minutes of the last meeting will only appear in next month's Journal and I would request that the confirmation of these minutes be held over." MEMBERSHIP The President: "I have much pleasure in announcing that the names of the undermentioned candidates, having been published in accordance with By-Law 5.2.2, Council has elected them to membership of the Institute in the following grades:" Members: Alexander Edward O'Meara, Anton Leopold Melvill, WilIiam Harold Wise, Eric John Dunstan, Frank Nel, Lubertus Hendrikus Jakob Poortier. Associate Members: Michael Irvine Britten, Selwyn Wilson Lange. James McCormack, Christiaan Lodewyk de Jongh, WilIiam Andrew Hustrulid, Reinhold Johannes Ortlepp, Felix Henry Lancaster. Graduates: Willem Adriaan Gericke, Hamish David Sneddon Miller, David lan Ossin, Robert Antony Layboume, Ewart John Shillaber, Colin Hewitt Wiggett. Affiliates: Bernard Andre Thomas, Waiter Arthur Wood, Andrew John George Paschalides, David John Perry, Alex Richardson, Gert Blekker Kotze. Student: Matthys Jacobus de Beer. MEMBERS TRANSFERRED TO A HIGHER GRADE From Associate Member to Member: David Alphonso Viljoen. From Student to Associate Member: Michael Charles Carruthers. "I welcome the newly elected members to the Institute and congratulate the members who have been transferred to a higher grade." PAPERS FOR PRESENTATION The President: "Professor Wyndham, may I call on you to deliver the paper entitled 'Factors affecting the mechanical efficiency of men shovelling rock in stopes', written jointly with J. F. Morrison, J. H. Viljoen, N. B. Strydom and A. Heyns." After the presentation of the paper the President said: "Gentlemen, I would like to thank Dr Wyndham and his colleagues for once again reporting through the medium of this Institute the results of the very important work they are carrying out at the Human Science Laboratories. It is most appropriate that this work which is leading to a better understanding of the capabilities and efficiency of the human body under the arduous conditions encountered underground should be reported to this forum. In this way our members, who are actively engaged in the job of mining, can firstly learn something of this research and secondly, can, with their practical knowledge of conditions underground, contribute to what has been learnt and possibly pose new problems for our scientists in the laboratories. The scientist should always have the opportunity of subjecting his research to the scrutiny of people engaged in practical operations. By the very nature of our gold mines we are unfortunately heavily dependent on a large labour force and while mechanization has been introduced wherever feasible, we are likely to continue to be heavily dependent on this labour. In accepting this fact we can be proud in this country of what has been achieved, not only in obtaining the best efficiency from labour but in ensuring that their working conditions are reasonable and that their health and well-being are adequately cared for. When one visits our gold mines, one cannot help being impressed with what is being done to ensure that we have a satisfied, happy and healthy labour force. The Human Sciences Laboratory with its scientific approach has assisted greatly in promoting a better understanding of the problems associated with labour under the conditions experienced on our mines. Thank you." Mr M. Martinson then contributed to the discussion. (This contribution will appear in a later issue of the Journal.) "Professor Wyndham, may I call on you to deliver the paper entitled 'Acclimatizing men to heat in climatic rooms on mines,' written jointly with Prof Strydom." After Dr Wyndham had presented the paper the President said: "Thank you Dr Wyndham for so ably describing the work associated with the acclimatization procedures on our gold mines. It has certainly been an eye-opener to those of us not familiar with this work and I believe it is very important that everyone and not only people in the gold mines should know about it. It is fortunate that all industries do not have the same arduous heat conditions experienced on our mines but other industries such as our chemical and metallurgical industries do have other problems relating to the adjustment of labour to the work situation. The scientific approach employed by the gold mines in tackling this problem is an example to these industries of what can be achieved by logical

