Satellite based synthetic aperture radar and optical spatial-temporal information as aid for operational and environmental mine monitoring

A sustainable society is a society that satisfies its resource requirements without endangering the sustainability of these resources. The mineral endowment on the African continent is estimated to be the first or second largest of world reserves. Therefore, it is recognised that the African continent still heavily depends on mineral exports as a key contributor to the gross domestic product (GDP) of various countries. These mining activities, however, do introduce primary and secondary environmental degradation factors. They attract communities to these mining areas, light and heavy industrial establishments occur, giving rise to artisanal activities. This study focussed on satellite RS products as an aid to a mine’s operations and the monitoring of its environment. Effective operational mine management and control ensures a more sustainable and profitable lifecycle for mines. Satellite based RS holds the potential to observe the mine and its surrounding areas at high temporal intervals, different spectral wavelengths and spatial resolutions. The combination of SAR and optical information creates a spatial platform to observe and measure the mine’s operations and the behaviour of specific land cover and land use classes over time and contributes to a better understanding of the mining activities and their influence on the environment within a specific geographical area. This study will introduce an integrated methodology to collect, process and analyse spatial information over a specific targeted mine. This methodology utilises a medium resolution land cover base map, derived from Landsat 8, to understand the predominant land cover types of the surrounding area. Using very high resolution mono- and stereoscopic satellite imagery provides a finer scale analysis and identifies changes in features at a smaller scale. Combining these technologies with the synthetic aperture radar (SAR) applications for precise measurement of surface subsidence or upliftment becomes a spatial toolbox for mine management. This study examines a combination of satellite remote sensing products guided by a systematic workflow methodology to integrate spatial results as an aid for mining operations and environmental monitoring. Some of the results that can be highlighted is the successful land cover classification using the Landsat 8 satellite. The land cover that dominated the Kolomela mine area was the “SHRUBLAND/GRASS” class with a 94% coverage and “MINE” class of 2.6%. Sishen mine had a similar dominated land cover characteristic with a “SHRUBLAND/GRASS” class of 90% and “MINE” class of 4.8%. The Pléiades time-series classification analysis was done using three scenes each acquired at a different time interval. The Sishen and Kolomela mine showed especially changes from the bare soil class to the asphalt or mine class. The Pléiades stereoscopic analysis provided volumetric change detection over small, medium, large and recessed areas. Both the Sishen and Kolomela mines demonstrated height profile changes in each selected category. The last category of results focused on the SAR technology to measure within millimetre accuracy the subsidence and upliftment behaviour of surface areas over time. The Royal Bafokeng Platinum tailings pond area was measured using 74 TerraSAR-X scenes. The tailings wall area was confirmed as stable with natural subsidence that occurred in its surrounding area due to seasonal changes of the soil during rainy and dry periods. The Chuquicamata mine as a large open pit copper mine area was analysed using 52 TerraSAR-X scenes. The analysis demonstrated significant vertical surface movement over some of the dumping sites. It is the wish of the researcher that this dissertation and future research scholars will continue to contribute in this scientific field. These contributions can only assist the mining sector to continuously improve its mining operations as well as its monitoring of the primary as well as the secondary environmental impacts to ensure improved sustainability for the next generation.Environmental SciencesM. Sc. (Environmental Science

Increasing geotechnical data confidence through the Integration of laser scanner face mapping data into the Sishen iron ore mine geotechnical database

