钒、钨离子在D201树脂上的吸附分离性能

Adsorption and separation of vanadium and tungsten ions using D201 resins

对废脱硝催化剂中的钒钨提取再利用具有重要的应用价值。以废脱硝催化剂碱浸液为研究对象,考察了不同吸附时间下碱浸液中钒、钨离子在D201树脂上的吸附量变化,测定了钒、钨离子在D201树脂上的吸附等温线及吸附穿透曲线,并研究了钨离子在D201树脂上的解吸行为。结果表明:在pH=12.8、25℃时,D201树脂对钒、钨离子的平衡吸附量分别为0.98与99.01 mg×g^-1,其优先吸附钨离子,表现出优异的吸附选择性;D201树脂对钨离子的等温吸附与吸附动力学过程分别符合Freundlich模型和拟二级动力学模型;钨离子在D201树脂内呈现出以颗粒内扩散为主的扩散方式。吸附穿透曲线实验结果显示:当停留时间为60 s时,钒、钨离子的分离系数高达97.6。此外,采用氯化铵+氨水混合液作为洗脱液,钨离子从D201树脂有效脱附,其最佳解吸率为99.43%。

Recycling vanadium and tungsten ions from the spent denitration catalysts has great values.Alkali leaching solutions of spent denitration catalysts containing vanadium and tungsten ions were used.Effects of adsorption time on adsorption capacities using D201 resin were discussed.In addition,adsorption isotherms and breakthrough curves of vanadium and tungsten ions on the resin and desorption behavior of tungsten ion were studied.The results show that vanadium and tungsten ions uptake reach 0.98 and 99.01 mg×g^-1 at pH=12.8 and 25℃,respectively.The D201 resin preferentially adsorbed tungsten ions with excellent adsorption selectivity.The adsorption isotherms and kinetics curves of tungsten ion on the D201 resin were well fitted by Freundlich and pseudo-second-order kinetics models,respectively.The diffusion of tungsten ion in D201 resins was dominated by the intra-particle diffusion.Breakthrough experiments suggest that the separation factor of V/W ions was high up to 97.6 at a dwell time of 60 s.The optimal desorption rate for W ion was 99.43%through an elution process using NH4Cl-NH3·H2O as the eluent.