2518
The Effect of an Anionic Polyacrylamide on the Flotation of
Chalcopyrite, Enargite and Bornite
Ginna Jiménez, Leopoldo Gutiérrez
Department of Metallurgical Engineering, University of Concepcion, Chile
Water Research Center for Agriculture and Mining (CRHIAM), University of Concepcion, Chile
Pablo Cabrera, Angie Rodríguez, Camilo Cuervo
Department of Metallurgical Engineering, University of Concepcion, Chile
ABSTRACT: Water recycling in mining is necessary to reduce the hydric consumption. However, this
industrial practice leads to the increase in the concentrations of inorganic and organic components in the
process water which has direct effects on the process of flotation. In this work, results on the effect of an anionic
polyacrylamide (PAM) of medium-low anionicity on the flotation of chalcopyrite, enargite, and bornite are
reported and analyzed. The results show that PAM molecules depress the flotation of chalcopyrite, enargite and
bornite under a wide range of pH. The experimental data indicate that the depressing effect of PAMs on copper
sulfides increases with pH. The results of zeta potentials show that this parameter becomes less negative with
the addition of PAM which indicates interactions between the PAM molecules 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.
Keywords: polyacrylamide, copper sulfides, flotation
INTRODUCTION
The significance of water quality in flotation underscores
the imperative for the mining sector to adopt more effec-
tive and sustainable practices which entails enhancing the
design and implementation of water systems to minimize
the negative effects of dissolved species on the concen-
tration processes (Liu et al., 2013 Michaux et al., 2020
Echeverry et al. 2021/2022 Estrada 2020). Water recycling
is already considered in the mining industry together with
the use of seawater (raw or desalinated) but it leads to chal-
lenges such the increase in the concentrations of inorganic
and organic components in the process water which has
direct effects on the process of flotation (Echeverry et al.
2021/2022 Estrada 2020 Liu et al., 2013 Michaux et al.,
2020 Santos et al., 2021 Castillo et al., 2020).
High molecular weight polymers based on anionic
polyacrylamides (PAMs) are frequently used as tailings floc-
culants in mineral processing plants (Arinaitwe and Pawlik,
2013 Arinaitwe and Pawlik, 2009). In the copper concen-
trators, water recovered from the tailings thickeners is recir-
culated to the milling and flotation stages, carrying residual
PAMs which affects the surface properties of copper and
molybdenum sulfides (Castro and Laskowski, 2015).
Previous studies showed that anionic PAMs affect metal
sulfides flotation which depends on variables such as pH,
mechanical degradation, degree of anionicity, and molecular
The Effect of an Anionic Polyacrylamide on the Flotation of
Chalcopyrite, Enargite and Bornite
Ginna Jiménez, Leopoldo Gutiérrez
Department of Metallurgical Engineering, University of Concepcion, Chile
Water Research Center for Agriculture and Mining (CRHIAM), University of Concepcion, Chile
Pablo Cabrera, Angie Rodríguez, Camilo Cuervo
Department of Metallurgical Engineering, University of Concepcion, Chile
ABSTRACT: Water recycling in mining is necessary to reduce the hydric consumption. However, this
industrial practice leads to the increase in the concentrations of inorganic and organic components in the
process water which has direct effects on the process of flotation. In this work, results on the effect of an anionic
polyacrylamide (PAM) of medium-low anionicity on the flotation of chalcopyrite, enargite, and bornite are
reported and analyzed. The results show that PAM molecules depress the flotation of chalcopyrite, enargite and
bornite under a wide range of pH. The experimental data indicate that the depressing effect of PAMs on copper
sulfides increases with pH. The results of zeta potentials show that this parameter becomes less negative with
the addition of PAM which indicates interactions between the PAM molecules 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.
Keywords: polyacrylamide, copper sulfides, flotation
INTRODUCTION
The significance of water quality in flotation underscores
the imperative for the mining sector to adopt more effec-
tive and sustainable practices which entails enhancing the
design and implementation of water systems to minimize
the negative effects of dissolved species on the concen-
tration processes (Liu et al., 2013 Michaux et al., 2020
Echeverry et al. 2021/2022 Estrada 2020). Water recycling
is already considered in the mining industry together with
the use of seawater (raw or desalinated) but it leads to chal-
lenges such the increase in the concentrations of inorganic
and organic components in the process water which has
direct effects on the process of flotation (Echeverry et al.
2021/2022 Estrada 2020 Liu et al., 2013 Michaux et al.,
2020 Santos et al., 2021 Castillo et al., 2020).
High molecular weight polymers based on anionic
polyacrylamides (PAMs) are frequently used as tailings floc-
culants in mineral processing plants (Arinaitwe and Pawlik,
2013 Arinaitwe and Pawlik, 2009). In the copper concen-
trators, water recovered from the tailings thickeners is recir-
culated to the milling and flotation stages, carrying residual
PAMs which affects the surface properties of copper and
molybdenum sulfides (Castro and Laskowski, 2015).
Previous studies showed that anionic PAMs affect metal
sulfides flotation which depends on variables such as pH,
mechanical degradation, degree of anionicity, and molecular