Alkaline leaching of nickel bearing ammonium jarosite precipitate using KOH, NaOH and NH4OH in the presence of EDTA and Na2S
- Ntumba Malenga, E., Mulaba-Bafubiandi, A. F., Nheta, W.
- Authors: Ntumba Malenga, E. , Mulaba-Bafubiandi, A. F. , Nheta, W.
- Date: 2015-04-11
- Subjects: Alkaline leaching , Reducing agents , Complexing agents
- Type: Article
- Identifier: uj:5128 , http://hdl.handle.net/10210/14091
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Ntumba Malenga, E. , Mulaba-Bafubiandi, A. F. , Nheta, W.
- Date: 2015-04-11
- Subjects: Alkaline leaching , Reducing agents , Complexing agents
- Type: Article
- Identifier: uj:5128 , http://hdl.handle.net/10210/14091
- Description: Please refer to full text to view abstract
- Full Text:
Determination of economic liberation and mineralogical characteristics of Nigerian iron ore for effective processing
- Authors: Ola-Omole, O. O. , Nheta, W.
- Date: 2020
- Subjects: Hematite , Magnetite , Economic liberation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/450636 , uj:39624 , Citation: Ola-Omole, O. O. & Nheta, W. 2020. Determination of economic liberation and mineralogical characteristics of Nigerian iron ore for effective processing.
- Description: Abstract: Iron and steel play very important role in the economy of any nation because it is the yardstick for determining the rate of industrialisation of the countries. The present work studied the economic liberation and mineralogical characteristics of Nigerian low grade iron ore for effective processing. The ore studied was sourced from Itakpe an iron ore deposit in Nigeria. The sample was crushed sieved and characterized to understand the economic liberation and mineralogical characterization. Sieve analysis carried out based on the 2 method to choose 2300, 1700, 1180, 850, 600, 425, 300, 212, 150, 106, 75, and 63 μm sieves. Thereafter, Scanning Electron Microscopy (SEM) and Xray diffraction was carried out to study the mineralogical characteristics of the sample. The results obtained shows that the economic liberation of Itakpe is between -425 and +300 μm. The sample identity by SEM and XRD shows that the ore majorly contains hematite, magnetite and silica. It was therefore suggested that the ore can be concentrated by a combination of gravity separation method (jigging hydroclassifying or using the wifely shaking table) and magnetic separation to process the ore. Thereafter, more studies can investigation can be carried out to determine optimum parameters for flotation at lower particle sizes.
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- Authors: Ola-Omole, O. O. , Nheta, W.
- Date: 2020
- Subjects: Hematite , Magnetite , Economic liberation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/450636 , uj:39624 , Citation: Ola-Omole, O. O. & Nheta, W. 2020. Determination of economic liberation and mineralogical characteristics of Nigerian iron ore for effective processing.
- Description: Abstract: Iron and steel play very important role in the economy of any nation because it is the yardstick for determining the rate of industrialisation of the countries. The present work studied the economic liberation and mineralogical characteristics of Nigerian low grade iron ore for effective processing. The ore studied was sourced from Itakpe an iron ore deposit in Nigeria. The sample was crushed sieved and characterized to understand the economic liberation and mineralogical characterization. Sieve analysis carried out based on the 2 method to choose 2300, 1700, 1180, 850, 600, 425, 300, 212, 150, 106, 75, and 63 μm sieves. Thereafter, Scanning Electron Microscopy (SEM) and Xray diffraction was carried out to study the mineralogical characteristics of the sample. The results obtained shows that the economic liberation of Itakpe is between -425 and +300 μm. The sample identity by SEM and XRD shows that the ore majorly contains hematite, magnetite and silica. It was therefore suggested that the ore can be concentrated by a combination of gravity separation method (jigging hydroclassifying or using the wifely shaking table) and magnetic separation to process the ore. Thereafter, more studies can investigation can be carried out to determine optimum parameters for flotation at lower particle sizes.
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Effect of CaO/MgO ratio and basicity during tin smelting on the metal and slag formation (II)
- Seema, M. C., Wa Kalenga, M. K., Nheta, W.
