Characterisation of jarosite, fly ash and clay for their possible usage in the construction industry
- Makhatha, Mamookho E., Ndou, Muneiwa O., Nheta, Willie, Mubiayi, Patrick M.
- Authors: Makhatha, Mamookho E. , Ndou, Muneiwa O. , Nheta, Willie , Mubiayi, Patrick M.
- Date: 2015-07-20
- Subjects: Clay , Jarosite , Fly-ash
- Type: Article
- Identifier: uj:5165 , http://hdl.handle.net/10210/14402
- Description: In this paper, the mineralogical and physical characterisation of Jarosite, Clay and Fly ash was investigated. The XRD results revealed the presence of alacranite (AsS) and jarosite (K (Fe3(SO4)2(OH)6)) mineral phases in the hazardous jarosite, while clay was composed of Kaolinite (Al2Si2O5 (OH)4), Anatase (TiO2) and Quartz (SiO2). Furthermore, Fly ash contained phases Mullite (Al4.64Si1.36O9.68), Quartz (SiO2) and Calcium oxide silicate chloride (Ca2O2Si3Cl2). The XRF results confirmed that the Fly ash used is in class F (Hazardous material) . There were hazardous elements such as As and Pb in the Jarosite sample. Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM/EDS) revealed differences in surfaces morphology and EDS results were in agreement with the XRF analysis. The densities of the samples were 3.13 g/cm3 , 2.67 g/cm3 and 2.21 g/cm3 for Jarosite, clay and Fly ash respectively. There was an increase in density with the increase of the percentage of Jarosite in the mixture whereas a decrease in density was noticed with the increase of Fly ash percentage in the mixture of Jarosite and clay.
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Characterisation of jarosite, fly ash and clay for their possible usage in the construction industry
- Authors: Makhatha, Mamookho E. , Ndou, Muneiwa O. , Nheta, Willie , Mubiayi, Patrick M.
- Date: 2015-07-20
- Subjects: Clay , Jarosite , Fly-ash
- Type: Article
- Identifier: uj:5165 , http://hdl.handle.net/10210/14402
- Description: In this paper, the mineralogical and physical characterisation of Jarosite, Clay and Fly ash was investigated. The XRD results revealed the presence of alacranite (AsS) and jarosite (K (Fe3(SO4)2(OH)6)) mineral phases in the hazardous jarosite, while clay was composed of Kaolinite (Al2Si2O5 (OH)4), Anatase (TiO2) and Quartz (SiO2). Furthermore, Fly ash contained phases Mullite (Al4.64Si1.36O9.68), Quartz (SiO2) and Calcium oxide silicate chloride (Ca2O2Si3Cl2). The XRF results confirmed that the Fly ash used is in class F (Hazardous material) . There were hazardous elements such as As and Pb in the Jarosite sample. Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM/EDS) revealed differences in surfaces morphology and EDS results were in agreement with the XRF analysis. The densities of the samples were 3.13 g/cm3 , 2.67 g/cm3 and 2.21 g/cm3 for Jarosite, clay and Fly ash respectively. There was an increase in density with the increase of the percentage of Jarosite in the mixture whereas a decrease in density was noticed with the increase of Fly ash percentage in the mixture of Jarosite and clay.
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Characterization of South African waste foundry molding sand : metallic contaminants
- Nyembwe, J. K., Makhatha, Mamookho E., Madzivhandila, T ., Nyembwe, K. D.
- Authors: Nyembwe, J. K. , Makhatha, Mamookho E. , Madzivhandila, T . , Nyembwe, K. D.
