Recovery of nickel from reverberatory furnace slag by sulfurization and flotation
- Nheta, Willie, Kalenga, Michel, Rasivhetshele, Ndivhuwo
- Authors: Nheta, Willie , Kalenga, Michel , Rasivhetshele, Ndivhuwo
- Date: 2019
- Subjects: Flotation , Nickel , Sulfurization
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/399403 , uj:33287 , Citation: Nheta, W., Kalenga, M. & Rasivhetshele, N. 2019. Recovery of nickel from reverberatory furnace slag by sulfurization and flotation.
- Description: Abstract: Due to depletion of high-grade ores, high cost of mining and environmental issues, many mines have reverted to retreatment of slags. The recovery of Nickel from reverberatory furnace slag using sulfurization and flotation was studied. Critical parameters such as sulfurization temperature, sulfurization agent (Gypsum containing 86.87% CaSO4) dosage and time were investigated for the sulfurization process and effect of collector type and dosage, pH, particle size and flotation time for the flotation process. It was found that the slag contained 0.37% Cu and 0.19 % Ni as Copper oxide and Nickel oxide and other mineral phases such as fayalite, cuprospinnel and pentlandite. Optimum conditions for sulfurization were addition 20g of gypsum, 8g of Coke at a temperature of 950 under inert environment (argon) in a tube furnace for one hour. All of the Nickel oxide was sulfurized to Nickel sulfide and Millerite. 88.3 % Nickel was recovered after flotation under optimum conditions of 0.20g/t Potassium amyl xanthate (PAX), 5 drops of Dowfroth 200, 80% passing 75 microns at a pH of 7 in a micro flotation cell. The recovery of Nickel sulphide was very much dependent on collector dosage.
- Full Text:
- Authors: Nheta, Willie , Kalenga, Michel , Rasivhetshele, Ndivhuwo
- Date: 2019
- Subjects: Flotation , Nickel , Sulfurization
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/399403 , uj:33287 , Citation: Nheta, W., Kalenga, M. & Rasivhetshele, N. 2019. Recovery of nickel from reverberatory furnace slag by sulfurization and flotation.
- Description: Abstract: Due to depletion of high-grade ores, high cost of mining and environmental issues, many mines have reverted to retreatment of slags. The recovery of Nickel from reverberatory furnace slag using sulfurization and flotation was studied. Critical parameters such as sulfurization temperature, sulfurization agent (Gypsum containing 86.87% CaSO4) dosage and time were investigated for the sulfurization process and effect of collector type and dosage, pH, particle size and flotation time for the flotation process. It was found that the slag contained 0.37% Cu and 0.19 % Ni as Copper oxide and Nickel oxide and other mineral phases such as fayalite, cuprospinnel and pentlandite. Optimum conditions for sulfurization were addition 20g of gypsum, 8g of Coke at a temperature of 950 under inert environment (argon) in a tube furnace for one hour. All of the Nickel oxide was sulfurized to Nickel sulfide and Millerite. 88.3 % Nickel was recovered after flotation under optimum conditions of 0.20g/t Potassium amyl xanthate (PAX), 5 drops of Dowfroth 200, 80% passing 75 microns at a pH of 7 in a micro flotation cell. The recovery of Nickel sulphide was very much dependent on collector dosage.
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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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Leaching of Nickel from a Jarosite Precipitate with Hydrochloric Acid
- Nheta, Wilie and Makhatha, Mamookho E.
- Authors: Nheta, Wilie and Makhatha, Mamookho E.
- Date: 2013
- Subjects: Hydrochloric acid , Jarosite precipitate , Leaching , Nickel
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15943 , uj:15721 , Nheta, W. and Makhatha, M.E. 2013. Leaching of Nickel from a Jarosite Precipitate with Hydrochloric Acid. International Conference on Chemical and Environmental Engineering (ICCEE'2013), 15-16 April, 2013, Johannesburg (South Africa).
- Description: Abstract 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.
- Full Text:
- Authors: Nheta, Wilie and Makhatha, Mamookho E.
- Date: 2013
- Subjects: Hydrochloric acid , Jarosite precipitate , Leaching , Nickel
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15943 , uj:15721 , Nheta, W. and Makhatha, M.E. 2013. Leaching of Nickel from a Jarosite Precipitate with Hydrochloric Acid. International Conference on Chemical and Environmental Engineering (ICCEE'2013), 15-16 April, 2013, Johannesburg (South Africa).
- Description: Abstract 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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Parametric effects on leaching behavior of nickel-copper matte in ammonia
- Muzenda, E., Ramatsa, I. M., Ntuli, F., Abdulkareem, A. S., Afolabi, A. S.