A research report submitted in partial fulfilment of the requirements for the degree of Master of Science in Engineering to the Faculty of Engineering and the Built Environment, School of Mining Engineering at the University of the Witwatersrand, Johannesburg, 2018Face 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 Mine 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 lab 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 Maptek 8810 terrestrial laser scanner with the resolution, photographic capabilities and software required to carry out geotechnical face mapping. The aims of this research project were to evaluate the capabilities of the Maptek scanner and system, set up a standard face mapping procedure, integrate face mapping data in the mine’s geotechnical database and compare face mapping acquired rock mass data with the mine’s existing borehole data set. Further potential uses for the laser scanner system and face mapping data were also explored throughout the course of the dissertation. A face mapping procedure was set up and faces were mapped from 86 individual scans, acquired between October 2015 and April 2017. The 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. Open Database Connectivity (ODBC) database links with the Micromine Computer Aided Design (CAD) package allowed for spatial overlays of mapping data with other geotechnical data as well as survey and mine planning data. In terms of data analysis mapping parameters such as joint spacing, Rock Quality Designation and Rock Mass Rating could be directly compared with borehole logging values for the same rock types. The comparison indicated that in general borehole measurements tend to slightly under estimate joint spacing and rock mass rating values while face mapping assessments tend to slightly over estimate these values. This is due to various intricacies of the two data capture techniques that tend to skew the data in one way or the other. Face mapping data was compared with Sishen’s existing structural model, which is based mainly on interpretation and implicit data. Structural orientations and features correlate well between the implicit model and actual mapped values gathered during the data collection phase of this project. Within the geotechnical design process, having actual mapping data in combination with increased confidence in the structural model allows for better definition of geotechnical design sectors. Overall the face mapping and geotechnical analysis features of the Maptek 8810 terrestrial laser scanner make it an invaluable geotechnical data capture tool, providing a system is in place to store mapping data in a manner that allows for meaningful rock mass and structural information to be produced.XL201

Paleomagnetism of a lateritic paleoweathering horizon and overlying Paleoproterozoic red beds from South Africa: Implications for the Kaapvaal apparent polar wander path and a confirmation of atmospheric oxygen enrichment

The Olifantshoek Group in southern Africa contains Paleoproterozoic red beds that are exceptionally well preserved, lying unconformably atop a regionally extensive lateritic paleoweathering profile. We studied the basal unit of this succession, known as the Gamagara or Mapedi Formation, and the lateritized substrate (so-called “Drakenstein” or “Wolhaarkop” paleosol) on which it developed. Two ancient magnetic components are observed. One (INT), usually with a distributed unblocking spectrum between 300° and 600°C but occasionally persisting to >675°C, is directed shallowly southward or northward. A mesoscale fold test at South Sishen Mine indicates that this component was acquired during deformation; similarity of the direction to previous results suggests that it was acquired at ∼1240 Ma, during early Namaqua orogenesis. Combining our INT results with existing data from the Namaqua eastern zone (NEZ), we calculate the NEZ pole at (44.9°N, 021.5°E, K = 23.2, A_95 = 12.8°, Q = 5). The most stable component from our data set (HIG), always persisting as a nonzero endpoint to demagnetization at >665°–680°C, is observed in 32 samples from South Sishen and Beeshoek Mines. Directed moderately east-downward (Sishen) or west-upward (Beeshoek), this component predates the mesoscale fold at Sishen. More importantly, a conglomerate test at Beeshoek indicates that HIG was acquired prior to Paleoproterozoic deposition of the Gamagara/Mapedi Formation. The concordance between directions from the paleoweathering zone and immediately overlying red beds indicates that HIG is a primary magnetic remanence for the basal Gamagara/Mapedi (BGM) Formation. The dual-polarity BGM paleomagnetic pole (02.2°N, 081.9°E, dp = 7.2°, dm = 11.5°, Q = 6) lies neatly between previous Kaapvaal poles with ages of ∼2220 (Ongeluk lavas) and 2060 Ma (Bushveld complex). Our data thus support recent correlations of the Gamagara/Mapedi Formation with pre-Bushveld sediments of the Pretoria Group. A pre-Bushveld age for BGM is also consistent with its substantial distance from a new, albeit less reliable, paleomagnetic pole from the ∼1930-Ma Hartley lavas, higher within the Olifantshoek succession (12.5°N, 332.8°E, K = 18.6, A95 = 16.0°, Q = 3). Our conglomerate test at Beeshoek confirms previous allegations that the intense hematitization observed in the Drakenstein-Wolhaarkop paleosol occurred during Paleoproterozoic weathering under a highly oxygenated atmosphere

