提高高铁酸钾产率和稳定性的方法

在至少一种高铁稳定剂存在下,用纯净的C l2与分析纯的KOH、Fe(NO3)3.9H2O反应制得了稳定的K2FeO4,研究了催化剂N i(Ⅱ)、Co(Ⅱ)及稳定剂Na3PO4、CuC l2.2H2O、Na2S iO3.9H2O、Na3H2IO6对高铁酸钾产率和稳定性的影响。实验结果表明,N i(Ⅱ)和Co(Ⅱ)具有很高的催化分解高铁酸钾的活性,当在反应体系中加入质量分数为30×10-6的N i(Ⅱ)或Co(Ⅱ),高铁酸钾的产率降低为0,因此,为降低N i(Ⅱ)和Co(Ⅱ)的含量,制备高铁酸钾应使用AR试剂。添加Na3PO4、Na3H2IO6、CuC l2.2H2O、Na2S iO3.9H2O等稳定剂,特别是同时添加CuC l2.2H2O、Na2S iO3.9H2O和Na3H2IO6等稳定剂,能大幅提高高铁酸钾的产率及稳定性:产率约从73%提高到88%;固态高铁酸钾在烧杯中经18 d敞开放置,分解率由46%降低到5%;在温度为80℃、pH=11的碱性溶液中,高铁酸钾完全分解的时间从8 h增加到16 h。

Improvement in the Yield and Stability of Potassium Ferrate(Ⅵ)

Stabilized potassium ferrate(Ⅵ) was prepared by reacting pure Cl_2,analytical grade KOH and Fe(NO_3)_3·9H_2O in the presence of at least one ferrate-stablizing reagent including Na_3PO_4,CuCl_2·2H_2O,Na_2SiO_3·9H_2O and Na_3H_2IO_6.Nickel(Ⅱ) and cobalt(Ⅱ) exhibit high catalytic activity for the decomposition of K_2FeO_4 that the yield of K_2FeO_4 decreases to 0 when only 30×10~(6) nickel(Ⅱ) or cobalt(Ⅱ) are added to the reaction system,so only analytical grade reagents should be employed for preparing potassium ferrate(Ⅵ) in order to reduce the contents of nickel(Ⅱ) and cobalt(Ⅱ).The yields and stability of K_2FeO_4 can be greatly improved by adding stabilizers,especially the combination of CuCl_2·2H_2O,Na_2SiO_3·9H_2O and Na_3H_2IO_6.The yield is raised from about 73% to about 88%.In the presence of stabilizer,decomposition percentage is decreased from about 46% to 5% when solid potassium ferrate(Ⅵ) is placed in an open beaker for 18 days,and the decomposition time of potassium ferrate(Ⅵ) increased from 8 h to 16 h at 80 ℃ in a solution of pH=11.