- Authors: Muzenda, E. , Ramatsa, I. M. , Ntuli, F. , Abdulkareem, A. S. , Afolabi, A. S.
- Date: 2013
- Subjects: Ammonia concentration , Copper , Leaching temperature , Leaching time , Nickel
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17296 , uj:15867 , Citation: Muzenda, E. et al. 2013. Parametric effects on leaching behaviour of nickel-copper matte in ammonia. Particulate Science and Technology : An international Journal. 31(4): 319-325
- Description: Abstract: Please refer to full text for abstract
- Full Text:
- Authors: Muzenda, E. , Ramatsa, I. M. , Ntuli, F. , Abdulkareem, A. S. , Afolabi, A. S.
- Date: 2013
- Subjects: Ammonia concentration , Copper , Leaching temperature , Leaching time , Nickel
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17296 , uj:15867 , Citation: Muzenda, E. et al. 2013. Parametric effects on leaching behaviour of nickel-copper matte in ammonia. Particulate Science and Technology : An international Journal. 31(4): 319-325
- Description: Abstract: Please refer to full text for abstract
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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
Carbon dioxide hydrogenation over nickel-, ruthenium- and copperbased catalysts: review of kinetics and mechanism
- Authors: Jalama, Kalala
- Date: 2017
- Subjects: CO2 hydrogenation , Nickel , Ruthenium
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/246276 , uj:25526 , Citation: Jalama, K. 2017. Carbon dioxide hydrogenation over nickel-, ruthenium- and copperbased catalysts: review of kinetics and mechanism.
- Description: Abstract: This study critically reviews the mechanism of CO2 hydrogenation over Ni, Ru and Cu, and the effect of catalyst properties and operating conditions on reaction kinetics. Most studies have reported the presence of CO and formate species on Ni-, Ru- and Cu-based catalysts, where subsequent conversion of these species depends on the type of catalyst and the physicochemical properties of the catalyst support. Methane is the major product that forms during CO2 hydrogenation over Ni and Ru catalysts, while methanol and CO are mainly produced on Cu catalysts. A different approach for catalyst formulations and/or process development is required where long chain hydrocarbons are desired.
- Full Text:
- Authors: Jalama, Kalala
- Date: 2017
- Subjects: CO2 hydrogenation , Nickel , Ruthenium
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/246276 , uj:25526 , Citation: Jalama, K. 2017. Carbon dioxide hydrogenation over nickel-, ruthenium- and copperbased catalysts: review of kinetics and mechanism.
- Description: Abstract: This study critically reviews the mechanism of CO2 hydrogenation over Ni, Ru and Cu, and the effect of catalyst properties and operating conditions on reaction kinetics. Most studies have reported the presence of CO and formate species on Ni-, Ru- and Cu-based catalysts, where subsequent conversion of these species depends on the type of catalyst and the physicochemical properties of the catalyst support. Methane is the major product that forms during CO2 hydrogenation over Ni and Ru catalysts, while methanol and CO are mainly produced on Cu catalysts. A different approach for catalyst formulations and/or process development is required where long chain hydrocarbons are desired.
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Effect of calcium lignosulphonate and ethylene maleic anhydride on the particulate processes during hydrogen reduction of nickel ammine sulphate solutions
- Authors: Iloy, Rama Achtar
- Date: 2015
- Subjects: Reduction (Chemistry) , Maleic anhydride , Polyethylene , Nickel
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/56173 , uj:16339
- Description: Abstract: Since the inception of metal precipitation by hydrogen, it has been recognized that adding some organic compounds to the reduction solution accelerates the reaction, inhibits plating and helps control the resulting powder properties such as morphology, microstructure and particle size distribution, to name but a few. The powder properties are directly linked to the particulate processes taking place during reduction. Controlling these properties is crucial for downstream processes. For instance, in fuel cell technologies, the porosity of materials used to construct the electrodes is a critical parameter amongst others. However, in addition to their relatively high cost, additives’ function and mechanism of action are not well understood. Furthermore most of the additives are used on a trial and error basis. Since additives constitute one of the major operational costs, it becomes evident their use should be optimized. One of the most plausible options to achieve this is to develop an understanding of their mechanism of action. This dissertation assesses the effect of calcium lignosulphonate and ethylene maleic anhydride on the particulate processes taking place during the reduction of nickel ammine sulphate solutions by hydrogen gas. Reactions were carried out in an autoclave operated at 28 bar and 180°C under stirring conditions of 850 rpm. Five densifications were performed for each additive at the dosage of 2, 5, 7 and 10 mg/L. Particulate processes were studied by analysing the particle size distribution and the corresponding normalized moments. These were further validated by scanning electron microscopy and nitrogen physisorption