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By M. Fener, S. Kahraman, O. Gunaydin, M. Alber

Falling into the weak rocks category, fault breccias have extremely poor engineering properties. These pebbles typically cause issues with slopes, subterranean construction, and building projects. Professionals will benefit from the creation of some predictive models for fault breccia triaxial strength, as smooth specimen preparation is typically challenging and timeconsuming. The purpose of this study is to develop some predictive models for the differential stress (Δσ) based on physical and textural properties. Artificial neural networks were used to analyse data related to Misis fault breccia. Initially, models with moderate (noticeable, but not good) correlation coefficients were created using multiple regression analysis. After that, the regression models and three distinct artificial neuron network models were contrasted. Regression models are weaker and less trustworthy than artificial neuron network models, as demonstrated by this comparison. Pointed out is the practicality and ease of use of the artificial neuron network model with S-wave velocity and volumetric block proportion. Ultimately, it can be concluded that artificial neuron networks analysis provides a reliable indirect method for predicting the differential stress of Misis fault breccia.

Sep 1, 2025

By T. Tamenti

The purpose of the project was to conduct a feasibility study to determine if the current operating bottom dump trucks that haul coal should be replaced with rear dump trucks. The engineering availability of the bottom dump trucks was lower than targeted while the operating costs are the highest of all coal haulers within the Anglo Coal opencasts. To determine if it is feasible to replace the current bottom dump trucks with rear dump trucks, a production profile simulation was conducted to determine the number of rear dump trucks that would be required to meet the annual coal hauling requirements. The total capital and operating costs of these rear dump trucks were also determined using a total cost of ownership model. These were compared with the current costs of the bottom dump trucks to determine if it is financially feasible to replace the bottom dump trucks with rear dump trucks. Having considered the capital outlay that would be required to replace the bottom dump trucks with rear dump trucks as well as their respective operating costs, it was concluded that the current bottom dump trucks should be replaced with rear dump trucks. Other factors were considered in coming to this conclusion.

Jan 1, 2007

By C. Dorfling, M. Tadie, M. Tucker

Electrowinning is the final step in the hydrometallurgical production of high purity copper, involving the passage of electric current through an electrolyte and consequent plating of solid copper to form cathode sheets. Key electrowinning performance indicators are the current efficiency, specific energy consumption, yield, and quality of the metal. The high energy demand and associated cost mean that determination of performance indicators is critical during operation, but ‘online’ measurement is impractical due to the nature of the measurements and corrosive environment brought about by acid mist. This research considered the development of a predictive electrowinning model as a shift towards a pre-emptive approach to attaining plant performance data. A steady-state model was created from input variables available in the industry, using a first-principles approach combining mass balances, electrochemical and thermodynamic equations, and property correlations. A circuit diagram equivalent of an electrowinning cell, containing multiple pairs of electrodes, was used as the backbone of the model. The kinetics of each electrochemical reaction were modelled including iron as a major impurity. Losses in current efficiency due to ineffective electrode contact, short circuits, and stray currents were also incorporated. The model was used to predict the current efficiencies for tests performed at varying conditions in a bench-scale electrowinning cell; the average absolute error between the measured and predicted current efficiencies was 3.2%. The model requires a unique parameter fitting approach for each industrial operation; if parameters are customised for specific plants, the model will be a useful tool to predict performance and can aid the development of effective process control systems in copper electrowinning tank houses. Keywords: Copper; current efficiency; electrowinning; modelling; plating rate

