Polarization and potentiometric studies of cobalt and copper oxidised ores in ammonium chloride medium
- Mbuyi, Noella M., Mulaba-Bafubiandi, Antoine F., Adams, Feyisayo V.
- Authors: Mbuyi, Noella M. , Mulaba-Bafubiandi, Antoine F. , Adams, Feyisayo V.
- Date: 2014
- Subjects: Ammonium chloride , Copper oxide ores , Cobalt oxide ores
- Type: Article
- Identifier: uj:4909 , ISSN 2349-1442 , http://hdl.handle.net/10210/13009
- Description: This research study was conducted to evaluate the dissolution and electrochemical behaviour of low grade Cu-Co oxide ore (0.4% Cu; 3% Co) in ammonium chloride media (NH4Cl) by means of polarization and potentiometric measurements. Polarization measurements were carried out to evaluate the electrochemical behaviour as well as the leaching and re-passivation behaviour of the ores at pH of 9.5, 9.6, 9.7 and 9.8 in NH4Cl solution. In all the pH tested, the potential changed from negative to electropositive values suggesting formation of passive film on the surface of the ore which lowered the dissolution rates. Stable behaviours as were as high dissolution rate were observed at pH of 9.5. Potentiometric measurements were carried out at constant current and varying potential to study the reactivity of Cu-Co oxide ores in 0.25M, 0.5M and 1M of NH4Cl solution. In this test the dissolution rates increased with increasing concentration and the pH decreased with increasing concentration and time suggesting production of acid as oxidation reaction takes place, the ranges of pH are depicted in the Pourbaix diagrams. Stable behaviours were observed in 1M of solution. All observations made in these measurements are confirmed by AAS, XRF, SEM and XRD analysis.
- Full Text:
- Authors: Mbuyi, Noella M. , Mulaba-Bafubiandi, Antoine F. , Adams, Feyisayo V.
- Date: 2014
- Subjects: Ammonium chloride , Copper oxide ores , Cobalt oxide ores
- Type: Article
- Identifier: uj:4909 , ISSN 2349-1442 , http://hdl.handle.net/10210/13009
- Description: This research study was conducted to evaluate the dissolution and electrochemical behaviour of low grade Cu-Co oxide ore (0.4% Cu; 3% Co) in ammonium chloride media (NH4Cl) by means of polarization and potentiometric measurements. Polarization measurements were carried out to evaluate the electrochemical behaviour as well as the leaching and re-passivation behaviour of the ores at pH of 9.5, 9.6, 9.7 and 9.8 in NH4Cl solution. In all the pH tested, the potential changed from negative to electropositive values suggesting formation of passive film on the surface of the ore which lowered the dissolution rates. Stable behaviours as were as high dissolution rate were observed at pH of 9.5. Potentiometric measurements were carried out at constant current and varying potential to study the reactivity of Cu-Co oxide ores in 0.25M, 0.5M and 1M of NH4Cl solution. In this test the dissolution rates increased with increasing concentration and the pH decreased with increasing concentration and time suggesting production of acid as oxidation reaction takes place, the ranges of pH are depicted in the Pourbaix diagrams. Stable behaviours were observed in 1M of solution. All observations made in these measurements are confirmed by AAS, XRF, SEM and XRD analysis.
- Full Text:
Technological assessment of product screens (137sc16/17) performance
- Mbuyi, Noella M., Randigwane, A., Bolha, W., Anyimadu, A., Mulaba-Bafubiandi, Antoine F.
- Authors: Mbuyi, Noella M. , Randigwane, A. , Bolha, W. , Anyimadu, A. , Mulaba-Bafubiandi, Antoine F.
- Date: 2014
- Subjects: Screens performance , Particle size distribution
- Type: Article
- Identifier: uj:4907 , ISSN 2349-1442 , http://hdl.handle.net/10210/13007
- Description: Performance of two product screens (137Sc-16/17) constantly flooding at UG2 plant were assessed. Root causes for the flooding were investigated as well as a benchmarking with the performance of non-flooding screens performance. Samples for the screens 137Sc-16/17 feed and oversize were collected for three days, and prepared according to plant standards for sample preparations in order to obtain the particle size distribution (PSD). The first PSD results of the feed were given to Barcandyle which is mechanical engineering experts for screen sizing and their findings were used in this project for optimization purposes. The PSDs of the screens undersize, oversize and feed were used to draw cumulative percent passing and these graphs were used with the effective formula in order to determine screen performances. It was observed that 137SC-17 was more efficient than 137SC-16 and also that the major cause of flooding was due to the woodchips blinding the screen panels. From these findings the aperture size of 137SC-16 was changed from 0.63mm to 0.8mm. The screens still flood during spikes time due insufficient picking points for wood at UG2 plant.
- Full Text:
- Authors: Mbuyi, Noella M. , Randigwane, A. , Bolha, W. , Anyimadu, A. , Mulaba-Bafubiandi, Antoine F.
- Date: 2014
- Subjects: Screens performance , Particle size distribution
- Type: Article
- Identifier: uj:4907 , ISSN 2349-1442 , http://hdl.handle.net/10210/13007
- Description: Performance of two product screens (137Sc-16/17) constantly flooding at UG2 plant were assessed. Root causes for the flooding were investigated as well as a benchmarking with the performance of non-flooding screens performance. Samples for the screens 137Sc-16/17 feed and oversize were collected for three days, and prepared according to plant standards for sample preparations in order to obtain the particle size distribution (PSD). The first PSD results of the feed were given to Barcandyle which is mechanical engineering experts for screen sizing and their findings were used in this project for optimization purposes. The PSDs of the screens undersize, oversize and feed were used to draw cumulative percent passing and these graphs were used with the effective formula in order to determine screen performances. It was observed that 137SC-17 was more efficient than 137SC-16 and also that the major cause of flooding was due to the woodchips blinding the screen panels. From these findings the aperture size of 137SC-16 was changed from 0.63mm to 0.8mm. The screens still flood during spikes time due insufficient picking points for wood at UG2 plant.
- Full Text:
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