XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2155
of the active sites on the surface of the minerals, as shown
in the figure, have a clear association with the adsorption
capacity of the agents on the mineral surface. The calcula-
tion results reveal that the upward movement of the d-band
center is beneficial to enhancing the adsorption of the agent
on the mineral surface active sites, as shown in Figure 8.
The position of the d-band center, inspired by d-band
theory in the field of catalysis, can also be employed as an
indicator of agent adsorption on the active sites of distinct
mineral surfaces.
The above DFT calculations have correlated the
adsorption energy of the agent at the active sites on the
mineral surface with the d-band centers of the transition
metals. This will provide theoretical support for flotation
separation between different minerals.
Flotation Results
The flotation studies of sphalerite at different pH in the
presence and absence of CuSO4 while employing ethyl xan-
thane (EX) as a collector are shown in Figure 9. It was deter-
mined that in the absence of CuSO4, the flotation recovery
of sphalerite was quite low, regardless of whether EX was
used. After CuSO4 activation, the recovery of sphalerite
was improved.
Adsorption Thermodynamics
It is clear from Figures 10 and 11 that when the adsorp-
tion temperature rises, xanthate’s ability to bind to the
surfaces of sphalerite and Cu-activated sphalerite increases
noticeably. This suggests that xanthate adsorption is endo-
thermic on sphalerite and Cu-activated sphalerite surfaces.
The thermodynamic parameters of xanthate adsorp-
tion on sphalerite and Cu-activated sphalerite were deter-
mined by fitting the isothermal adsorption data using the
Langmuir and Van’t Hoff equations.Table 1 contains the
collected adsorption thermodynamic data. According to the
data, xanthate’s adsorption enthalpy on Cu-activated sphal-
erite is –59.25 kJ/mol, whereas sphalerite’s surface adsorp-
tion enthalpy is –38.99 kJ/mol. The results unequivocally
demonstrate that xanthate exhibits a higher adsorption
capacity on the surface of Cu-activated sphalerite surface
compared to sphalerite surface.
CONCLUSION
In conclusion, this research sheds light on the crucial rela-
tionship between collector adsorption and mineral surfaces,
revealing that the selective adsorption of collectors remains
a challenging and persistent topic in mineral processing.
Through the application of density functional theory
(DFT), the connection between mineral floatability and
electronic structure was successfully resolved.
A direct correlation was established between the
d-band center and the adsorption capacity of xanthane on
the mineral surface. Specifically, the larger copper d-band
center on the copper-activated sphalerite surface contrib-
utes to enhanced stability in the adsorption of xanthane,
outperforming the interactions between xanthane and zinc
(Zn) on the regular sphalerite surface.
Zn Cu
0
-50
-100
-150
-200
-250
-300
-350
-400
-450
-500
Adsorption energy
d band centre
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
Figure 8. Correlation between the adsorption energy and d band center
Adsorpti
energy
(kJ/mol)
d
band
cent
(eV)
of the active sites on the surface of the minerals, as shown
in the figure, have a clear association with the adsorption
capacity of the agents on the mineral surface. The calcula-
tion results reveal that the upward movement of the d-band
center is beneficial to enhancing the adsorption of the agent
on the mineral surface active sites, as shown in Figure 8.
The position of the d-band center, inspired by d-band
theory in the field of catalysis, can also be employed as an
indicator of agent adsorption on the active sites of distinct
mineral surfaces.
The above DFT calculations have correlated the
adsorption energy of the agent at the active sites on the
mineral surface with the d-band centers of the transition
metals. This will provide theoretical support for flotation
separation between different minerals.
Flotation Results
The flotation studies of sphalerite at different pH in the
presence and absence of CuSO4 while employing ethyl xan-
thane (EX) as a collector are shown in Figure 9. It was deter-
mined that in the absence of CuSO4, the flotation recovery
of sphalerite was quite low, regardless of whether EX was
used. After CuSO4 activation, the recovery of sphalerite
was improved.
Adsorption Thermodynamics
It is clear from Figures 10 and 11 that when the adsorp-
tion temperature rises, xanthate’s ability to bind to the
surfaces of sphalerite and Cu-activated sphalerite increases
noticeably. This suggests that xanthate adsorption is endo-
thermic on sphalerite and Cu-activated sphalerite surfaces.
The thermodynamic parameters of xanthate adsorp-
tion on sphalerite and Cu-activated sphalerite were deter-
mined by fitting the isothermal adsorption data using the
Langmuir and Van’t Hoff equations.Table 1 contains the
collected adsorption thermodynamic data. According to the
data, xanthate’s adsorption enthalpy on Cu-activated sphal-
erite is –59.25 kJ/mol, whereas sphalerite’s surface adsorp-
tion enthalpy is –38.99 kJ/mol. The results unequivocally
demonstrate that xanthate exhibits a higher adsorption
capacity on the surface of Cu-activated sphalerite surface
compared to sphalerite surface.
CONCLUSION
In conclusion, this research sheds light on the crucial rela-
tionship between collector adsorption and mineral surfaces,
revealing that the selective adsorption of collectors remains
a challenging and persistent topic in mineral processing.
Through the application of density functional theory
(DFT), the connection between mineral floatability and
electronic structure was successfully resolved.
A direct correlation was established between the
d-band center and the adsorption capacity of xanthane on
the mineral surface. Specifically, the larger copper d-band
center on the copper-activated sphalerite surface contrib-
utes to enhanced stability in the adsorption of xanthane,
outperforming the interactions between xanthane and zinc
(Zn) on the regular sphalerite surface.
Zn Cu
0
-50
-100
-150
-200
-250
-300
-350
-400
-450
-500
Adsorption energy
d band centre
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
Figure 8. Correlation between the adsorption energy and d band center
Adsorpti
energy
(kJ/mol)
d
band
cent
(eV)