Jan 1, 2020

By G. Kleyn

"Sub-standard practices and their adverse impact on safety performance remain a challenge in the South African gold mining industry. The purpose of this study was to investigate the root causes of sub-standard practices and the effect on safety performance in South African gold mines. The focus of the study was on the underground production operations at a gold mine in the Free State. The study consisted of three parts: a personal investigation into the causes of sub-standard practices at the mine, a comparison with the results of a cultural study performed at the West Wits mines, and a behavioural survey.The studies described in this article yielded similar results in terms of the key drivers behind sub-standard practices. It was found that substandard practices had a number of causes, and the origin lies within the habits, attitude, and behaviour of employees. Current methods of addressing sub-standard practices and improving safety performance were found to discourage employees from performing work safely and according to procedure. It was concluded that the lack of critical behavioural habits for the given work environment and job title could possibly be the primary reason for the occurrence of sub-standard practices. IntroductionSince the implementation of the Mine Health and Safety Act, 1996 (Act 29 of 1996) and the Mine Health and Safety Regulations, the South African mining industry has been striving to improve health and safety performance and has placed great emphasis on adherence to mine standards.The Act requires employers in the mining industry to report accidents, incidents, and dangerous situations to the Regional Principal Inspector of Mines in their area. The data provided by employers is captured and analysed by the South African Mines Reportable Accident Statistical System (SAMRASS) and made available for public viewing (Department of Mineral Resources, 2011).A review of the national mine-related accident statistics shows clearly that the South African gold mining industry has improved its safety performance markedly over the past decade, but is still facing major challenges (Figure 1). These include meeting the Mine Health and Safety Milestones (Department of Mineral Resources, 2011)."

Jan 1, 2016

By H. von Blottnitz, B. E. Isheloke

Mining is a significant economic activity in most Southern African Development Community (SADC) countries, and mineral beneficiation has been identified, and controversially discussed as one of the possibilities for industrialisation. With many member countries being economically too small to muster the human and financial resources which beneficiation requires, the recently adopted Regional Mining Vision (RMV) envisages interventions at a regional level. An opportunity arose to ask industry role players to what extent the SADC appears to support regional beneficiation policy interventions undertaken by member countries, and what the challenges are in undertaking beneficiation regionally, as a complement to, or substitute for country-specific beneficiation policies. Twenty-five semistructured interviews were conducted with experts from SADC member countries during the 2019 Mining Indaba. Participants were divided on whether beneficiation should be carried out nationally or in the SADC region. While beneficiation could support value-keeping, key challenges were found to be infrastructure development (i.e. energy, water), scarce skills, access to technology and related costs, but also lack of free trade and movement. We submit that a more integrated beneficiation strategy for the SADC region, as is being developed through the RMV, would indeed be relevant in the future. Keywords: Mineral beneficiation, regional integration, beneficiation policy interventions, African mining vision, mining, SADC

Jan 1, 2020

By B. Hart, B. K. Gorain, A. Chattopadhyay, S. Dimovc

This paper presents a detailed and systematic approach to metallurgy diagnostics using an integrated novel gold deportment technique for complex copper-gold and refractory gold ore bodies. This uantitative gold deportment for these complex ore bodies is a challenging task due to reasons such as lower grades, high variability of visible and invisible gold content in different sulphides and iron oxide phases, significant presence of disseminated and composite carbonaceous matters along with associations of various copper sulphide phases. Gold mostly occurs as "invisible gold" (sub-microscopic gold) as solid solution or as colloidal-sized particles in different sulphides and other phases. The dominance of invisible gold and presence of highly preg-robbing and finely disseminated carbonaceous matter adversely affects gold recovery in flotation and leach circuits. Studies were initiated on various complex ore deposits and also on samples representing various process streams. Some case studies are presented in this paper to demonstrate the value of a high confidence gold deportment methodology in developing insights for problem diagnostics and to identify opportunities for metallurgical improvements. A systematic and holistic approach involving different fields of expertise is critical for successful development and delivery of solutions for complex ore bodies. Keywords: Integrated gold deportment, complex copper-gold ores, double refractory gold ores, carbonaceous matter, diagnostic metallurgy, preg-robbed surface gold

Jan 1, 2020

By C. Hsu

Underground coal gasification (UCG) is becoming more popular as the reserves of good quality, mineable coal are starting to diminish, and yet the global energy demand from coal is still increasing. The purpose of this research project was to investigate cavity formation within a coal block due to the combustion reactions in the context of UCG. The cavity plays a pivotal role in the UCG process, as it is essentially the gasification reactor. Cavity formation in an in situ gasification process using the forward combustion linking method (FCL) had been investigated, and a laboratory model was created to simulate the process. The experiment was performed by drilling a U-shaped tunnel into a coal block, which was then combusted internally with air that was fed through an injection hole. A heating element (at approximately 500°C) was used to supply the required heat for combustion at the base of the injection well. The coal blocks were analysed using micro-focus X-ray tomography. The tomography results showed that the coal tended to crack along the bedding plane after a short duration of combustion, due to either the formation of clinker or the expansion of swelling vitrinite along the horizontal tunnel. The deposit was thicker at the base of the injection well compared to the base of the production well; this may have been caused by the turbulence of the air flow and the relatively high oxygen concentration at the base of the injection well. A comparison of the results with work by Daggupati et al. (2010) showed the same trend, despite the slightly different methodology applied.