By M. J. Deats

INTRODUCTION To prepare the reader adequately, reference should be made to the paper 'The Pioneering of Fully Mechanized Longwall Coal Mining in South Africa' by R. T. Naude and M. J. Deats, published in the February, 1967, edition of the Journal. At the time mechanized longwalling had been proved operationally feasible with encouraging results since its inception in South Africa in mid 1965. Subsequently, further top seam panels were successfully extracted with improved productivity and with some modification to equipment. In 1968, after an overseas visit by mine officials, equipment specific to suit local conditions was acquired and lower seam trials commenced. Despite initial obstacles and difficulties the first panel was successfully mined. Modification and improvements to equipment and techniques resulted in the second lower seam panel being extracted economically during 1969-1970 and with productivity exceeding even that of top seam faces. During extraction of the second lower seam panel, gradual and complete surface subsidence occurred over the panel without affecting face operations. Rock mechanics investigations had originally indicated some uncertainty regarding adverse dolerite sill behaviour which could have caused longwall mining to be hazardous. All such doubts have now been removed. RESUMÉ AS AT FEBRUARY, 1967 Mechanized longwalling was introduced in 1965 on an experimental basis in an effort to improve productivity in the newer area of the mine and to increase the quality of the comparatively dirty run of mine feed to the washing plant. In addition advantages could be predicted in the long term by better utilizing reserves of straight coking coal and increasing the life of the mine. The top seam unit was obtained on a rental basis and by the beginning of 1967, two panels, the first having a face length of 215 m, a panel length of 345 m, seam section of 1 219 mm, and the second the same face length, a panel length of 453 m and a seam section of 1 067 mm had been successfully longwalled. At this stage a best month of 24 602 metric tons with an average of 17 364 metric tons per full working month could be reported. Results were sufficiently encouraging for the company to exercise its right to acquire the equipment as its own asset and from 1967 onward, the unit has operated on this basis. From the point of view of rock mechanics, the dolerite sill over the first two panels was known to have 'bridged', only the material below the base of the sill having truly 'goafed'. No adverse pressure effects had significantly affected face operations except for two 'bumps' towards the end of operations in each panel. Gate road maintenance presented no problem. The strong inflows of water experienced on the first face were now known to be associated with an isolated water bearing fault plane and were not experienced on the second face. TOP SEAM EXPERIENCE - MAY, 1966, TO DATE Panel 2 (February, 1966, to November, 1966) The operations in panel 2 (see Fig. 1 for location of panels) continued uneventfully until the final month in this panel. At this stage, the chocks behaved most inconsistently often lowering under the weight of the canopies alone. Roof trouble became so severe that the unit was unable to produce adequately and blasting of chocks became a daily occurrence. Finally 24 m short of the planned limit it was decided that a complete overhaul was the only solution and the extraction operations commenced. At this time, the only fatal accident associated with longwalling occurred when a Non-White inadvertently fell into the panzer conveyor transfer point at the main gate. Some gate road difficulties in this panel were overcome by bolting tapes to the roof as decking and allowing them to pass over the gate chocks and collapse into the goaf. Two cribbed roof falls were also negotiated by the gate chocks at the face ends without undue difficulties. It was decided in the light of maintenance problems encountered on this face that the best solution would be to appoint a foreman solely in charge of face maintenance crews. This step has to a large extent contributed to success achieved subsequently. Panel 2-face length 213 m panel length 456 m cutting height 1 092 mm average monthly output 16 443 t best month 19 130 t Panel 3 (December, 1966, to June, 1967) By the end of 1966 results were sufficiently encouraging for the company to exercise its right to acquire the equipment. This was negotiated and the unit has operated as such to the present date. Prior to installation in panel 3, all face equipment was thoroughly overhauled underground and the chocks boost-tested to yield-load. The costs of overhauling, including almost complete hose replacement, were much higher than anticipated. Advice had been received that complete hose replacement was common practice after +/- 18 months' operation. Shortly after commencement of operations in panel 3 the chocks again failed as they had towards the end of panel 2. At this stage, the suppliers advised that the valve gear should have been repaired during the overhaul as the needle and seat seals could no longer be relied upon. This operation was impossible to carry out on the face and would have been e1ttremely time consuming. Fortunately a new type of valve gear was then available from the suppliers, termed the capsule-type valve, and a complete change over could be made on the face. The encapsulated valve has a delrin pad sealing over a raised

