Chen Li,Chuncai Zhou,Ye Quan,Shihai Xu,Zixuan Wang,Zhiguo Li,Xin Li,Guijian Liu,Jin Wang
Adsorption of gallium (Ga) utilizing solid waste synthetic materials can achieve both high-value solid waste use and solve the supply–demand paradox of Ga. To efficiently recover Ga in solution, this article describes a hydrothermal synthesis technique of mesoporous materials from the acid leaching residue of coal fly ash (CFA). According to the findings, the mesoporous silica synthesized by hydrothermal reaction with CTAB: nSiO 3 2- =1:0.085 around 120℃ during 24 h exhibits a maximum specific surface area (771.25 m 2 /g) along with hexagonal mesoporous structure. Pseudo-second-order kinetic model that has an excellent correlation coefficient (R 2 > 0.99) can explain this adsorption system. Since Freundlich model fits this adsorption action better, the process is multi-molecular layer adsorption. The thermodynamic fitting results show that the adsorption of Ga by mesoporous silica is an endothermic and spontaneous chaotic reaction. The adsorption mechanism could be depicted using ion exchange and coupling. The adsorption efficiency of Ga is still higher than 80 % after the material has been regenerated by multiple resolution. In conclusion, mesoporous silica prepared by CFA acid leaching residue has the potential to adsorb Ga.
Efficient recovery of gallium (Ga) from vanadium slag processing residue (VSPR) solution is of great significance for environmental protection and resource utilization, but improving its selective adsorption against the coexisting Sc3+and In3+is still challenging. Herein, a novel adsorbent consisting of 4-amino-3-hydrazino-1,2,4-triazol-5-thiol (AHTZT)-modified graphene oxide (GO-AHTZT) was successfully synthesized that exhibits a higher adsorption selectivity for Ga3+in VSPR solution with coexisting Sc3+and In3+. Under optimal conditions, the adsorption capacity of GO-AHTZT for Ga3+can reach 23.92 mg g−1, which is 4.9 and 12.6 times higher than that for Sc3+(4.87 mg g−1) and In3+(1.90 mg g−1) adsorption, indicating the excellent anti-interference ability of GO-AHTZT against Sc3+and In3+. The process and mechanism of Ga3+adsorption onto GO-AHTZT was also studied and discussed in detail. By measuring the adsorption process and by characterizing the adsorbent before and after adsorption, we demonstrate that the selective interaction between the Ga3+- and N-containing groups in AHTZT is the main reason for the improved adsorption selectivity. This work opens up an avenue for the design and synthesis of highly selective adsorbents for Ga3+in complex VSPR solutions.
Wenwen Li,Chuncai Zhou,Chen Li,Wenrui Zhu,Jiaqian Shi,Guijian Liu
To alleviate the supply–demand contradiction of gallium metal (Ga), this study reports a method of preparing 2-CNT/UiO-66-NH 2 composite materials by combining carbon nanotubes (CNTs) with UiO-66 series metal–organic frameworks (MOFs) to improve the recovery and utilization efficiency of Ga in solution. The adsorbent material is used for selective adsorption and recovery of Ga in aqueous solutions. The physical properties of the composite adsorbent, such as morphology, structure, and elemental composition, were explored by analyzing the surface characteristics of the samples. The impacts of variables like the amount of adsorbent used, time, solution concentration, pH value, and coexisting ions on adsorption efficiency were explored during the experiment. The results indicate that ion exchange and chelation play a major role in the adsorption of Ga by 2-CNT/UiO-66-NH 2 , and Ga ions can be separated and recovered from the mixed solution through selective adsorption. At 313 K and pH = 8, the greatest amount of adsorption is 925.44 mg/g, and the rate at which it is absorbed can reach 99% when the adsorption time is only 1 h. The hybrid absorbent generally has a high adsorption efficiency and good selective adsorption performance for Ga, providing more efficient and economical technical assistance for the future recovery and exploitation of Ga supplies.
Gallium has important applications in new energy, semiconductor, and many other fields. Although a lot of work has been done in the field of preparing amidoxime resin to obtain gallium, there are still problems such as low adsorption capacity and relatively slow adsorption rate. In this paper, we report several high-performance porous amidoxime membranes (HPAOM). (Theoretical maximum adsorption capacity of gallium is 88.339 mg/g at 25 ºC, and the fastest adsorption equilibrium time is only 16.9 min which prepared by non-solvent-induced phase separation.) We studied the effect of pore structure on the adsorption properties of porous amidoxime membranes. The comparative analysis of the adsorption kinetics of the porous amidoxime membrane prepared by adding different contents of pore-forming agent PMMA and spray method shows that the surface through-hole structure is very important for the improvement in the adsorption rate. The amidoxime film prepared by spraying also showed good selective adsorption. It is also found that it has good adsorption performance in a wide temperature range via the analysis of adsorption isotherm curve of amidoxime porous membrane. It provides a new method for the preparation of gallium adsorption materials with large adsorption capacity, fast adsorption speed, good selective adsorption of Ga and V, and wide adsorption temperature range.
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