Assessing land degradation and the effectiveness of calcrete bontveld rehabilitation in a grassridge PPC cement mining area using multi-sensor remotely sensed data and machine learning techniques
- Authors: Mpisane, Khanyisa
- Date: 2023-12
- Subjects: Land degradation -- South Africa , Environmental degradation , Mines and mineral resources -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62527 , vital:72821
- Description: This study uses multi-temporal remote sensing data to spatially visualise and quantify land degradation due to mining as well as Calcrete Bontveld rehabilitation at the Grassridge PPC Cement mine, Gqeberha formerly known as Port Elizabeth in the Eastern Cape, South Africa. Botanical field data is also used to verify the suasses of rehabilitation in the area. SPOT-6 and Landsat multi-spectral images were compared, and Support Vector Machine and Random Forest algorithms were used for classification in order to determine which yields more accurate results for a limestone mine. Support Vector Machine analysis using SPOT-6 images yielded the best results. This was due to the high spatial resolution of SPOT-6 compared to Landsat and Support Vector Machine classifier was able to classify images with fewer training points compared to Random Forest. The spatio-temporal land cover change at the mine was then determined between the years 2000, 2015 and 2020. Land cover classification is useful for monitoring land degradation and, in this case, was able to show the extent of rehabilitation success. For the year 2020, a 17% area was rehabilitated; however, the algorithm could not distinguish between unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years. The performed change detection also showed that 29.50% of unmined Calcrete Bontveld matrix had changed to “mature rehabilitation” (rehabilitation sites older than five years). Again, for this percentage in some areas the algorithm could not distinguish between the unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years due to high similarities between the two land cover types. Area changes of the different land cover classes could also be used to demonstrate how rehabilitation areas have matured over time and lead to the conclusion that most of the Calcrete Bontveld which was mined, has over the years been successfully rehabilitated. Vegetation analysis was conducted to further validate the rehabilitation success of Calcrete Bontveld matrix. Multivariant Detrended Correspondent Analysis showed that rehabilitation sites which were younger than five years (2–year-old rehabilitation plots that were sampled) had great dissimilarity to the natural unmined Calcrete Bontveld matrix and that rehabilitation sites older than five years, in this case 16–years older, had high similarity and resemblance to natural unmined Calcrete Bontveld matrix and therefore could be considered as being mature. This was a more definitive assessment as it considers all aspects of the vegetation. Species cover and species richness also showed that Calcrete Bontveld matrix rehabilitation sites which have been rehabilitated for more than 5 years had greater similarity to natural unmined vegetation compared to areas that have been rehabilitated for less than five years. This study, therefore, demonstrates that due to the high similarity between mature rehabilitation sites and unmined Calcrete Bontveld, rehabilitation has been successful. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
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- Date Issued: 2023-12
Sedimentology, petrography and geochemistry of the Kuruman Banded Iron Formation in the Prieska area, Northern Cape Province of South Africa
- Authors: Mbongonya, Mainly Abongile https://orcid.org/0000-0003-2241-8558
- Date: 2021-01
- Subjects: Mines and mineral resources -- South Africa , Sedimentology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21345 , vital:48492
- Description: The sedimentary sequences hosted by the Griqualand West Basin within the Transvaal Supergroup, Northern Cape Province of South Africa, contain several iron and manganese ore deposits. Many studies have been conducted in the Griqualand West basin, particularly within the northern Ghaap plateau compartment where most iron and manganese mines are located, with less attention to the southern Prieska Compartment. Thus, the current study is targeted at the Kuruman Formation in the Prieska area to investigate the geological occurrence, including sedimentology, geochemistry, origin, and post-depositional alteration of the banded iron formation (BIF). Four stratigraphic sections were measured, and the fifth section was only mapped for lithology and sedimentary facies. These sections constitute portions of the stratigraphic sequence of the Transvaal Supergroup that occurs within the study area. The stratigraphic sequence of the area comprises nine successional cycles with five upward fining cycles and four upward-coarsening cycles. These cycles reflect fluctuation of the sea level and shallowing- and filling-up processes of the final basin. Four mineral paragenetic groups constituting primary minerals, diagenetic minerals, low-grade minerals, and weathering mineral assemblages were encountered in the area. The primary mineral assemblage includes magnetite, hematite, siderite, chert, quartz, and smectite. The diagenetic assemblage minerals in the area are martite, quartz (cement), illite, calcite, ankerite, and stilpnomelane. Low-grade assemblage minerals are riebeckite, crocidolite, and minnesotaite, whereas goethite, limonite, calcite (calcrete), quartz (silcrete), and clay minerals are the supergene (weathering) assemblage minerals. These mineral assemblages