Liu Dong-Bin,Li Ye,Zhou Yu-Zhi,Xu Li-Dong,Liu Dong-Xue,Li Bo-Lin,Zhao Shao-Lin
In this study, (3-mercaptopropyl) trimethoxysilane as a modifier, the mercapto group (-SH) was grafted onto the surface of attapulgite (ATP) by ultrasonic stirring. Before and after modification, the surface feature and structure of attapulgite and mercapto attapulgite (ATP-SH) were
characterized by using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), the results indicated that the physicochemical changes of the materials and the mercapto groups were jointed on the surface of attapulgite. In this work, mercapto
attapulgite was used as an adsorbent for manganese adsorption, adsorption experiments were implemented to investigate the effects of different influencing conditions, the results shown that the solution pH showed a slightly impact in the sorption process, because of the presence of manganese
in the solution is Mn2+ and MnOH+. The Fourier transform infrared characterization results illustrated that the mercapto attapulgite had a number of active functional groups on the surface, which can combine with manganese. Moreover, the sorption process was more suitable
for the pseudo-second-order model (R
2 = 0.9986), which was illustrated that the chemical sorption plays a major role, and also existed physisorption. The sorption experiments date were more suitable for fitted to Langmuir isotherm model (R
2 = 0.9961), illustrated
that the adsorption process was dominated by monolayer adsorption. These results of the removal ratio, sorption capacity and adsorption mechanism of manganese suggest that the mercapto attapulgite could be applied as an adsorbent for extracting manganese from sewage.
Shaolei Xie,Yuze Zhang,Xiaowu Peng,Yong Niu,Hailong Lu,Fugen Song,Dong Shi,Lijuan Li
Adsorption is a popular method for the recovery of low-grade lithium. It is a low-cost and highly efficient way to treat solutions with low lithium concentrations. The impurity content determines the industrial application. This study investigated a novel strategy to remove divalent cations from a desorption solution containing Mg2+, Ca2+, and Mn2+, generated by a manganese absorbent using an organophosphoric acid, followed by precipitation of lithium carbonate from the concentrated raffinate by evaporation. Di(2-ethylhexyl)phosphoric acid (P204) was selected as the preferred extractant. The saponification method and degree of saponification were determined, and the extraction parameters (pH, extractant concentration, and phase ratio) were investigated. A three-stage countercurrent extraction process was tested. Removal efficiencies of Mg2+, Ca2+, and Mn2+from the manganese-containing desorption solution exceeded 99%, leaving <1.0 mg/L divalent cations in the raffinate. The raffinate was evaporated and concentrated to >23 g/L lithium. The total concentration of divalent cations in the lithium-rich solution was approximately 10.0 mg/L. Further conversion with sodium carbonate was carried out to prepare a battery-grade lithium carbonate product with a purity of 99.83%. The present work may provide a novel means of lithium recovery from a manganese-containing desorption solution.
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