Evaluation of selected oxidising reagents, as an attempt to replace FeCl3 in the mirror face cleaning process
- Authors: Motsogi, Gladness
- Date: 2019
- Subjects: Oxidizing agents , Mirrors
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418350 , uj:35466
- Description: Abstract: The necessity of a clean face of a mirror goes as far as ensuring that its reflection abilities are not questioned. Reflection is what attracts people to a mirror. During mirror manufacturing, silver, copper and other chemicals overlap to the reflection side of a mirror, making a mirror have metals on both sides. In order to remove the copper and silver metals on the wrong side, we report the comparison of Na2FeO4 and prepared copper chloride (or a mixture of CuSO4.5H2O and NaCl) in cleaning the mirror face by oxidation reaction as a substitute to the currently used FeCl3. We report on the comparison of the three reagents, in terms, of the effluent plant contamination using XRD and XRF to analyse precipitates that formed because of their use. The comparison of equipment corrosion by determining the corrosion rate (gravimetric weight loss method) is also reported. We report the comparison of corrosion resistance of the final mirror using the CASS test or salt spray test. We also tested a much better stainless, steel duplex 2205, using the two reagents to see if it can be used in future, for mirror making equipment to overcome the challenge of equipment corrosion caused by inorganic oxidants. When compared by time parameter, the prepared CuCl2 solution is the fastest; removing 95.63 % copper and 62.83 % silver, and outdoing the currently used FeCl3 which only removed 12.45 % of the deposited silver on the glass within 20 seconds. The prepared CuCl2 did not cause more toxicity to the effluent water generated after its use. The use of Na2FeO4 did not result in mirror corrosion because it passed the CASS test. , M.Sc. (Chemistry)
- Full Text:
- Authors: Motsogi, Gladness
- Date: 2019
- Subjects: Oxidizing agents , Mirrors
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418350 , uj:35466
- Description: Abstract: The necessity of a clean face of a mirror goes as far as ensuring that its reflection abilities are not questioned. Reflection is what attracts people to a mirror. During mirror manufacturing, silver, copper and other chemicals overlap to the reflection side of a mirror, making a mirror have metals on both sides. In order to remove the copper and silver metals on the wrong side, we report the comparison of Na2FeO4 and prepared copper chloride (or a mixture of CuSO4.5H2O and NaCl) in cleaning the mirror face by oxidation reaction as a substitute to the currently used FeCl3. We report on the comparison of the three reagents, in terms, of the effluent plant contamination using XRD and XRF to analyse precipitates that formed because of their use. The comparison of equipment corrosion by determining the corrosion rate (gravimetric weight loss method) is also reported. We report the comparison of corrosion resistance of the final mirror using the CASS test or salt spray test. We also tested a much better stainless, steel duplex 2205, using the two reagents to see if it can be used in future, for mirror making equipment to overcome the challenge of equipment corrosion caused by inorganic oxidants. When compared by time parameter, the prepared CuCl2 solution is the fastest; removing 95.63 % copper and 62.83 % silver, and outdoing the currently used FeCl3 which only removed 12.45 % of the deposited silver on the glass within 20 seconds. The prepared CuCl2 did not cause more toxicity to the effluent water generated after its use. The use of Na2FeO4 did not result in mirror corrosion because it passed the CASS test. , M.Sc. (Chemistry)
- Full Text:
Evolution of South African minerals law and incorporation of the African mining vision
- Authors: Mdluli, Zinzile
- Date: 2019
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418334 , uj:35464
- Description: Abstract: The Mineral and Petroleum Resources Development Act, Act 28 of 2002 is the legislation that regulates the minerals industry of South Africa. In terms of this Act, the mineral resources of the country belong to all of the citizens and the state is the custodian. The Republic of South Africa, as a member state of the African Union, is in agreement to the continent’s policy document with regards to minerals, the African Mining Vision. This study evaluates evolution of the mineral law of South Africa from the colonial age until the promulgation of the 2002 legislation. In addition, it also reviews if the African mining vision policies are incorporated into the legislation. The methodology used in this work is of a qualitative nature, reviewing the history of the legislation. This work is presented in an attempt to benefit other prospective students and professionals in the minerals industry who are not legal experts by providing a simplified academic guide to mineral law history of South Africa and how the pillars of the African Mining Vision is integrated into the legislation. The findings of this research are presented in comparative tabular form culminating in a graphical timeline of the development of South African mineral law. The accomplishments of the African Mining Vision Action Plan, as expected at national level by the African Union are also corresponded with the South African legislation that would be applicable to address them. Based on the analysis the study concludes that historical statutes have had an impact in how the objectives of the MPRDA have been set. It is further indicated that current legislation is sufficient in its capability to integrate the AMV Action plan. , M.Tech. (Extraction Metallurgy)
- Full Text:
- Authors: Mdluli, Zinzile
- Date: 2019
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418334 , uj:35464
- Description: Abstract: The Mineral and Petroleum Resources Development Act, Act 28 of 2002 is the legislation that regulates the minerals industry of South Africa. In terms of this Act, the mineral resources of the country belong to all of the citizens and the state is the custodian. The Republic of South Africa, as a member state of the African Union, is in agreement to the continent’s policy document with regards to minerals, the African Mining Vision. This study evaluates evolution of the mineral law of South Africa from the colonial age until the promulgation of the 2002 legislation. In addition, it also reviews if the African mining vision policies are incorporated into the legislation. The methodology used in this work is of a qualitative nature, reviewing the history of the legislation. This work is presented in an attempt to benefit other prospective students and professionals in the minerals industry who are not legal experts by providing a simplified academic guide to mineral law history of South Africa and how the pillars of the African Mining Vision is integrated into the legislation. The findings of this research are presented in comparative tabular form culminating in a graphical timeline of the development of South African mineral law. The accomplishments of the African Mining Vision Action Plan, as expected at national level by the African Union are also corresponded with the South African legislation that would be applicable to address them. Based on the analysis the study concludes that historical statutes have had an impact in how the objectives of the MPRDA have been set. It is further indicated that current legislation is sufficient in its capability to integrate the AMV Action plan. , M.Tech. (Extraction Metallurgy)
- Full Text:
Harvesting mining engineering graduate’s potential for value added to the organisation
- Authors: Gaula, Mabatho
- Date: 2019
- Subjects: Mining engineering , Engineering - Management
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/297324 , uj:32411
- Description: M.Ing. (Engineering Management) , Abstract: The research was conducted at Sibanye Stillwater, a gold and platinum group metals (PGM) mining company with operations in the Witwatersrand Basin, along the platinum belt and in the United States (US). The research was titled “Harvesting mining engineering graduate’s potential for adding value to the organisation” and aimed at producing a framework for mining engineering graduate utilisation and retention within the organisation. A quantitative study was done by means of a questionnaire with a population of 53 and a sample size of 17 participants. The composition of graduates in terms of their qualifications is as follows: 47% BSc, 35% B Tech, 6% BEng and 12% chose not to specify their qualifications. The composition of their current roles is as follows: 10% miners, 32% production supervisors, 16% other (shadowing production supervisor), 26% chose not to specify their role, 5% other roles, 11% other roles in service departments. The questionnaire was divided into three sections namely; Technical Knowledge Utilisation, Job Satisfaction and Potential to Add Value. The results generally indicated that when analysed as per individual responses, the result was negative for technical knowledge utilisation. However, in the various groups (per qualification, per role), utilisation was found to be adequate. Job satisfaction was found to be generally dissatisfactory and this being largely attributed to working conditions and company culture, key performance indicators that do not reflect the true performance of the graduates and unattainable targets targets. Potential to add value yielded inconclusive results since equal proportions of the participants responded positively as those who were neutral. Based on the results of the study obtained, the researcher proposed a theoretical framework as a means through which the organisation can harvest the full potential of its mining engineering graduates such that they add value to the organisation. The framework identified 3 components: Talent Management, Competency Development and Retention as foundational pillars which the organisation can use to aid the organisation in harvesting the full potential of its mining engineering graduates to add value to the organisation.
