Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (10): 933-937.doi: 10.3866/PKU.WHXB20031010

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Preparation of MnO2(Li) and Its Ion Exchange Kinetics

Zhao Li-Li;Wang Rong-Shu   

  1. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050;
  • Received:2003-04-26 Revised:2003-06-10 Published:2003-10-15
  • Contact: Zhao Li-Li E-mail:zll@mail.sic.ac.cn

Abstract: The effects of calcination temperatures and extractants on the structure and chemical stability of LiMn2O4 were examined by XRD, βLi (degree of Li+ extraction) and γMn(degree of Mn2+ dissolution) analyses, the results show that MnO2(Li) prepared at 750 ℃ for 2 h has larger exchange capacities using (NH4)2S2O8 as extractant. In addition, the mechanism of ion exchange reaction was studied by distribution coefficient measurement and kinetic experiment, and the mathematical model for ion exchange reaction kinetics in a finite solution has been established. The results indicate that this ion exchange process is controlled by particle diffusion; ion exchange reaction mainly occurs in the outer layer of MnO2(Li). The experimental results are in good agreement with the calculated values.

Key words: Extractant of Li, LiMn2O4, MnO2(Li) exchanger, Kinetics