By Y. Zhou, G. Chisakuta, P. Bwando, G. Mitshabu

A newly started copper hydrometallurgical plant was confronted with a manganese oxidation issue in electrowinning. This oxidation, in the absence of the amount of iron required to stabilise the electrolyte oxidation-reduction potential, is known to produce oxidants (MnO2, MnO4) that can cause accelerated degradation of the organic phase components in solvent extraction and corrosion of lead anodes in electrowinning. The overpotential required to build up the protection layer on new anodes causes an increased electrolyte potential that creates oxidized species in the electrowinning tankhouse, and these species come back to solventextraction plant with the recycled spent electrolyte. This paper discusses the impacts of manganese oxidants on the health of a plant organic phase. It also outlines the actions taken using iron scraps and sulfur dioxide to mitigate the problem that happened due to the lack of ferrous iron sulfate available on site, as recommended for better control.

Jan 1, 2023

By J. Fu

"Since it was first identified in 1817, selenium has received considerable interest. Native selenium and a few selenium minerals were discovered several decades later. With the increasing number of selenium minerals, the occurrence of selenium minerals became the focus of much research. A great number of selenium deposits were reported all over the world, although few independent selenium deposits were discovered. Selenium is obtained mainly as a byproduct of other metals, and is produced primarily from the anode mud of copper refineries. This paper presents a comprehensive review of selenium minerals, as well as the treatment of copper refinery anode slimes for the recovery of selenium. Our focus is on the selenium minerals, including their discovery and occurrence, and the distribution of selenium resources. In addition, the main methods of recovering selenium from copper anode slimes are summarized. IntroductionSelenium (Se) was first observed in 1817 in a laboratory (Greenwood et al., 1984). The discovery of selenium was made by the Swedish chemist J.J. Berzelius and J.G. Gahn, who isolated selenium from a red residue in sulphuric acid from pyrite mined at Fahlun, Sweden. Selenium was named from the Greek word selene (moon), since it resembled tellurium, which had been discovered a few years earlier and named from the Latin word tellus (Earth).After the first observation of selenium in the laboratory, selenium received considerable interest. In 1954, E.P. Kaiser pointed out that Se is enriched in sulphide ores and often associated with Bi, Co, Sn etc. (Kaiser 1954). In 1959, Hawley and Nichol investigated selenium in Canadian sulphide minerals, and presented the content of selenium in sulphide from several deposits of different types. They also proposed that Se is enriched in lowtemperature hydrothermal pyrite (Hawley and Nichol, 1959). The thermodynamic conditions for forming native selenium and selenium minerals in sedimentary rocks were discussed, as well as geochemical behaviour of selenium near the oxidation zones of sulphides in the 1970s (Howard III, 1977; Zhu et al., 2003). Zhu et al. examined the morphology, features, and genesis of native selenium from Yutangba, Enshi City, Hubei Province, China in 2004, and pointed out, from the different forms of native Se, that selenium can be activated,transformed, remobilized, and enriched at sites such as in the unsaturated subsurface zone or in the saturated zone (Zhu et al., 2005). The transport and deposition of selenium in felsic volcanic-hosted massive sulphide deposits of the Yukon Territory, Canada was studied and reported by Layton- Matthews et al. (2005)."

Jan 1, 2016

By L. Pretorius, S. Uludağ

This paper explores how to apply system dynamics principles to surface mining problems towards understanding the consequences of mining efficiencies. Some simulation examples related to machine and people performance have been used to demonstrate systems engineering concepts to mining engineers. The simulation tool used is Vensim, which is widely used in industrial engineering applicable to systems thinking, and systems dynamics. The science and mathematics behind the system dynamics as well as benefits and typical challenges are discussed to explore the applicability to mining problems. The benefit of having one less drill is easily quantifiable with the developed model which is one of many other measurable benefits, using the developed model. Some of the benefits of the improved quality of drill holes are not fully quantified as this depends on the mine specific inputs. There are examples of quantifying this in the other industries using system dynamics tools.