- Full Text:
- Authors: Gaula, Mabatho
- Date: 2019
- Subjects: Mining engineering , Engineering - Management
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/297324 , uj:32411
- Description: M.Ing. (Engineering Management) , Abstract: The research was conducted at Sibanye Stillwater, a gold and platinum group metals (PGM) mining company with operations in the Witwatersrand Basin, along the platinum belt and in the United States (US). The research was titled “Harvesting mining engineering graduate’s potential for adding value to the organisation” and aimed at producing a framework for mining engineering graduate utilisation and retention within the organisation. A quantitative study was done by means of a questionnaire with a population of 53 and a sample size of 17 participants. The composition of graduates in terms of their qualifications is as follows: 47% BSc, 35% B Tech, 6% BEng and 12% chose not to specify their qualifications. The composition of their current roles is as follows: 10% miners, 32% production supervisors, 16% other (shadowing production supervisor), 26% chose not to specify their role, 5% other roles, 11% other roles in service departments. The questionnaire was divided into three sections namely; Technical Knowledge Utilisation, Job Satisfaction and Potential to Add Value. The results generally indicated that when analysed as per individual responses, the result was negative for technical knowledge utilisation. However, in the various groups (per qualification, per role), utilisation was found to be adequate. Job satisfaction was found to be generally dissatisfactory and this being largely attributed to working conditions and company culture, key performance indicators that do not reflect the true performance of the graduates and unattainable targets targets. Potential to add value yielded inconclusive results since equal proportions of the participants responded positively as those who were neutral. Based on the results of the study obtained, the researcher proposed a theoretical framework as a means through which the organisation can harvest the full potential of its mining engineering graduates such that they add value to the organisation. The framework identified 3 components: Talent Management, Competency Development and Retention as foundational pillars which the organisation can use to aid the organisation in harvesting the full potential of its mining engineering graduates to add value to the organisation.
- Full Text:
Bioleaching of chalcopyrite and pyritic chalcocite using indigenous mesophilic microorganisms
- Authors: Bampole, Lukumu David
- Date: 2018
- Subjects: Bacterial leaching , Chalcopyrite , Metallurgy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/294962 , uj:32104
- Description: Abstract: This scientific endeavour is a comparative study of the copper (bio)leaching process from chalcopyrite and pyritic chalcocite and its application as an alternative route for the conventional treatment of copper from sulphide ores around the Lufilian Arc in the Katanga copper belt (case study of Kamoa deposit) in the Democratic Republic of the Congo (DRC). The first findings were linked to the characterisation of the two campaigns in the form of bulk core samples collected from the Kamoa ore body: ‘campaigns 1 and campaign 2’ (chalcopyrite and pyritic chalcocite). The chemical and mineralogical characterisations confirmed that assumption, which means that copper, is mainly bearing under the form of chalcopyrite for the first campaign and chalcocite enclosed in pyritic ore. The second result was related to the bacterial isolation, physicochemical control of bacterial activities and the bacterial identification and numeration by means of 16SrRNA sequencing analysis. The Biomolecular analysis confirmed the presence of five DNA classes identified which are Gammaproteobacteria, beta proteobacteria, Alphaproteobacteria, Bacilli, Acidobacteria that were highly identified and numbered from the designed synthetic sample, among them, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans species which are most known for their biotechnological interest. The third findings from correlating the comparative study of copper leaching in ferric sulphate and copper bioleaching from chalcopyrite and pyritic chalcocite. The tests were in atmospheric conditions and in autoclave for predicting the chemical solubilisation and mechanisms to be considered in this research during bioleaching. Regarding the conventional method (leaching in ferric sulphate) several variables were studied, and optimal conditions were retained with pH 1.5, a pulp density of 2% (w/v) with 4g/L at 70° C, a stirring speed of 150 rpm, and hydrogen peroxide of 1.5 M was also retained as a supplementary additive for both campaigns (78. 52% for chalcopyrite and 82. 5% for pyritic chalcocite). During the chemical leaching process, it was noted that stirring speed does not have a significant effect during the leaching process this why, the optimal condition was fixed at 150 (rpm), which can be predicted due to the high presence of silica, carbonated compound and iron by-product formed during the dissolution time. Concentration below 1.5 M has a significant influence on increasing the dissolution yield – but with a limitation due to the slight destruction of the jarosite formation. Thus, above this limit, the copper dissolution action emerges as too faulty and enriches the inhibited character over the grain surface. Furthermore, the positive effect related to the added catalyst on the pH was reported as conversely proportional to the concentration increase – thereby highlighting an optimal output with 86.60 % at pH level 1. 5, taking into consideration the acid consumption for chalcopyrite and 89.70% for pyritic chalcocite. The copper dissolution rates and iron were correlated in these leaching conditions. Refractory copper sulphide ores can be leached with mesophilic bacteria and took an average of 7 days... , M.Tech. (Extraction Metallurgy)
- Full Text:
- Authors: Bampole, Lukumu David
- Date: 2018
- Subjects: Bacterial leaching , Chalcopyrite , Metallurgy
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/294962 , uj:32104
- Description: Abstract: This scientific endeavour is a comparative study of the copper (bio)leaching process from chalcopyrite and pyritic chalcocite and its application as an alternative route for the conventional treatment of copper from sulphide ores around the Lufilian Arc in the Katanga copper belt (case study of Kamoa deposit) in the Democratic Republic of the Congo (DRC). The first findings were linked to the characterisation of the two campaigns in the form of bulk core samples collected from the Kamoa ore body: ‘campaigns 1 and campaign 2’ (chalcopyrite and pyritic chalcocite). The chemical and mineralogical characterisations confirmed that assumption, which means that copper, is mainly bearing under the form of chalcopyrite for the first campaign and chalcocite enclosed in pyritic ore. The second result was related to the bacterial isolation, physicochemical control of bacterial activities and the bacterial identification and numeration by means of 16SrRNA sequencing analysis. The Biomolecular analysis confirmed the presence of five DNA classes identified which are Gammaproteobacteria, beta proteobacteria, Alphaproteobacteria, Bacilli, Acidobacteria that were highly identified and numbered from the designed synthetic sample, among them, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans species which are most known for their biotechnological interest. The third findings from correlating the comparative study of copper leaching in ferric sulphate and copper bioleaching from chalcopyrite and pyritic chalcocite. The tests were in atmospheric conditions and in autoclave for predicting the chemical solubilisation and mechanisms to be considered in this research during bioleaching. Regarding the conventional method (leaching in ferric sulphate) several variables were studied, and optimal conditions were retained with pH 1.5, a pulp density of 2% (w/v) with 4g/L at 70° C, a stirring speed of 150 rpm, and hydrogen peroxide of 1.5 M was also retained as a supplementary additive for both campaigns (78. 52% for chalcopyrite and 82. 5% for pyritic chalcocite). During the chemical leaching process, it was noted that stirring speed does not have a significant effect during the leaching process this why, the optimal condition was fixed at 150 (rpm), which can be predicted due to the high presence of silica, carbonated compound and iron by-product formed during the dissolution time. Concentration below 1.5 M has a significant influence on increasing the dissolution yield – but with a limitation due to the slight destruction of the jarosite formation. Thus, above this limit, the copper dissolution action emerges as too faulty and enriches the inhibited character over the grain surface. Furthermore, the positive effect related to the added catalyst on the pH was reported as conversely proportional to the concentration increase – thereby highlighting an optimal output with 86.60 % at pH level 1. 5, taking into consideration the acid consumption for chalcopyrite and 89.70% for pyritic chalcocite. The copper dissolution rates and iron were correlated in these leaching conditions. Refractory copper sulphide ores can be leached with mesophilic bacteria and took an average of 7 days... , M.Tech. (Extraction Metallurgy)