Explicit and implicit geological modelling methods on resource definition and resource utilisation-sishen iron ore deposit case study

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Masters in Engineering. 1 October 2017Technological advances make geological modelling easier and more intuitive than ever before. There is a clear shift in the mining industry concerning the needs of the geological model and its function. Geological modelling is one of the first steps in the resource evaluation process; its primary function is to define the orebody’s physical properties and characteristics. It can, therefore, be argued that the geological model has a commanding impact on the entire resource evaluation process. Although many publications exist regarding modelling conventions, few truly compare the explicit versus implicit approaches and document the observed differences. This case study on the Sishen iron ore deposit shows that modern implicit modelling techniques can create geological models comparable to those created using traditional wireframing techniques. In many aspects, these implicit models are superior to their explicit counterparts due to their increased modelling speed and multiple data source inclusion. The implicit modelling process delivered a geological model with modelled ore volumes equivalent to those of the traditional explicit geological model. However, spatial reconciliation between the explicit and implicit versions of the Sishen geological models showed substantial discrepancies due to fundamental differences in geometry and connectivity, and modelling conventions. These differences in the geological models are manifested in considerable change in the final, defined Sishen resource. This case study for the Sishen iron ore deposit confirms that geological models are critical to the entire resource definition and extraction process. Any resource evaluation and planned extraction activity is only as accurate as the geological model used to define the resource originally. This study also shows how critical it is to test geological model performance through the entire mining value chain. Basic volumetric comparisons or tonnage reconciliations can mask the effects of geological modelling approaches on resource definition and extraction.MT 201

Evaluation of two different mechanized earth moving technologies truck and shovel and IPCC for handling material from a large open pit mine using requesite design and operational conditions, efficiency, cost , skills and safety as criteria using sishen iron ore mine as a case study

