XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2999
reported in Table 3 for comprehensive understanding and
analysis.
The analysis of Figure 5 reveals that, in the presence
of Cu+ ions, the interaction of IPETCdp with the mineral
surfaces involves indirect binding. Specifically, the mol-
ecule forms bonds with Cu ions that are adsorbed onto
sulfur atoms on the surface, evident in both Py and Asp
cases. Notably, the interaction of IPETCdp with Py occurs
exclusively through a Cu—S bond, while in the case of Asp,
bonding involves both Cu—S and As—N interactions.
The computed interaction energies further shed light on
this phenomenon, indicating a lower adsorption energy for
Py at –51.55 kcal/mol compared to Asp, which records a
higher energy of –61.40 kcal/mol (Table 4). This difference
in interaction energies provides a quantitative rationale
for the observed higher recovery of Asp compared to Py at
higher pH in the presence of Cu ions, as reported by Forson
et al. (2022).12 It further underscores the pivotal role of Cu
ions adsorbed on these surfaces as the bridge that enables
the binding of collector molecules to the mineral surface.
These findings contribute valuable insights into the intrica-
cies of the adsorption process, aiding in the understanding
of mineral separation processes in the presence of Isopropyl
Ethylthiocarbamate and Cu ions.
CONCLUSION
In our comprehensive study, we carried out detailed DFT
analyses to elucidate the electronic structures of both
neutral and deprotonated Isopropyl Ethylthiocarbamate
(IPETC) and subsequently investigated their adsorption
behavior on Pyrite (Py) and Arsenopyrite (Asp) surfaces.
The computed quantum chemical descriptors, including
the energy gap (Egap) and the lowest unoccupied molecu-
lar orbital (ELUMO), indicate that the deprotonated form,
IPETCdp, exhibits increased reactivity and a propensity
for strong adsorption compared to the neutral molecule.
The HOMO-LUMO plots underscore the significance of
S-atoms in the neutral case and S/N-atoms in the depro-
tonated case as major electron-donating sites, suggest-
ing their potential to form chemical bonds with mineral
surfaces. Adsorption studies reveal that neutral IPETC
Table 3. Adsorption energies of IPETCdp on Arsenopyrite
and pyrite surfaces in presence of Cu ions
Mineral-
IPETCdp complex Conformations
Adsorption
Energy, kcal/mol
FeAsS_Cu_OH Conf1 -56.83
Conf2 -61.40
FeS2_Cu_OH Conf1 -51.55
Conf2 -45.35
Figure 5. Adsorption geometries of IPETCdp adsorbed on Py (upper
panel) and Asp (lower panel) in presence of Cu+ ions
reported in Table 3 for comprehensive understanding and
analysis.
The analysis of Figure 5 reveals that, in the presence
of Cu+ ions, the interaction of IPETCdp with the mineral
surfaces involves indirect binding. Specifically, the mol-
ecule forms bonds with Cu ions that are adsorbed onto
sulfur atoms on the surface, evident in both Py and Asp
cases. Notably, the interaction of IPETCdp with Py occurs
exclusively through a Cu—S bond, while in the case of Asp,
bonding involves both Cu—S and As—N interactions.
The computed interaction energies further shed light on
this phenomenon, indicating a lower adsorption energy for
Py at –51.55 kcal/mol compared to Asp, which records a
higher energy of –61.40 kcal/mol (Table 4). This difference
in interaction energies provides a quantitative rationale
for the observed higher recovery of Asp compared to Py at
higher pH in the presence of Cu ions, as reported by Forson
et al. (2022).12 It further underscores the pivotal role of Cu
ions adsorbed on these surfaces as the bridge that enables
the binding of collector molecules to the mineral surface.
These findings contribute valuable insights into the intrica-
cies of the adsorption process, aiding in the understanding
of mineral separation processes in the presence of Isopropyl
Ethylthiocarbamate and Cu ions.
CONCLUSION
In our comprehensive study, we carried out detailed DFT
analyses to elucidate the electronic structures of both
neutral and deprotonated Isopropyl Ethylthiocarbamate
(IPETC) and subsequently investigated their adsorption
behavior on Pyrite (Py) and Arsenopyrite (Asp) surfaces.
The computed quantum chemical descriptors, including
the energy gap (Egap) and the lowest unoccupied molecu-
lar orbital (ELUMO), indicate that the deprotonated form,
IPETCdp, exhibits increased reactivity and a propensity
for strong adsorption compared to the neutral molecule.
The HOMO-LUMO plots underscore the significance of
S-atoms in the neutral case and S/N-atoms in the depro-
tonated case as major electron-donating sites, suggest-
ing their potential to form chemical bonds with mineral
surfaces. Adsorption studies reveal that neutral IPETC
Table 3. Adsorption energies of IPETCdp on Arsenopyrite
and pyrite surfaces in presence of Cu ions
Mineral-
IPETCdp complex Conformations
Adsorption
Energy, kcal/mol
FeAsS_Cu_OH Conf1 -56.83
Conf2 -61.40
FeS2_Cu_OH Conf1 -51.55
Conf2 -45.35
Figure 5. Adsorption geometries of IPETCdp adsorbed on Py (upper
panel) and Asp (lower panel) in presence of Cu+ ions