Sep 1, 2021

By K. A. du Preez, P. J. van Staden, M. van Rooyen

Mine-impacted water, including acid mine drainage (AMD), is a global problem. While precipitation of dissolved metals and neutralization of acidity from mine-impacted water is accomplished relatively easily with lime addition, removal of sulphate to permissible discharge limits is challenging. This paper presents a high-level comparison of four sulphate removal technologies, namely reverse osmosis, ettringite precipitation, barium carbonate addition, and biological sulphate reduction. Primarily operating costs, based on reagent and utility consumptions, are compared. Each process is shown to be subject to a unique set of constraints which might favour one over another for a specific combination of location and AMD composition. Access to and cost of reagents would be a key cost component to any of the processes studied. The total cost calculated for each process also depends on the type of effluents that are allowed to be discharged.

Oct 1, 2021

By S. Dey, C. Bhar, S. K. Mandal

Loading and hauling of ore and waste are the key operations of an opencast coal mine and entail a high operational cost. The productivity of a mine can be increased by reducing the cycle time of loading equipment as well as utilizing dumpers optimally. In this paper we discuss the impact of rock type, bucket fill factor, rock fragmentation, the height of the cut, and angle of swing of the bucket on shovel performance. A time study is conducted on shovels in an opencast coal mine with experimental blasts of rocks to assess the impact of different factors on the performance of the shovel. Based on the data, the authors applied multiple regression (MR) and artificial neural network (ANN) techniques to develop different models for the prediction of the shovel cycle time. Developed models are validated by comparing the predicted data with actual field data. With the help of the best model, the plausible fleet size is determined in order to utilize the shovel and dumper optimally and to improve the performance of shovel–dumper operation.

Oct 1, 2022

By S. J. Baumgartner

The ferromanganese industry is under pressure to deal with the slag arising from the production of ferromanganese, which is discarded in landfills or slag heaps. This material poses an environmental and health risk to surrounding ecosystems and communities, and disposal costs are increasing. Ferromanganese slag contains an appreciable amount of residual manganese metal, which can be exploited. Previous work has shown that the slag can be leached fully, while rejecting the silica to a residue. The methods that were investigated to recover manganese from the leach solution included hydroxide precipitation to upgrade the leach solution followed by manganese carbonate precipitation to produce a pure manganese carbonate product or a manganese carbonate furnace feed material, which would be recycled to increase manganese recoveries in the production of ferromanganese. In addition, electrowinning of electrolytic manganese dioxide from the leach solution was studied. The methods were compared in terms of selectivity, costs, and product quality. Co-recovery of the leach residue, which is a potential cement additive, is discussed. Among the methods investigated to upgrade the pregnant leach solution, hydroxide precipitation utilizing ammonia to adjust the pH appears to be the most effective in removing major impurities such as iron, aluminium, and silica to less than 1 ppm. The manganese carbonate and impure manganese carbonate furnace feed products met quality specifications. However, although the production of these materials was technically viable, the large amounts of base reagent that were required to raise the pH, and the associated high operating costs, rendered the process uneconomic. An optimization study was therefore carried out with the primary objective to determine the ideal acid amount to be utilized in the waterstarved digestion stage, thereby decreasing acid and base consumption while optimizing the quality of the pregnant leach solution, and producing a leach residue that contained <1% Mn. The outcome was an economically viable process. Additional benefits included an increase in the manganese content of the impure manganese carbonate furnace feed material, and a substantial reduction in the dilution of the pregnant leach solution, thereby maintaining high manganese concentrations that rendered the solution viable for electrowinning of electrolytic manganese dioxide, the production of which yielded a current efficiency of 74%.

Jan 1, 2014

By I. A. Mwamba

Titanium aluminide of composition Ti-47.5 at.% Al was prepared by melting titanium and aluminium of commercial purity with additions of precious metals of 0, 0.2, 1, 1.5 and 2 at.% content. The microstructure, hardness and oxidation properties were assessed. It was found that at 47.5 at.% Al, the microstructure of plain TiAl alloys was duplex, consisting of duplex lamellar grains and ? grains. The lamellar grains consisted of alternating lamellae of ? (TiAl) and a2 (Ti3Al), with overall aluminium content in the range of 43?47 at.%. The ? grains had a aluminium content above 50 at.%. The addition of precious metals to the TiAl alloy resulted in the formation of a new phase, with a high precious metal content, occurring mostly in the ? phase, without any major change to the microstructure. Increasing the amount of precious metals resulted in an increase of the new phase amount, at the expense of the ? phase. The hardness of the different alloys was around 300HV10. Overall, the research has shown that addition of precious metals to TiAl resulted in a slight increase in hardness and a significant improvement of the oxidation resistance. This shows that alloying TiAl with precious metals, at the addition levels investigated, does not alter the mechanical properties very much, but improves oxidation resistance.