An advanced coursework and a project submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements of MSc. Engineering (Mining), November 2015General For mining operations, both underground and open cast, there are generally accepted criteria used to arrive at the optimum mining method with which to exploit the ore body economically. Having selected the optimum mining method, mining companies should then make the decision to also select the optimum technology to apply given the various options that are now available. In the case of a shallow massive ore body where open-pit mining has been selected as the optimum mining method, the use of conventional trucks and shovels has been the popular choice but over the years, as pit become deeper, and stripping ratios increase, growing interest and adoption of in-pit crushing and conveying for both ore and waste has been gaining ground with several mining sites currently now operating, testing the systems or conducting studies at various stages for In-pit Crushing and Conveying (IPCC) in its different configurations (Chadwick, 2010). Open pit mining general involves the movement of pre-blasted or loose waste ahead of underlying ore out of the pit or to a previously mined part of the pit. This is then followed by the drilling and blasting or loosening of the ore and transportation to the processing plant or stockpiles. The conventional Truck and Shovel open pit operation involves the use of shovels – electric rope shovels, diesel or electric hydraulic shovels or excavators or front-end loaders to load the blasted, or loose waste and ore material in the pit onto mining trucks which haul the material to crushers or stockpiles if it is ore or to waste dumps in the case of waste. In a Fully Mobile IPCC (FMIPCC) system, the broken or loose material in the pit is loaded into a crusher or sizer by a shovel, continuous miner or dozer, crushed to a manageable size and transported by conveyor belts to the waste dump where it is deposited in place using spreaders if it is waste or onto stockpiles if it is ore. A combination of the two systems is where trucks dump material loaded at the face into a semi mobile crusher or sizer located in the pit close to the loading points N BANDA 392438 before conveying to destination thereby reducing truck haulage distance. In the semi-mobile configuration, the crusher is relocated closer to the loading points to minimise the hauling distance. Other various configurations are also employed depending on the various considerations. Although the Truck and Shovel system is considered as the convention in open pit mining, the IPCC system is not a new concept and has been operational on a number of mines worldwide for quite a number of years (Szalanski, 2010). Loading and hauling receive great attention especially in a high volume open pit mines due to the high cost contribution to the overall operation and therefore, if optimised, good cost savings can be realised (Lamb, 2010). Figure 1: Sishen Mining Cost Breakdown In the case of Sishen Loading and Hauling costs constituted 67% of the mining costs including labour mining support services in 2013 (Kumba Iron Ore, 2013). This picture remains unchanged to a large extent. In some cases the hauling cost alone can make up as much as 60% of the mining operating cost (Meredith May, 2012) Selection of a materials handling system between Truck and Shovel (T/S) and In-pit Crushing and Conveying (IPCC) has proven to be difficult due to limited understanding of the IPCC system especially its advantages and disadvantages relative to the Truck and Shovel system. The aim of this research was to unpack these two systems in terms of their applicability using studies conducted at Sishen 6,5% 8,8% 29,1% 22,7% 9,7% 0,6% 1,3% 0,4% 7,0% 4,2% 3,7% 5,9% Sishen Mining Cost 2013 Blasting Drilling Hauling L&H Contractors Loading Maintenance Other Mining Manangement Mining Engineering Mining Other Resource Management SHEQ Mining Support N BANDA 392438 Mine as well as develop some scorecard that could be used to select one over the other one. Sishen Case Study Sishen Mine is an iron ore open pit mine located in the Northern Cape province of South Africa and is part of Kumba Iron Ore Company which is Anglo American PLC. The mine has been in operation since 1953 with the current life of mine going up to 2030. It produces 44Mt tonnes of product from a 56Mt mine ore at a life of mine strip ratio of 4. One of the planned expansion the north part of the mine known as the GR80 and GR50 areas. Mining in these areas will require pre-stripping of 290Mt of clay material over the life of mine to expose the ore in pre volume phases. Figure2: Sishen Pit –Sishen Mine 2014. Sishen mine is constantly evaluating various technologies in its mining operations aimed at improving its bottom line by way of increasing productivity and efficiency, reducing costs and improving safety, however, the last time that the mine considered evaluating a technology that significantly could have resulted in a totally different operational philosophy was i contracted to institute a study to evaluate technology options for mining and moving majority owned by a minimum of 437Mt of calcrete and the underlying pre- g in 2007 when Snowden