Jan 1, 2014

By V. Moodley

Strict implementation of International Standards for representative sampling of coal is difficult for routine monitoring, due to time, technical, and economic constraints. A large percentage of the total sampling variance arises from errors accumulated during the earliest stages of sample collection. Modified procedures on the precision of the final result leads to controversies between the sellers and customers for coal. Manual collection of coal samples violates the principle of correct sampling, that all fragments must have an equiprobable chance of being in the sample. In addition, manual size reduction of large numbers of samples is time consuming and involves human errors. A coal quality management procedure in alignment with the relevant ISO standards that describes the sampling protocol has been implemented, and current sampling and laboratory analysis of coal from base load mines (mines situated at the mouth of the power station) are well established. For import coal, sampling is performed during unloading by auto-mechanical sampling (AMS). Due to logistical and safety issues associated with multiple suppliers, Eskom opted for the coal to be sampled at source on a pre-certification basis. Online analysers provide a fast, accurate, real-time method of determining the total moisture and elemental composition of coal and is important to the coal industry for pricing, quality control, and reduction of SO2 emissions. Elemental analyses include S, Si, Al, Fe, Ca, Na, Mg, Mn, Ti, K and Cl. Measurement of S is dictated by the control of SO2 emissions from coal-fired power plants. Elements such as Na and Cl have adverse effects on boilers, causing fouling and slagging. Available online elemental analyser technologies include prompt gamma neutron activation analyses (PGNAA), recommended for major element determination, and pulsed fast and thermal neutron analysis(PFTNA), that is capable of measuring the major and minor chemical elements contained in coal. These systems utilize nuclear reactions to produce characteristic gamma rays that are used for identifying various chemical elements. By acquiring the gamma rays in three different time windows, there is a significant reduction of the background as compared with the spectra taken with a radio isotopic source.

Jan 1, 2009

By E. P. Preis, R. C. W. Webber-Youngman

The real cost of any mining incident has, empirically, proven to be estimation-driven, rather than factdriven. One of the main reasons for this lies with the complexity of the cost composition of any given mining incident. Incident costs comprise both direct and indirect cost factors, and in many cases the costs associated with these factors are incurred during different time periods following the incident. In this paper we aim to identify the various cost factors arising from mining incidents, provide a thorough understanding of all the potential cost factors identified, and draw general conclusions on the knowledge obtained. Furthermore, recommendations are made on how mining companies could use the results, in order to assist them in calculating the costs of mining incidents. The paper also provides suggestions for further research, with the emphasis on the most significant immeasurable cost factors, namely the costs of implementing job accommodations following an incident, the harm to company reputation, and the decreased productivity due to low worker morale/psychological factors following an incident. If mining companies are aware of and understand which factors could contribute to the cost of any given incident, future planning and incident cost estimations could be easier. It should, however, be noted that although this study provides a comprehensive list of cost factors (and detailed explanations), other unknown cost factors relating to mine incidents could prevail in extreme cases.

Jan 1, 2021

By M. Buchmann, T. Mütze, F. Heinicke

Dry air classification is a well-known technique used for decades in the cement industry to separate material in the size range of 0.01-1.0 mm. Additionally, in corresponding dry grinding circuits with effective machines such as High Pressure Grinding Rolls (HPGR), the energy consumption can be reduced compared to wet applications. These dry systems are not state of the art in minerals processing plants, but first prototypes have been installed and an increasing number of projects are starting to evaluate this option. One challenge in this field is the mineral composition of ores, which have, by far, a higher variety in density and size than those of cement. High density particles such as iron- containing ones have higher settling rates than low density silica particles of the same size. The main question to answer in this paper is how to evaluate this effect, so a quantitative method using Mineral Liberation Analyses was developed to calculate two-dimensional partition curves. Additional statistical analyses allow for isolation and quantifying the interaction of density and size, enabling engineers to consider this effect for the sizing of process plants. The paper will present the method and selective results for a compounded ore of iron and silica. Keywords: HPGR, air classification, partition curve, MLA