were confirmed by microscope petrography, XRD, SEM-EDX, and diagenesis studies. Eight sedimentary facies including Horizontal-laminated BIF facies (Hlb), Horizontal thin to medium bedded BIF facies (Hbb), Ripple laminated BIF facies (Rlb), Thin to medium bedded mudstone facies (Mbm), Medium to thick-bedded mudstone facies (Tbm), Medium to thick-bedded fine-sandstone facies (Mts), Laminated dolomite stromatolite facies (Ld), and Dome-shaped stromatolitic BIF facies (Dbif) were identified in the field. Five facies associations including Facies association 1 (Hlb + Hbb), Facies association 2 (Hlb + Hbb + Mbm + Tbm), Facies association 3 (Hlb + Hbb + Mbm + Tbm + Rlb), Facies association 4 (Mbm + Tbm + Mts), and Facies association 5 (Ld + Dbif + Mts) have been recognised. Mineralogy, petrography, and geochemical studies indicate that the studied samples have all been subjected to recent weathering that altered the primary mineralogy and the geochemical composition. Mineral assemblages of the Kuruman BIF within the Prieska area are dominated by quartz, which constitutes about 53 wt.percent, followed by the iron oxides averaging about 44 wt.percent. Other minerals such as carbonates and silicates are only occurring in concentrations of less than 3 wt. percent combined. The Prieska BIF is enriched in cobalt, tungsten, molybdenum, barium (Ba), and nickel compared to the BIF in the northern parts of the Griqualand West basin and other localities. Post-depositional mineral alteration studies show that most of the primary minerals had suffered various degrees of alteration. The bulk of quartz, silicate, and iron oxide minerals in the area have been recrystallized, partially replaced, dissolved, or leached out. Multiple formation processes were involved in the origin of the banded iron formation: (1). Deposition of iron-rich mud material in the deep ocean floor and formation of a mixture of iron-rich mud (felutite) on the seafloor; (2). Differentiation of felutite and formation of disseminated iron-oxide from mud; (3). Cohesion and diagenesis of disseminated iron-oxide and formation of iron-rich (magnetite/hematite) and silica-rich (chert/quartz) patches, lenses (pod), microbands, and laminations; (4). Consolidation and compaction, leading to the formation of the final banded iron formation (BIF). , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-01
The South African mining industry towards 2055: scenarios
- Authors: Du Plessis, Rudolf
- Date: 2015
- Subjects: Mines and mineral resources -- South Africa , Geology, Economic -- South Africa , Forecasting -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/4215 , vital:20568
- Description: The strained commodity price environment has triggered strong measures of cost containment and control by global and South African mining industries with workforce reductions, mine closures and shelved projects. Added to this, the South African mining industry is facing an unparalleled number of challenges, including an uncertain regulatory environment, infrastructure constraints, frequent industrial actions, rising costs and shortages of skills. The dynamism of discontinuous change has increased considerably and the South African mining industry is today facing an uncertain future with a blurred outlook. The results of the detailed analysis of future studies theory and practice in this research study support the argument that there is a strong need to fundamentally change the ways of planning for the future of the South African mining industry. The practice of developing new insight through the application of futures studies is central to this process. Today, collective decisions and strategies are progressively more founded on and informed by futures studies. The research study sought to develop insight regarding the future of the South African mining industry through the construction of four scenarios towards 2055: Divided We Fall, where a confident industry is threatened by social divisions as industry transformation is disregarded; Rock Bottom, where weak global economic conditions coincide with lacklustre industry innovation; Rising from Ashes, with similar economic conditions, but the industry responding positively through accelerated industry innovation; and Renaissance, set against positive global economic conditions with the South African mining industry adopting a collaborative, innovative approach to industry transformation. The research study further strived to uncover the preferred future for the South African mining industry as basis for the South African Mine of the Future Vision towards 2055. Throughout the research study, Inayatullah’s pillars of futures studies were applied as a guideline in mapping the present and future, deepening the future, broadening the future through the development of scenarios, and transforming the future by narrowing it down to the preferred. The study provides valuable insight into the driving forces relevant to the South African mining landscape. In addition, it provides insight on how to anticipate the changes these driving forces may bring about for the industry over the next 40 years from a decision-maker’s point of view. It is up to the mining industry to select the road to follow in terms of progress and sustainable development. Through an innovative approach, the creation of an environment of trust, the sharing of values, purposes and benefits, the South African Mine of the Future Vision is attainable. The South African mining industry must commit itself to working in collaborative partnerships with local communities, government, society and labour; stepping boldly into a world of social, environmental, technological and commercial innovation.
