678 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
the use of SPW has a positive impact on Gn flotation as it
dampens the detrimental effects of dissolved Fe and Pb ions
on Pb recovery.
CONCLUSIONS
This paper reports on an investigation into the role which Fe
ions may have on the flotation performance of a synthetic
mixture of pyrite and galena. In order to decouple the effect
of Fe ions emanating from the pyrite ore from those com-
ing from the milling media, experiments were carried out
using either forged steel media which would create Fe spe-
cies through dissolution from either the media or the pyrite
ore and ceramic media in which case the only source of the
Fe would be the pyrite ore. Moreover, experiments were car-
ried out using deionised water and a synthetic water sample
typical of those occurring on flotation concentrators. Eh
values were also determined to investigate whether galvanic
interactions may be influencing the system. The Fe grades
and recoveries were comparable for both the FS-DI (11.6
wt.% Fe 59.5%) and FS-SPW (13.3 wt.% Fe 55.6%) case
suggesting that water type did not significantly impact Py
flotation. However, Fe recoveries were always greater when
ceramic media were used indicating that the Fe species
emanating from the media reduced the recoveries of pyrite.
Fe grades were higher when FS media were used suggesting
that the Fe species from the media were reducing gangue
(quartz) recovery. In the case of galena, the recoveries were
generally higher when ceramic media were used, again indi-
cating that Fe from the milling media was reducing galena
recoveries. As in the case of pyrite, the presence of ions in
the water did not have any significant effect on flotation
performance when using ceramic media the highest solid
and water recoveries were obtained when ceramic media
were used irrespective of water quality. Eh values followed
the pH trends, but it is difficult to draw any conclusions
about the galvanic interactions which may be occurring.
The values at the lower pHs suggest that the formation of
dixanthogen is favoured. Overall, it can be concluded that
using forged steel media reduced recoveries of both pyrite
and galena but marginally increased grades probably due to
reducing quartz/gangue recovery. Water quality, in most of
the conditions under investigation, did not have a signifi-
cant effect indicating that using recycled water high in ionic
strength would not adversely flotation performance. This
study provides some key insights into the factors affecting
mixed ore flotation processes when different milling media,
operating pH, and process water quality are used and may
contribute to a better understanding of when such param-
eters are to be changed in operations.
REFERENCES
[1] W. Liu, C. J. Moran, and S. Vink, ‘A Review of the
Effect of Water Quality on Flotation’, Miner. Eng.,
vol. 53, pp. 91–100, Nov. 2013, doi: 10.1016/j.
mineng.2013.07.011.
[2] D. Pashkevich, R. Li, and K. Waters, ‘Temperature
and climate-induced fluctuations in froth flotation:
an overview of different ore types’, Can. Metall.
Q., vol. 62, no. 3, pp. 511–548, Jul. 2023, doi:
10.1080/00084433.2022.2127788.
[3] A. Rabieh, B. Albijanic, and J. J. Eksteen, ‘A Review
of the Effects of Grinding Media and Chemical
Conditions on the Flotation of Pyrite in Refractory
Gold Operations’, Miner. Eng., vol. 94, pp. 21–28,
Aug. 2016, doi: 10.1016/j.mineng.2016.04.012.
[4] D. Fornasiero and J. Ralston, ‘Iron hydroxide com-
plexes and their influence on the interaction between
ethyl xanthate and pyrite’, J. Colloid Interface Sci.,
vol. 151, no. 1, pp. 225–235, Jun. 1992, doi:
10.1016/0021-9797(92)90253-I.
[5] M. Jefferson et al., ‘Effect of pyrite textures and com-
position on flotation performance: A review’, Miner.
Eng., vol. 201, p. 108234, Oct. 2023, doi: 10.1016/j.
mineng.2023.108234.
[6] Y. Peng, S. Grano, D. Fornasiero, and J. Ralston,
‘Control of Grinding Conditions in the Flotation of
Galena and Its Separation from Pyrite’, Int. J. Miner.
Process., vol. 70, no. 1, pp. 67–82, Jun. 2003, doi:
10.1016/S0301-7516(02)00153-9.
[7] Y. Mu, Y. Cheng, and Y. Peng, ‘The Interaction of
Grinding Media and Collector in Pyrite Flotation at
Alkaline pH’, Miner. Eng., vol. 152, p. 106344, Jun.
2020, doi: 10.1016/j.mineng.2020.106344.
[8] C. Greet, ‘The Significance of Grinding Environment
on the Flotation of UG2 Ores’, J. South. Afr. Inst.
Min. Metall., vol. 109, no. 1, pp. 31–37, 2009.
[9] H. Majima, ‘How Oxidation Affects Selective
Flotation of Complex Sulphide Ores’, Can. Metall.
Q., vol. 8, no. 3, pp. 269–273, Jul. 1969, doi:
10.1179/cmq.1969.8.3.269.
[10] S. R. Rao and J. A. Finch, ‘Galvanic Interaction
Studies on Sulphide Minerals’, Can. Metall. Q., vol.
27, no. 4, pp. 253–259, Oct. 1988, doi: 10.1179/
cmq.1988.27.4.253.
[11] K. L. Pinetown, C. R. Ward, and W. A. van der
Westhuizen, ‘Quantitative Evaluation of Minerals
in Coal Deposits in the Witbank and Highveld
Coalfields, and the Potential Impact on Acid Mine
Drainage’, TSOP 2004, vol. 70, no. 1, pp. 166–183,
Apr. 2007, doi: 10.1016/j.coal.2006.02.013.
the use of SPW has a positive impact on Gn flotation as it
dampens the detrimental effects of dissolved Fe and Pb ions
on Pb recovery.
