【摘要】 通过对Te(Ⅳ)-Pb(Ⅱ)-Cu(Ⅱ)-As(Ⅲ)-H2O和Te(Ⅳ)-MeS-H2O系热力学分析,得到溶液中Te(Ⅳ),Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子总浓度与溶液pH值、温度以及溶液中S2-浓度的关系。热力学分析结果表明:采用硫化物沉淀法可以深度净化Na2TeO3溶液,去除其中大部分重金属离子及砷离子,确定理论上去除Na2TeO3溶液中Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子的最佳pH值为11左右。采用硫化物沉淀法对Na2TeO3溶液中Pb(Ⅱ),Cu(Ⅱ)和As(Ⅲ)离子的净化实验验证了热力学分析的正确性,通过实验使粗TeO2中的Pb,Cu和As杂质的质量分数由0.273 0%,0.165 9%和0.280 0%分别降低到3.24×10-4%,1.00×10-4%和1.30×10-3%,但S2-浓度过量对As的去除不利。实验确定硫化沉淀法去除杂质离子的最佳条件是:pH=11,温度为373 K,反应时间为50 min。更多还原

【Abstract】 By thermodynamic analysis on system of Te（Ⅳ）-Pb（Ⅱ）-Cu（Ⅱ）-As（Ⅲ）-H₂O and（Te（Ⅳ））-MeS-H₂O,the relationship between total concentration of Te（Ⅳ）, Pb（Ⅱ）,Cu（Ⅱ）,（As（Ⅲ）） and pH value,reaction temperature,concentration of S^2- was established.Thermodynamic analysis results show that most heavy metallic ions and As（Ⅲ） in Na₂TeO₃ solution can be removed thoroughly by sulfide precipitation method.The theoretic optimum pH value for sulfide precipitation to remove the impurities from Na₂TeO₃ solution is about 11.The experimental results confirm the thermodynamic analysis results.Pb,Cu and As in raw TeO₂ are removed from（0.2730%,） 0.1659% and 0.2800% to 3.24×10^-4%,1.00×10^-4% and 1.30×10^-3%,respectively.And an excess of S^2- is not in favor of As removal from Na₂TeO₃ solution.According to experimental results the optimum process parameters are as follows: pH=11,reaction temperature of 373K,reaction time of 50min.更多还原