XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2525
by the generation of surface elemental sulfur, and flotation
is reduced at high pH because of the presence of surface
oxidized copper-iron-arsenic compounds. The experimen-
tal results presented in this work suggest that PAM mol-
ecules adsorption on enargite is explained by the presence
of these oxidized compounds. Bornite is a mineral that
readily oxidizes during grinding which affects its surface
properties causing low recoveries in flotation (Moimane,
2020 Suyantara et al., 2020). The presence of these oxi-
dized surface compounds explains PAM adsorption. It is
important to acknowledge that in the mining industry the
degradation of PAMs can be caused by mechanical shear-
ing of water impulsion pumps, exposure to sunlight, and
bacterial activity. These factors can influence the depressing
effect of these molecules on the flotation of copper sulfides.
CONCLUSIONS
• PAMs depress the flotation of chalcopyrite, enargite
and bornite under a wide range of pH. The experi-
mental data indicate that the depressing effect of
PAM on the copper sulfides increases with pH.
• The results of zeta potentials show that this param-
eter becomes less negative with the addition of PAM
which indicates interactions between the PAM mol-
ecules and the surfaces of the copper sulfides.
• PAM adsorption on copper sulfides increases with
pH which correlates with the flotation and zeta
potential data.
• It is proposed that the interactions between PAM
molecules and copper sulfides are explained by the
presence of surface iron and copper hydroxides that
create chemically active adsorption sites.
ACKNOWLEDGMENTS
The authors acknowledge the financial support of the Water
Research Centre for Agriculture and Mining (CRHIAM) of
the Universidad de Concepcion sponsored by the ANID/
FONDAP/15130015 y ANID/FONDAP/1523A0001
project. Leopoldo Gutierrez also wants to thank ANID/
ACT210030, ANID/Fondecyt/1211705, ANID/
FONDEF IDeA I+D/ID22I10102 projects.
REFERENCES
Arinaitwe, E., Pawlik, M. (2009). A method for measuring
the degree of anionicity of polyacrylamide-based floc-
culants. International Journal of Mineral Processing,
91(1–2), 50–54. doi: 10.1016/j.minpro.2008.12.002.
Arinaitwe, E., Pawlik, M. (2013). A role of flocculant
chain flexibility in flocculation of fine quartz. Part I.
Intrinsic viscosities of polyacrylamide-based floccu-
lants. International Journal of Mineral Processing, 124,
50–57. doi: 10.1016/J.MINPRO.2013.01.006.
Attia, Y. “Flocculation” In: Colloid Chemistry in Mineral
Processing, J.S. Laskowski J. Ralston (Ed.). 12 (1992)
277–308.
Bahmani-Ghaedi, A., Hassanzadeh, A., Sam, A., Entezari-
Zarandi, A. (2022). The effect of residual flocculants
in the circulating water on dewatering of Gol-e-Gohar
iron ore. Minerals Engineering, 179, 107440. doi:
10.1016/j.mineng.2022.107440.
Boulton, A. Fornasiero, D. Ralston, J. Selective depression
of pyrite with polyacrylamide polymers. Int. J. Miner.
Process. 2001, 61(1), 13–22.
Butt, H.J., Graf, K., Kappl, M. Physics and Chemistry of
Interfaces. Third Edition. Wiley‐VCH Verlag GmbH
&Co. KGaA. 2013.
Castillo I., Gutiérrez L., Hernández V., Díaz E., Ramírez
A. (2020). Hemicelluloses monosaccharides and their
effect on molybdenite flotation. Powder Technology,
373, 758–764. doi: 10.1016/j.powtec.2020.07.032.
Castro, S., Laskowski, J. (2015). Depressing effect of floccu-
lants on molybdenite flotation. Minerals Engineering,
74, 13–19. doi: 10.1016/j.mineng.2014.12.027.
Echeverry, L., Estrada, D., Toledo, P.G., Gutierrez, L.
(2021). The depressing effect of an anionic poly-
acrylamide on molybdenite flotation and the impor-
tance of polymer anionicity. Colloids and Surfaces
A: Physicochemical and Engineering Aspects, 629,
127506. doi: 10.1016/j.colsurfa.2021.127506.
Echeverry-Vargas, L., Estrada, D., Gutierrez, L. (2022).
Molecular Dynamics Simulations of the Interactions
between a Hydrolyzed Polyacrylamide with the Face
and Edge Surfaces of Molybdenite. Polymers, 14(17),
3680. doi: 10.3390/polym14173680.
Elhaei, R., Kharrat, R., Madani, M. (2021). Stability, floc-
culation, and rheological behavior of silica suspen-
sion-augmented polyacrylamide and the possibility
to improve polymer flooding functionality. Journal
of Molecular Liquids, 322, 114572. doi: 10.1016/j.
molliq.2020.114572.
Estrada, D., Echeverry, L., Ramirez, A., Gutierrez, L.
(2020). Molybdenite Flotation in the Presence
of a Polyacrylamide of Low Anionicity Subjected
to Different Conditions of Mechanical Shearing.