- Full Text:
Development and application of molecularly imprinted polymers for selective separation and recovery of gold and silver from industrial wastewaters
- Ahamed, Mohammed Elbushra Hassan
- Authors: Ahamed, Mohammed Elbushra Hassan
- Date: 2018
- Subjects: Extraction (Chemistry) , Heavy metals , Polymers - Separation , Polymers - Analysis
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/261571 , uj:27582
- Description: Ph.D. (Chemistry) , Abstract: Due to the continued global demand for silver and gold, there is constantly a need for more efficient and cost-effective methods to recover these precious metals from industrial aqueous solutions. The recovery of these metals is not easy owing to their presence in complex matrices. As selective recognition elements materials, molecularly imprinted polymers (MIPs) have been attracting great attention for their application in metals extraction. In this research, the performance of imprinted polymers as an adsorbent for the selective recovery of precious metal ions from mining and metallurgical wastewaters was investigated. The imprinted polymers were prepared using various functional monomers (vinylated monomers) and modified chitosan-biopolymers. Various techniques were used to characterize the prepared polymers and to elucidate their interaction mechanisms with the studied precious metal ion. The study also investigated the adsorption behavior of these materials in single and co-adsorption metal ions systems. In the first part of the study, ion-imprinted polymers (IIPs) were prepared by bulk polymerization method using three coordinating monomers namely: 4-vinyl pyridine (4-VP), N-(4-vinyl benzyl) ethylenediamine (EDA) and N-(allyl)-N-diethylthiophosphate (ADT), and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. Comparative studies on the adsorption performance of these IIPs for gold ion were conducted. The results obtained indicated that IIPs containing 4-VP had superior adsorption capability and selectivity towards gold compared to the other IIPs. Molecular modeling, using a Gaussian software package, was used to understand this difference in the adsorption ability. The results obtained indicated that the interaction between gold ion and 4-VP monomer is the strongest (ΔG = -4143.75 kcal mol-1) than its interaction with the other two monomers, suggesting that the adsorption process is more feasible for the IIP derived from 4-VP. FTIR and XRD analysis were done in order to understand and elucidate the adsorption mechanisms. It was proposed that gold ion adsorbed onto IIPs 4-VP and EDA by coordination and ion exchange mechanisms, while complexation – reduction mechanism was the one that accounted for its adsorption onto ADT produced polymeric material. In another attempt, IIPs synthesized from two functional monomers, 4-VP and 1-vinyl imidazole (1-VID), and N, N-ethylene bisacrylamide (EBAm) as the crosslinker via a precipitation polymerization method were found to be suitable for Ag(I) extraction...
- Full Text:
- Authors: Ahamed, Mohammed Elbushra Hassan
- Date: 2018
- Subjects: Extraction (Chemistry) , Heavy metals , Polymers - Separation , Polymers - Analysis
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/261571 , uj:27582
- Description: Ph.D. (Chemistry) , Abstract: Due to the continued global demand for silver and gold, there is constantly a need for more efficient and cost-effective methods to recover these precious metals from industrial aqueous solutions. The recovery of these metals is not easy owing to their presence in complex matrices. As selective recognition elements materials, molecularly imprinted polymers (MIPs) have been attracting great attention for their application in metals extraction. In this research, the performance of imprinted polymers as an adsorbent for the selective recovery of precious metal ions from mining and metallurgical wastewaters was investigated. The imprinted polymers were prepared using various functional monomers (vinylated monomers) and modified chitosan-biopolymers. Various techniques were used to characterize the prepared polymers and to elucidate their interaction mechanisms with the studied precious metal ion. The study also investigated the adsorption behavior of these materials in single and co-adsorption metal ions systems. In the first part of the study, ion-imprinted polymers (IIPs) were prepared by bulk polymerization method using three coordinating monomers namely: 4-vinyl pyridine (4-VP), N-(4-vinyl benzyl) ethylenediamine (EDA) and N-(allyl)-N-diethylthiophosphate (ADT), and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. Comparative studies on the adsorption performance of these IIPs for gold ion were conducted. The results obtained indicated that IIPs containing 4-VP had superior adsorption capability and selectivity towards gold compared to the other IIPs. Molecular modeling, using a Gaussian software package, was used to understand this difference in the adsorption ability. The results obtained indicated that the interaction between gold ion and 4-VP monomer is the strongest (ΔG = -4143.75 kcal mol-1) than its interaction with the other two monomers, suggesting that the adsorption process is more feasible for the IIP derived from 4-VP. FTIR and XRD analysis were done in order to understand and elucidate the adsorption mechanisms. It was proposed that gold ion adsorbed onto IIPs 4-VP and EDA by coordination and ion exchange mechanisms, while complexation – reduction mechanism was the one that accounted for its adsorption onto ADT produced polymeric material. In another attempt, IIPs synthesized from two functional monomers, 4-VP and 1-vinyl imidazole (1-VID), and N, N-ethylene bisacrylamide (EBAm) as the crosslinker via a precipitation polymerization method were found to be suitable for Ag(I) extraction...
- Full Text:
Strategies for noise control in the mining of hard rock and processing of sedimentary rock
- Kombo Tsoumbou, Amour Dorick
- Authors: Kombo Tsoumbou, Amour Dorick
- Date: 2018
- Subjects: Noise control - South Africa - Northern Cape , Noise control - Case studies , Industrial noise - South Africa - Northern Cape , Mineral industries - Health aspects - South Africa - Northern Cape
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/269579 , uj:28638
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Occupational noise has been recognised as being one of the major causes of many adverse health effects worldwide. Long exposure to high noise levels is believed to have resulted in considerable physiological and social changes in the life of the person exposed, particularly in the form of noise-induced hearing loss. Noise-induced hearing loss (NIHL) has over the years become a critical issue in most industries around the world. According to Mizan and colleagues, the iron and steel industry has been identified as one of the highest industry risk in terms of NIHL in South Africa (Mizan, et al., 2014). Furthermore, the South African mining industry has been spending millions of rands in compensations and claims due to NIHL. This has made occupational noise a major problem in South Africa, where the South African Department of Labour issued regulations prescribing all employees exposed to a noise exposure level greater or equal to 85 dBA to undergo medical surveillance. This study was conducted in two different mining sites, notably Wessels Mine (Northern Cape) and Fikale Moriti Sandstone Mine of Qwaqwa (Free State). Wessels Mine is one of the biggest underground manganese mine in the country, and Fikale Moriti is one of the most successful artisanal small scale sandstone mine in the Qwaqwa region. At Fikale Moriti, focus was placed on the processing plant, where the greatest amount of noise was generated, as compared to the mining area, where the noise produce was below the threshold limit (85 dBA). The primary objective in this study was to investigate occupational noise and its effect on employees in the two mining operations cited above. The researcher aimed, in so doing, to develop and recommend strategies that will help the mines further control the noise hazard. Controlling noise will improve work’s conditions that will reflect positively on the health and availability of the workers. In order to do this, a review of literature was performed to ascertain what was known on the subject, and control that was already in place through previous research work. The process that ensued entailed elaborating a strategy for the collection, analysis and interpretation of data both from Wessels Mine and Fikale Moriti sandstone. The study made use of occupational noise survey as method to quantify the noise level at both mining operations and work practice observation to observe compliance from noise standards. A review of audiometric testing results of employees was also performed, in order to establish the prevalence of NIHL amongst Wessels Mine employees over the past years. In order to further control noise at the mines, the focus was given more to engineering control, with a little mention of administrative control. Upgrading to less noisy equipment, buy quite policy, upgrading to low-noise plant and making use of noise control equipment, such as silencers for fans and enclosures for crushers, were among some of the solutions posed