- Authors: Seema, M. C. , Wa Kalenga, M. K. , Nheta, W.
- Date: 2019
- Subjects: Tin production , Basicity , CaO/MgO effect
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/399411 , uj:33288 , Citation:
- Description: Abstract: The current demand of some specific metals (alloys) in the HiTech industry has pushed researchers to increase the number of investigations to improve the quality of products on the market. Generally, coltan is a byproduct of tin metallurgy and is collected in the slag. The formation of phases in the slag needs to be investigated in order to optimize the collection of coltan in specific phases by trying different ratios in fluxes. Also, cassiterite is associated with iron ores and during smelting the iron get reduced together with tin and ends up contaminating the metal. The basicity is always a useful parameter that govern the behavior of the slag. Basicity was varied through addition of CaO and MgO. The CaO/MgO was varied by changing CaO and keeping MgO constant as opposed to previous study where CaO/MgO was varied by changing MgO and keeping CaO constant. Different basicities of 0.8, 1, 1.2, 1.3 and 1.4 were used...
- Full Text:
- Authors: Seema, M. C. , Wa Kalenga, M. K. , Nheta, W.
- Date: 2019
- Subjects: Tin production , Basicity , CaO/MgO effect
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/399411 , uj:33288 , Citation:
- Description: Abstract: The current demand of some specific metals (alloys) in the HiTech industry has pushed researchers to increase the number of investigations to improve the quality of products on the market. Generally, coltan is a byproduct of tin metallurgy and is collected in the slag. The formation of phases in the slag needs to be investigated in order to optimize the collection of coltan in specific phases by trying different ratios in fluxes. Also, cassiterite is associated with iron ores and during smelting the iron get reduced together with tin and ends up contaminating the metal. The basicity is always a useful parameter that govern the behavior of the slag. Basicity was varied through addition of CaO and MgO. The CaO/MgO was varied by changing CaO and keeping MgO constant as opposed to previous study where CaO/MgO was varied by changing MgO and keeping CaO constant. Different basicities of 0.8, 1, 1.2, 1.3 and 1.4 were used...
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Kinetic studies of nickel dissolution from ammonium jarosite precipitate in an alkaline medium
- Malenga, Edward Ntumba, Nheta, W., Mulaba-Bafubiandia, A.F.
- Authors: Malenga, Edward Ntumba , Nheta, W. , Mulaba-Bafubiandia, A.F.
- Date: 2014
- Subjects: Kinetics , Dissolution , Ammonium jarosite precipitate
- Type: Article
- Identifier: uj:4801 , http://hdl.handle.net/10210/12055
- Description: The dissolution kinetics of nickel from ammonium jarosite precipitate in an alkaline medium was investigated. The effects of various parameters were studied to optimize the dissolution conditions and to determine the kinetics on the leaching process based on the shrinking core model...
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- Authors: Malenga, Edward Ntumba , Nheta, W. , Mulaba-Bafubiandia, A.F.
- Date: 2014
- Subjects: Kinetics , Dissolution , Ammonium jarosite precipitate
- Type: Article
- Identifier: uj:4801 , http://hdl.handle.net/10210/12055
- Description: The dissolution kinetics of nickel from ammonium jarosite precipitate in an alkaline medium was investigated. The effects of various parameters were studied to optimize the dissolution conditions and to determine the kinetics on the leaching process based on the shrinking core model...
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Kinetics of vanadium bearing slag leaching with a mixture of organic acids
- Ola-omole, O. O., Nheta, W., Ntita, J.
- Authors: Ola-omole, O. O. , Nheta, W. , Ntita, J.
- Date: 2020
- Subjects: Bioleaching , Waste treatment , Leaching kinetics
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/459462 , uj:40848 , Citation: Ola-omole, O.O., Nheta, W. & Ntita, J. 2020. Kinetics of vanadium bearing slag leaching with a mixture of organic acids.