Jan 1, 2020

By J. C. N. Ashukem, F. Agyemang

One understudied area of environmental law is the socio-ecological impact of ownerless mines. This impact is particularly pronounced in resource-dependent regions like South Africa and Western Australia, creating significant rehabilitation challenges. This article hypothesises that effectively managed financial provision could be valuable for rehabilitating legacy mines. Using a qualitative, comparative methodology, the article analyses the financial provisions for mine rehabilitation in South Africa and Western Australia, focusing on statutory provisions, funding mechanisms, and rehabilitation outcomes. Key themes, such as context, measures, and outcomes, are explored to assess the effectiveness of each financial model. Purposive sampling is used to select case studies from both regions, and thematic analysis is applied to interpret the data. The analysis highlights the financial rehabilitation measures in both regions, providing a structured framework for ownerless mine rehabilitation. South Africa's approach, guided by the Mineral and Petroleum Resources Development Act (MPRDA) of 2002, depends on state budget allocations, leading to funding inconsistencies and slow rehabilitation progress. In contrast, Western Australia’s Mine Rehabilitation Fund Act (MRFA) of 2012 uses a levy-based system, ensuring continuous financial support for mine rehabilitation. South Africa's state-dependent model has led to delays in rehabilitating derelict and ownerless mines, while Western Australia’s funding model has facilitated steady progress. The article recommends that South Africa adopt a levy-based financial mechanism, strengthen legislative enforcement, improve financial oversight, and integrate proactive mine closure strategies to accelerate rehabilitation, reduce environmental hazards, and promote sustainable development in mining-affected communities.

Dec 15, 2025

By S. Saeed, N. Coulson, P. F. Stewart

"The Mine, Health and Safety Act No. 29 of 1996, as amended, embodies worker self-regulation to advance health and safety in the workplace. An important provision for this is the Right to Refuse Dangerous Work (RRDW). This paper explores worker perspectives about the implementation of RRDW on South African mines against a backdrop of revised guidance in the sector: ‘Guideline for a Mandatory Code of Practice on the Right to Refuse Dangerous Work And Leave Dangerous Working Places’, gazetted in February 2016 by the Department of Mineral Resources (DMR). A mixed methods study conducted at mines (n = 14) included a survey of workers (n = 293), focus groups (n = 6) and in-depth interviews (n = 16). Workers reported a high level of awareness, a positive attitude, and experience of the formal RRDW. However constraints to the formal RRDW meant that informal worker resistance to dangerous work was commonplace. Evidence of informal non-confrontational consultation, cooperation, and collaboration in the event of a dangerous workplace also emerged between workers, and supervisors. The research underscores the importance of the RRDW and worker health and safety representatives to mine health and safety. The revised guidance addresses RRDW implementation gaps, but of concern is the potential partiality towards management interests. IntroductionEnsuring that mineworkers act on their duties and responsibilities for health and safety remains a concern across the globe. Article 13 of the International Labour Organization (ILO) Convention Safety and Health in Mines (176 of 1995) entrenched the Right to Refuse Dangerous Work (RRDW) as an important mechanism through which workers act in the best interests of their own occupational health and safety (OHS) and is considered a cornerstone of worker self-regulation (ILO, 1995). Countries ratifying Convention 176 are under obligation to make this right available to workers through OHS legislation that frames the circumstances, procedure, and protection of workers from discrimination in the event of a formal work refusal. The Convention has been ratified by 31 countries, with South Africa becoming a signatory in June 2000 (ILO, 2000). Worldwide studies show that workers use this right with caution (Hilgert, 2013) and cases associated with work refusal are rarely presented in court (Gunningham, 2007; Cooper, 2013). Rather, in cases of formal notification of a work refusal, issues arising out of this are addressed either in the immediate workplace or through the site OHS system and/or at industrial tribunals or similar mechanisms (Harcourt and Harcourt, 2000)."