- Full Text:
- Authors: Kombo Tsoumbou, Amour Dorick
- Date: 2018
- Subjects: Noise control - South Africa - Northern Cape , Noise control - Case studies , Industrial noise - South Africa - Northern Cape , Mineral industries - Health aspects - South Africa - Northern Cape
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/269579 , uj:28638
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Occupational noise has been recognised as being one of the major causes of many adverse health effects worldwide. Long exposure to high noise levels is believed to have resulted in considerable physiological and social changes in the life of the person exposed, particularly in the form of noise-induced hearing loss. Noise-induced hearing loss (NIHL) has over the years become a critical issue in most industries around the world. According to Mizan and colleagues, the iron and steel industry has been identified as one of the highest industry risk in terms of NIHL in South Africa (Mizan, et al., 2014). Furthermore, the South African mining industry has been spending millions of rands in compensations and claims due to NIHL. This has made occupational noise a major problem in South Africa, where the South African Department of Labour issued regulations prescribing all employees exposed to a noise exposure level greater or equal to 85 dBA to undergo medical surveillance. This study was conducted in two different mining sites, notably Wessels Mine (Northern Cape) and Fikale Moriti Sandstone Mine of Qwaqwa (Free State). Wessels Mine is one of the biggest underground manganese mine in the country, and Fikale Moriti is one of the most successful artisanal small scale sandstone mine in the Qwaqwa region. At Fikale Moriti, focus was placed on the processing plant, where the greatest amount of noise was generated, as compared to the mining area, where the noise produce was below the threshold limit (85 dBA). The primary objective in this study was to investigate occupational noise and its effect on employees in the two mining operations cited above. The researcher aimed, in so doing, to develop and recommend strategies that will help the mines further control the noise hazard. Controlling noise will improve work’s conditions that will reflect positively on the health and availability of the workers. In order to do this, a review of literature was performed to ascertain what was known on the subject, and control that was already in place through previous research work. The process that ensued entailed elaborating a strategy for the collection, analysis and interpretation of data both from Wessels Mine and Fikale Moriti sandstone. The study made use of occupational noise survey as method to quantify the noise level at both mining operations and work practice observation to observe compliance from noise standards. A review of audiometric testing results of employees was also performed, in order to establish the prevalence of NIHL amongst Wessels Mine employees over the past years. In order to further control noise at the mines, the focus was given more to engineering control, with a little mention of administrative control. Upgrading to less noisy equipment, buy quite policy, upgrading to low-noise plant and making use of noise control equipment, such as silencers for fans and enclosures for crushers, were among some of the solutions posed
- Full Text:
Artisanal fired clay bricks in Dididi and QwaQwa : their production and related environmental issues
- Authors: Monatshebe, Tshiyoyo
- Date: 2017
- Subjects: Brick trade - South Africa , Brickworks - Economic aspects , Brickworks - Environmental aspects
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/286010 , uj:30940
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Artisanal in South Africa is found many fields and different types of applications. This study examined the populations of the Dididi and QwaQwa villages, who are involved in brick-making production as their principal daily activity. These artisanal brick-makers have to maintain their daily livelihood by producing fired clay bricks. However, the production of these bricks has resulted in environmental degradation. Finding a balance between economic and environmental considerations is therefore crucial. This study intended to investigate the quality of artisanal bricks manufactured in Dididi and QwaQwa, together with the effects on the environment. The environmental issues were studied using a survey questionnaire with statistics (descriptive methods and principal component analysis). The life cycle of artisanal brick-making was assessed in terms of renewability of resources, ecosystem conservation, minimisation of pollution and so on. The quality of bricks was studied first by mechanical properties, followed by an examination of the mineralogy of these bricks using analytical techniques (X-ray fluorescence, X-ray diffraction, scanning electron microscopy and Fourier Transform Infrared Spectrometer). Lastly, the mechanical properties of the artisanal bricks were compared to commercially produced bricks according to the South Africa National Standard using the unconfined compressive strength test and water absorption analysis. The principal component analysis of the survey showed that brick-makers were interested in both the economic and environmental aspects. It was also found that these brick-makers do not use the Proctor compaction technique, explaining weak results for the artisanal fired and burnt bricks of the Dididi site, with 4.3 and 9 MPa respectively. The burnt bricks from the QwaQwa site, however, reached the recommended quality with 15 MPa. When considering the minimum unconfined compressive strength test set out by the South African National Standard (SANS 227:2007), it was shown that the new mineral formations could strengthen the bricks – especially if the artisans used the Proctor compaction technique. In comparison to commercial bricks, some of the results met the requirement of SANS 227:2007. Lastly, the results of the life-cycle analysis showed that the labour was intensive due to the small tools applied, and because minerals cannot be renewed, they require good management. The cash-flow tables show that artisanal brick-makers can improve their activities to the standard of industrial brick-making.
- Full Text:
Artisanal fired clay bricks in Dididi and QwaQwa : their production and related environmental issues
- Authors: Monatshebe, Tshiyoyo
- Date: 2017
- Subjects: Brick trade - South Africa , Brickworks - Economic aspects , Brickworks - Environmental aspects
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/286010 , uj:30940
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Artisanal in South Africa is found many fields and different types of applications. This study examined the populations of the Dididi and QwaQwa villages, who are involved in brick-making production as their principal daily activity. These artisanal brick-makers have to maintain their daily livelihood by producing fired clay bricks. However, the production of these bricks has resulted in environmental degradation. Finding a balance between economic and environmental considerations is therefore crucial. This study intended to investigate the quality of artisanal bricks manufactured in Dididi and QwaQwa, together with the effects on the environment. The environmental issues were studied using a survey questionnaire with statistics (descriptive methods and principal component analysis). The life cycle of artisanal brick-making was assessed in terms of renewability of resources, ecosystem conservation, minimisation of pollution and so on. The quality of bricks was studied first by mechanical properties, followed by an examination of the mineralogy of these bricks using analytical techniques (X-ray fluorescence, X-ray diffraction, scanning electron microscopy and Fourier Transform Infrared Spectrometer). Lastly, the mechanical properties of the artisanal bricks were compared to commercially produced bricks according to the South Africa National Standard using the unconfined compressive strength test and water absorption analysis. The principal component analysis of the survey showed that brick-makers were interested in both the economic and environmental aspects. It was also found that these brick-makers do not use the Proctor compaction technique, explaining weak results for the artisanal fired and burnt bricks of the Dididi site, with 4.3 and 9 MPa respectively. The burnt bricks from the QwaQwa site, however, reached the recommended quality with 15 MPa. When considering the minimum unconfined compressive strength test set out by the South African National Standard (SANS 227:2007), it was shown that the new mineral formations could strengthen the bricks – especially if the artisans used the Proctor compaction technique. In comparison to commercial bricks, some of the results met the requirement of SANS 227:2007. Lastly, the results of the life-cycle analysis showed that the labour was intensive due to the small tools applied, and because minerals cannot be renewed, they require good management. The cash-flow tables show that artisanal brick-makers can improve their activities to the standard of industrial brick-making.
