Engineering and the Built Environment Departments

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Browsing Engineering and the Built Environment Departments by Author "Amponsah-Dacosta, F."

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    Analysis of work accidents data: A case study of the South African mining industry
    (2023-10-05) Masindi, Masala Theron; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel
    For any industry to be successful, its production needs must be met while the highest safety standards are maintained. Mining accidents and their subsequent fatalities have enormous social and economic consequences. The current study was undertaken to better understand the fundamental causes of mine accidents so that major remedial actions can be developed and implemented to improve safety in the mining industry. The purpose of this study was to analyse work accident data of the South African industry that was compiled for the period 2008–2017. Secondary data on accidents was requested from the Department of Mineral and Energy Resources (DMRE). Accident data obtained from DMR was summarized, characterized, and described in a meaningful manner to determine the variables or factors which contribute to accidents in the mining industry. Variables that contribute to accidents in the mining includes fall of ground/rock fall, machinery, transportation and mining, general, conveyance accidents, electricity, fires, explosive, heat sickness and miscellaneous. Descriptive statistics, figures, and tables were used to describe and understand the accidents within the mining industry. A chi-square test was used to quantify the extent to which accident outcomes and commodities are independent of each other by year and injury type. This was done to examine the association between the dependent accident outcome and the independent variables such as year, commodity type, and casualty type. The study was significant in that its findings will contribute to building a culture of safety within the mining environment1, which was not only to reduce the risks of miners being exposed to potential workplace accidents but also had an impact on their attitude and perceptions towards workplace safety and their perception of zero as this is one of the priorities which the mining industries need to achieve. The study produced results that summarize the influence of year, commodity type, and casualty type on accident outcome. In particular, the analysis of accidents helped in establishing the relationship between the dependent accident outcome variable and several independent variables, such as year, commodity type, and casualty type, there was an increased number of accidents with respect to different commodities with different in years. The findings of this study vi will be used in planning, designing, and implementing health and safety programmes that will contribute to decrease in the number of accidents for mining different commodities in South Africa. Keywords: mining accidents, accidents data
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    Assessment of impact of corporate social responsiblity on sustainable development of Shamva Mining Community in Zimbabwe
    (2016-05) Laisani, John; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel
    See the attached abstract below
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    Development of a computer-based advisory system for a selection of appropriate rehabilitation strategies for designated abandoned mine sites in Limpopo Province of South Africa
    (2020-09) Mhlongo, Sphiwe Emmanuel; Amponsah-Dacosta, F.; Kadyamatimba, A.
    South Africa has many abandoned mines which seriously affect the environment and the livelihood of the host communities. The lack of in-depth knowledge of the problems of these mines, limited resources for their rehabilitation, lack of clearly assigned responsibilities for rehabilitation, and the absence of criteria and standards of rehabilitation have led to the use of inappropriate strategies to rehabilitate abandoned mines. The main objective of this research was to develop a computer-based advisory system for selecting suitable rehabilitation strategies for designated abandoned mines. The research methodology involved characterization of the selected abandoned mine sites, devising methods for prioritization of mine features for rehabilitation, development of three expert systems that provide guidance on different aspects of rehabilitation of abandoned mines, and