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The selection of raw materials to produce quality artisanal bricks is imperative for sustainable building in rural regions. Artisanal brick-making process often employs traditional kiln to fire brick because it is an affordable, and applicable technology in the rural region. However, there are noticeable cracks, increasing among buildings constructed with artisanal bricks from the rural region in South Africa. In response, this study aims to evaluate the soil and artisanal brick specimens to understand the suitability of the raw materials and quality of products in the study area. A total of twenty soil samples and twenty-seven artisanal burnt bricks were collected from three different artisanal brick-making sites designated as Site A, B, and C. In all samples, the geotechnical tests revealed a sandy loam soil type with a predominance of chlorite clay minerals and non-clay minerals. Furthermore, the sand-size particles depict a relatively higher proportion compared to clay-size particles. Besides, Atterberg's limit test plotted above the A-line of the plasticity chart indicates an inorganic clay of low plasticity with a low to medium compressibility property. Based on the empirical workability and mechanical tests, most of the studied soils are suitable for optimum and acceptable extrusion bricks and suitable for an on-site single-story construction based on SANS 227:2007 standards. [ABSTRACT FROM AUTHOR]

The paleo-environmental setting of an organic-rich shale remains an essential controlling factor for shale reservoir distribution. The scarcity of generalised data on paleo-environment settings has been spurred using a simple investigative approach to decipher the provenance of organic-rich shale in various regions. This study investigates the organic-rich Madzaringwe shale of the Tuli Basin to reconstruct the provenance of the organic material for shale gas generation potential. Representative shale core samples were analysed for the stable isotopic fractions, functional groups, and major and trace compositions. The carbon isotopic composition, δ13C value, ranging from −21.01 to −24.0‰, averaging at −22.4‰. Inference from the stable isotopic compositions and functional group analysis indicate Type-III kerogen prone to gas generation in the studied Madzaringwe shale. The micro-Fourier transformed infrared (micro-FTIR) analysis reveals infrared absorption peaks between 2800 and 3300 cm−1 wavelengths corresponding to gaseous hydrocarbon. The x-ray fluorescence (XRF) result reveals major elements comprising Al2O3 (29.25–29.11%), CaO (0.29–0.28%), Fe2O3 (1.16–1.09%), K2O (0.97–0.98%), MgO (0.13–0.12%), Na2O (0.12–0.09%), P2O5 (0.22–0.21%), SiO2 (52.50–52.30%), and TiO2 (1.20–1.18%). The major element ratio of Al2O3/TiO2 values ≥ 25 indicates felsic and intermediate provenance from a terrigenous paleo-environment. In addition, laser ablation inductively coupled plasma mass spectrometry (LAICP-MS) reveals the trace elements in which elemental proxy of V/(V + Ni) with a value greater than 0.5 represent reducing environments. Furthermore, the geochemical proxies and isotopic compositions have revealed an anoxic paleo-environment for the non-marine-derived organic matter in the studied carbonaceous shale. [ABSTRACT FROM AUTHOR]

South Africa has numerous voluminous tailings dumps that will certainly require rehabilitation. The aim of this work was to develop a methodological approach for prioritization of rehabilitation of abandoned tailings dumps. To test the applicability of the developed method in different conditions, it was applied on six abandoned tailings dumps denoted as FGMT, LMMT, KLMT, MCMT, NMMT-A and NMMT-B found in the Giyani and Musina areas of South Africa. The method involved integration of quantitative and qualitative techniques in making sound decision on the order of rehabilitation of the tailings dumps in the area. It considered the contamination potential of the dumps, the ease of their dispersion to the surroundings and the impact they have on the appearance of the natural landscape. The use of the tool on abandoned tailings dumps in the study area revealed that gold tailings dumps are to be rehabilitated first than magnesite and copper tailings dumps. The study indicated that the dump with the highest pollution potential was the FGMT and that physical stabilization was considered the most suitable rehabilitation option for abating its high toxic metals from polluting the environment. The combination of methods that improve physical stability of the dump while enhancing nutrient availability for plant growth were found appropriate for rehabilitation of MCMT. The rehabilitation of the rest of the dumps required the use of chemical methods that promote growth of vegetation. According to the study, the developed tool can be used to guide rehabilitation of abandoned tailings dumps in different settings. [ABSTRACT FROM AUTHOR]

Mining has been the backbone of the South African economy for many years. For over a century it has contributed considerably in the welfare of the people of South Africa. As a result of South Africa’s long history of mining, the country has many abandoned mines that are currently the major source of various environmental and social problems. This review looks at the general problems of abandoned mines in South Africa and the efforts made towards rehabilitation of abandoned mine sites. The issues discussed include the controversy around the definition of abandoned mines, their associated problems, regulatory issues, prioritisation of rehabilitation and the rehabilitation cost estimation concerns. It was concluded that in order to fast track the work of cleaning up the negative legacy of abandoned mines in South Africa, appropriate definition for these mines should be identified and used in guiding the work of developing the country’s abandoned mines inventory while assisting in the prioritisation of rehabilitation efforts. The abandoned mines rating system and the cost estimation model that can account for the site-specific issues in the rehabilitation of abandoned mines were recommended. [ABSTRACT FROM AUTHOR]