- Full Text:
Dissolution of minerals from geophagic clays from selected areas and their probiotics behaviours
- Authors: Uchenna, Okereafor Godwin
- Date: 2017
- Subjects: Mineralogical chemistry , Probiotics - Therapeutic use , Clay minerals , Clay - Analysis
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/243004 , uj:25080
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Clay and its associated minerals are crucial materials with various applications ranging from industrial, health to traditional activities. Since time immemorial, the application of clays for traditional and health purposes have remained evident amongst Africans and rapidly gaining grounds in the world at large. Indigenous knowledge has constantly supported geophagia – the deliberate consumption of earthy material for several benefits such as mineral supplement to the body and treatment of diseases. In Southern Africa, geophagia is becoming a common practice irrespective of the social class, age and religion of the geophagists. Few reports on the characterisation of geophagic clays are available but none had considered probiotics and volatile fatty acids. Characterisation plays a vital role in the study of geophagic clays, as it provides useful information about the safety of its application by humans. The quality of such earthy material had been solely based on characterisation, which stirs issues of safety and environmental health. It was therefore imperative to consider other studies beside characterisation of geophagic clays to better appreciate the effects upon consumption by humans. Probiotics are known to be beneficial as they help maintain a healthy gut in humans. The effect of clays on these microorganisms and the possible impacts on humans is necessary. This current research study considered the application of Atomic absorption spectroscopy (AAS) together with Infrared fluorescence (XRF) and Infrared diffraction (XRD) as well as a front-line chromatographic and mass spectrometric analytical technique, i.e. two dimensional gas chromatography coupled with a time-of-flight mass spectrometry (GC×GC-TOFMS) for investigating the production of volatile fatty acids (VFAs) by the probiotics upon interaction with geophagic clays. The first phase of the study considered the physicochemical characterisation of geophagic clays sold in informal South African markets using 2g of the various samples moistened with 100mL of 0.5M, 1M and 2M HCl acid. The subsequent analysis of the filterate on AAS revealed the different clay samples containing several heavy metals such as copper (Cu), lead (Pb), zinc (Zn), iron (Fe), cobalt (Co), manganese (Mn), chromium (Cr). These heavy metals have been reported to have deleterious effects on humans when above the minimum permissible level. Further analysis using infrared fluorescence indicated average values of major elements such as SiO2 (54.02%), Al2O3...
- Full Text:
- Authors: Uchenna, Okereafor Godwin
- Date: 2017
- Subjects: Mineralogical chemistry , Probiotics - Therapeutic use , Clay minerals , Clay - Analysis
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/243004 , uj:25080
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Clay and its associated minerals are crucial materials with various applications ranging from industrial, health to traditional activities. Since time immemorial, the application of clays for traditional and health purposes have remained evident amongst Africans and rapidly gaining grounds in the world at large. Indigenous knowledge has constantly supported geophagia – the deliberate consumption of earthy material for several benefits such as mineral supplement to the body and treatment of diseases. In Southern Africa, geophagia is becoming a common practice irrespective of the social class, age and religion of the geophagists. Few reports on the characterisation of geophagic clays are available but none had considered probiotics and volatile fatty acids. Characterisation plays a vital role in the study of geophagic clays, as it provides useful information about the safety of its application by humans. The quality of such earthy material had been solely based on characterisation, which stirs issues of safety and environmental health. It was therefore imperative to consider other studies beside characterisation of geophagic clays to better appreciate the effects upon consumption by humans. Probiotics are known to be beneficial as they help maintain a healthy gut in humans. The effect of clays on these microorganisms and the possible impacts on humans is necessary. This current research study considered the application of Atomic absorption spectroscopy (AAS) together with Infrared fluorescence (XRF) and Infrared diffraction (XRD) as well as a front-line chromatographic and mass spectrometric analytical technique, i.e. two dimensional gas chromatography coupled with a time-of-flight mass spectrometry (GC×GC-TOFMS) for investigating the production of volatile fatty acids (VFAs) by the probiotics upon interaction with geophagic clays. The first phase of the study considered the physicochemical characterisation of geophagic clays sold in informal South African markets using 2g of the various samples moistened with 100mL of 0.5M, 1M and 2M HCl acid. The subsequent analysis of the filterate on AAS revealed the different clay samples containing several heavy metals such as copper (Cu), lead (Pb), zinc (Zn), iron (Fe), cobalt (Co), manganese (Mn), chromium (Cr). These heavy metals have been reported to have deleterious effects on humans when above the minimum permissible level. Further analysis using infrared fluorescence indicated average values of major elements such as SiO2 (54.02%), Al2O3...
- Full Text:
Mineralogy, microbial characterisation and microwave processing of selected geophagic clays
- Authors: Megne Tiegoum, Adeline
- Date: 2017
- Subjects: Mineralogical chemistry , Clay - Analysis , Clay minerals - Microscopy , Clay soils
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/280454 , uj:30136
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Please refer to full text to view abstract.
- Full Text:
- Authors: Megne Tiegoum, Adeline
- Date: 2017
- Subjects: Mineralogical chemistry , Clay - Analysis , Clay minerals - Microscopy , Clay soils
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/280454 , uj:30136
- Description: M.Tech. (Extraction Metallurgy) , Abstract: Please refer to full text to view abstract.
- Full Text:
Application of neural network techniques to the ion-exchange process and prediction of abrasiveness characteristics of thermal coal
- Authors: Tshilenge, Kabuba John
- Date: 2016
- Subjects: Chemical process control , Chemical process control - Simulation methods , Sustainable engineering , Heavy metals
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/225117 , uj:22729
- Description: Abstract: The construction of a model for the prediction of process outputs is a valuable tool in the field of engineering. The models play an important role in the simulation and optimization of systems leading to the design of efficient and economical processes. Since 1943 neural network (NN) techniques have been considered as promising tools for use in simulation, prediction and modelling because of their simplicity. In this thesis a feed-forward neural network (FFNN) with back-propagation (BP) is used to test its effectiveness in modelling the ion-exchange process. The ion-exchange process has been widely employed in the removal of heavy metals from industrial wastewater. This process is a complex non-linear process involving many factors influencing the chemical process which is not well understood (the ions uptake mechanisms from the pregnant solution, the subsequent step being the elution). In order to improve the performance of the ion-exchange process, optimization and analysis of the process should be accomplished. Modelling and simulation are tools which can be used to achieve the objectives. The experimental design using analysis of variance (ANOVA) was chosen to compare to the NN techniques and for optimizing the effective input parameters (pH, temperature and initial concentration). The FFNN successfully tracked the non-linear behaviour of the ion-exchange process versus the input parameters with a mean square error (MSE), correlation coefficient (R) and mean square relative error (MSRE) of 0.102, 0.998 and 0.004, respectively. The results showed that the FFNN modelling techniques could effectively predict and simulate the highly complex system and non-linear process such as the ion exchange using activated zeolite... , D.Tech. (Chemical Engineering)
- Full Text:
- Authors: Tshilenge, Kabuba John
- Date: 2016
- Subjects: Chemical process control , Chemical process control - Simulation methods , Sustainable engineering , Heavy metals
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/225117 , uj:22729
- Description: Abstract: The construction of a model for the prediction of process outputs is a valuable tool in the field of engineering. The models play an important role in the simulation and optimization of systems leading to the design of efficient and economical processes. Since 1943 neural network (NN) techniques have been considered as promising tools for use in simulation, prediction and modelling because of their simplicity. In this thesis a feed-forward neural network (FFNN) with back-propagation (BP) is used to test its effectiveness in modelling the ion-exchange process. The ion-exchange process has been widely employed in the removal of heavy metals from industrial wastewater. This process is a complex non-linear process involving many factors influencing the chemical process which is not well understood (the ions uptake mechanisms from the pregnant solution, the subsequent step being the elution). In order to improve the performance of the ion-exchange process, optimization and analysis of the process should be accomplished. Modelling and simulation are tools which can be used to achieve the objectives. The experimental design using analysis of variance (ANOVA) was chosen to compare to the NN techniques and for optimizing the effective input parameters (pH, temperature and initial concentration). The FFNN successfully tracked the non-linear behaviour of the ion-exchange process versus the input parameters with a mean square error (MSE), correlation coefficient (R) and mean square relative error (MSRE) of 0.102, 0.998 and 0.004, respectively. The results showed that the FFNN modelling techniques could effectively predict and simulate the highly complex system and non-linear process such as the ion exchange using activated zeolite... , D.Tech. (Chemical Engineering)
- Full Text:
Engineering management concepts for sustainable productivity improvements in small scale mining and minerals processing operations in South Africa
- Authors: Singh, Nirdesh
- Date: 2016
- Subjects: Mineral industries - Production control , Mine management
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/242346 , uj:24993
- Description: M.Ing. (Engineering Management) , Abstract: Literature has shown that a number of concerns have been raised with regards to the definition of small scale mining. It has been argued that the formal definition does not capture all the intricacies of small scale mining. The definition does not take into account the level of technology deployed, production output, nature and motivation of miners etc. The objectives of the research conducted were to firstly develop a formal and scientific definition for Small Scale Mining in South Africa and secondly to use and apply Engineering Management concepts to optimise and improve the productivity of selected Small Scale Mining and Minerals Processing operations in South Africa. The methodology used involved conducting a literature review of the types of small scale mining and mineral processing operations that exist within South Africa. A case study approach was used and a questionnaire was developed to gather information from selected legal small scale mining and processing operations in South Africa. A survey was developed and submitted to experts/specialists in the field of small scale mining in order to use the Pairwise Comparison Decision Making Tool to develop a scientific definition of small scale mining. By comparing the information studied in the literature with the data obtained from visiting two small scale operations (semi-precious gemstones and diamonds) and using engineering management concepts it was found that the recommended improvements that one can make to small scale mining and minerals processing operations in South Africa can essentially be categorised into four critical areas namely: Management, Chemical Analysis, Technology and Skills. These areas are captured in more detail in the Integrated Management Model proposed for Small Scale Mining and Minerals Processing Operations in South Africa within this dissertation. All aims and objectives set-out for the research conducted were achieved. The recommended improvements if implemented by small scale mining and mineral processing operations in South Africa will result in a safer and healthier working environment, increased productivity, higher production rates and improved profitability.