development of a framework for estimation of costs of rehabilitation of abandoned mines. The first part of this research involved development of methods for characterization and prioritization of abandoned mine entries and tailings dumps as well as selection of strategies for rehabilitation. These methods were written in an expert system shell to create expert systems (ESs) for ranking of abandoned mine entries and tailings dumps for rehabilitation. The study also used semi-quantitative methods such as SWOT (Strength, Weaknesses, Opportunities, and Threats) analysis as well as the Quantitative Strategic Planning Matrix (QSPM) technique and Multi-Criteria Decision-Making (MCDM) methods such as Analytic Hierarchy Process (AHP) and Pugh Matrix to evaluate different strategies for their suitability to deal with the issues of abandoned mines. Based on the current situation of abandoned mines in the study area, a framework for estimation of costs of rehabilitation of abandoned mines was developed by taking into consideration direct cost and other key cost estimates which were previously disregarded. The method for ranking the problems of abandoned mine entries was developed based on information collected during preliminary assessment of the mine entries while that of ranking the abandoned mine tailings was based on the potential of the dumps to pollute the surrounding environment and the landscape and the visual impact they present. These approaches are relatively less data demanding than the current tools used for rehabilitation of abandoned mines. Thus, these methods have the advantage of being suitable for use in developing countries where there are many abandoned mines but limited resources for their rehabilitation. The application of these methods at selected abandoned mines in Giyani and Musina areas showed that mine shafts had moderate physical and environmental hazards. The risks of people and animals falling into the shafts and the problems of ground movement around the shafts were identified as the major concerns. Strategies that provide long-term or permanent closure of the abandoned mine shafts were identified as the most suitable options. These include backfilling of the shafts, use of concrete plugs to seal the shafts, use of blast closure and injection/inclusion strategies. The results of the study showed that tailings dumps in the study area have the potential to pollute the environment with toxic materials such as Cd, As, Ni, Pb, Zn and Cu. Based on the determined mean pollution index, dispersion index and the index of landscape and visual impact of the tailing dumps in the study area it was found that rehabilitation of these mines is likely to require moderate efforts. The priority of rehabilitation of these mines should be in the following decreasing order: Fumani Gold Mine Tailings, Klein Letaba Gold Mine Tailings, Nyala Magnesite Mine Tailings (A), Nyala Magnesite Mine Tailings (B), Louis Moore Gold Mine Tailings, and Mesina Copper Mine Tailings. The description of the hazards and evaluation of the strategies for dealing with the problems of abandoned surface mine excavations and other structures demonstrated that repurposing of these features should be considered before application of traditional rehabilitation methods. The rule-based expert systems that provide guidance on the rehabilitation of abandoned mines were developed. The fact that these expert systems are web-based make them easily accessible for use in different parts of the world. Based on this, the characterization, prioritization and selection of strategies for rehabilitation of abandoned mines can be conducted in different regions following the same procedures and methods as described in this thesis. The framework which was developed for estimation of the costs of abandoned mines rehabilitation emphasized the need for inclusion of critical indirect costs in the estimation process to reduce elements in the risks of under estimation.
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    Development of a modeling framework for design of low-cost and appropriate rehabilitation strategies for Nyala abandoned mine
    (2013-10-01) Mhlongo, Sphiwe Emmauel; Amponsah-Dacosta, F.; Mphephu, N. F.
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    Development of an integrated approach for prioritization of mine features of selected abandoned mines for rehabilitation in the Giyani Greenstone Belt
    (2022-11-10) Mbebe, Noxolo Kindness; Amponsah-Dacosta, F.; Muzerengi, C.; Mhlongo, S. E.
