从提锂废液中提取RbCs及其动力学基础研究

Basic study on the extraction and its kinetics of Rb and Cs from waste solution obtained by lithium recovery

  • 摘要: 本文利用t-BAMBP + 液体石蜡从提锂废液中同时提取Rb、Cs,并进行萃取动力学分析。此外,还研究了废液碱度、温度、相比等因素对萃取率的影响。在c(OH-)=0.4 mol/L、t-BAMBP的体积分数为35%、相比(VO /VA)为1.2、萃取温度为25 ℃、萃取时间为2 min、振荡速度为180 r/min的条件下,Rb+、Cs+的萃取率分别为68.22%、97.57%。并在此条件下进行了三级逆流萃取,Rb+、Cs+的萃取率分别达到96.06%、99.96%。对负载的有机相进行二级洗涤-二级反萃,结果显示洗涤阶段去除了绝大部分的Li+、Na+、K+,而Rb+保持较低的洗涤率,Cs+不被洗涤;99.15%的Rb+和99.98%的Cs+被有效地反萃。Rb的萃取动力学分析表明:Rb+的萃取表观活化能Ea = -11.48 kJ/mol,传质过程受扩散和化学反应混合控制。

     

    Abstract: Rb and Cs were simultaneously extracted from a waste solution resulting from the recovery of lithium by the t-BAMBP and liquid paraffin system, and the extraction kinetics were analyzed. The effect of waste solution alkalinity, temperature, phase ratio and other factors on extraction rate was studied. Under the conditions of c(OH-) of 0.4 mol/L, t-BAMBP volume fraction of 35%, phase ratio (VO /VA) of 1.2, extraction temperature of 25 ℃, extraction time of 2 min, and oscillation speed of 180 r/min, extraction rates of Rb+ and Cs+ reached 68.22% and 97.57%, respectively. Under the same condition, the extraction rates of Rb+ and Cs+ reached 96.06% and 99.96% using a three-stage countercurrent extraction. The loaded organic phase after two-stage scrubbing and two-stage stripping,the results showed that the majority of Li+, Na+ and K+ were removed in the scrubbing stage, while Rb+ kept a lower scrubbing rate and Cs+ was not scrubbed. 99.15% of Rb+ and 99.98% of Cs+ were effectively stripped. Extraction kinetic analysis of Rb showed that the apparent activation energy of Rb+ extraction was -11.48 kJ/mol, with the conclusion that mass transfer was controlled by diffusion and chemical reaction mixing.

     

/

返回文章
返回