Browsing by Subject "Mines"

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    The mobility of metals in acid mine drainage from abandoned coal mines
    (1997) Halbich, Torsten Franz Joachim; Willis, James; Fey, Martin
    The acid mine-drainage contaminated Blesbokspruit catchment west of Witbank in Mpumalanga province, South Africa has been investigated, by analysis of its waters, sediments, precipitates and algae, to obtain an understanding of the processes which control the mobility of metals in these waters. The Blesbokspruit drains acid mine drainage originating in surrounding, abandoned coal mine workings. The upper Blesbokspruit (approximately 8 km) including the stream origin, AMD outwelling points, downstream AMD retention ponds and a small wetland were selected for this study. Water, sediment, precipitate, and algae samples were collected from the Blesbokspruit. The water quality of the catchment was determined and compared to mineralogical and major and trace element analyses of sediments, precipitates, and algae. The pH and total dissolved solids of the catchment waters ranged from pH 2.6 to 7.4 and 147 to 3071 mg/ t, respectively. Associated precipitates consisted primarily of jarosite with minor amounts of goethite, lepidocrocite, ferrihydrite and gypsum, with ferrihydrite being the major component of only one precipitate sample. The presence of algae at one of the sampling sites appeared to act as a template for the precipitation of ferrihydrite in a low pH and high acidity environment. Speciation modelling of the Blesbokspruit waters indicated waters saturated with respect to jarosite, goethite, and quartz, in equilibrium with jurbanite, alunite and gypsum, and undersaturated with respect to ferrihydrite and kaolinite. The mobility of iron in the sulphate rich Blesbokspruit waters appeared to be controlled by pyrite oxidation and the solubility of the basic iron sulphate mineral jarosite. In contrast Al mobility appeared to be influenced by different mechanisms. Acidity of the Blesbokspruit waters correlated well (r = 0.942) with Al concentrations in the waters. Dissolved Al correlated with dissolved silica (r = 0.757) in the Blesbokspruit waters and exchangeable acidity correlated with exchangeable Al (r = 0.761) in the associated sediments. The data suggested that Al behaved conservatively in the pH < 4 Blesbokspruit waters and that Al solubility is controlled by dissolution of clay minerals and adsorption to organic matter in the sediments. Although precipitates contain trace elements, precipitation does not have a major effect on the concentration of trace elements in the associated low pH waters. Trace elements were, however, accumulated in the sediments of the Blesbokspruit streambed and the wetland. The wetland acts as a sink for dissolved Na, Ca, Mg, Fe, Mn, Zn, Ni, Pb U, Cu and Co. The mobility of these elements appeared to be controlled by the dissolution of minerals containing these elements and adsorption to organic matter in the wetland and streambed sediments. Not all metals were, however, completely immobilised, and toxic concentrations of Pb (1.3 mg/ t) and elevated concentrations of Al (40 mg/ t ), Fe (1.6 mg/t) and Mn (6.5 mg/t) remained in the water downstream of the wetland.
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    Open Access
    Will implementing pillar two measures hinder the rehabilitation of South African Mines?
    (2025) Gouws, Janke; Futter, Alison; Ger, Barry
    South Africa imposes rehabilitation obligations on mining right holders to address the damage caused by mining operations. The National Environmental Management Act, 17 of 1998 (“NEMA”) requires each mining right holder to make financial provision to cover their rehabilitation costs in the future. A rehabilitation trust is one of the allowable financial vehicles listed under NEMA for purposes of financial provisioning. The mining right holder funds the rehabilitation trust through contributions that the trust invests in. Under section 37A, read with section 10(1)(cP) of the South African Income Tax Act, 1962 (“ITA”), the mining right holder can deduct these contributions for income tax purposes. The rehabilitation trust is also granted a tax exemption for all receipts accruing to it. In December 2024, the Global Minimum Tax Act, 46 of 2024 (“GMT Act”) was enacted in South Africa to implement Pillar Two measures in South Africa. Pillar Two imposes a global minimum tax of 15 per cent on multinational entities with revenue of EUR750 million or more to prevent large multinationals from shifting their profits to low-taxed jurisdictions. The Global Anti-Base Erosion (“GloBE”) rules and commentary guide the calculations to determine the effective tax rate and resulting top-up tax payable in terms thereof. This dissertation evaluates whether imposing Pillar Two measures in South Africa would render rehabilitation trusts ineffective and inefficient due to the ITA tax incentive that may result in a lower GloBE effective tax rate, ultimately forcing mining groups to pay a top-up tax for rehabilitation compliance. The main finding of this dissertation is that rehabilitation trusts, as members of a multinational group (“MNE”) with revenue of EUR 750 million or more, will have their financials included in the mining group's effective tax rate calculation regarding Pillar Two. The tax incentive provided in the ITA could affect the calculation by lowering the mining group's effective tax rate to below 15 per cent, resulting in the payment of top-up taxes. The concern is that mining groups will be deterred from using rehabilitation trusts, which would abandon them and complicate their regulation, as the other vehicles are not as regulated. The solution presented in this dissertation is to include rehabilitation trusts as an excluded entity for purposes of Pillar Two, as they operate similarly to governmental entities.