    Mining has a potential to provide sustainable economic and social benefits to communities and the regions in which mining companies operate. However, many mines have been abandoned and/or improperly closed which has lasting impacts on public health and safety and the environment. South Africa has more than 5906 abandoned mine sites that were left unrehabilitated. Although the problems of abandoned mine sites are well documented, little has been done to rehabilitate the mine sites. This may be attributed to costs associated with rehabilitation and standard criteria to aid the rehabilitation process. Most of the existing rehabilitation approaches do not adequately address the physical, chemical, and environmental hazards associated with abandoned mines. The purpose of this study was therefore to develop an integrated approach that will not only assess impacts of abandoned mines but also prioritize abandoned mine features for rehabilitation based on their associated physical, chemical, and environmental hazards. In developing an integrated rehabilitation approach, two abandoned mines were selected, and all the mine features were studied by identifying, locating, mapping, and documenting them. The hazards linked to the mine features were classified as physical, chemical, and environmental hazards. A scoring and ranking approach was developed to quantify physical, chemical and environmental hazards of each abandoned mine feature. Sources of contamination, pathways and impacts of abandoned mine features were scored and ranked for physical and environmental hazards. Abandoned mine features with greater physical, environmental, and chemical scores were then prioritized for rehabilitation. In quantifying and ranking chemical hazards posed by the abandoned mine features, parameters such as Pollution Load Index, Geo-accumulation index, Contamination Factor and Potential Ecological Risk Index were used. The physical, chemical, and environmental scores were combined to determine the total hazard score for the abandoned mine sites. The hazard scores were then integrated to determine the overall hazard score per mine site. The results of the study showed that physical, environmental, and chemical hazard scores for Klein Letaba were 2.5, 1.5 and 2.2 times respectively higher than those of Louise Moore. The total hazard score for Louis Moore and Klein Letaba was 47.44 and 89.46 respectively. The results also revealed that the overall hazard score at Klein Letaba was higher than that of Louis Moore and this suggests that the associated risks at Klein Letaba are higher. Based on these findings, abandoned mine features at Klein Letaba must be prioritized for rehabilitation over features at Louis Moore. The new and integrated approach provides a framework to identify, characterize, quantify, and prioritize high risk abandoned mine features for rehabilitation. The drawbacks of the existing rehabilitation prioritization methods have been identified and examined and the new integrated approach of prioritization of mine site rehabilitation addresses these concerns. As such, this new integrated approach provides a holistic, transparent, unique, cost-saving and practicable technique of prioritizing and addressing undesirable impacts of abandoned mine sites. It is recommended that best practicable strategies be developed to mitigate the adverse impacts of the abandoned features and their detailed cost analysis conducted. Additionally, the involvement of local authorities and all other stakeholders will be crucial in increasing awareness of the seriousness of the environmental and safety concerns of the abandoned mine features at the mine sites.
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    Development of an integrated approach of dealing with challenges of selected small-scale rock aggregate mines in Vhembe District, Limpopo Province, South Africa
    (2016-05) Rembuluwani, Ndivhudzanyi; Amponsah-Dacosta, F.; Mhlongo, S. E.
    See the attached abstract below
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    Development of framework for streamlining prospecting and mining right application process in South Africa
    (2023-10-05) Madilonga, Rudzani Charlotte; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel
    Mining has been one of the most significant contributors to South Africa's social and economic progress. South Africa is endowered with a diverse of minerals and mining activities are driven by large corporations and small-scale miners. However, the legislative uncertainty undermines the role of the small miners in society and the economy. This is despite interventions by the government, through legislation, which affords everyone an opportunity to participate in mining, through acquiring prospecting and mining right applications. The promulgation of the Mineral and Petroleum Resources Development Act (MPRDA), 28 of 2002, was meant to address the imbalances of the past which amongst others include inequitable access to “the nation's mineral and petroleum resources”. Some of the requirements needed for exploration and mining rights applications to be granted have been seen as stumbling blocks for Historically Disadvantaged South Africans (HDSA’s) and emerging junior miners, to fully participate in the sector. For example, finances and technical availability is one of the main reasons why HDSA’s haven’t participated fully in the mining activities of the country. This study proposes a framework, which aims to assist HDSAs and emerging miners to participate in the mining industry through acquisition prospecting and mining rights. The research data was collected in two phases. Phase one was the quantitative phase. In this phase, questionnaires were circulated to more than 50 potential respondents involved in the mining and related sectors. The quantitative data was analyzed statistically for interpretation. The second phase of data collection was done through qualitative method, where specific questions were sent to 10 experts in the sector. The results were also analyzed through the identification of common themes and interpreted to contribute to the design of the framework. The results of this study show that although the MPDRA provides emerging junior miners with the prospect to enter the mining industry, there are still barriers or hindrances blocking them from entering the mining industry. Challenges ranged from the initial compilation of documents, processing of the applications and requirements which need to be met, to departmental challenges. The study reveals that historically disadvantaged South African and emerging miners, do not have the necessary skills to compile applications and attach relevant documents to meet certain regulatory requirements. In addition, the study shows that the Department of Mineral Resources and Energy (DMRE) expects historically disadvantaged individuals and emerging miners to provide proof that they have the financial and technical ability to carry out the proposed prospecting and mining right works programmes. Financial and technical requirements have been the common areas that results in prospecting and mining rights applications being declined. Moreover, the internal process at the DMRE seemed to favor large-scale mining companies, who have financial resources and technical expertise to carry out prospecting or mining rights. The framework for streamlining prospecting and mining rights applications will create an environment that enables indigenous people and emerging junior miners to obtain prospecting and mining rights and will provide economic growth for smaller communities. It will also afford the DMRE to have better control, by providing a section, which will be dedicated to assisting historically disadvantaged people and emerging junior miners by providing guidance in terms of the application process and also recommending for funding.
