Papers by Author: Ling Li

Abstract: Based on preparing high purity powdered lithium ion-sieve precursor LiMn2O4, using lithium carbonate and manganese carbonate as raw materials, through roasting at high temperature of 800°C, laminar lithium ion-sieve precursor was prepared by commixing poly (vinyl chloride) (PVC) and powdered precursor in DMF (N, N-dimethylformamide) as solvent, and then powder and lithium ion-sieve flat sheet membrane was obtained through washing with HCl solution respectively. Their adsorption capacity and morphology was also characterized. The results show that both powdered lithium ion-sieve and laminar one have high adsorption capacity and selectivity for Li in solutions, and the effect of their retest is good. All these can provide a good foundation for the further study on lithium ion-sieve flat sheet membrane and lithium extraction from seawater.

Abstract: Solid solutions with different compositions, mNH₄Cl·KCl and NH₄Cl·nKCl (m，n≥1), were prepared by the constant speed cooling method. The thermal stability of the solid solutions was determined by TG-DTA. The results show that mNH₄Cl·KCl crystals change its crystal form at 180°C, decompose into ammonia and hydrogen chloride gas at 330°C, melt at 790°C, and finally evaporate at around 820°C. Its evaporation temperature increases with the increasing of potassium chloride content in the samples. The Solid solution of NH₄Cl·nKCl decomposes to ammonia and hydrogen chloride gas at 230°C, melts at 790°C, and evaporates at 800°C. The continuous specific heat curve of the solid solution (NH₄, K)Cl were also determined. These data provide a theoretical basis for further research on solid solution properties.