XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2149
the interactions between agents and mineral surface-active
sites. Chen studied the coordination structure of Fe on the
surface of marcasite (101) surface and the coordination
structure of Cu on the copper-activated sphalerite surface.
The study demonstrated that the chemical properties of
metal ions on mineral surfaces are influenced by their coor-
dination structures[11–13]. Ye investigated the electronic
structures of bulk sphalerite containing 14 typical kinds of
impurities and their effects on flotation performance[14]. Li
explored the influence of spatial and electrical structure on
Z200s absorption on mineral surfaces[15].
In recent years, researchers have developed a novel
descriptor (d-band center) that enables the quantitative
characterization of the correlation between the electronic
structure and adsorption properties of metal ions[16–20]. The
d-band center is a parameter used to understand the activ-
ity trends in metal-surface-catalyzed reactions in terms of
the linear Brønsted–Evans–Polanyi relation and Hammer–
Nørskov d-band model[21,22]. It is defined as the energy of
the d-band center (εd) relative to the Fermi level (Ef). The
d-electrons of transition metals play a central role in chemi-
sorption, and the d-band center (εd – Ef) for various met-
als is calculated using Density Functional Theory (DFT) as
an indicator to explain the adsorption energy trends for a
given adsorbate: the higher the d-states are in energy rela-
tive to the Fermi level, the more empty the anti-bonding
states and the larger the adsorption energy (strong bonding
between the adsorbate and metal surface). This model has
been verified with experimental and theoretical studies by
various research groups[23~27].
Therefore, in this research, we propose to use the DFT
approach to comprehensively examine the variations in the
coordination structures of the active sites on the surfaces
of sphalerite and Cu-activated sphalerite, to investigate the
effects of the electronic structure variations on the adsorp-
tion. Additionally, it is proposed to use the molecular orbital
theory (MOT) and the hypothesis of d-band centers, which
is proven by employing single-mineral flotation as well as
microcalorimetry studies, to connect the electronic struc-
ture of the active sites of mineral surfaces with the adsorp-
tion capacity of medicines on the mineral surfaces. The
results of this study may provide valuable information for
the study of the complex mechanism of surface adsorption
and Cu activation on sphalerite.
MATERIALS AND METHODOLOGY
Samples and Reagents
Sphalerite samples were obtained from the Dafang mine
in Guangxi, China. The ore sample was crushed and finely
ground to a particle size of 0.074 mm. XRD and chemical
analyses, as shown in Figure 1, showed that the purity of the
sphalerite sample met the test requirements. The methylx-
anthine was purchased from the Tieling Mineral Processing
Pharmacy Plant, City, Country? CuSO4 was purchased
from Shanghai Aladdin Chemical Reagent Company, City,
Country?. Deionized water was used for all the tests.
0 20 40 60 80 100
0
2000
4000
6000
8000
10000
2θ(°)
sphalerite
Figure 1. XRD patterns of sphalerite
I(count/s)
the interactions between agents and mineral surface-active
sites. Chen studied the coordination structure of Fe on the
surface of marcasite (101) surface and the coordination
structure of Cu on the copper-activated sphalerite surface.
The study demonstrated that the chemical properties of
metal ions on mineral surfaces are influenced by their coor-
dination structures[11–13]. Ye investigated the electronic
structures of bulk sphalerite containing 14 typical kinds of
impurities and their effects on flotation performance[14]. Li
explored the influence of spatial and electrical structure on
Z200s absorption on mineral surfaces[15].
In recent years, researchers have developed a novel
descriptor (d-band center) that enables the quantitative
characterization of the correlation between the electronic
structure and adsorption properties of metal ions[16–20]. The
d-band center is a parameter used to understand the activ-
ity trends in metal-surface-catalyzed reactions in terms of
the linear Brønsted–Evans–Polanyi relation and Hammer–
Nørskov d-band model[21,22]. It is defined as the energy of
the d-band center (εd) relative to the Fermi level (Ef). The
d-electrons of transition metals play a central role in chemi-
sorption, and the d-band center (εd – Ef) for various met-
als is calculated using Density Functional Theory (DFT) as
an indicator to explain the adsorption energy trends for a
given adsorbate: the higher the d-states are in energy rela-
tive to the Fermi level, the more empty the anti-bonding
states and the larger the adsorption energy (strong bonding
between the adsorbate and metal surface). This model has
been verified with experimental and theoretical studies by
various research groups[23~27].
Therefore, in this research, we propose to use the DFT
approach to comprehensively examine the variations in the
coordination structures of the active sites on the surfaces
of sphalerite and Cu-activated sphalerite, to investigate the
effects of the electronic structure variations on the adsorp-
tion. Additionally, it is proposed to use the molecular orbital
theory (MOT) and the hypothesis of d-band centers, which
is proven by employing single-mineral flotation as well as
microcalorimetry studies, to connect the electronic struc-
ture of the active sites of mineral surfaces with the adsorp-
tion capacity of medicines on the mineral surfaces. The
results of this study may provide valuable information for
the study of the complex mechanism of surface adsorption
and Cu activation on sphalerite.
MATERIALS AND METHODOLOGY
Samples and Reagents
Sphalerite samples were obtained from the Dafang mine
in Guangxi, China. The ore sample was crushed and finely
ground to a particle size of 0.074 mm. XRD and chemical
analyses, as shown in Figure 1, showed that the purity of the
sphalerite sample met the test requirements. The methylx-
anthine was purchased from the Tieling Mineral Processing
Pharmacy Plant, City, Country? CuSO4 was purchased
from Shanghai Aladdin Chemical Reagent Company, City,
Country?. Deionized water was used for all the tests.
0 20 40 60 80 100
0
2000
4000
6000
8000
10000
2θ(°)
sphalerite
Figure 1. XRD patterns of sphalerite
I(count/s)