- Description: Abstract: An environmentally-friendly method based on hydrometallurgy was examined for the extraction of Vanadium (V) from vanadium steel slag using a mixture of organic acids. This method was utilized to mimic a bioleaching process of vanadium slag with microorganisms such as Pseudomonas putida which produce organic acids that act as leaching agents. A slag roasted with sodium carbonate was leached using a mixture of Gluconic, Citric and Oxalic acid (mixed in equal volumes of similar concentration) under the growing conditions of the microorganisms considered. The impact of various parameters such as acid concentration, solid-liquid ratio, particle size and temperature were examined. It was discovered that leaching with the mixed organic acids in the optimum conditions gave a V dissolution of 78%. The kinetics of the leaching process revealed that the V leaching process was an intermediate between a diffusion and a chemically controlled reaction with an activation energy of 34 kJ/mol during the initial ten minutes of the leaching process. After 10 minutes, the dissolution is a diffusion controlled reaction with an activation energy of 13kJ/mol. The main impurity (Al) was remarkably co-leached at an average of 66%.
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- Authors: Ola-omole, O. O. , Nheta, W. , Ntita, J.
- Date: 2020
- Subjects: Bioleaching , Waste treatment , Leaching kinetics
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/459462 , uj:40848 , Citation: Ola-omole, O.O., Nheta, W. & Ntita, J. 2020. Kinetics of vanadium bearing slag leaching with a mixture of organic acids.
- Description: Abstract: An environmentally-friendly method based on hydrometallurgy was examined for the extraction of Vanadium (V) from vanadium steel slag using a mixture of organic acids. This method was utilized to mimic a bioleaching process of vanadium slag with microorganisms such as Pseudomonas putida which produce organic acids that act as leaching agents. A slag roasted with sodium carbonate was leached using a mixture of Gluconic, Citric and Oxalic acid (mixed in equal volumes of similar concentration) under the growing conditions of the microorganisms considered. The impact of various parameters such as acid concentration, solid-liquid ratio, particle size and temperature were examined. It was discovered that leaching with the mixed organic acids in the optimum conditions gave a V dissolution of 78%. The kinetics of the leaching process revealed that the V leaching process was an intermediate between a diffusion and a chemically controlled reaction with an activation energy of 34 kJ/mol during the initial ten minutes of the leaching process. After 10 minutes, the dissolution is a diffusion controlled reaction with an activation energy of 13kJ/mol. The main impurity (Al) was remarkably co-leached at an average of 66%.
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Quantitative leaching of nickel from jarosite using sulphuric acid
- Authors: Makhatha, M. E , Nheta, W.
- Date: 2013
- Subjects: Sulphuric acid , Nickel , Jarosite , Leaching
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15446 , uj:15662 , Citation: Makhatha, M.E., Nheta, W. & Lamya, R. 2013. Quantitative leaching of nickel from jarosite using sulphuric acid. 23rd International Mining Congress and Exhibition of Turkey, 16-19 April, Antalya
- Description: Abstract: Please refer to full text to view abstract
- Full Text: false
- Authors: Makhatha, M. E , Nheta, W.
- Date: 2013
- Subjects: Sulphuric acid , Nickel , Jarosite , Leaching
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15446 , uj:15662 , Citation: Makhatha, M.E., Nheta, W. & Lamya, R. 2013. Quantitative leaching of nickel from jarosite using sulphuric acid. 23rd International Mining Congress and Exhibition of Turkey, 16-19 April, Antalya
- Description: Abstract: Please refer to full text to view abstract
- Full Text: false
Recent developments in beneficiation of fine and ultra-fine coal - Review paper
- Ramudzwagi, M., Tshiongo-Makgwe, N., Nheta, W.
- Authors: Ramudzwagi, M. , Tshiongo-Makgwe, N. , Nheta, W.
- Date: 2020
- Subjects: Coal fines , Ultra-fine coal , Beneficiation
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/450639 , uj:39625 , Citation: Ramudzwagi, M., Tshiongo-Makgwe, N. & Nheta, W. 2020. Recent developments in beneficiation of fine and ultra-fine coal - Review paper.