Jan 1, 2018

By M. Bueno, T. Chavez Matus, M. S. Powell, S. Michaux, S. Luukkanen

Comminution tests are an essential element in the design of ore beneficiation plants. Many methods have been developed to assess the breakage characteristics of rocks to generate parameters for modelling. However, most of the existing methods are laborious, expensive and require large samples. Consequently, test work has been traditionally conducted with a few representative reference samples. On the other hand, geometallurgical modelling programs require an extensive amount of test work to allow understanding the variability of ore properties within the deposit and establish spatial geometallurgical domains that show the differential responses to mineral processing. Therefore, comminution tests for geometallurgy need to be more efficient in terms of time, cost and sample size. This paper introduces a new testing device (Geopyörä) which is capable of measuring forces and energy applied to rock particles during the breakage process. The new testing method uses smaller samples and can be up to 50 times faster than other commonly used tests in the industry. This paper presents the concept prototype and the preliminary test work results, which have been benchmarked against some of the industry standard tests, such as the JK Drop Weight Test (JKDWT), the SMC Test® and the Bond ball mill test. Keywords: Geometallurgy, comminution, ore breakage characterization, variability.

Jan 1, 2020

By M. J. Kanda, T. R. Stacey

Thin spray-on liners (TSLs) have been used as sealants and rock support in tunnels for over 25 years. Laboratory tests have indicated satisfactory properties that can provide adequate strength, adhesion, toughness, and elasticity as part of rock support systems in mining excavations. These characteristics are, however, not always demonstrated in practice, when mine environmental conditions do not correspond with laboratory environmental conditions. The shortcomings of TSLs experienced in the mining industry have raised concerns, resulting in scepticism from some operators regarding their utilization. The research described in this paper aims to investigate TSL performance in environmental conditions similar to those experienced in mines. Brazilian indirect tensile (BIT) specimens were prepared from precast shotcrete and coated with TSLs. The specimens were then exposed to different environmental conditions for up to 112 days before BIT testing under various conditions: laboratory room temperature and humidity; saturated room temperature; and combined saturated and high temperature (50°C). Additional uncoated shotcrete and TSL BIT specimens were prepared for comparison purposes. The results of the BIT tests showed that environmental conditions have a significant influence on the tensile strength enhancement of shotcrete by TSLs. Water-based TSLs are most likely to be suitable for high humidity environments, although their performance decreases at higher temperatures. Numerical modelling of TSL-coated BIT samples confirms the potential limitations of designing TSL support based only on laboratory testing carried out under room conditions.

Jul 1, 2021

By X. Chen, F. An, H. Chen, Z. Wang

The bottom drainage roadway plays a crucial role in preventing coal and gas outbursts by using underground gas drainage methods. Therefore, it is essential to select the ideal position of the bottom drainage roadway. In this paper use a combination of geological data and numerical simulation to study the ideal position of the bottom drainage roadway, we taking the gas drainage of the first workface of No. 3 coal seam in the Yuxi coal mine in China as an example. The geological study showed a limestone marker layer at an average vertical distance of 14 m from the first mining face. Using this marker layer, the bottom drainage roadway could be excavated without the risk of accidentally exposing the coal seam, and less crosscutting borehole drilling from the bottom drainage roadway would be required. Based on the needs of gas control, the layout of the bottom drainage roadway was selected as an external stagger type. Combined with the numerical simulation results, when located 20 m outside of the mining workface ‘footprint’ on the horizontal projection, the bottom drainage roadway was a sufficient distance from the stress concentration area during mining of workface 1301, which facilitated roadway maintenance. Furthermore, the length of the crosscutting boreholes is also relatively short, which reduces the amount and cost of drilling. The results of this study are expected to provide a reference for the selection of an ideal position of the bottom drainage roadway in field engineering.

May 2, 2022

By S. Zhang, Z. Hua, D. Feng, X. Tong, X. Xie

The separation and beneficiation of low grade collophanite has long been a technical challenge in phosphorous production. It requires the joint efforts of process design, reagents optimisation and operational control. In this study, the statistical response surface method was applied for determining the optimum reagent dosing in the flocculate flotation of a low grade (18.59%) collophanite ore. The dosage of three reagents, including a pH regulator (Na2CO3), depressant (Na2SiO3) and flocculant (modified starch), were input parameters of the modelling design. Two quadratic mathematical models were derived for prediction of grade and recovery based on the statistical design. Statistical analysis of the experimental results validates the reliability of the models. Through further calculation, the optimum dosage of the three reagents were found to be 3,020g/t Na2CO3, 1,990g/t Na2SiO3 and 880g/t modified starch, with which a maximum recovery of 75.81% and P2O5 grade of 30.08% was obtained from flocculate flotation test. Keywords: Process optimisation, modelling, froth flotation, collophanite ore, response surface methodology

