XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 687
of ATC is about 62.1%, while the removal efficiencies of
MTC and BTC can reach 80.7% and 91.5%, respectively.
Meanwhile, the dosage of ATC is set as 0.3 g/L, while the
dosage of MTC and BTC is only 0.2 g/L. For ATC, the
visible light responsiveness can mainly attribute to the sur-
face plasmon resonance (SPR) effect of Ag NPs, which can
promote the quantum yield of the photocatalytic process
and thus enhance the degradation efficiency of composite
photocatalysts [19]. While for MTC, the improvement
of photocatalytic activity is regarded as the formation of
MoS2/TiO2 heterojunction and the construction of a novel
hierarchical structure. Moreover, clinoptilolite can prevent
the agglomeration of single TiO2 or MoS2 and subse-
quently decrease the crystalline size. The overall adsorption
ability of the composite photocatalysts will be reinforced.
The above explanation about the enhanced photocatalytic
activity of MTC also applies to the description of BTC
composites. Furthermore, the photodegradation rate of
BTC (0.01120 min–1) is superior to that of ATC (0.00220
min–1) and MTC (0.00665 min–1) as shown in Figure 8b,
which further demonstrates the superiority of BTC among
all composite photocatalysts in current work.
Applicability Test
As we all know, xanthates are the general term for a series of
collectors with the molecular general formula of ROCSSM.
Herein, R represents the aliphatic hydrocarbon chain
(CnH2n+1, n=2~5), and M is Na or K generally. Particularly,
Na-based xanthates are more widely used in the flotation
process owing to their outstanding flotation performance
and relatively low production cost. In this work, sodium
ethyl xanthate (SEX), sodium isopropyl xanthate (SIPX),
sodium butyl xanthate (SBX), and sodium isoamyl xan-
thate (SIAX) are set as the object contaminants to study
the applicability of composite photocatalysts. It demon-
strates that binary TC composites and three ternary com-
posites can degrade the four kinds of xanthates. As shown
in Figure 9a, all xanthates can be degraded within 30 min
under 300 W of UV irradiation when using TC photocat-
alysts, and all photodegradation processes still follow the
pseudofirst-order kinetics (Figure 9b). Figure 9c–h indicate
that three ternary composites can degrade the xanthates
within 180 min under 400 W xenon lamp irradiation, and
all degradation processes are consistent with pseudo-first-
order kinetics. Generally, the photodegradation rates of all
composites towards four kinds of xanthates increase gradu-
ally with the increase of alkyl group molecular weight. The
degradation efficiencies for the four kinds of xanthates are
obtained in the order of DSEX DSIPX DSBX DSIAX,
which may be caused by the instability of xanthate molecu-
lar structure with a branch. Moreover, the adsorption abil-
ity is also improved distinctly with the increase of xanthate
formula weight for all composites. The possible reason is
that xanthate molecules with complicated hydrocarbon
chains have strong hydrophobic interaction and an obvi-
ous steric-hindrance effect, which is beneficial for the com-
posite photocatalysts to capture the xanthate molecules and
thus leads to the improvement of degradation rate.
Possible Photodegradation Mechanism
To visually display the xanthate degradation process, the
real-time spectral evolution of the SIPX solution is shown
Figure 8. (a) Degradation efficiency curves and (b) kinetic curves of ternary composites
of ATC is about 62.1%, while the removal efficiencies of
MTC and BTC can reach 80.7% and 91.5%, respectively.
Meanwhile, the dosage of ATC is set as 0.3 g/L, while the
dosage of MTC and BTC is only 0.2 g/L. For ATC, the
visible light responsiveness can mainly attribute to the sur-
face plasmon resonance (SPR) effect of Ag NPs, which can
promote the quantum yield of the photocatalytic process
and thus enhance the degradation efficiency of composite
photocatalysts [19]. While for MTC, the improvement
of photocatalytic activity is regarded as the formation of
MoS2/TiO2 heterojunction and the construction of a novel
hierarchical structure. Moreover, clinoptilolite can prevent
the agglomeration of single TiO2 or MoS2 and subse-
quently decrease the crystalline size. The overall adsorption
ability of the composite photocatalysts will be reinforced.
The above explanation about the enhanced photocatalytic
activity of MTC also applies to the description of BTC
composites. Furthermore, the photodegradation rate of
BTC (0.01120 min–1) is superior to that of ATC (0.00220
min–1) and MTC (0.00665 min–1) as shown in Figure 8b,
which further demonstrates the superiority of BTC among
all composite photocatalysts in current work.
Applicability Test
As we all know, xanthates are the general term for a series of
collectors with the molecular general formula of ROCSSM.
Herein, R represents the aliphatic hydrocarbon chain
(CnH2n+1, n=2~5), and M is Na or K generally. Particularly,
Na-based xanthates are more widely used in the flotation
process owing to their outstanding flotation performance
and relatively low production cost. In this work, sodium
ethyl xanthate (SEX), sodium isopropyl xanthate (SIPX),
sodium butyl xanthate (SBX), and sodium isoamyl xan-
thate (SIAX) are set as the object contaminants to study
the applicability of composite photocatalysts. It demon-
strates that binary TC composites and three ternary com-
posites can degrade the four kinds of xanthates. As shown
in Figure 9a, all xanthates can be degraded within 30 min
under 300 W of UV irradiation when using TC photocat-
alysts, and all photodegradation processes still follow the
pseudofirst-order kinetics (Figure 9b). Figure 9c–h indicate
that three ternary composites can degrade the xanthates
within 180 min under 400 W xenon lamp irradiation, and
all degradation processes are consistent with pseudo-first-
order kinetics. Generally, the photodegradation rates of all
composites towards four kinds of xanthates increase gradu-
ally with the increase of alkyl group molecular weight. The
degradation efficiencies for the four kinds of xanthates are
obtained in the order of DSEX DSIPX DSBX DSIAX,
which may be caused by the instability of xanthate molecu-
lar structure with a branch. Moreover, the adsorption abil-
ity is also improved distinctly with the increase of xanthate
formula weight for all composites. The possible reason is
that xanthate molecules with complicated hydrocarbon
chains have strong hydrophobic interaction and an obvi-
ous steric-hindrance effect, which is beneficial for the com-
posite photocatalysts to capture the xanthate molecules and
thus leads to the improvement of degradation rate.
Possible Photodegradation Mechanism
To visually display the xanthate degradation process, the
real-time spectral evolution of the SIPX solution is shown
Figure 8. (a) Degradation efficiency curves and (b) kinetic curves of ternary composites