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- Date Issued: 2015
Distribution of iron-titanium oxides in the vanadiferous main magnetite seam of the upper zone : Northern limb, Bushveld complex
- Authors: Gwatinetsa, Demand
- Date: 2014
- Subjects: Igneous rocks -- South Africa -- Bushveld Complex , Sulfide minerals -- South Africa -- Bushveld Complex , Vanadium -- South Africa -- Bushveld Complex , Titanium dioxide -- South Africa -- Bushveld Complex , Ferric oxide -- South Africa -- Bushveld Complex , Geology -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5063 , http://hdl.handle.net/10962/d1013281
- Description: The main magnetite seam of the Upper Zone of the Rustenburg Layered Suite (SACS, 1980) on the Bushveld Complex is known to host the world‘s largest vanadium bearing titaniferous iron ores. The vanadiferous titanomagnetites, contain vanadium in sufficient concentrations (1.2 - 2.2 per cent V₂O₅) to be considered as resources and vanadium has been mined historically by a number of companies among them Anglo-American, Highveld Steel and Vanadium and VanMag Resources as well as currently by Evraz Highveld Steel and Vanadium Limited of South Africa. The titanomagnetites contain iron ore in the form of magnetite and titanium with concentrations averaging 50-75 per cent FeO and 12-21 per cent TiO₂. The titaniferous iron ores have been historically dismissed as a source of iron and titanium, due to the known difficulties of using iron ore with high titania content in blast furnaces. The economic potential for the extractability of the titaniferous magnetites lies in the capacity of the ores to be separated into iron rich and titanium rich concentrates usually through, crushing, grinding and magnetic separation. The separatability of iron oxides and titanium oxides, is dependent on the nature in which the titanium oxide occurs, with granular ilmenite being the most favourable since it can be separated from magnetite via magnetic separation. Titanium that occurs as finely exsolved lamellae or as iron-titanium oxides with low titania content such as ulvospinel render the potential recoverability of titanium poor. The Upper Zone vanadiferous titanomagnetites contain titanium in various forms varying from discrete granular ilmenite to finely exsolved lamellae as well as occurring as part of the minerals ulvospinel (Fe₂TiO₄) and titanomagnetite (a solid solution series between ulvospinel and magnetite) . Discrete ilmenite constitutes between 3-5 per cent by volume of the massive titanomagnetite ores, and between 5-10 per cent by volume of the magnetite-plagioclase cumulates with more than 50 per cent opaque oxide minerals. The purpose of this research was to investigate the mineralogical setting and distribution of the iron and titanium oxides within the magnetitite layers from top to bottom as well as spatially along a strike length of 2 000m to determine the potential for the titanium to be extracted from the titanomagnetite ores. The titanomagnetites of the Upper Zone of the Bushveld Complex with particular reference to the Northern Limb where this research was conducted contains titanium oxides as discrete ilmenite grains but in low concentrations whose potential for separate economic extraction will be challenging. The highest concentration of titanium in the magnetite ores is not contained in the granular ilmenite, but rather in ulvospinel and titanomagnetite as illustrated by the marked higher concentration of TiO₂ in the massive ores which contain less granular ilmenite in comparison to the disseminated ores which contain 3 to 8 percentage points higher granular ilmenite than the massive ores. On the scale of the main magnetite seam, the TiO₂ content increases with increasing stratigraphic height from being completely absent in the footwall anorthosite. The V₂2O₅ content also increases with stratigraphic height except for in one of the 3 boreholes where it drops with increasing height. The decrease or increase patterns are repeated in every seam. The titanomagnetites of the main magnetite seam display a variety of textures from coarse granular magnetite and ilmenite, to trellis ilmenite lamellae, intergranular ilmenite and magnesian spinels and fine exsolution lamellae of ulvospinel and ferro-magnesian spinels parallel to the magnetite cleavage. The bottom contact of the main magnetite seam is very sharp and there is no titanium or vanadium in the footwall barely 10cm below the contact. Chromium is present in the bottom of the 4 layers that constitute the main magnetite seam and it upwards decreases rapidly. In boreholes P21 and P55, there are slight reversals in the TiO₂ and V₂O₅ content towards the top of the magnetite seams.