Jan 1, 2012

By K. Dagdelen , S. K. A. Owusu

Uncertainty with regard to estimated grades and tonnages of a mineral deposit demands risk assessment in order to build investor confidence and attract the interest of other stakeholders in the success of a project. Uncertainties associated with Mineral Resource estimates can lead to unreliable production schedules and unpredictable cash flows. However, the techniques used in the mining industry to determine these uncertainties are inconsistent, because the important decisions taken in the process are solely dependent on the responsible Competent Person (CP), without limitations. This leads to disparities between different CPs’ results, using data-sets from the same drill-holes. The various standard codes for public disclosure provide guidelines and recommendations for the classification of Mineral Resources and Reserves but do not provide details on, for example, the amount of geological and geostatistical information needed to qualify for each category of Resources and Reserves. The parameters used to generate the classification categories are subjectively assumed by the responsible CP. In this paper we investigate the impacts of different CPs’ judgements on resource classification, using the same data-sets. The results underpin the need for the mining industry to develop a uniform Mineral Resources and Reserves classification framework that can minimize or avoid significant discrepancies that lead to potential misleading public disclosures.

Aug 8, 2024

By X. Ndlovu

Underground observations in a coal mine have indicated failure oft he immediate roof above the bords. Careful observations and photographic recording of occurrences of these roof failures, termed ?roof guttering?, have been made. The occurrence of guttering results directly in roof instability, and indirectly, due to the interaction of the guttering with natural planes of weaknesses in the immediate roof rock. In this paper, relevant observations of roof guttering, possible mechanisms of formation of roof gutters, laboratory testing for determination of material strength and deformation properties, and numerical analyses to explain underground observations are described. Mapping of roof failures showed that these took place mainly towards the centre of the roadways. Roof guttering was observed often to occur violently and with little warning. Occurrence of roof guttering has a negative impact on production?some panels are abandoned, production times are increased and safety of workers is compromised. The numerical stress analyses showed that, although none of the constitutive behaviour criteria used predicted the observed underground failures correctly, the extension strain criterion gave the best agreement.

Jan 1, 2007

By L. Petzold

The demand for stainless steel is ever-increasing. As an essential element in stainless steel-making process, so is the demand of chromite concentrate. At the same time, the industry proven technologies for beneficiation of chromite are limited. Chromite is only crushed, screened and jigged to produce a concentrate. However, for ultrafine and low-grade material, no satisfactory beneficiation methods for the enrichment of chromite fines exist in industrial operation. This poses a clear challenge for the industry, which Primetals Technologies has addressed with the development of a new beneficiation process. The aim of this process was to enrich low grade chromite tailings to a quality suitable for the smelting process. Required concentrate grades are different over the world, concentrate grades of Cr2O3=40% and lower are found at the Bushveld Complex, South Africa. The target for the present study was a Cr2O3-grade in the area of 49%. Three different chromite tailings with Cr2O3 grades between 16 % and 29 % were part of a study, executed by Primetals Technologies. All three tailing materials were characterised by Mineral Liberation Analysis (MLA). Based on the physical, chemical and mineralogical findings, process flowsheets were developed. The process flowsheets included grinding to ensure a full liberation of the chromite. The liberated material was classified at a cut size of 63 μm to a coarse and fine fraction. Gravity separation and flotation processes were tested with the coarse particle fraction. Due to the limitations of gravity separation with fine particles, only the flotation process is suitable and was tested with the fine fraction < 63 μm. A Design of Experiment (DoE) with six factors, each three levels, was conducted to identify optimal parameters for the fine chromite flotation. Two different collectors were tested: a phosphoric acid ester and a fatty acid type collector. In small scale test work a chromite concentration suitable for the smelting process was achieved. On this basis Primetals Technologies will develop a pilot-scale test program to research recirculation effects and upscale potential of the process. Keywords: Mineral processing, tailings beneficiation, flotation, density separation, process development, chromite

