氧化铋从废水中除氯机理研究  

Reaction Process of Circular Dechloridation by Bismuth Oxide from Wastewater

作　　者：周正华 叶龙刚[2] ZHOU Zhenghua;YE Longgang(Zhuzhou Smelter Group Company Limited,Zhuzhou 412007,China;College of Materials and Advanced Manufacturing,Hunan University of Technology,Zhuzhou 412007,China)

机构地区：[1]株洲冶炼集团股份有限公司,湖南株洲412007 [2]湖南工业大学材料与先进制造学院,湖南株洲412007

出　　处：《矿产保护与利用》2023年第1期132-139,共8页Conservation and Utilization of Mineral Resources

基　　金：湖南省教育厅优秀青年项目(20B175)。

摘　　要：氧化铋在锌冶炼中用于废水脱氯已有研究和应用,但除氯机理和边界条件仍有不明之处。在热力学计算的基础上,研究了氧化铋在酸化—吸附除氯—碱性脱氯—再生循环全流程使用中的物相和形貌转变。热力学计算结果表明,Bi^(3+)-ClH_2O系在pH为0~10范围内,Cl可通过形成BiOCl沉淀除去,随着pH值的升高,Bi的物相依次从Bi^(3+)向BiOCl、Bi_(2)O_(3)转变。在n(Bi)∶n(Cl)=1∶1时,溶液中最低Cl质量浓度为3.91 mg/L,而SO_(4)^(2-)的存在对氯的分布没有影响。试验研究显示,氧化铋(Bi_(2)O_(3))在硫酸质量浓度高于和低于60 g/L酸化时分别生成硫酸铋和碱式硫酸铋,形貌也从簇状向规则棒状转变,两者均可与Cl在酸性溶液中吸附形成BiOCl沉淀,BiOCl沉淀经NaOH碱洗后再生为Bi_(2)O_(3),可返回利用。氧化铋经10个循环后,Cl去除率仍高于90%,除氯稳定性好。Bismuth oxide was used for dechlorination from wastewater in zinc smelting,but the detailed dechlorination mechanism and boundary conditions are still unclear.Based on thermodynamic calculation,the phase and morphology transitions of bismuth oxide in the whole process included acidification-adsorption dechlorination-alkaline dechlorination-regeneration cycle were investigated.The thermodynamic calculations show that,in Bi^(3+)-Cl-H2O system,Cl can be removed by forming the precipitation of BiOCl in the pH range of 0~10.With the increase of pH,the main phase of Bi was transformed from Bi^(3+)to BiOCl and Bi_(2)O_(3) in turn.When n(Bi)∶n(Cl)=1∶1,the lowest Cl concentration in the solution was 3.91 mg/L,and the presence of SO_(4)^(2-)had no effect on the chlorine distribution.Experimental studies show that bismuth oxide was changed to bismuth sulfate and basic bismuth sulfate respectively below and above 60 g/L sulfuric acid when acidified with sulfuric acid,and the morphology changed from cluster to regular rod.Both of them can adsorbed with Cl in acid solution to form BiOCl precipitation.The BiOCl can be regenerated into Bi_(2)O_(3) after NaOH alkali washing and returned to utilization.After 10 cycles of bismuth oxide,the Cl removal rate was still higher than 90%,and the chlorination removal stability was good.

关 键 词：除氯 湿法炼锌 废水 氧化铋 酸化 

分 类 号：TF813[冶金工程—有色金属冶金]