- Date: 2015-07-20
- Subjects: Foundry waste , Leaching , Hazardous wastes
- Type: Article
- Identifier: uj:5173 , http://hdl.handle.net/10210/14414
- Description: Waste foundry sands are invariably contaminated to some extent during the manufacturing of cast alloys. As such the sand is regarded as a hazardous material that requires exceptional precautions for its disposal. Therefore, the study is initiated to identify, quantify and to classify metallic contaminants present in these sands. To achieve these objectives in conjunction with the South African Waste Management Act which plays as the guideline for industrial waste disposal, samples were collected from various South African foundries. In the present study, ten waste sand samples were characterised using XRF, XRD, SEM-EDS and Sulphur analyser. It was found after comparison with a virgin sand used as control or reference sand, that the cast alloy and the moulding additives are the main pollutants present in the waste foundry sand. The additional sulphur and acid potential characterisation, showed that the waste foundry sand has a low potential for sulphuric acid and acid sulphate soil formation when submerged in aquatic medium. The leaching behaviour and the total metallic concentration of the waste was similar to the virgin soil thus their similar classification in the same waste class category.
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- Authors: Nyembwe, J. K. , Makhatha, Mamookho E. , Madzivhandila, T . , Nyembwe, K. D.
- Date: 2015-07-20
- Subjects: Foundry waste , Leaching , Hazardous wastes
- Type: Article
- Identifier: uj:5173 , http://hdl.handle.net/10210/14414
- Description: Waste foundry sands are invariably contaminated to some extent during the manufacturing of cast alloys. As such the sand is regarded as a hazardous material that requires exceptional precautions for its disposal. Therefore, the study is initiated to identify, quantify and to classify metallic contaminants present in these sands. To achieve these objectives in conjunction with the South African Waste Management Act which plays as the guideline for industrial waste disposal, samples were collected from various South African foundries. In the present study, ten waste sand samples were characterised using XRF, XRD, SEM-EDS and Sulphur analyser. It was found after comparison with a virgin sand used as control or reference sand, that the cast alloy and the moulding additives are the main pollutants present in the waste foundry sand. The additional sulphur and acid potential characterisation, showed that the waste foundry sand has a low potential for sulphuric acid and acid sulphate soil formation when submerged in aquatic medium. The leaching behaviour and the total metallic concentration of the waste was similar to the virgin soil thus their similar classification in the same waste class category.
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Experimental characterization of physicochemical and geological properties of granite from Olowu, Ibadan, Oyo State, Nigeria
- Oluwagbemiga Alayande, S., Mubiayi, Mukuna P., Makhatha, Mamookho E., Derek, Rose
- Authors: Oluwagbemiga Alayande, S. , Mubiayi, Mukuna P. , Makhatha, Mamookho E. , Derek, Rose
- Date: 2015
- Subjects: Geology - Nigeria , Granite - Nigeria
- Type: Article
- Identifier: uj:5184 , ISBN 9781927877173 , http://hdl.handle.net/10210/14426
- Description: Understanding of the nature and chemistry of valuable minerals in our environment is an asset for maximum exploitation for human need. The physicochemical and geological properties of natural rock samples from Egbeda, Oyo State, Nigeria were studied to categorize the rock samples and to establish their potential applications. The rock samples were characterized using various techniques including XRD, XRF, FTIR, SEM/EDS, TAS plot, BET and water absorption properties. Physicochemical and geological properties confirmed the sample to be granite with low water absorption capacity. The granite is a potential raw material that can be used for exterior walls, interior walls, floor tiles and kitchen walls.
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- Authors: Oluwagbemiga Alayande, S. , Mubiayi, Mukuna P. , Makhatha, Mamookho E. , Derek, Rose
- Date: 2015
- Subjects: Geology - Nigeria , Granite - Nigeria
- Type: Article
- Identifier: uj:5184 , ISBN 9781927877173 , http://hdl.handle.net/10210/14426
- Description: Understanding of the nature and chemistry of valuable minerals in our environment is an asset for maximum exploitation for human need. The physicochemical and geological properties of natural rock samples from Egbeda, Oyo State, Nigeria were studied to categorize the rock samples and to establish their potential applications. The rock samples were characterized using various techniques including XRD, XRF, FTIR, SEM/EDS, TAS plot, BET and water absorption properties. Physicochemical and geological properties confirmed the sample to be granite with low water absorption capacity. The granite is a potential raw material that can be used for exterior walls, interior walls, floor tiles and kitchen walls.