Mining Consultants run-ofmine areas is in -planned time and were N BANDA 392438 55 Mt of the calcrete/clay material per year from the waste pushback area in the GR80/GR50 area of the mine from 2009 till 2030. Snowden completed the Prefeasibility study in early 2008 in which they evaluated a conventional Truck and Shovel operation as well as IPCC. Economic viability of both systems in various configurations was demonstrated with the use of larger trucks and shovels ranked as the most economic option in terms of Net Present Cost (NPC), unit owning and operating cost per mined tonne and, to a less extent, in terms of risk and other considerations. In this case, the Truck and Shovel option was more economic than both IPCC configurations. However the small difference in the cost figures gave rise to interest in further evaluations. Following the Snowden study, Sishen engaged Sandvik Mining and Construction in 2008, to review the work done by Snowden and provide more detail and practical input to the IPCC system at scoping level. In the review, the IPCC system was shown to be the economic approach for the waste removal from the target area in terms of owning and operating cost. Practicality was also demonstrated and the case for the consideration of the IPCC system was put forward to Sishen. A further consultant, Sinclair Knight Merz (SKM) of Australia, was engaged, in the later part of 2008, to further evaluate and optimise the IPCC option to further demonstrate practically in detail at a feasible study level and strengthen its case by mitigating perceived risk. This included equipment specifications, mine and equipment layout per period per bench and risk assessment on the IPCC options. The mine, however, implemented the conventional truck and shovel option using larger equipment. The final decision was to stick with the current set up of Truck and Shovel system and gradually replace the current fleet of 730E Komatsu (190 tonne payload) trucks with the 930E or equivalent ( 320 tonne payload) and the current XPB 2300 P& H electric rope shovels and CAT 994/Komatsu WA1200 front end loaders with XPC 4100 P&H electric rope shovels, Komatsu PC8000/Liebherr 996 diesel hydraulic shovels and LeTournea L-2350 front end loaders to reduce the number of equipment and manage the operational cost. This decision was based on issues around initial capital investment, flexibility of the system to suit changing mining plans, ability of current personnel to run the system and general low risk appetite for change. The adopted option has its own challenges N BANDA 392438 such as supporting infrastructure requirements, labour intensity and associated low productivity and high cost, fleet management challenges to achieve required productivity constantly, supplies such as fuel and tyres and safety issues due to traffic density. A high level recalculation of the costs using current information was done as part of this research. For simplicity, no escalations or discounting were applied on future expenditure. The estimated unit owning and operating costs in 2014 terms for the study area were as follows:- Fully Mobile IPCC (FMIPCC) option ZAR 10.38/t, Semi Mobile IPCC (SMIPCC) option ZAR 13.12/t, Truck and Shovel option ZAR 15.80/t. The objective of this research is to use lessons from the Sishen case as well as other operations and gather expert views with the aim of establishing criteria that could be applied in a preliminary evaluation that would determine the suitability of either of the materials handling options. General Approach The costs were recalculated using as much current information as possible. Other considerations including advantages and disadvantages of either of the systems were examined in more detail, with real life examples examined where possible. This resulted in the establishment of generalized criteria for the selection of mining and transport technology for a large open pit mine with focus on conventional Truck and Shovel systems on one hand and IPCC systems, in their various formats, on the other. These criteria which identify conditions necessary for the successful adoption and implementation of either of the systems could then be used as input into the decision to carry out any further detailed studies of the options. The previous study reports on the Sishen mine case were examined, input parameters to the calculations checked and the general approached analyzed for practicality. The relative costs were also viewed for comparative purposes. Literature on these two main systems was reviewed including that from conferences. Other large operations running either one or both systems were looked at to gain N BANDA 392438 further insight. Original Equipment suppliers’ views on these systems were also looked at through many articles in the public domain. Sishen mine has previously had the IPCC system running in the same part of the mine in a semi mobile configuration, crushing and conveying waste. It was then changed to become a supplementary system for the ore handling system and the in pit crusher has never been relocated. The Truck and Shovel system took over the movement of all the waste and most of the ore at the mine. Lessons from these experiences were incorporated in this study

