2522 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
through chemical and coordination bonds, and hydrogen
bonds also lead to the attachment of PAMs onto mineral
particles, case in which the polymers must surpass the elec-
trostatic repulsion between the polymer and mineral sur-
faces (Attia, 1992 Bahmani-Ghaedi et al., 2022 Hocking
et al., 1999). Previous work also showed that ions dissolved
in the aqueous medium neutralize the functional groups
of the PAM molecules leading to polymer coiling and less
adsorption on the mineral particles (Echeverry et al., 2021
Gurina et al., 2020).
The surfaces of ground copper sulfides are believed to
display hydrophobic patches formed by sulfur-based enti-
ties, and hydrophilic patches of hydroxides compounds
(Senior and Trahar, 1991). The extent to which hydropho-
bic patches outweigh the hydrophilic ones determines their
floatability, therefore, less hydrophobic copper sulfide sur-
faces at highly alkaline conditions create adsorption sites
for PAMs.
The balance of repulsive and attractive interactions
that develops between PAM molecules and copper sulfides
defines the extent of polymer adsorption. Repulsive forces
are originated from the electrostatic interactions between
the anionic molecules and the negative surface charge of
copper sulfides. Attractive interactions arise due to the
presence of surface iron and copper hydroxides that cre-
ate chemically active adsorption sites on copper sulfides.
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Bornite
No PAM
5 mg/L PAM
10 mg/L PAM
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Enargite
No PAM
5 mg/L PAM
10 mg/L PAM
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Chalcopyrite
No PAM
5 mg/L PAM
10 mg/L PAM
Figure 3. Zeta potentials of copper sulfides as a function of pH and different concentrations of PAM
Zeta
potential,
mV
Zeta
potential,
mV
Zeta
potential,
mV
through chemical and coordination bonds, and hydrogen
bonds also lead to the attachment of PAMs onto mineral
particles, case in which the polymers must surpass the elec-
trostatic repulsion between the polymer and mineral sur-
faces (Attia, 1992 Bahmani-Ghaedi et al., 2022 Hocking
et al., 1999). Previous work also showed that ions dissolved
in the aqueous medium neutralize the functional groups
of the PAM molecules leading to polymer coiling and less
adsorption on the mineral particles (Echeverry et al., 2021
Gurina et al., 2020).
The surfaces of ground copper sulfides are believed to
display hydrophobic patches formed by sulfur-based enti-
ties, and hydrophilic patches of hydroxides compounds
(Senior and Trahar, 1991). The extent to which hydropho-
bic patches outweigh the hydrophilic ones determines their
floatability, therefore, less hydrophobic copper sulfide sur-
faces at highly alkaline conditions create adsorption sites
for PAMs.
The balance of repulsive and attractive interactions
that develops between PAM molecules and copper sulfides
defines the extent of polymer adsorption. Repulsive forces
are originated from the electrostatic interactions between
the anionic molecules and the negative surface charge of
copper sulfides. Attractive interactions arise due to the
presence of surface iron and copper hydroxides that cre-
ate chemically active adsorption sites on copper sulfides.
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Bornite
No PAM
5 mg/L PAM
10 mg/L PAM
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Enargite
No PAM
5 mg/L PAM
10 mg/L PAM
1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 11,0 12,0
pH
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Chalcopyrite
No PAM
5 mg/L PAM
10 mg/L PAM
Figure 3. Zeta potentials of copper sulfides as a function of pH and different concentrations of PAM
Zeta
potential,
mV
Zeta
potential,
mV
Zeta
potential,
mV