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Leaching of nickel from a jarosite precipitate with hydrochloric acid
- Nheta, Willie, Makhatha, Mamookho E.
- Authors: Nheta, Willie , Makhatha, Mamookho E.
- Date: 2013
- Subjects: Hydrochloric acid , Leaching , Nickel , Jarosite precipitates
- Type: Article
- Identifier: uj:4969 , http://hdl.handle.net/10210/13070
- Description: Jarosite precipitates produced at Impala’s Base Metal Refineries contain substantial amounts of nickel. Laboratory-scale experiments were carried out in an attempt to recover nickel by leaching with hydrochloric acid. The leaching efficiency of nickel was 60% at 25oC. The acid concentration of 0.5 – 1 molar, pulp density of 10% and leaching time of 90 min was found to be optimum under the present conditions. High pH could break the jarosite structure and release more iron into the solution which will adversely affect the following precipitation process to recover nickel. 27% of the nickel lost is by entrainment. The reaction is diffusion independent.
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- Authors: Nheta, Willie , Makhatha, Mamookho E.
- Date: 2013
- Subjects: Hydrochloric acid , Leaching , Nickel , Jarosite precipitates
- Type: Article
- Identifier: uj:4969 , http://hdl.handle.net/10210/13070
- Description: Jarosite precipitates produced at Impala’s Base Metal Refineries contain substantial amounts of nickel. Laboratory-scale experiments were carried out in an attempt to recover nickel by leaching with hydrochloric acid. The leaching efficiency of nickel was 60% at 25oC. The acid concentration of 0.5 – 1 molar, pulp density of 10% and leaching time of 90 min was found to be optimum under the present conditions. High pH could break the jarosite structure and release more iron into the solution which will adversely affect the following precipitation process to recover nickel. 27% of the nickel lost is by entrainment. The reaction is diffusion independent.
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Physico-chemical characterization of South African waste moulding sands
- Nyembwe, Kolela J., Makhatha, Mamookho E., Madzivhandila, Takalani
- Authors: Nyembwe, Kolela J. , Makhatha, Mamookho E. , Madzivhandila, Takalani
- Date: 2016
- Subjects: Waste sands , Mineralogical composition
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/217483 , uj:21645 , Citation: Nyembwe, K.J., Makhatha, M.E. & Madzivhandila, T. 2016. Physico-chemical characterization of South African waste moulding sands. Engineering journal, 20(5):35-49. http://www.engj.org/ DOI:10.4186/ej.2016.20.5.35 , ISSN: 0125-8281
- Description: Abstract: Dry analysis techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscope (SEM-EDS) and Fourier Transform Infra-red (FTIR) have been used to assess the physico-chemical of waste sand samples, obtained from different local foundry. The casting process involved included Aluminum in shell sand, brass under alky urethane, grey iron in greensand moulding, high chrome using furan sand, steel casting in alkaline phenolic and lastly cast iron from greensand mould. The study revealed the transformations and changes which have taken place in the waste sand due to the casting process, in terms of chemical composition, mineralogy, morphology and bonding types. The study demonstrated that the waste sand after the casting process was a completely new material, compared to the original virgin sand used for moulding process.
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- Authors: Nyembwe, Kolela J. , Makhatha, Mamookho E. , Madzivhandila, Takalani
- Date: 2016
- Subjects: Waste sands , Mineralogical composition
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/217483 , uj:21645 , Citation: Nyembwe, K.J., Makhatha, M.E. & Madzivhandila, T. 2016. Physico-chemical characterization of South African waste moulding sands. Engineering journal, 20(5):35-49. http://www.engj.org/ DOI:10.4186/ej.2016.20.5.35 , ISSN: 0125-8281
- Description: Abstract: Dry analysis techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscope (SEM-EDS) and Fourier Transform Infra-red (FTIR) have been used to assess the physico-chemical of waste sand samples, obtained from different local foundry. The casting process involved included Aluminum in shell sand, brass under alky urethane, grey iron in greensand moulding, high chrome using furan sand, steel casting in alkaline phenolic and lastly cast iron from greensand mould. The study revealed the transformations and changes which have taken place in the waste sand due to the casting process, in terms of chemical composition, mineralogy, morphology and bonding types. The study demonstrated that the waste sand after the casting process was a completely new material, compared to the original virgin sand used for moulding process.