Jan 1, 2020

By K. C. Sole, M. Makonese

Bushveld Belco is commissioning a plant for production of electrolyte used in vanadium redox flow batteries. Owing to the source material, the electrolyte is contaminated with Fe, at concentrations up to 140 mg/L, which negatively affects battery performance. This study examined the use of ion exchange to reduce the Fe concentration to the target value of < 100 mg/L from a feed solution containing 100 g/L V in 4 M H2SO4. Four resins with possible application were identified: Puromet MTS9570, Puromet MTX7010, Puromet MTS9500, and Puromet MTC1600H. Puromet MTS9570 outperformed the other three resins in all batch experiments with respect to loading capacity and selectivity over V, and was evaluated for Fe removal in fixed-bed column loading tests. Based on these data, preliminary sizing and design of a full-scale column was undertaken. Owing to the difficulty of eluting this resin, a philosophy of discarding the resin on loading to full capacity was considered. These data revealed that, despite the high selectivity of this resin for Fe over V, it would be too expensive and impractical to use this resin for full-scale operation under such conditions. It is recommended to remove iron earlier in the flowsheet prior to generation of the 4 M H2SO4 electrolyte.

Dec 11, 2024

By T. Field, N. D. Nxumalo

Since the discovery of gold on the Witwatersrand in 1886, mining has been at the centre of South Africa’s development. Although mining continues to contribute significantly to the country’s economy, it is a temporary land-use activity, and mine closure is inevitable. This paper reviews mine closure planning at Tshikondeni coal mine, which commenced in 2014 with the initiation of mine closure. The review presents the mine closure processes undertaken at the Tshikondeni coal mine as regulated by South Africa’s principal mining legislation, the Mineral and Petroleum Resources Development Act 28 of 2002, and other relevant regulatory frameworks. To compile this review: (1) A desktop study was conducted; (2) empirical data was collected through one-on-one interviews with research participants at Tshikondeni coal mine; and 3) physical observations were made of the rehabilitation at various mine operations within the Tshikondeni coal mine complex. Research participants consisted of mine officials from different departments, i.e., human resources, and environmental, social, and business strategy, who were directly involved with the Tshikondeni coal mine closure. A questionnaire with semi-structured questions was developed. It was utilised to acquire a better understanding of mine closure planning at Tshikondeni coal mine and identify mine closure processes that aim to achieve post-mining land uses and align with Tshikondeni coal mine’s post-closure strategy, namely the Tshikondeni Legacy Project, with a post-closure strategy that has the potential to transition a mining economy to an eco-tourism economy that can preserve livelihoods and selfreliant communities.

Dec 15, 2025

"Chairman: Dr W. S. RAPSON Rapporteur: Mr J. W. WILSONPapers:Computer applications in rock mechanics by F. H. Deist, E. Georgiadis and J. P. E. Moris Rock mechanics in the design of mine layouts by K. Hodgson and N. G. W. Cook Automated regulation of mine ventilation by P. NiskanenThe rock mechanics papers, because of their complementary nature, were presented in succession and discussion on both followed directly. The paper on automated ventilation control at a mine in Finland was then presented and the session was closed with several contributions to this paper.By and large the papers and discussions which followed in this session showed how a classic tie-up had developed between the use of computing techniques in important fields of mining, and their practical application. In fact, the dis-cussion following the rock mechanics papers showed clearly that without the aid of high-speed digital computers the rate of progress in applied research in deep-level hard-rock mines, would have been severely hindered. Furthermore, it became apparent from the comments made by several contributors that the rock mechanics techniques and computer progress described in Deist&apos;s and Cook&apos;s papers could be used to provide useful data in the solving of rock mechanics and design problems on mines other than flat dipping deep tabular deposits.The paper by Niskanen, which described an automated ventilation control system at a mine in Finland, showed how effective computers could be in areas where the reversal of mine ventilation occurs due to severe seasonal temperature ranges. Although the system described in the paper could not be introduced easily in complex underground mines, several contributors gave examples of similar ventilation problems that could be solved mechanically,In introducing his paper, Dr Deist said that the purpose of the paper was to give a brief account of some of the programs designed by himself and his co-authors to aid in the solution of rock mechanics problems,The first system presented by Dr Deist was known as MINSIM in the South African mining circles. This system was designed specifically to aid in the solution of rock mechanics problems in the South African gold mining industry. It was particularly designed to handle tabular deposits at great depth but it has been used satisfactorily on a number of occasions to obtain at least approximate solutions in other mining situations. Dr Deist said that the principles embodied in the programs were easily extended and, in fact, there was a project in progress at that time which was aimed to do this. He said that the principles could easily be extended to shallow-depth mining at steep or very steep inclinations."