Highlights: [•] The mine site was assessed based on it associated physical and environmental hazards. [•] The identified hazards were quantified to establish their seriousness. [•] Hazard maps assisted in pin-pointing with accuracy hazardous sections of the mine. [•] Priority of rehabilitation has to be given to extremely and moderately hazardous features of the mine. [•] The hazard maps provided a more robust scientific basis for making decisions and action to be taken. [ABSTRACT FROM AUTHOR]

Carbonaceous shale is more topical than ever before due to the associated unconventional resources of methane. The use of FTIR, SEM-EDX, and mineralogical analyses has demonstrated a promising approach to assess methanogenesis potentials in a more rapid and reliable manner for preliminary prospecting. Representative core samples from the borehole that penetrated the carbonaceous Mikambeni shale Formations were investigated for methanogenesis potentials. The absorption band stretches from 1650 cm−1 to 1220 cm−1 in wavenumber, corresponding to C-O stretching and OH deformation of acetic and phenolic groups in all studied samples, thereby suggesting biogenic methanogenesis. The CO2 was produced by decarboxylation of organic matter around 2000 cm−1 and 2300 cm−1 and served as a source of the carboxylic acid that dissolved the feldspar. This dissolution process tended to release K+ ions, which facilitated the illitization of the smectite minerals. The SEM-EDX spectroscopy depicted a polyframboidal pyrite structure, which indicated a sulfate reduction of pyrite minerals resulting from microbial activities in an anoxic milieu and causes an increase in alkalinity medium that favors precipitation of dolomite in the presence of Ca and Mg as burial depth increases. The contact diagenesis from the proximity of Sagole geothermal spring via Tshipise fault is suggested to have enhanced the transformation of smectite to chlorite via a mixed layer corrensite in a solid-state gradual replacement reaction pathway. The presence of diagenetic chlorite mineral is characteristic of low-grade metamorphism or high diagenetic zone at a temperature around 200 °C to 230 °C and corresponds to thermal breakdown of kerogen to methane at strong absorption band around 2850 cm−1 and 3000 cm−1, indicating thermal methanogenesis. [ABSTRACT FROM AUTHOR]

In order to improve the safety status and the quality of the landscape affected by surface mining, it is important that practical strategies for dealing with the excavations are identified. The aim of the work presented in this paper was to carry out an appraisal of the strategies for addressing the physical hazards of abandoned surface mine excavations in two mines in the Limpopo Province, South Africa. The method used involved carrying out field characterization of the current state and uses of the excavations, as well as their physical hazards of the surface mine excavations in the study area. The characterization took into consideration. Possible strategies for addressing the physical hazards of the excavations are identified, and their strengths, weaknesses, opportunities, and threats (SWOT) analyzed. The Quantitative Strategic Planning Matrix (QSPM) was performed on each of the identified strategies with the purpose of determining their attractiveness based on their SWOT factors. The results of the study showed that using a combination of strategies to deal with the physical hazards of the abandoned mine excavations was the most attractive approach followed by the grading of the slopes of the excavations to improve their stability, while promoting their safe alternative uses. The no-action option and backfilling of the excavations were the least attractive strategies for dealing with the abandoned surface mine excavations. The study demonstrated how semi-quantitative tools, such as the SWOT analysis and QSPM could assist in finding practical approaches for dealing with the problems of abandoned mine sites or features. [ABSTRACT FROM AUTHOR]

The work of quantifying the problems of abandoned mines is the first step towards the rehabilitation of these mines. As the result, in all countries that have many abandoned mines, researchers and different organizations have been making efforts to develop decision-making tools, methods, and techniques for rehabilitation of abandoned mines. This paper describes the work conducted to incorporate the method for ranking the problems of abandoned mine entries into a rule-based expert system. This is done using the web-based expert system platform provided by expert system (ES)-Builder Shell. The ES is tested by applying it to the case study of the problems of abandoned mine entries in the areas of Giyani and Musina, Limpopo Province of South Africa. This paper gives details of the procedure followed in creating the production rules of the ES for ranking problems of abandoned mine entries (ES-RAME), its attributes, and the results of its application to the selected case study. The use of the ES-RAME is found to be important for setting the objectives and priorities of the rehabilitation of abandoned mine entries. In addition, the incorporation of the ranking method into the expert system ensured that the procedure of the tanking method is clearly communicated and preserved as the rules of the ES. The expert system also has the advantages of being consistent in its guidance, and it gives the user an opportunity to go through the ranking process of the system using any possible fictitious information; this gives the user a feel for the ranking process and the data required when using the ES-RAME. [ABSTRACT FROM AUTHOR]

Treatment of old mine shafts can be a tedious and costly process if not carefully planned and managed. This paper presents the work conducted with the aim of evaluating the risk of abandoned mine shafts in the Giyani and Musina areas to guide the work of their treatment. The method that allowed the ranking of physical and environmental hazards of the shafts together with their corresponding socio-economic concerns was developed and applied in this work. The results showed that the risks of falling into the shafts and the problems of ground movement were the major physical hazards and environmental stresses of the shafts. Based on the results of the study, it was concluded that in addressing the problems of abandoned mine shafts, priority should be given to mitigation strategies for the major hazards followed by those that prevent release of toxic gases and discharge of contaminated mine water by the shafts. The method used in this work is recommended for preliminary evaluation of the hazards of abandoned mines in developing countries which have many abandoned mine sites and limited resources to conduct their rehabilitation. [ABSTRACT FROM AUTHOR]