Minerals, 10(10), 895. doi: 10.3390/min10100895.
by the generation of surface elemental sulfur, and flotation
is reduced at high pH because of the presence of surface
oxidized copper-iron-arsenic compounds. The experimen-
tal results presented in this work suggest that PAM mol-
ecules adsorption on enargite is explained by the presence
of these oxidized compounds. Bornite is a mineral that
readily oxidizes during grinding which affects its surface
properties causing low recoveries in flotation (Moimane,
2020 Suyantara et al., 2020). The presence of these oxi-
dized surface compounds explains PAM adsorption. It is
important to acknowledge that in the mining industry the
degradation of PAMs can be caused by mechanical shear-
ing of water impulsion pumps, exposure to sunlight, and
bacterial activity. These factors can influence the depressing
effect of these molecules on the flotation of copper sulfides.
CONCLUSIONS
• PAMs depress the flotation of chalcopyrite, enargite
and bornite under a wide range of pH. The experi-
mental data indicate that the depressing effect of
PAM on the copper sulfides increases with pH.
• The results of zeta potentials show that this param-
eter becomes less negative with the addition of PAM
which indicates interactions between the PAM mol-
ecules and the surfaces of the copper sulfides.
• PAM adsorption on copper sulfides increases with
pH which correlates with the flotation and zeta
potential data.
• It is proposed that the interactions between PAM
molecules and copper sulfides are explained by the
presence of surface iron and copper hydroxides that
create chemically active adsorption sites.
ACKNOWLEDGMENTS
The authors acknowledge the financial support of the Water
Research Centre for Agriculture and Mining (CRHIAM) of
the Universidad de Concepcion sponsored by the ANID/
FONDAP/15130015 y ANID/FONDAP/1523A0001
project. Leopoldo Gutierrez also wants to thank ANID/
ACT210030, ANID/Fondecyt/1211705, ANID/
FONDEF IDeA I+D/ID22I10102 projects.
REFERENCES
Arinaitwe, E., Pawlik, M. (2009). A method for measuring
the degree of anionicity of polyacrylamide-based floc-
culants. International Journal of Mineral Processing,
91(1–2), 50–54. doi: 10.1016/j.minpro.2008.12.002.
Arinaitwe, E., Pawlik, M. (2013). A role of flocculant
chain flexibility in flocculation of fine quartz. Part I.
Intrinsic viscosities of polyacrylamide-based floccu-
lants. International Journal of Mineral Processing, 124,
50–57. doi: 10.1016/J.MINPRO.2013.01.006.
Attia, Y. “Flocculation” In: Colloid Chemistry in Mineral
Processing, J.S. Laskowski J. Ralston (Ed.). 12 (1992)
277–308.
Bahmani-Ghaedi, A., Hassanzadeh, A., Sam, A., Entezari-
Zarandi, A. (2022). The effect of residual flocculants
in the circulating water on dewatering of Gol-e-Gohar
iron ore. Minerals Engineering, 179, 107440. doi:
10.1016/j.mineng.2022.107440.
Boulton, A. Fornasiero, D. Ralston, J. Selective depression
of pyrite with polyacrylamide polymers. Int. J. Miner.
Process. 2001, 61(1), 13–22.
Butt, H.J., Graf, K., Kappl, M. Physics and Chemistry of
Interfaces. Third Edition. Wiley‐VCH Verlag GmbH
&Co. KGaA. 2013.
Castillo I., Gutiérrez L., Hernández V., Díaz E., Ramírez
A. (2020). Hemicelluloses monosaccharides and their
effect on molybdenite flotation. Powder Technology,
373, 758–764. doi: 10.1016/j.powtec.2020.07.032.
Castro, S., Laskowski, J. (2015). Depressing effect of floccu-
lants on molybdenite flotation. Minerals Engineering,
74, 13–19. doi: 10.1016/j.mineng.2014.12.027.
Echeverry, L., Estrada, D., Toledo, P.G., Gutierrez, L.
(2021). The depressing effect of an anionic poly-
acrylamide on molybdenite flotation and the impor-
tance of polymer anionicity. Colloids and Surfaces
A: Physicochemical and Engineering Aspects, 629,
127506. doi: 10.1016/j.colsurfa.2021.127506.
Echeverry-Vargas, L., Estrada, D., Gutierrez, L. (2022).
Molecular Dynamics Simulations of the Interactions
between a Hydrolyzed Polyacrylamide with the Face
and Edge Surfaces of Molybdenite. Polymers, 14(17),
3680. doi: 10.3390/polym14173680.
Elhaei, R., Kharrat, R., Madani, M. (2021). Stability, floc-
culation, and rheological behavior of silica suspen-
sion-augmented polyacrylamide and the possibility
to improve polymer flooding functionality. Journal
of Molecular Liquids, 322, 114572. doi: 10.1016/j.
molliq.2020.114572.
Estrada, D., Echeverry, L., Ramirez, A., Gutierrez, L.
(2020). Molybdenite Flotation in the Presence
of a Polyacrylamide of Low Anionicity Subjected
to Different Conditions of Mechanical Shearing.
Minerals, 10(10), 895. doi: 10.3390/min10100895.