- Full Text:
- Authors: Singh, Nirdesh
- Date: 2016
- Subjects: Mineral industries - Production control , Mine management
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/242346 , uj:24993
- Description: M.Ing. (Engineering Management) , Abstract: Literature has shown that a number of concerns have been raised with regards to the definition of small scale mining. It has been argued that the formal definition does not capture all the intricacies of small scale mining. The definition does not take into account the level of technology deployed, production output, nature and motivation of miners etc. The objectives of the research conducted were to firstly develop a formal and scientific definition for Small Scale Mining in South Africa and secondly to use and apply Engineering Management concepts to optimise and improve the productivity of selected Small Scale Mining and Minerals Processing operations in South Africa. The methodology used involved conducting a literature review of the types of small scale mining and mineral processing operations that exist within South Africa. A case study approach was used and a questionnaire was developed to gather information from selected legal small scale mining and processing operations in South Africa. A survey was developed and submitted to experts/specialists in the field of small scale mining in order to use the Pairwise Comparison Decision Making Tool to develop a scientific definition of small scale mining. By comparing the information studied in the literature with the data obtained from visiting two small scale operations (semi-precious gemstones and diamonds) and using engineering management concepts it was found that the recommended improvements that one can make to small scale mining and minerals processing operations in South Africa can essentially be categorised into four critical areas namely: Management, Chemical Analysis, Technology and Skills. These areas are captured in more detail in the Integrated Management Model proposed for Small Scale Mining and Minerals Processing Operations in South Africa within this dissertation. All aims and objectives set-out for the research conducted were achieved. The recommended improvements if implemented by small scale mining and mineral processing operations in South Africa will result in a safer and healthier working environment, increased productivity, higher production rates and improved profitability.
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Estimation and characterization of coal particulates emitted during the laboratory determination of coal abrasive index values
- Authors: Murivhula, Makeetse Phollen
- Date: 2016
- Subjects: Coal dust - Analysis , Coal dust - Health aspects , Chemical laboratory technicians - Health and hygiene
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/293730 , uj:31945
- Description: M.Tech. (Metallurgy) , Abstract: Abrasive index (AI) is expressed as the total mass loss of four carbon steel blades when rotated for a fixed number of revolutions in a known mass of coal under specific conditions. During the testing of coal to ascertain its AI, coal dust is generated. Coal dust is a fine powdered form of coal, which is created from the crushing of the coal samples, grinding or pulverizing of coal. Exposure to coal dust can occur through inhalation, ingestion and eye contact. Such exposure is associated with the development of occupational respiratory diseases including simple coal workers pneumoconiosis (CWP), progressive massive fibrosis (PMF) and chronic obstructive pulmonary diseases (COPD). The aim of the study was to measure all the coal dust explosion hazards to determine the levels of minerals and trace elements present in coal dust and the extent of exposure of laboratory operators to coal dust whilst performing the AIT. The objectives were to: · determine the levels of minerals and trace elements present in coal dust emitted during the coal AIT. · determine the awareness of laboratory operators and managers of the health effects of coal dust exposure by using structured interviews. · assess laboratory operators’ exposure (personal and environmental exposure) to coal dust by visual observation. In this study, the X-ray diffraction analysis was undertaken on the coal dust in order to establish which minerals are present in the sample. The mineral matter is the source of unwanted abrasion, corrosion or environmental pollution that are associated with coal usage. They are a public health concern because at sufficient exposure levels they adversely affect human health. Physical obervations and questionnaires were used to determine the awareness of laboratory operators and managers of the health effects of coal dust exposure...
- Full Text:
- Authors: Murivhula, Makeetse Phollen
- Date: 2016
- Subjects: Coal dust - Analysis , Coal dust - Health aspects , Chemical laboratory technicians - Health and hygiene
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/293730 , uj:31945
- Description: M.Tech. (Metallurgy) , Abstract: Abrasive index (AI) is expressed as the total mass loss of four carbon steel blades when rotated for a fixed number of revolutions in a known mass of coal under specific conditions. During the testing of coal to ascertain its AI, coal dust is generated. Coal dust is a fine powdered form of coal, which is created from the crushing of the coal samples, grinding or pulverizing of coal. Exposure to coal dust can occur through inhalation, ingestion and eye contact. Such exposure is associated with the development of occupational respiratory diseases including simple coal workers pneumoconiosis (CWP), progressive massive fibrosis (PMF) and chronic obstructive pulmonary diseases (COPD). The aim of the study was to measure all the coal dust explosion hazards to determine the levels of minerals and trace elements present in coal dust and the extent of exposure of laboratory operators to coal dust whilst performing the AIT. The objectives were to: · determine the levels of minerals and trace elements present in coal dust emitted during the coal AIT. · determine the awareness of laboratory operators and managers of the health effects of coal dust exposure by using structured interviews. · assess laboratory operators’ exposure (personal and environmental exposure) to coal dust by visual observation. In this study, the X-ray diffraction analysis was undertaken on the coal dust in order to establish which minerals are present in the sample. The mineral matter is the source of unwanted abrasion, corrosion or environmental pollution that are associated with coal usage. They are a public health concern because at sufficient exposure levels they adversely affect human health. Physical obervations and questionnaires were used to determine the awareness of laboratory operators and managers of the health effects of coal dust exposure...