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    Development of product quality management guidelines for informal small-scale brick manufacturing enterprises in Dididi, Limpopo Province, South Africa
    (2018-05-18) Matsiketa, Khensani Eullen; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel
    Although clay brick manufacturing has been going on for many years in South Africa, informal small-scale clay brick manufacturing enterprises are not officially regulated. Consequently, informal brick makers in the study area do not adhere to the demanding requirements of the South African National Standards for burnt clay masonry. Therefore, their clay bricks lack uniformity in terms of quality. Preliminary work revealed that over time, buildings constructed with these bricks develop cracks, thereby compromising safety. The importance of product quality management is not well understood in the informal brick manufacturing enterprises. As a result, they do not have any product quality management guidelines. The main purpose of this research was to develop the product quality management guidelines for ensuring quality in small-scale brick making enterprises in Dididi area. The specific objectives were to characterize the raw materials for clay brick manufacturing, identify and assess the technical problems of clay brick production, analyse the process of clay brick production and determine areas where product quality improvement is warranted. The research involved fieldwork which included soil sampling, analysis of clay brick production through the use of questionnaires and onsite observation of the production process, collection of samples of burnt bricks which were examined for compressive strength, water absorption as well as dimension measurements. These were then compared with the prescribed quality standards. Laboratory analyses of samples of raw materials were conducted and these included sieve analysis which was conducted in order to establish the particle size distribution of the raw materials; Atterberg limit tests were conducted in order to establish the physical characteristics of the soil. Chemical and mineralogical analyses were carried out to determine the chemical and mineralogical composition of the soil using XRF and XRD respectively. The textural characterisation of the material revealed abundance of sand sized particles and significantly low amounts of clay and silt. The plasticity of the soil used for bricks manufacturing in the study area was found to be ranging from slight to medium plasticity. Chemical analysis showed elevated silica contents with minor amounts of alumina and iron oxide. XRD analysis revealed the dominance of non-clay minerals with the highest concentration of quartz. The average compressive strengths of the tested brick samples for site A was 3.8, and 2.9 and 3.8 MPa for sites B and C respectively. The water absorption of the bricks was 13.5, 15.0 and 16.1% for samples from Site A, B and C respectively. The bricks dimensions met the recommended standards although their sizes were not uniform. v The survey conducted on brick manufacturing process revealed that the technical inefficiencies were mostly influenced by human and mechanical factors as well as the material inappropriateness. The production process was found to be too manual and labour intensive. Selection of the raw materials for brick manufacturing was based on indigenous knowledge and experience and most of the brick manufacturers lacked the prerequisite experience for making quality bricks. On the basis of the results of this research, it can be concluded that the materials used for manufacturing of clay bricks in Dididi are not well suited for making good quality bricks due to the reduced plasticity of the soil and the high concentration of quartz. These render the bricks brittle. It was also concluded that the production process also contributes to the poor quality of the bricks as the nature of the process was too manual. Selection of materials based merely on knowledge and experience and no scientific tests resulted in selection of inadequate materials which in turn affect the quality of the final bricks. It is therefore recommended that plastic clays be added to the raw clay materials to enhance its moulding property. In addition, materials such as internal fuels and anti-shrinkage materials should be incorporated into the process cycle to prevent cracking during drying and firing. Based on the findings of the analysis of the production process, it is recommended that mechanized techniques be employed in the operation and awareness training conducted to improve the understanding and skills of the brick manufacturers and to ensure production of good quality bricks.