The case for economic hardship in South Africa: Lessons to be learnt from international practice and economic theory

Although most leading legal systems provide for some form of legal relief in the case of economic hardship, South African law still does not address the issue of changed circumstances beyond that of objective impossibility or where the parties have provided for these instances contractually. Scholars have argued for an expansion of the doctrine of supervening impossibility in exceptional cases. However, the courts have to date not made any pronouncements in this regard. This article argues that a new default rule should be adopted that will reduce transaction costs and facilitate international trade. It is suggested that such a rule should build on the existing requirements set for the doctrine of supervening impossibility, but at the same time fuse international practice with the rules of economic theory

Optimization of dense medium cyclone plant for the beneficiation of low grade iron ore with associated high proportion of near-density material at Sishen Iron Ore Mine

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the Degree of Master of Science in Engineering (Metallurgy and Materials Engineering) July 2015The research report is premised on three aspects which are critical in the heavy mineral beneficiation. These aspects are classified as (i) understanding the densimetric profile of the available ore body, (ii) understanding the properties of the heavy medium utilised at the plant to beneficiate the ore, and (iii) the automation and modelling of the processing plant in order to maximise plant efficiency. Ore characterisation is mainly focused on understanding the densimetric profile of the ore body, in order to determine the probability of producing a saleable product as well as predicting the expected yields and quality. This is done to utilise the endowment entrusted upon the operating entity by the government and shareholders to treat the mineral resource to its full potential. Understanding of the beneficiation potential of the ore body will assist the mine planning and processing plant to optimise the product tons and quality. This will ensure the marketing plans are in accordance with the expected product as beneficiation will vary depending on the mining block reserves. The mining blocks have potential to produce varying product grades with different recoveries. Ore characterisation was conducted on the GR80 mining block, low-grade stockpiles (i.e. C-grade ore reserves & Jig discard and dense medium separation (DMS) run-of-mine (ROM) material. The GR80 material was characterised as having low proportion of near-density material and would be easy to beneficiate as well as produce high volumes of high grade product. Furthermore, it was revealed that the 2014 DMS ROM had an increased proportion of low-density material; however this material was also had low proportion of near-density material. The low-grade stockpiles was characterised by high proportion of near density material, which necessitate the beneficiation process to operate at high density in excess of 3.8 t/m3. Maintaining a higher operating density requires more dense medium which leads to viscosity problems and impact performance. The characterisation of the FeSi medium was imperative to understand its behaviour and potential influence on beneficiation of low-grade stockpiles and mining blocks with elevated proportion of near-density material. As the proportion of near-density waste material increases in the run-of-mine (ROM), it is necessary to beneficiate the material at elevated operating medium densities. However, when cyclones are operated at high densities, the negative influence of the medium viscosity becomes more apparent and thus influences the separation efficiency. Heavy medium, ferrosilicon (FeSi) characterisation looked at identifying the effects of viscosity on the FeSi stability and whether there would be a need for a viscosity modifier. Thus, the importance of controlling the stability, viscosity, and density of the medium cannot be under-estimated and can very often override the improvements attainable through better designs of cyclones. Furthermore, the slurry mixture of the heavy medium utilised for the purpose of dense medium separation should be non-detrimental to the effectiveness of separation in the DMS Fine cyclone plant. Medium characterisation showed that removal of ultra-fines leads to unstable media as indicated by faster settling rates. This would result in medium segregation in the beneficiation cyclone thereby leading to unacceptable high density differential which will negatively impact the cut-point shift and cause high yield losses to waste. The overall control of the metallurgical processes at Sishen’s Cyclone Plant is still done on manually and thus operation still varies from person-to-person and/or from shift-to-shift. This result in some of the process data and trends not being available online as well as being captured inaccurately. Furthermore, this negatively affects the traceability and reproducibility of the production metallurgical key performance indicators (KPI’s) as well as process stability and efficiency. It has been demonstrated that real-time online measurements are crucial to maintaining processing plant stability and efficiency thereby ensuring that the final product grade and its value is not eroded. Modelling and automation of the key metallurgical parameters for the cyclone plant circuit was achieved by installation of appropriate instrumentation and interlocking to the programmable logic control (PLC). This allowed for the control of the correct medium sump level, cyclone inlet pressure, medium-to-ore ratio as well as online monitoring of density differential as “proxy” for medium rheological characteristics. The benefit of modelling and simulation allows the virtual investigation and optimisation of the processing plant efficiency as well as analysis of the impact of varying ore characteristics, throughput variations and changing operating parameters. Therefore it is imperative that all cyclone operating modules are operated at the same efficiency which can be achieved by optimized process through proper automation and monitoring, thereby improving the total plant profitability. Keywords: dense medium separation; densimetric profile; dynamic modelling; FeSi rheology; iron-ore beneficiation; process automation; process control

Biobenefication of Sishen Hematite Iron Ore, using bacterial cultures to remove potassium (Muscovite) and phosphorous (Apatite)