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- Date Issued: 2014
Exploring the use of mineral corridors and stranded ore deposits in order to alleviate rural poverty and effect environmental and social change through a proposed rural development corridor in South Africa
- Authors: Baartjes, Joan Charlaine
- Date: 2011
- Subjects: Mines and mineral resources -- South Africa , Rural poor -- South Africa , Poverty -- Economic aspects -- South Africa , Rural development projects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11517 , http://hdl.handle.net/10353/389 , Mines and mineral resources -- South Africa , Rural poor -- South Africa , Poverty -- Economic aspects -- South Africa , Rural development projects -- South Africa
- Description: South Africa has less than 1 percent of the global land surface, yet it is ranked highly in terms of remaining mineral resources. Mineral wealth has not translated into a better life for all. Poverty, however, abounds; particularly in the rural areas and this study seeks to identify a solution or partial solution to this situation. The study combines two critical areas, Mineral Based Rural Development, and Mineral Based Enterprise Development and draws from it a model for Mineraldriven Rural Economic Development viable for all parts of South Africa. This study comprised research on a national scale and thus covered a section of each of South Africa‟s nine provinces. It investigated the conditions in rural and urban centres, and geologically, it traversed examples of Archaean, Proterozoic and Phanerozoic formations. The field visits deliberately set out to look at some of the lowest value commodities; typically the only minerals available to the surrounding rural communities. This was done to see if a case could be made for even the lowest value commodities which are often found furthest from the large markets. This study indicates that for a rural area to be able to compete nationally or internationally, it is important to be competitive so that the area can participate in the economy. The creation of regional competitive areas allow for the focusing of strategies and funding for targeted rural projects. Enterprises, typically the product of entrepreneurial activity, are required to increase economic intensity and activity. xxvii The goal of poverty reduction, has been identified by government so that enterprises, as products of economic development, can be focused on the situation. Interviews conducted by the researcher indicated that part of the problem to overcome is the bureaucracy created by government which hinders enterprise development. Recommendations are made that government should exempt rural enterprises from some of the compliance hurdles. This will serve to accelerate rural development. An important aspect of urban enterprises is that they have access to labour without too many problems. Thirteen developed or developing corridors were visited of the five types of development corridors identified. It was found that those in areas of high poverty (for example the corridors of the Eastern Cape) are difficult to develop and make self-sustaining. The corridors linked to any point of Gauteng (Johannesburg or Pretoria) are more robust, although the relatively short length of the corridor is not an indicator of effectiveness. The key recommendations made include the completion of a national rural mineral-asset audit; the use of the information to demarcate rural-regions that can be developed as nationally and internationally competitive regions; the establishment of a rural Resource and Training Academy(ies) so that skills are developed close to areas where they will be deployed; provision of an easier way to launch mineral-based rural enterprises and incentivise these for accelerated development; and the development of an indigenous body of knowledge to mine small scale deposits
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- Date Issued: 2011
Interpretation of regional geochemical data as an aid to exploration target generation in the North West Province South Africa
- Authors: Mapukule, Livhuwani Ernest
- Date: 2009
- Subjects: Ore deposits -- South Africa , Prospecting -- South Africa , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11519 , http://hdl.handle.net/10353/268 , Ore deposits -- South Africa , Prospecting -- South Africa , Mines and mineral resources -- South Africa
