2152 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
with the coordinating S atoms are124.986°, 125.001° and
108.166°, and the sum of the three angles is 358.153°.
Thus, the Cu atom is situated in the planar triangle formed
by the three S atoms.
The PDOS on the surface of sphalerite (110) as well
as on the surface of sphalerite (110) after Cu activation is
shown in Figure 4. Figure 4 reveals that the DOS of Zn
3d is localized in the deep energy level from –7.5 to –5 eV,
indicating that the Zn 3d state is not a very active orbital,
and the 3p state is distributed near the Fermi energy level,
with two DOS peaks in the range of –2.5 to 0 eV. The
Cu-activated sphalerite surface is shown in Figure 4. The
DOS of the Cu 3d state is located at a higher energy level
(–5–0.25 eV) relative to the Zn 3d state, indicating that the
Cu atoms have fewer electrons and are more reactive on the
sphalerite surface than the surface Zn atoms. It indicates
that Cu atoms have better activity than Zn atoms on the
sphalerite surface.
The Geometry and Electron Density of Collector
Adsorption
In order to study the difference between sphalerite (110)
surface and Cu activated sphalerite (110) surface, the
adsorption of xanthane on the surface of sphalerite (110)
surface and Cu activated sphalerite (110) surface was stud-
ied by density functional method.
Figure 5(a) illustrates the geometry structure of xan-
thane adsorbed on the surfaces of sphalerite (110) sur-
face. It was found that the xanthane was adsorbed on the
sphalerite (110) surface through two S atoms. The distance
between the two S atoms and the Zn atoms on the sphal-
erite (110) face was 2.482Å and 2.566Å. This is roughly
similar to the radii of Zn and S atoms of 2.54Å. Therefore,
it can be seen that the adsorption of the xanthane on the
sphalerite (110) face is weak and the adsorption energy is
only –227.32 kJ/mol. The coordination structure of Zn
and S atoms is transformed from a planar triangular to a
tetrahedral structure after the xanthane is adsorbed on the
sphalerite (110) surface.
Figure 5(b) illustrates the geometry structure of xan-
thane adsorbed on the surfaces of Cu activated sphalerite
(110) surface. From inspection of Figure 5 (b), it can be
seen that the two S atoms of the xanthane are adsorbed on
the Zn atoms and Cu atoms on the surface of the copper-
activated sphalerite (110), and the distances between the
S atoms and the Cu atoms are 2.316 and 2.277Å, which
is smaller than the radius between the S atoms and the
Cu atoms and 2.44Å. The adsorption energy of the xan-
thane on the surface of copper-activated sphalerite (110)
is –372.69 kJ/mol.. The coordination structure of Cu
and S atoms is transformed from a planar triangular to a
0
6
12
0
6
12
-15 -10 -5 0 5 10 15 20
0
3
Zn 4s
Zn 4p
Zn 3d (a)
(b)
Zn 4s
Zn 4p
Zn 3d
(c)
Energy(eV)
Cu 4s
Cu 4p
Cu 3d
Figure 4. PDOS of Zn atom in bulk(a), Zn on the sphalerite (110) surface(b), Cu on the Cu
activated sphalerite (110) surface(c)
Density
of
states(electrons/eV)
with the coordinating S atoms are124.986°, 125.001° and
108.166°, and the sum of the three angles is 358.153°.
Thus, the Cu atom is situated in the planar triangle formed
by the three S atoms.
The PDOS on the surface of sphalerite (110) as well
as on the surface of sphalerite (110) after Cu activation is
shown in Figure 4. Figure 4 reveals that the DOS of Zn
3d is localized in the deep energy level from –7.5 to –5 eV,
indicating that the Zn 3d state is not a very active orbital,
and the 3p state is distributed near the Fermi energy level,
with two DOS peaks in the range of –2.5 to 0 eV. The
Cu-activated sphalerite surface is shown in Figure 4. The
DOS of the Cu 3d state is located at a higher energy level
(–5–0.25 eV) relative to the Zn 3d state, indicating that the
Cu atoms have fewer electrons and are more reactive on the
sphalerite surface than the surface Zn atoms. It indicates
that Cu atoms have better activity than Zn atoms on the
sphalerite surface.
The Geometry and Electron Density of Collector
Adsorption
In order to study the difference between sphalerite (110)
surface and Cu activated sphalerite (110) surface, the
adsorption of xanthane on the surface of sphalerite (110)
surface and Cu activated sphalerite (110) surface was stud-
ied by density functional method.
Figure 5(a) illustrates the geometry structure of xan-
thane adsorbed on the surfaces of sphalerite (110) sur-
face. It was found that the xanthane was adsorbed on the
sphalerite (110) surface through two S atoms. The distance
between the two S atoms and the Zn atoms on the sphal-
erite (110) face was 2.482Å and 2.566Å. This is roughly
similar to the radii of Zn and S atoms of 2.54Å. Therefore,
it can be seen that the adsorption of the xanthane on the
sphalerite (110) face is weak and the adsorption energy is
only –227.32 kJ/mol. The coordination structure of Zn
and S atoms is transformed from a planar triangular to a
tetrahedral structure after the xanthane is adsorbed on the
sphalerite (110) surface.
Figure 5(b) illustrates the geometry structure of xan-
thane adsorbed on the surfaces of Cu activated sphalerite
(110) surface. From inspection of Figure 5 (b), it can be
seen that the two S atoms of the xanthane are adsorbed on
the Zn atoms and Cu atoms on the surface of the copper-
activated sphalerite (110), and the distances between the
S atoms and the Cu atoms are 2.316 and 2.277Å, which
is smaller than the radius between the S atoms and the
Cu atoms and 2.44Å. The adsorption energy of the xan-
thane on the surface of copper-activated sphalerite (110)
is –372.69 kJ/mol.. The coordination structure of Cu
and S atoms is transformed from a planar triangular to a
0
6
12
0
6
12
-15 -10 -5 0 5 10 15 20
0
3
Zn 4s
Zn 4p
Zn 3d (a)
(b)
Zn 4s
Zn 4p
Zn 3d
(c)
Energy(eV)
Cu 4s
Cu 4p
Cu 3d
Figure 4. PDOS of Zn atom in bulk(a), Zn on the sphalerite (110) surface(b), Cu on the Cu
activated sphalerite (110) surface(c)
Density
of
states(electrons/eV)