Kumba Iron Ore, Ltd. is the world‘s fourth largest supplier of sea-borne iron ore and currently operates two mines in South Africa namely: the Sishen mine in the Northern Cape and Thabazimbi mine in Limpopo. The Sishen mine, located at the northern end of the Maremane anticline where the bulk of the hematite ore is buried beneath younger cover lithologies, was our focus area. Here the iron resources are made up by laminated and massive ore bodies that belong to the Asbestos Hills Subgroup. These ore bodies are overlain by conglomerates, shales, flagstone and quartzite. The alkalis, potassium and phosphorous, are common constituents of iron ore, which is known to have a deleterious effect on the manufacturing of iron and steel. Therefore steel making companies charge penalties when purchasing iron ore concentrates with alkali concentrations above predetermined levels. To ensure that the export batches at the Sishen mine stay within set limits, the ores from different batches (with alkali concentration greater and below set limits) are mixed to produce a batch which meet requirements. However this solution will soon become ineffective as the low alkali ore is progressively depleted. Conventional methods used to treat high alkali ores include pyro-and hydrometallurgical methods. These approaches have several limitations such as poor product recovery, involvement of high process and energy cost and an increase in pollution load of water resources. Therefore necessitating research and development of alternative cheap and environment friendly procedures, which could supplement or replace conventional methods to ensure that mining stays economically feasible at the Sishen Iron Ore mine. The application of microorganisms to mining practices is collectively referred to as biohydrometallurgy and includes bioleaching and biooxidation processes. The phrase bioleaching refers to the conversion of an insoluble metal (typically a metal sulfide) into a soluble form (typically a metal sulfate), via microbial activity. When metals are extracted into solution, the process is referred to as bioleaching, whereas if the metal remains in the mineral, it is referred to as biooxidation. The latter term biobeneficiation refers to the selective dissolution of undesired minerals from the ores by direct or indirect action of microbes, thereby enriching the desirable mineral content. Therefore the objective of this study was to determine whether bacteria (naturally occurring on the ore or introduced species) could be used to selectively remove the alkalis from the iron ore mined at Sishen. The species evaluated were able to change the solution pH and/or form biofilms, which is assumed to have affected mineral mobilization. Data obtained during this study suggests that the composition of the ore plays a significant role in its susceptibility to bioleaching. Furthermore we also found that the indigenous cultures were more effective than the introduced species to mobilize the alkalis, which could possibly be ascribed to an adaptation of the microbes present. These preliminary results suggest that bioleaching is an effective alternative cost effective approach to treat iron ore and could possibly be implemented in future into the mining schedule at Sishen.Dissertation (MSc)--University of Pretoria, 2011.Microbiology and Plant Pathologyunrestricte

The use of stories and storytelling as knowledge sharing practices : a case study in the South African mining industry

A great deal has been written in the management literature concerning the field of knowledge management. Some of that literature has focused on the use of stories and storytelling, including for the sharing of knowledge. However, the field of knowledge management is relatively immature in South Africa. In particular within that field, there is not a clear understanding of the use of stories and storytelling for knowledge sharing within the country. The purpose of the study was to improve that understanding through research into a case study within the South African mining industry, with a focus on world-class performance. To assist in the performance evaluation of the case study organisation, a framework for world-class performance was developed and used as an analytical tool in conjunction with a research instrument that was based on the findings of the non-empirical research into the fields of knowledge management and stories and storytelling. The empirical research then focused on the activities of a particular community of practice within the case study organisation and sought to understand the way in which stories and storytelling were used to support the sharing of knowledge in the organisation, as a contributor to world-class performance. Whilst conducting the empirical research, assessment and analysis, it was identified that the case study organisation made use of a number of practices and tools to support the use of stories and storytelling, in particular graphical representations (storyboards) of the stories to complement their oral delivery. The analysis of the case study data indicated that a significant opportunity existed to improve the extent of world-class performance for the use of stories and storytelling and a number of recommendations were made in that regard.Thesis (DPhil)--University of Pretoria, 2007.Information Scienceunrestricte

Establishing project management guidelines for successfully managing resettlement projects

Although millions of people globally are displaced annually, resettlement has a poor history for achieving the objective of leaving people who are resettled 'no worse off after project implementation than before'. While excellent guidelines and policies for resettlement have been established, resettlement/displacement projects still do not succeed in resettling affected peoples in a way that they are eventually better off. Consensus was reached by a Delphi panel of experts on a set of guidelines for resettlement projects. It is proposed that, supplementing the existing frameworks and guidelines for resettlement with well-established project management principles - including a phased project management approach - the chances of executing a resettlement project successfully are much higher. This paper proposes an improved framework and valuable guidelines for future resettlement projectshttp://www.journals.co.za/ej/ejour_busman.htmlam2013ai201