analyses. The powder phase identification and purity were determined by means of X-ray diffraction and X-ray fluorescence respectively. Both calcium lignosulphonate and ethylene maleic anhydride acted as reduction catalysts under experimental conditions. Calcium lignosulphonate promoted growth and by extension agglomeration which was more pronounced at 10 mg/L. At lower concentrations of calcium lignosulphonate, the system was found to be dominated by breakage as validated by scanning electron micrographs. Although there was no significant difference in the nickel content of the powder obtained in the presence and absence of calcium lignosulphonate, the powder obtained at 10 mg/L additive dosage resulted in the highest sulphur content. Ethylene maleic anhydride on the other hand acted as a growth inhibitor and an anti-agglomerating agent, thus... , M.Tech. (Chemical Engineering)
- Full Text:
- Authors: Iloy, Rama Achtar
- Date: 2015
- Subjects: Reduction (Chemistry) , Maleic anhydride , Polyethylene , Nickel
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/56173 , uj:16339
- Description: Abstract: Since the inception of metal precipitation by hydrogen, it has been recognized that adding some organic compounds to the reduction solution accelerates the reaction, inhibits plating and helps control the resulting powder properties such as morphology, microstructure and particle size distribution, to name but a few. The powder properties are directly linked to the particulate processes taking place during reduction. Controlling these properties is crucial for downstream processes. For instance, in fuel cell technologies, the porosity of materials used to construct the electrodes is a critical parameter amongst others. However, in addition to their relatively high cost, additives’ function and mechanism of action are not well understood. Furthermore most of the additives are used on a trial and error basis. Since additives constitute one of the major operational costs, it becomes evident their use should be optimized. One of the most plausible options to achieve this is to develop an understanding of their mechanism of action. This dissertation assesses the effect of calcium lignosulphonate and ethylene maleic anhydride on the particulate processes taking place during the reduction of nickel ammine sulphate solutions by hydrogen gas. Reactions were carried out in an autoclave operated at 28 bar and 180°C under stirring conditions of 850 rpm. Five densifications were performed for each additive at the dosage of 2, 5, 7 and 10 mg/L. Particulate processes were studied by analysing the particle size distribution and the corresponding normalized moments. These were further validated by scanning electron microscopy and nitrogen physisorption analyses. The powder phase identification and purity were determined by means of X-ray diffraction and X-ray fluorescence respectively. Both calcium lignosulphonate and ethylene maleic anhydride acted as reduction catalysts under experimental conditions. Calcium lignosulphonate promoted growth and by extension agglomeration which was more pronounced at 10 mg/L. At lower concentrations of calcium lignosulphonate, the system was found to be dominated by breakage as validated by scanning electron micrographs. Although there was no significant difference in the nickel content of the powder obtained in the presence and absence of calcium lignosulphonate, the powder obtained at 10 mg/L additive dosage resulted in the highest sulphur content. Ethylene maleic anhydride on the other hand acted as a growth inhibitor and an anti-agglomerating agent, thus... , M.Tech. (Chemical Engineering)
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Synthesis and characterization of commercial pure titanium-nickel alloy behavior reinforced with titanium diboride
- Falodun, Oluwasegun Eso, Oke, Samuel Ranti, Olubambi, Peter Apata
- Authors: Falodun, Oluwasegun Eso , Oke, Samuel Ranti , Olubambi, Peter Apata
- Date: 2020
- Subjects: Titanium , Nickel , TiB2
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/458331 , uj:40705 , Falodun, O.E., Oke, S.R., Olubambi, P.A.: Synthesis and characterization of commercial pure titanium-nickel alloy behavior reinforced with titanium diboride.
- Description: Abstract: Commercial pure titanium alloy with Ni-TiB2 ceramic additions (5, 10, 15 and 20 vol.%) were synthesized through the spark plasma sintering approach with sintering temperature of 1000 oC, the heating rate of 100 oC/min, holding time of 5 min at a constant pressure of 50 MPa. The study investigated the effect of Ni-TiB2 on the densification, phase change, microhardness, microstructure, and wear properties of the sintered titanium-based composites. Results showed that Ti-Ni-TiB2 composites relative density ranges from 97 to 99 %, while microhardness values increase with addition of nickel and titanium diboride from 228 to 587 HV0.1. The microstructural evolution shows that pure titanium transformed from lamellar phase to equiaxed alpha phase upon addition of nickel alloy and further get refined with a distinct grain boundary comprises of titanium diboride around the boundaries. The average coefficient of friction for the titanium-based composite was higher for commercially pure titanium (0.73) while the addition of TiB2 exhibit (0.66, 0.63, 0.58, 0.55 and 0.46 respectively) improvement in the wear behavior.