- Full Text:
Recovery of base and heavy metals from nitric and aqueous solutions using grapefruit resin
- Authors: Phali, Caleb Motlatsi
- Date: 2015
- Subjects: Grapefruit resin
- Language: English
- Type: Master’s Thesis
- Identifier: http://hdl.handle.net/10210/57316 , uj:16379
- Description: Abstract: In the mineral beneficiation the use of aqueous solution such as mineral acids (HCl, H2SO4 and HNO3) is important particularly for the recovery of base metals (Ni, Cu, Co etc.), and the recovery of heavy metals from water samples from coal, clay and other mineral processing. The environmental monitoring of heavy and base metals pollution due to small scale mineral beneficiation is critical and of equal importance in the identification of cost effective measures for the recovery this metals. Small scale mineral beneficiation is increasing in South Africa with severe consequences such as non- adherence to the documented mining protocols with regard to the mining process. In the same breath treatment of base and heavy metals contamination from the environment has become an expensive and complex process. The study investigate possible use of a synthetic grapefruit resin as an inexpensive alternative for bio sorption of heavy and base metals from small scale mineral beneficiation. Bio sorption process is observed as a cost-effective, high efficient and simple technique for water treatment as compared to conventional methods (Volesky, 1998). Due to high content of pectin grapefruit was cross-linked and used as a bio sorbent for the following selected metals: Pb, Co, Ni, Cu and Mn. The characterization of the modified grapefruit resin included: particle size distribution, FTIR, cationic exchange capacity and BET. Factors that affected bio sorption were investigated and optimized. The FTIR spectra of the grapefruit resin revealed that the active functional groups on the grapefruit resin are –COOH and OH. It was observed the uptake of Pb and Co were 0.01675 and 0.01782 mg/g respectively this values then drop to 0.01210 and 0.01317 mg/g when the -COOH and OH functional groups are chemically blocked. The best pH for metal... , M.Tech.
- Full Text:
- Authors: Phali, Caleb Motlatsi
- Date: 2015
- Subjects: Grapefruit resin
- Language: English
- Type: Master’s Thesis
- Identifier: http://hdl.handle.net/10210/57316 , uj:16379
- Description: Abstract: In the mineral beneficiation the use of aqueous solution such as mineral acids (HCl, H2SO4 and HNO3) is important particularly for the recovery of base metals (Ni, Cu, Co etc.), and the recovery of heavy metals from water samples from coal, clay and other mineral processing. The environmental monitoring of heavy and base metals pollution due to small scale mineral beneficiation is critical and of equal importance in the identification of cost effective measures for the recovery this metals. Small scale mineral beneficiation is increasing in South Africa with severe consequences such as non- adherence to the documented mining protocols with regard to the mining process. In the same breath treatment of base and heavy metals contamination from the environment has become an expensive and complex process. The study investigate possible use of a synthetic grapefruit resin as an inexpensive alternative for bio sorption of heavy and base metals from small scale mineral beneficiation. Bio sorption process is observed as a cost-effective, high efficient and simple technique for water treatment as compared to conventional methods (Volesky, 1998). Due to high content of pectin grapefruit was cross-linked and used as a bio sorbent for the following selected metals: Pb, Co, Ni, Cu and Mn. The characterization of the modified grapefruit resin included: particle size distribution, FTIR, cationic exchange capacity and BET. Factors that affected bio sorption were investigated and optimized. The FTIR spectra of the grapefruit resin revealed that the active functional groups on the grapefruit resin are –COOH and OH. It was observed the uptake of Pb and Co were 0.01675 and 0.01782 mg/g respectively this values then drop to 0.01210 and 0.01317 mg/g when the -COOH and OH functional groups are chemically blocked. The best pH for metal... , M.Tech.
- Full Text:
Post-mining ground instability due to natural re-watering of dolomitic aquifer in the Merefong area
- Authors: Phogole, Kedibone Solomon
- Date: 2014-09-17
- Subjects: Subsidences (Earth movements) - South Africa - Gauteng , Dolomite - South Africa - Gauteng , Formations (Geology) - South Africa - Gauteng , Sinkholes - South Africa - Gauteng
- Type: Thesis
- Identifier: uj:12337 , http://hdl.handle.net/10210/12123
- Description: M.Tech. (Extraction Metallurgy) , The discovery of gold at Langlaagte in 1886 led to the development of gold mining in the Far West Rand in 1934. When shafts were sunk, water from the dolomites posed a serious threat to mining. Despite cementation that sealed the many fissures, water still found its way into the underground workings. This led to the “uniform” policy of dewatering. The farming communities in the area that were dependent on the ground water had to be considered, as they had lost their livelihood. As the water levels lowered, dolines and sinkholes were formed, posing a serious threat to life and property. When the mines eventually cease to operate, be it due to high working costs, or the declining grade of the ore body, the re-watering of the dolomitic compartments will occur as a natural consequence. When water comes to within six metres of the original water level, ground instability, the formation of dolines and sinkholes, both new and existing, will occur, threatening the important rail link between Pretoria and Cape Town as it passes through Far West Rand, as well as the N12 between Johannesburg and Potchefstroom, as well as the N14 which lies to the east connecting the Gauteng Province and the North West Province. The dewatering of the compartments caused the soil which formed the roof of the cavities to dry. Re-watering will cause this dry, stable material to become wet and unstable. Where mixtures of slime and/or other material, which is not part of the geological composition of that area was used, the same phenomenon will apply. A further complication is caused by the slimes dams which are unlined. In fact, some of the slime dams were deliberately constructed over cavernous dolomite. This large mass of mine tailings over the dolomitic aquifers will “liquefy”. If the re-watering is not carefully managed the rising water table will undoubtedly trigger a rash of new sinkholes, with catastrophic consequences for unsuspecting communities that may have been established in sensitive areas. The results of previous investigations by the Departments Minerals, Energy and Water Affairs who, due to the loss of institutional memory, might not be able to find the relevant information. Other organizations such as the Council for Geoscience could be using the results for consultancy. The information should be digitized and be available to the broader South African public. FWRDWA is currently in charge of monitoring events in the area. Levelling observations have been carried out quarterly and, so far the movement of ground is minimal. The potential hazard of ground instability will recur with the re-watering of the dolomitic compartments of the Far West Rand. To support what could happen, reference is made to events which took place in the late seventies when the Far West Rand had an above average rainfall. The Donaldson Dam overflowed into the Wonderfontein Spruit and into the dewatered Venterspost compartment. As a result, the water level of the Venterspost Compartment rose rapidly which led to the re-activation of sinkholes and the formation of new ones in the Venterspost area. In the present work levelling has been carried out along most of the loops affected and the results of the levelling give an impression that the surface is currently relatively stable. This Dissertation is presented as an attempt to alert the authorities to the potential dangers if the post mining period is not carefully monitored and insufficient provision made to deal with potential contingencies.
- Full Text:
- Authors: Phogole, Kedibone Solomon
- Date: 2014-09-17
- Subjects: Subsidences (Earth movements) - South Africa - Gauteng , Dolomite - South Africa - Gauteng , Formations (Geology) - South Africa - Gauteng , Sinkholes - South Africa - Gauteng
- Type: Thesis
- Identifier: uj:12337 , http://hdl.handle.net/10210/12123
- Description: M.Tech. (Extraction Metallurgy) , The discovery of gold at Langlaagte in 1886 led to the development of gold mining in the Far West Rand in 1934. When shafts were sunk, water from the dolomites posed a serious threat to mining. Despite cementation that sealed the many fissures, water still found its way into the underground workings. This led to the “uniform” policy of dewatering. The farming communities in the area that were dependent on the ground water had to be considered, as they had lost their livelihood. As the water levels lowered, dolines and sinkholes were formed, posing a serious threat to life and property. When the mines eventually cease to operate, be it due to high working costs, or the declining grade of the ore body, the re-watering of the dolomitic compartments will occur as a natural consequence. When water comes to within six metres of the original water level, ground instability, the formation of dolines and sinkholes, both new and existing, will occur, threatening the important rail link between Pretoria and Cape Town as it passes through Far West Rand, as well as the N12 between Johannesburg and Potchefstroom, as well as the N14 which lies to the east connecting the Gauteng Province and the North West Province. The dewatering of the compartments caused the soil which formed the roof of the cavities to dry. Re-watering will cause this dry, stable material to become wet and unstable. Where mixtures of slime and/or other material, which is not part of the geological composition of that area was used, the same phenomenon will apply. A further complication is caused by the slimes dams which are unlined. In fact, some of the slime dams were deliberately constructed over cavernous dolomite. This large mass of mine tailings over the dolomitic aquifers will “liquefy”. If the re-watering is not carefully managed the rising water table will undoubtedly trigger a rash of new sinkholes, with catastrophic consequences for unsuspecting communities that may have been established in sensitive areas. The results of previous investigations by the Departments Minerals, Energy and Water Affairs who, due to the loss of institutional memory, might not be able to find the relevant information. Other organizations such as the Council for Geoscience could be using the results for consultancy. The information should be digitized and be available to the broader South African public. FWRDWA is currently in charge of monitoring events in the area. Levelling observations have been carried out quarterly and, so far the movement of ground is minimal. The potential hazard of ground instability will recur with the re-watering of the dolomitic compartments of the Far West Rand. To support what could happen, reference is made to events which took place in the late seventies when the Far West Rand had an above average rainfall. The Donaldson Dam overflowed into the Wonderfontein Spruit and into the dewatered Venterspost compartment. As a result, the water level of the Venterspost Compartment rose rapidly which led to the re-activation of sinkholes and the formation of new ones in the Venterspost area. In the present work levelling has been carried out along most of the loops affected and the results of the levelling give an impression that the surface is currently relatively stable. This Dissertation is presented as an attempt to alert the authorities to the potential dangers if the post mining period is not carefully monitored and insufficient provision made to deal with potential contingencies.