Jan 1, 2020

A Special General Meeting, followed by the February General Meeting of the Institute, was held in Kelvin House, Johannesburg, on 18th February, 1970, at 4.30 p.m. Mr J. K. E. Douglas (President) was in the Chair. There were also present 24 Members: Messrs A. R. C. Fowler, R. C. J. Goode, Prof D. D. Howat, Messrs D. G. Maxwell, J. A. Nixon, P. W. J. van Rensburg (Council Members), C. A. Border, J. C. Fritz, E. K. Gibson, P. L. Grimbeek, S. D. Hill, D. A. Immelman, P. J. Uoyd, M. Mrost, C. S. Macphail, D. G. Malan, W. D. Ortlepp, R. S. Pearson, A. J. H. Pole, Dr W. S. Rapson, L. W. P. van den Bosch, R. A. von Maltitz and Dr A. Whillier. Eight Associate Members: Dr M. I. Brittan, Messrs J. Brett, I. E. Clarke, C. L. de Jongh, W. B. Evans, D. Loubser, R. C. More O'Ferrall and G. R. Still. One Graduate: Mr T. J. Kotze. One Student: Mr J. A. Cruise. Nine Visitors: including Dr N. G. W. Cook, Messrs M. D. Labuschagne, A. Nicoll, S. Sadowski, Dr A. M. Starfield and Dr H. Wagner. Secretary: Mr D. C. Visser. Total present: 45. SPECIAL GENERAL MEETING The President: "You will have received notices of the Special General Meeting and I declare it duly constituted. In keeping with the trend of overseas and local institutes, your Council recommends that we should change our membership classification as indicated in the notes of the meeting. The new grades are proposed to replace those presently in the Constitution and By-Laws. In terms of Clause 4.8 of the Constitution a special general meeting must be held for the purpose of considering and, if approved, adopting with or without amendments, the revision of the undermentioned clauses of the Constitution, which Council now recommends should read as follows. Clause 2.2 'Corporate Members shall comprise the grades of Honorary Life Fellow, Fellow and Member', these being the equivalent of Honorary Life Member, Member and Associate Member. Clause 2.6. 'Non-Corporate Member shall comprise the grade of Honorary Fellow, Graduate, Associate and Student.' Are there any questions in regard to this proposal? If not would someone propose that these clauses be amended and adopted?" Proposer: Mr A. J. Nixon. Seconder: Prof D. D. Howat. The motion was then adopted. The President: "It is recommended that Clause 2.15 should read, 'A Corporate of the Member of the Institute shall be entitled to use the following authorised letters designating the grade of Membership in Honorary Life Fellow and Fellow, F.S.A.I.M.M. and Member, M.S.A.I.M.M.' Previously we used the letters M.S.A.Inst.M.M. and your Council considered that we should adopt the simpler lettering. Could I ask someone to propose that this amendment be adopted?" Proposer: Mr R. C. J. Goode.