CONCLUSIONS
This paper reports on an investigation into the role which Fe
ions may have on the flotation performance of a synthetic
mixture of pyrite and galena. In order to decouple the effect
of Fe ions emanating from the pyrite ore from those com-
ing from the milling media, experiments were carried out
using either forged steel media which would create Fe spe-
cies through dissolution from either the media or the pyrite
ore and ceramic media in which case the only source of the
Fe would be the pyrite ore. Moreover, experiments were car-
ried out using deionised water and a synthetic water sample
typical of those occurring on flotation concentrators. Eh
values were also determined to investigate whether galvanic
interactions may be influencing the system. The Fe grades
and recoveries were comparable for both the FS-DI (11.6
wt.% Fe 59.5%) and FS-SPW (13.3 wt.% Fe 55.6%) case
suggesting that water type did not significantly impact Py
flotation. However, Fe recoveries were always greater when
ceramic media were used indicating that the Fe species
emanating from the media reduced the recoveries of pyrite.
Fe grades were higher when FS media were used suggesting
that the Fe species from the media were reducing gangue
(quartz) recovery. In the case of galena, the recoveries were
generally higher when ceramic media were used, again indi-
cating that Fe from the milling media was reducing galena
recoveries. As in the case of pyrite, the presence of ions in
the water did not have any significant effect on flotation
performance when using ceramic media the highest solid
and water recoveries were obtained when ceramic media
were used irrespective of water quality. Eh values followed
the pH trends, but it is difficult to draw any conclusions
about the galvanic interactions which may be occurring.
The values at the lower pHs suggest that the formation of
dixanthogen is favoured. Overall, it can be concluded that
using forged steel media reduced recoveries of both pyrite
and galena but marginally increased grades probably due to
reducing quartz/gangue recovery. Water quality, in most of
the conditions under investigation, did not have a signifi-
cant effect indicating that using recycled water high in ionic
strength would not adversely flotation performance. This
study provides some key insights into the factors affecting
mixed ore flotation processes when different milling media,
operating pH, and process water quality are used and may
contribute to a better understanding of when such param-
eters are to be changed in operations.
REFERENCES
[1] W. Liu, C. J. Moran, and S. Vink, ‘A Review of the
Effect of Water Quality on Flotation’, Miner. Eng.,
vol. 53, pp. 91–100, Nov. 2013, doi: 10.1016/j.
mineng.2013.07.011.
[2] D. Pashkevich, R. Li, and K. Waters, ‘Temperature
and climate-induced fluctuations in froth flotation:
an overview of different ore types’, Can. Metall.
Q., vol. 62, no. 3, pp. 511–548, Jul. 2023, doi:
10.1080/00084433.2022.2127788.
[3] A. Rabieh, B. Albijanic, and J. J. Eksteen, ‘A Review
of the Effects of Grinding Media and Chemical
Conditions on the Flotation of Pyrite in Refractory
Gold Operations’, Miner. Eng., vol. 94, pp. 21–28,
Aug. 2016, doi: 10.1016/j.mineng.2016.04.012.
[4] D. Fornasiero and J. Ralston, ‘Iron hydroxide com-
plexes and their influence on the interaction between
ethyl xanthate and pyrite’, J. Colloid Interface Sci.,
vol. 151, no. 1, pp. 225–235, Jun. 1992, doi:
10.1016/0021-9797(92)90253-I.
[5] M. Jefferson et al., ‘Effect of pyrite textures and com-
position on flotation performance: A review’, Miner.
Eng., vol. 201, p. 108234, Oct. 2023, doi: 10.1016/j.
mineng.2023.108234.
[6] Y. Peng, S. Grano, D. Fornasiero, and J. Ralston,
‘Control of Grinding Conditions in the Flotation of
Galena and Its Separation from Pyrite’, Int. J. Miner.
Process., vol. 70, no. 1, pp. 67–82, Jun. 2003, doi:
10.1016/S0301-7516(02)00153-9.
[7] Y. Mu, Y. Cheng, and Y. Peng, ‘The Interaction of
Grinding Media and Collector in Pyrite Flotation at
Alkaline pH’, Miner. Eng., vol. 152, p. 106344, Jun.
2020, doi: 10.1016/j.mineng.2020.106344.
[8] C. Greet, ‘The Significance of Grinding Environment
on the Flotation of UG2 Ores’, J. South. Afr. Inst.
Min. Metall., vol. 109, no. 1, pp. 31–37, 2009.
[9] H. Majima, ‘How Oxidation Affects Selective
Flotation of Complex Sulphide Ores’, Can. Metall.
Q., vol. 8, no. 3, pp. 269–273, Jul. 1969, doi:
10.1179/cmq.1969.8.3.269.
[10] S. R. Rao and J. A. Finch, ‘Galvanic Interaction
Studies on Sulphide Minerals’, Can. Metall. Q., vol.
27, no. 4, pp. 253–259, Oct. 1988, doi: 10.1179/
cmq.1988.27.4.253.
[11] K. L. Pinetown, C. R. Ward, and W. A. van der
Westhuizen, ‘Quantitative Evaluation of Minerals
in Coal Deposits in the Witbank and Highveld
Coalfields, and the Potential Impact on Acid Mine
Drainage’, TSOP 2004, vol. 70, no. 1, pp. 166–183,
Apr. 2007, doi: 10.1016/j.coal.2006.02.013.