- Full Text:
Recovery of base metals from nitric and sulphiric solutions using carbon nanotubes
- Authors: Mgwetyana, Unathi
- Date: 2014-01-27
- Subjects: Nanotubes , Extraction (Chemistry) , Heavy metals - Absorption and adsorption , Water - Purification - Adsorption
- Type: Thesis
- Identifier: uj:7961 , http://hdl.handle.net/10210/8861
- Description: M.Tech. (Extraction Metallurgy) , For many decades, carbon nanotubes (CNTs) have been used as adsorbents for the removal of pollutants from wastewaters because of their unique properties such as inert surface, resistance to acid and base environment, rigidity and strength. Herein is a report of application of functionalised CNTs on the adsorption of metal ions from aqueous solutions and mine leachates. The CNTs were first synthesised in-house, purified, functionalised and characterised with various characterisation techniques: FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscopy, TEM (Transmission Electron Microscopy), EDS (Energy Dispersive Spectroscopy), Raman Spectroscopy, TGA (Thermal Gravimetric Analysis) and BET (Brunauer-Emmet-Teller). Together, these techniques gave substantiation for structure, surface and chemical modification of the synthesised moieties. After characterisation, the functional groups were attached to the walls of the tubes and this implies successful functionalisation...
- Full Text:
- Authors: Mgwetyana, Unathi
- Date: 2014-01-27
- Subjects: Nanotubes , Extraction (Chemistry) , Heavy metals - Absorption and adsorption , Water - Purification - Adsorption
- Type: Thesis
- Identifier: uj:7961 , http://hdl.handle.net/10210/8861
- Description: M.Tech. (Extraction Metallurgy) , For many decades, carbon nanotubes (CNTs) have been used as adsorbents for the removal of pollutants from wastewaters because of their unique properties such as inert surface, resistance to acid and base environment, rigidity and strength. Herein is a report of application of functionalised CNTs on the adsorption of metal ions from aqueous solutions and mine leachates. The CNTs were first synthesised in-house, purified, functionalised and characterised with various characterisation techniques: FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscopy, TEM (Transmission Electron Microscopy), EDS (Energy Dispersive Spectroscopy), Raman Spectroscopy, TGA (Thermal Gravimetric Analysis) and BET (Brunauer-Emmet-Teller). Together, these techniques gave substantiation for structure, surface and chemical modification of the synthesised moieties. After characterisation, the functional groups were attached to the walls of the tubes and this implies successful functionalisation...
- Full Text:
An attempt into identification of suitable recovery process for nickel value from nickel sulfide ore and tailings
- Authors: Madiba, Mapilane S.
- Date: 2013-11-25
- Subjects: Nickel - Metallurgy , Nickel sulfide , Tailings (Metallurgy) , Leaching
- Type: Thesis
- Identifier: uj:7796 , http://hdl.handle.net/10210/8691
- Description: M.Tech (Metallurgy) , Nickel in South Africa is scarce. Other than as a by-product from platinum mining, its only source is the Uitkomst Complex, a satelite of the Bushveld Igneous Complex, located between Machadodorp and Barberton and mined by Nkomati Nickel. Pentlandite occurs as the main nickel-bearing mineral, disseminated within a sulfide matrix of pyrrhotite, pyrite and chalcopyrite. Accessories are of chromite and platinum in solid solution with the sulfides. The sulfides are hosted in mainly ultramafic rocks. The presence of talc is of particular nuisance. Head grade is in the decline, from earlier 0.7 to more recently 0.3% or even lower. Standard froth flotation yields a concentrate of 7 – 9% nickel at a recovery of up to 70%. A higher nickel recovery from such low – grade feed stock would be desirable. To achieve these two methods were investigated and reported in the following: Non-oxidative leaching as an alternative to flotation, using strong hydrochloric and sulfuric acid and also aqueous ammonia solutions at various liquid-to-solid ratios. Only the degree of nickel dissolution over time at room temperature was studied and no attempt was made to recover the dissolved metal from solution. Froth flotation after pre-treatment with microwaves at various power levels and over various periods of time of irradiation. It was surmised that a certain amount of inter-granular cracking could thus be achieved that would improve the flotation behavior in respect of grade and recovery. An extensive literature study, in particular, of the nature of microwaves, their interaction with matter and possible metallurgical benefits derived as a consequence of such interaction, forms part of the investigation and is reported in detail. A lot of theoretical and experimental work has been done in this respect, although the obtained results were not conclusive.
- Full Text:
- Authors: Madiba, Mapilane S.
- Date: 2013-11-25
- Subjects: Nickel - Metallurgy , Nickel sulfide , Tailings (Metallurgy) , Leaching
- Type: Thesis
- Identifier: uj:7796 , http://hdl.handle.net/10210/8691
- Description: M.Tech (Metallurgy) , Nickel in South Africa is scarce. Other than as a by-product from platinum mining, its only source is the Uitkomst Complex, a satelite of the Bushveld Igneous Complex, located between Machadodorp and Barberton and mined by Nkomati Nickel. Pentlandite occurs as the main nickel-bearing mineral, disseminated within a sulfide matrix of pyrrhotite, pyrite and chalcopyrite. Accessories are of chromite and platinum in solid solution with the sulfides. The sulfides are hosted in mainly ultramafic rocks. The presence of talc is of particular nuisance. Head grade is in the decline, from earlier 0.7 to more recently 0.3% or even lower. Standard froth flotation yields a concentrate of 7 – 9% nickel at a recovery of up to 70%. A higher nickel recovery from such low – grade feed stock would be desirable. To achieve these two methods were investigated and reported in the following: Non-oxidative leaching as an alternative to flotation, using strong hydrochloric and sulfuric acid and also aqueous ammonia solutions at various liquid-to-solid ratios. Only the degree of nickel dissolution over time at room temperature was studied and no attempt was made to recover the dissolved metal from solution. Froth flotation after pre-treatment with microwaves at various power levels and over various periods of time of irradiation. It was surmised that a certain amount of inter-granular cracking could thus be achieved that would improve the flotation behavior in respect of grade and recovery. An extensive literature study, in particular, of the nature of microwaves, their interaction with matter and possible metallurgical benefits derived as a consequence of such interaction, forms part of the investigation and is reported in detail. A lot of theoretical and experimental work has been done in this respect, although the obtained results were not conclusive.
- Full Text:
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