By T. M. Russell

"Face mapping is a simple but invaluable means of geological and geotechnical data acquisition whereby intact rock properties, rock mass properties, discontinuity properties, and structural orientation can be assessed. Although traditionally done via direct contact with the mapping face through techniques such as line mapping or window mapping, remote face mapping using various digital techniques has become increasingly popular in recent years. Sishen is a large open pit mining operation requiring a comprehensive geotechnical data-set to evaluate pit wall design and stability with the necessary level of confidence. Geotechnical borehole data, face mapping data, geotechnical laboratory testing data, and implicit structural models provide the main sources of this information. Although a large geotechnical borehole database has always been maintained at the mine, face mapping has in the past been restricted to sporadic and isolated stability assessments. In 2013 the mine acquired a terrestrial laser scanner with the resolution, photographic capabilities, and software required to carry out geotechnical face mapping. A face mapping procedure was set up based on accepted face mapping methods, the data requirements of the mine, and capabilities of the laser scanner system. Mapping data obtained from the scans was integrated into the Acquire geological data management system, a purpose-designed structured query language (SQL) database system used for storing the mine’s geotechnical data. Within the geotechnical design process, having face mapping data available has improved confidence in the properties of the rock mass and structural environment, allowing for better definition of geotechnical design sectors. Overall, the face mapping and geotechnical analysis features of the terrestrial laser scanner in use make it an invaluable geotechnical data capture tool, provided a system is in place to store mapping data in a manner that allows for meaningful rock mass and structural information to be produced. IntroductionFundamental to the geotechnical design process is the acquisition of a reliable and complete geotechnical data-set. Geotechnical data acquisition will typically commence during the early stages of a project and continue well into the operational life of the mine, with the data confidence progressively increasing as the amount of data captured increases. Sishen mine currently bases all open pit geotechnical designs and geotechnical risk assessment on geotechnical borehole data in conjunction with interpreted structural models. Boreholes are logged and the data is captured in an ongoing process. This process forms the initial step in the geotechnical design and risk assessment process whereby the raw data is used to classify the strength properties for each lithology, provide inputs for geotechnical block models, and ultimately provide the inputs for slope design analyses. To date, borehole data has provided the only largescale, organized data-set for input into geotechnical analyses at Sishen. Although borehole data is the best and most comprehensive form of geotechnical data, there are some shortfalls that can be addressed by other data collection methods. These shortfalls are as follows."

Jan 1, 2018

By J. H. C. Pretorius, P. Nelwamondo

"Although South Africa possesses more than 80% of the world’s platinum reserves, its reputation for reliability in supplying platinum to global markets is under threat. This is due to the 49% decrease in output per worker (1999–2014), while the domestic costs have risen by more than 10% annually for the past 5 years. In addition, the continued decline in the commodity price by 38.3% (2012–2016) has resulted in a significant portion of the sector producing at a loss in 2015. The Chamber of Mines (now the Minerals Councilof South Africa) has suggested that solutions to improve productivity and reduce cost pressures are required. This research aims to provide operational excellence through the application of event chain project management (ECPM) to improve productivity and reduce operational costs. A case study was used to carry out research in platinum mines, with data collected using a motion-time study to measure the current efficiency of operations in each mining stope through actual activity durations. The results indicate that through the application of the event chain project management methodology, risks affecting the mining stope schedule can be managed, the efficiency of operations was improved by reducing the time spent on each activity, productivity was increased by shortening the project duration, and operational costs were reduced in the process. IntroductionSouth Africa’s total mining industry production was 4.9% lower in 2016 than in 2015; it decreased by 1.9% year-on-year in December 2016, with the main contributor to this negative trend being the platinum group metals (PGMs) with a drop of 15.1% and contributing -3.8% percentage points (Statistics South Africa, 2016). Although South Africa possesses more than 80% of the world’s platinum reserves, the 8% drop in production output since 2008 has put the platinum mining industry under the threat of being seen as an unreliable supplier to global markets. This decline in production is caused by the 49% decrease in output per worker between 1999 and 2014. In addition, the continued decline in the commodity price by 38.3% from 2012 to 2016 and an increase in operational costs during the same period resulted in a significant portion of the sector producing at a loss in 2015. A turnaround strategy is required to overcome these challenges. The Chamber of Mines has suggested, among others, the need for solutions to improve productivity and reduce cost pressures. The implementation of these solutions will ensure that the PGM industry thrives and reaches its potential of growing production to more than 322 t by 2020 (Baxter, 2016)."

Jan 1, 2018

By M. Tangstad, J. D. Steenkamp

In April 2013 a 48 MVA submerged arc furnace producing silicomanganese was excavated in South Africa. Since the high shell temperatures recorded in the tap-hole area resulted in the furnace being switched out for relining, the tap-hole area was excavated systematically. A refractory wear profile of the tap-hole area with affected hearth and sidewall refractory was obtained in elevation. The carbon ramming paste in front of, above, andbelow the tap-hole was worn, as was the SiC with which the tap-hole was built. A clay mushroom formed but was detached from the refractories. Thermodynamic and mass-transfer calculations were conducted to quantify the potential for wear by chemical reaction between refractory and slag and refractory and metal in the tap-hole area. It was found that chemical reaction between refractory and slag or metal could offer only a partial explanation for the wear observed; erosion is expected to contribute significantly to wear.

Jan 1, 2015