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    Evaluation of major clay deposits for potential industrial utilization in Vhembe District Municipality, Limpopo Province of South Africa
    (2018-05-18) Akintola, George Oluwole; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel
    Vhembe District has several clay deposits which are traditionally use for clay products such as burnt bricks without taking into account the chemical and mineralogical characteristics of clay being used. The ever-increasing market demand for these clay products cannot be met with the traditional method of clay utilization due to the paucity of scientific information on properties of the clay in the area. Consequently, there is a need to gain better understanding of the characteristics of the clay in Vhembe District and to establish the suitability of the variety of clay for different purposes. The current study was undertaken to better understand the compositional relationship between the clay deposits and surrounding rocks present in the study area. It further aimed at characterizing the clay deposits on the basis of chemical, mineralogy, physical, mechanical, thermal and micro structural properties with a view of evaluating the clays for possible industrial use. A total of thirty-nine clay and rock samples were collected from thirteen different locations across the Vhembe District. Thirteen representative samples from each location were obtained after thorough mixing until homogenization was attained and then quartered for subsequent analyses. The mineralogical and chemical characteristics of the clay and rock samples were determined using XRD and XRF respectively. Thin-sections of the rock samples were prepared and examined under petrographic microscope to better understand the mineral assemblages present in the rocks. The thermal and micro structural properties of the clays were determined using DTA-TGA and SEM analyses and the physical properties which include colour, cation exchange capacity (CEC) and soil pH were assessed. The particle distribution and Atterberg limits tests of the clay samples were also conducted in order to establish their mechanical properties. The petrographic results showed that the clay deposits exhibited an intense weathering and sedimentation processes which incorporated detrital minerals from the surrounding rock units. The rock units which include basalt, granodiorite, gneiss and quartzofeldspathic gneiss were found to be differentiated from subalkaline and/or tholeiitic magmatic composition. Although the value of SiO2 content in rock samples was higher when compared with clay samples, it indicated an ongoing desilicication and allitization processes. The high values of chemical index of alteration (CIA), low values of K/Cs (<6200), Ce* normalized value and higher values of LILE enrichment in the clay deposits indicated oxidizing environments during period of deposition. v The mineralogical composition of the studied clayey deposits showed that smectite (8.25 - 29.32%), kaolinite (14.91 - 59.26%) and chlorite (5.94 -16.54%) were present as clay minerals although associated with other non-clay minerals such quartz, plagioclase, talc and geothite. The chemical composition results revealed high silica and alumina content in most studied clay samples. Their fluxing oxides which include K2O, Na2O, CaO, and MgO, varied slightly from 0.06% to 1.78% in abundance while the Fe2O3 and TiO2 contents in most samples averages at 9.2% and 1.3% respectively. The plasticity index of the studied deposits ranged from 9.50 to 62.00% while liquid limit ranged from 31.34 to 73.62%. The microanalysis using SEM indicated that the microstructure framework of most studied clay exhibited a porous skeleton structure owing to numerous tiny voids. The composite results of SEM and CEC analyses suggested their possible application in water filter and chemical fertilizer industries since they provided passage for water and soil cations transmission. The particle size distribution demonstrated that the studied soils have clayey silt texture with wide range coverage of the well graded and sorted particle sizes. Compressibility and plasticity properties were found to be high in Mukondeni, Mashamba-1, Mashamba-2 and Mashamba-3 clay samples. The thermal behavior of Mukondeni, Mashamba-1, Mashamba-2 and Mashamba-3 samples showed relatively high shrinkage (>9%). The high shrinkage percentage suggests the preponderance of smectite minerals. Other samples which are rich in kaolinite and chlorite minerals exhibited low shrinkage (<2%). The drying trends of the studied clay suggest their suitability for fast drying processes like soft and hard refractoriness, sanitary wares and ceramics. Empirical assessment of most studied clay showed their suitability for pottery-making and manufacturing of roofing tiles and masonry bricks.