Jan 1, 2014

By P H. Ferreira

The mechanisation of mine development is becoming increasingly important in our South African and Southern African mines with increased emphasis on safe and efficient mining. Raise, blind and shaft boring offer mechanised solutions for excavations such as:- [reef raises stope boxholes and shaft ore passes ventilation passes and shafts chairlifts large vertical hoisting shafts (in excess of 1200 metres in depth) angled hoisting shafts (from small to large diameter bored holes)] These techniques will be discussed with reference to relevant applications and the author?s comparison between conventional drill and blast techniques.

Jan 1, 2005

By F. Samimi Namin

One of the main tasks in exploitation of mines is to select a method suitable for the deposits, specific features including geometric, geo-mechanical and geological features. The purpose of selecting a mining method at this stage is to choose one or more method(s) having the most coordination with the deposit?s conditions and external factors, including the allocated budget and local technology for detailed feasibility studies. Several methods have been developed in the past to evaluate suitable mining methods for an ore deposit, based on its physical characteristics. These approaches can be classified into three groups: (1) profile and checklist methods, (2) numerical ranking (scoring) methods, and (3) decision-making models. Most of these methods have shortcomings. Considering the fact that most of the specifications of mineral deposits, such as dip and depth, are linguistic variables, absoluteness of the explaining parameters by previous methods can be mentioned as the most important disadvantage of these methods. This paper discusses the Fuzzy technique for order performance by similarity to ideal solution (Fuzzy TOPSIS) to determine the mining method. The fuzzy decision making (FDM) software tool is employed to develop a Fuzzy TOPSIS based model. Application of this model with various values (crisp, linguistic and fuzzy) of the deposit eliminated the existing disadvantages of other methods. Two empirical illustrations demonstrate the effectiveness and feasibility of the evaluation procedure. These show that the proposed model performs better than its alternatives. Keywords: mining method selection, fuzzy TOPSIS, decision making, mining engineering, linguistic variables.

Jan 1, 2008

By C. N. Eze, C. K. Ezeh, O. Nnabuife, N. M. Ugwoju, S. C. Enemuor, V. Okechukwu

In this study, the efficacy of Providencia vermicola KUBT-1 in the leaching and beneficiation of Agbaja iron ore was evaluated under varying conditions of temperature, ore particle size, and pH. Agbaja iron ore is a Nigerian low-grade ore containing about 43%–52% iron and a high amount of gangue materials, including phosphorus (1.4%–2.0%) and sulphur (0.12%). The study was organised in triplicate in shake flasks with 48 samples. One millilitre of washed cells of Providencia vermicola KUBT-1 suspended in normal saline at 0.5 McFarland standard (108 cells ml-1) was introduced into each flask containing 50 g of sterilised ore in 100 ml of bioleaching medium, and the samples incubated at room temperature for eight weeks. The levels of upgraded iron, mobilised sulphur, and phosphorus were determined by atomic absorption and ultraviolet spectrophotometric analyses, respectively. Results showed that a particle size of 0.8 mm was optimal for iron upgrading and sulphur mobilisation while 1.0 mm ore size was optimal for phosphorus mobilisation. Up to 89.60% of the iron was upgraded while phosphorus and sulphur were mobilised, leaving residual values of 0.223% and 0.02%, in the ore, respectively. The organism produced best beneficiation results at a pH of 2.5 and a temperature of 3ºC. Correlation analysis with the Pearson’s correlation model showed a positive correlation between iron upgrading and sulphur-phosphorus removal (r =1.000, and r =0.967), respectively. These results present Providencia vermicola KUBT-1 as a promising candidate for large scale leaching and beneficiation of Agbaja iron ore.

Dec 15, 2025