摘要
采用二次水热合成法,在板式α-Al_2O_3基膜上,以n(Si)∶n(Al)∶n(模板剂)∶n(KOH)∶n(H_2O)=36.8∶8∶1∶24.8∶771为原料配比,在200℃下合成钾离子筛膜,并考察了晶化时间、模板剂、合成次数对钾离子筛膜的影响.利用XRD、SEM、EDS和单一气体渗透测试进行表征,表明成功合成厚度约为30μm的钾离子筛膜,其H2渗透率为20.6×10-6mol/(m^2·s·Pa),N2渗透率为8.1×10^(-6) mol/(m^2·s·Pa),αH_2/N_2=2.54,表明该膜致密均匀.电驱动实验结果表明,K^+、Na^+、Mg^(2+)和Ca^(2+)的平均渗透通量分别为852.61、112.38、12.44及5.26mmol/(m^2·h),钾离子筛膜对钾离子的选择性系数分别为αK/Na=7.25、αK/Mg=69.85、αK/Ca=166.06;离子通量随着浓度、电压和温度的增大均增大;离子选择性随着电压的增大而增大,随着浓度的增大和温度的升高而降低.结果表明,在直流电场的作用下,板式钾离子筛膜对钾离子具有良好的选择分离性能.
α- Al2O3 supported potassium ionic sieve membrane was synthesized by the secondary hydrothermal growth method with the synthetic liquid ratio of n（Si） ： n（A l） ： n（template） ： n（K O H ） ： n （H2O） = 36. 8 ： 8 ： 1 ： 24. 8 ： 771 under 200 °C . Further studies on the synthetic time, template agent and number of synthesis of the influence on the potassium ion sieve membrane crystal growth were carried out. Then it was characterized by XRD？ SEM,EDS and gas permeation. I t turns out that the potassium ion sieve membrane about 30 jitm thickness was synthesized successfully. The permeability of H 2 is 20. 6 × 10-6mol/（m2 s Pa） while N2 8. 1×10-6 mol/（m2 s Pa）. And the separation factor of H 2/N2 is 2. 54. The permeation flux of K ＋,Na＋,Mg2＋ and Ca2＋ are 852. 61,112. 38,12. 44,5. 26 mmol/（m2 h ） respectively in the electric drive experiments. The separation factors of K ＋/Na＋ , K ＋/Mg2＋ and K ＋/Ca2＋ are equal to 7. 25 69. 85,166. 06. Ion fluxes are increase with the increase of concentration, voltage and temperature. Ion selectivities are decrease with the increase of concentration and temperature but increase with voltage. The results show that the disc-shaped ion sieve membrane for the separation of potassium ion has a good performance under the effect of DC field.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2017年第1期27-35,共9页
Membrane Science and Technology
基金
国家科技支撑计划项目(2015BAB09B00)
长江学者和创新团队发展计划(IRT14R14)
关键词
板式钾离子筛膜
电驱分离
浓海水提钾
disc-shaped potassium ion sieve membrane
separation performance in the electric drive process
extraction of potassium from concentrated seawater