- Description: Abstract: Generation of fines and ultra-fine is concept that mining and metallurgical sector can never shy away from since exploration coal commodity began. These coal fines and ultra-fines are what coal mines regard(ed) as waste material without economic value until present moment. Poor technologies in the past lead to stockpiling of large quantity of fines and ultra-fines and again increase in mechanization in mining has led to the generation what is considered as waste in large quantities making it thus difficult to treat the coal. This paper reviews recent developments in minerals processing beneficiation technologies of coal fines and coal ultra-fines.
- Full Text:
- Authors: Ramudzwagi, M. , Tshiongo-Makgwe, N. , Nheta, W.
- Date: 2020
- Subjects: Coal fines , Ultra-fine coal , Beneficiation
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/450639 , uj:39625 , Citation: Ramudzwagi, M., Tshiongo-Makgwe, N. & Nheta, W. 2020. Recent developments in beneficiation of fine and ultra-fine coal - Review paper.
- Description: Abstract: Generation of fines and ultra-fine is concept that mining and metallurgical sector can never shy away from since exploration coal commodity began. These coal fines and ultra-fines are what coal mines regard(ed) as waste material without economic value until present moment. Poor technologies in the past lead to stockpiling of large quantity of fines and ultra-fines and again increase in mechanization in mining has led to the generation what is considered as waste in large quantities making it thus difficult to treat the coal. This paper reviews recent developments in minerals processing beneficiation technologies of coal fines and coal ultra-fines.
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Selective leaching of vanadium from vanadium slag using organic acids
- Ntita, J., Nheta, W., Staden, Petrus V.
- Authors: Ntita, J. , Nheta, W. , Staden, Petrus V.
- Date: 2017
- Subjects: Leaching , Organic acids , Slag
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/256874 , uj:26973 , Citation: Ntita, J., Nheta, W. & Staden, Petrus V. 2017. Selective leaching of vanadium from vanadium slag using organic acids.
- Description: Abstract: Large amounts of vanadium bearing slags are produced during steel making and discarded to the environment. Bioleaching has proved that it is an environmentally friendly route which has been lately used for recovery of metals. The leaching of vanadium from a roasted slag was studied using gluconic, citric and oxalic acids. The vanadium slag was roasted at 900oC in presence of Na2CO3 prior to leaching. The effect of acid concentration, solid/liquid ratio, particles size and temperature were investigated. It was observed that at a concentration of 150mM for gluconic acid and 100mM of citric and oxalic acid, 2% of S/L ratio, -38μm and temperature of 45oC, 91, 86 and 81% of vanadium were recovered from gluconic, citric and oxalic acid respectively. Recovery of vanadium using gluconic acid is affected more by the acid concentration compared to citric and oxalic acids. The solid/ liquid ratio as well as the particle size increase have a negative effect on the recovery of each acid and the temperature increase allows to enhance the recovery.
- Full Text:
- Authors: Ntita, J. , Nheta, W. , Staden, Petrus V.
- Date: 2017
- Subjects: Leaching , Organic acids , Slag
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/256874 , uj:26973 , Citation: Ntita, J., Nheta, W. & Staden, Petrus V. 2017. Selective leaching of vanadium from vanadium slag using organic acids.
- Description: Abstract: Large amounts of vanadium bearing slags are produced during steel making and discarded to the environment. Bioleaching has proved that it is an environmentally friendly route which has been lately used for recovery of metals. The leaching of vanadium from a roasted slag was studied using gluconic, citric and oxalic acids. The vanadium slag was roasted at 900oC in presence of Na2CO3 prior to leaching. The effect of acid concentration, solid/liquid ratio, particles size and temperature were investigated. It was observed that at a concentration of 150mM for gluconic acid and 100mM of citric and oxalic acid, 2% of S/L ratio, -38μm and temperature of 45oC, 91, 86 and 81% of vanadium were recovered from gluconic, citric and oxalic acid respectively. Recovery of vanadium using gluconic acid is affected more by the acid concentration compared to citric and oxalic acids. The solid/ liquid ratio as well as the particle size increase have a negative effect on the recovery of each acid and the temperature increase allows to enhance the recovery.
- Full Text:
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