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Waste foundry sand mineralogical characterisation : the impact of cast alloy, casting temperature and molding additive on the nature waste foundry sand
- Nyembwe, Kolela J., Makhatha, Mamookho E., Mageza, Kulani
- Authors: Nyembwe, Kolela J. , Makhatha, Mamookho E. , Mageza, Kulani
- Date: 2017
- Subjects: Foundry , Waste sand , Mineral
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/255634 , uj:26818 , Citation: Nyembwe, K.J., Makhatha, M.E. & Mageza, K. 2017. Waste foundry sand mineralogical characterisation : the impact of cast alloy, casting temperature and molding additive on the nature waste foundry sand. ENGINEERING JOURNAL Volume 21 Issue 7. Online at http://www.engj.org/ DOI:10.4186/ej.2017.21.7.1 , DOI: 10.4186/ej.2017.21.7.1
- Description: Abstract: The metal casting industry discharges huge volumes of waste foundry sand yearly. It was estimated to be 250 thousand tons of spent silica foundry sand for the existing 200 casting facilities in South Africa. Even though, establish documents exist in regards to the foundry sand composition, few well documented theories are available in regards to changes or mutations taking place after casting process. Four waste silica casting sands were qualitatively analyzed for they mineralogical phases composition using the X-ray diffraction (XRD). The investigation was conducted on various waste casting sand alloy including aluminum, cast iron, high chrome and steel. The result revealed a significant compositional difference related to the molding binder and casting temperature. Different silica phase’s polymorph, related to the various alloy casting temperature, were observed in waste sand samples. Theses phases included alpha quartz, tridymite, and alpha cristobelite. The molding binder favored the crystalisation of bentonite related mineral such as periclase, microcline and wustite, within the greensand system. The chemically bonded sand exposed the presence of anorthite as the only existing mineralized phase in the resin sand. The mineralogical content of the waste foundry sand provides information on the molding binder used. In addition to that, silica polymorph it informs about the pouring temperature related to the cast alloy.
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- Authors: Nyembwe, Kolela J. , Makhatha, Mamookho E. , Mageza, Kulani
- Date: 2017
- Subjects: Foundry , Waste sand , Mineral
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/255634 , uj:26818 , Citation: Nyembwe, K.J., Makhatha, M.E. & Mageza, K. 2017. Waste foundry sand mineralogical characterisation : the impact of cast alloy, casting temperature and molding additive on the nature waste foundry sand. ENGINEERING JOURNAL Volume 21 Issue 7. Online at http://www.engj.org/ DOI:10.4186/ej.2017.21.7.1 , DOI: 10.4186/ej.2017.21.7.1
- Description: Abstract: The metal casting industry discharges huge volumes of waste foundry sand yearly. It was estimated to be 250 thousand tons of spent silica foundry sand for the existing 200 casting facilities in South Africa. Even though, establish documents exist in regards to the foundry sand composition, few well documented theories are available in regards to changes or mutations taking place after casting process. Four waste silica casting sands were qualitatively analyzed for they mineralogical phases composition using the X-ray diffraction (XRD). The investigation was conducted on various waste casting sand alloy including aluminum, cast iron, high chrome and steel. The result revealed a significant compositional difference related to the molding binder and casting temperature. Different silica phase’s polymorph, related to the various alloy casting temperature, were observed in waste sand samples. Theses phases included alpha quartz, tridymite, and alpha cristobelite. The molding binder favored the crystalisation of bentonite related mineral such as periclase, microcline and wustite, within the greensand system. The chemically bonded sand exposed the presence of anorthite as the only existing mineralized phase in the resin sand. The mineralogical content of the waste foundry sand provides information on the molding binder used. In addition to that, silica polymorph it informs about the pouring temperature related to the cast alloy.
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