- Full Text:
- Authors: Falodun, Oluwasegun Eso , Oke, Samuel Ranti , Olubambi, Peter Apata
- Date: 2020
- Subjects: Titanium , Nickel , TiB2
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/458331 , uj:40705 , Falodun, O.E., Oke, S.R., Olubambi, P.A.: Synthesis and characterization of commercial pure titanium-nickel alloy behavior reinforced with titanium diboride.
- Description: Abstract: Commercial pure titanium alloy with Ni-TiB2 ceramic additions (5, 10, 15 and 20 vol.%) were synthesized through the spark plasma sintering approach with sintering temperature of 1000 oC, the heating rate of 100 oC/min, holding time of 5 min at a constant pressure of 50 MPa. The study investigated the effect of Ni-TiB2 on the densification, phase change, microhardness, microstructure, and wear properties of the sintered titanium-based composites. Results showed that Ti-Ni-TiB2 composites relative density ranges from 97 to 99 %, while microhardness values increase with addition of nickel and titanium diboride from 228 to 587 HV0.1. The microstructural evolution shows that pure titanium transformed from lamellar phase to equiaxed alpha phase upon addition of nickel alloy and further get refined with a distinct grain boundary comprises of titanium diboride around the boundaries. The average coefficient of friction for the titanium-based composite was higher for commercially pure titanium (0.73) while the addition of TiB2 exhibit (0.66, 0.63, 0.58, 0.55 and 0.46 respectively) improvement in the wear behavior.
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Advances in microbial leaching processes for nickel extraction from lateritic minerals
- Behera, S.K., Mulaba-Bafubiandi, A.F.
- Authors: Behera, S.K. , Mulaba-Bafubiandi, A.F.
- Date: 2015-04-23
- Subjects: Nickel , Microbial mineral processing , Laterite
- Type: Article
- Identifier: uj:5116 , http://hdl.handle.net/10210/14074
- Description: Lateritic nickel minerals constitute about 80% of nickel reserves in the world, but their contribution for nickel production is about 40%. The obstacles in extraction of nickel from lateritic minerals are attributed to their very complex mineralogy and low nickel content. Hence, the existing metallurgical techniques are not techno-economically feasible and environmentally sustainable for processing of such complex deposits. At this juncture, microbial mineral processing could be a benevolent approach for processing of lateritic minerals in favor of nickel extraction. The microbial mineral processing route offers many advantages over conventional metallurgical methods as the process is operated under ambient conditions and requires low energy input; thus these processes are relatively simple and environment friendly. Microbial processing of the lateritic deposits still needs improvement to make it industrially viable. Microorganisms play the pivotal role in mineral bio-processing as they catalyze the extraction of metals from minerals. So it is inevitable to explore the physiological and bio-molecular mechanisms involved in this microbe-mineral interaction. The present article offers comprehensive information about the advances in microbial processes for extraction of nickel from laterites.
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- Authors: Behera, S.K. , Mulaba-Bafubiandi, A.F.
- Date: 2015-04-23
- Subjects: Nickel , Microbial mineral processing , Laterite
- Type: Article
- Identifier: uj:5116 , http://hdl.handle.net/10210/14074
- Description: Lateritic nickel minerals constitute about 80% of nickel reserves in the world, but their contribution for nickel production is about 40%. The obstacles in extraction of nickel from lateritic minerals are attributed to their very complex mineralogy and low nickel content. Hence, the existing metallurgical techniques are not techno-economically feasible and environmentally sustainable for processing of such complex deposits. At this juncture, microbial mineral processing could be a benevolent approach for processing of lateritic minerals in favor of nickel extraction. The microbial mineral processing route offers many advantages over conventional metallurgical methods as the process is operated under ambient conditions and requires low energy input; thus these processes are relatively simple and environment friendly. Microbial processing of the lateritic deposits still needs improvement to make it industrially viable. Microorganisms play the pivotal role in mineral bio-processing as they catalyze the extraction of metals from minerals. So it is inevitable to explore the physiological and bio-molecular mechanisms involved in this microbe-mineral interaction. The present article offers comprehensive information about the advances in microbial processes for extraction of nickel from laterites.
- Full Text:
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