- Description: This study involves the application, interpretation and utilization of regional geochemical data for target generation in the North West Province, South Africa. A regional soil geochemical survey programme has been carried out by the Council of Geoscience South Africa since 1973. A number of 1:250 000 sheet areas have been completed, but there are no interpretative maps which could aid in mineral exploration and other purposes. In order to utilize the valuable and expensive data, the project was motivated through data acquisition and interpretation to generate exploration targets. The study area is confined to Mafikeng, Vryburg, Kuruman and Christiana in the Northwest Province, where potential exploration and mining opportunities exist in areas of great geological interest. These include geological events such as the Bushveld Complex, the Kalahari manganese field and the Kraaipan greenstone belts. The aim of this project was to utilize geochemical data together with geophysical and geological information to verify and identification of possible obscured ore bodies or zones of mineralization, and to generate targets. Another objective was the author to be trained in the techniques of geochemical data processing, interpretation and integration of techniques such as geophysics, in the understanding of the geology and economic geology of the areas. Approximately 5 kg of surface soil was collected per 1 km2 by CGS from foot traversing. Pellets of the samples were prepared and analyzed for TiO2, MnO and Fe2O3, Sc, V, Cr, Ni, Co, Cu, Zn, As, Y, Ba, Nb, Rb, Th, W, Zr, Pb, Sr and U using the simultaneous wavelengthdispersive X-ray fluorescence spectrometer technique at the Council for Geoscience, South Africa. For each element the mean +2 standard deviations were used as a threshold value to separate the negative from the positive anomalies. The integration of geological, geophysical and geochemical information was used to analyze and understand the areas of interest. A number of computer programmes were extensively used for data processing, manipulation, and presentation. These include Golden Software Surfer 8®, Arc-View 3.2a®, TNT-Mips®, JMP 8 ®, and Microsoft Excel®. Through geochemical data processing and interpretation, together with the low resolution aeromagnetic data, gravity data and geological data, seven (7) exploration target areas have been generated: These have been numbered A to G. It is concluded that there is good potential for Cr, PGMs, vanadium, nickel, iron, copper, manganese, uranium and niobium in the targets generated. The results provide some indication and guide for exploration in the target areas. In Target A, Cu, Cr, Fe, Ni and V anomalies from the lower chromitite zone of far western zone of the Bushveld Complex, which has be overlain buy the thick surface sand of the Gordonia Formation. Target B occurs over the diabase, norite, andesitic lava and andalusite muscovite hornfels of the Magaliesberg Formation. This target has the potential for Cu, Fe and Ni mineralization. The felsic rocks of the Kanye Formation and the Gaborone Granite in target C have shown some positive anomalies of niobium, uranium, yttrium and rubidium which give the area potential for Nb, REE and U exploration. Target D is located on the Allanridge Formation, and has significant potential for Ni-Cu mineralization, and is associated with the komatiitic lava at the base of the Allanridge Formation in the Christiana Area. The light green tholeiitic, calc-alkali basalt and andesitic rocks of the Rietgat Formation are characterized by a north-south trending yttrium anomaly with supporting Ba and Y anomalies (Target E). This makes the area a potential target for rare earth elements. Calcrete on the west of the Kuruman has a low b potential target for vanadium. It is believed that the area might be potential for potassium-uranium vanadate minerals, carnotite which is mostly found in calcrete deposits. This study has proved to be a useful and approach in utilizing the valuable geochemical data for exploration and future mining, generated by Council for Geoscience Science. It is recommended that further detailed soil, rock and geochemical surveys and ultimately diamond drilling be carried out in the exploration target areas generated by this study.
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- Date Issued: 2009