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    Evaluation of the suitably of proposed site for construction of photovoltaic solar facility at Kakamas in the Northern Cape of South Africa
    (2019-05-18) Tshilate, Lindelani; Amponsah-Dacosta, F.; Mhlongo, Sphiwe Emmanuel; Muzerengi, Confidence
    Solar energy development is experiencing significant growth due to national interest in increasing energy efficiency, reducing dependence on fossil fuels, increasing domestic energy production, and curbing greenhouse gas emissions. Northern Cape is generally known to be one of the preferred areas for the generation of solar energy in South Africa, and even in the world, due to its abundant solar radiation. Although this area has abundant potential for solar power generation, not all the areas are suitable for construction of solar plant facilities especially those that are prone to sand storm and dust accumulation. Consequently, site evaluation is very crucial for planning, design and construction of the solar facility. The main objective of this study was to determine the suitability of a proposed site at Kakamas in the Northern Cape for construction of a photovoltaic solar facility. The specific objectives of this research were to assess and establish all the geotechnical aspects that may have an impact on the development of the site, to explore the surface conditions at the proposed site and to establish the soil properties and comment on the use of the on-site soils in the construction of the solar facility. Other specific objectives included to determine the variability of ground conditions and effects of such variability on the proposed development and to provide foundation recommendations for the design and construction of the solar facility. In order to obtain this information, methods such as desktop studies, geological survey, soil survey, magnetic survey and soil profiling were employed to obtain information about the geotechnical aspects of the study area and properties of the on-site soil. Field tests such as cone penetration and resistivity survey and laboratory tests such as foundation indicator test, California Bearing Ratio, pH and permeability test were also performed in order to determine the engineering, behavioral and hydraulic properties of the soil. The results of the geologic and magnetic survey indicated that the study area is underlain by mainly igneous and metamorphic rocks such as gneiss, quartzite, pegmatite, gneiss and calcrete. The results of the soil profiling and the resistivity survey showed that the study area is comprised of sandy soil with either two or three horizons while the cone penetration results revealed high variable soil consistency and stiffness which ranged from very loose to very stiff soils. The particle size distribution, atterberg limits and grading modulus indicated that the study area is characterized mainly by dry, cohesionless and non-plastic to slightly plastic coarse-grained sandy soil with sand content ranging from 71- 96%. From the CBR results, it was found that the soils in the study area generally classifies as G6 material and can be used as base, sub base and backfilling material in accordance with the TRH 14 specifications. The permeability test results indicated moderately permeable sandy silt soils with coefficient of permeability ranging between 1x10-3 to 8x10-3 cm/sec and ground water was encountered at 1.3 m depth. The material excavatability indicated variable material on site ranging from soft calcretes with soft excavation to highly competent material such as quartz and dorbank which require hard excavation while the side wall stability of trial pits indicated stable pit walls during the investigation giving an indication of stability of long pit excavations. The foundation analysis showed that driven piles and earth screws are the ideal foundation types for this site and that the site is generally suitable for construction of the solar facility provided all the recommendations are implemented.
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    Investigation of Groundwater Potential in Naledi Local Municipality, North West Province, South Africa
    (2016-05) Ndwambi, Khuthadzo; Tessema, A.; Amponsah-Dacosta, F.
    See the attached abstract below