砷锑烟尘与冶炼污酸的联合处置

Combined Disposal of Arsenic-Antimony Dust and Smelting Waste Acid

基于砷、锑在酸性溶液中的溶解差异性,结合砷锑烟尘和冶炼污酸的成分特征,提出氧化酸浸分砷—湿法还原固砷的砷锑烟尘与冶炼污酸的联合处置工艺。结果表明,在过氧化氢加料系数1、过氧化氢质量分数30%、液固比5、温度30℃、浸出时间4 h、污酸酸度1 mol/L条件下,砷的浸出率可达99%以上,所得浸出渣锑含量高达90%,砷含量仅为0.2%,实现了高砷锑烟尘中砷和锑的初步分离;采用氯化亚锡二段还原工艺,在酸度12 mol/L、温度90℃、n(NaCl)/n(As)=3、还原剂系数1、反应时间4 h的条件下,砷还原率可达99.75%,反应后液中锑浓度为6.72 g/L,砷浓度仅为0.17 g/L,实现砷和锑的二次分离。

Based on the dissolution difference of arsenic and antimony in acid solution,combined with the composition characteristics of arsenic-antimony dust and smelting waste acid,a combined disposal process of arsenic-antimony dust and smelting waste acid was proposed,which is arsenic separation by oxidizing acid leaching and arsenic fixation by hydro-reduction.The experimental results show that the leaching rate of arsenic can reach 99% above under the conditions including hydrogen peroxide feeding coefficient of 1,hydrogen peroxide mass fraction of 30%,liquid-solid ratio of 5,leaching temperature of 30 ℃,leaching time of 4 h,and waste acid acidity of 1 mol/L,and antimony content in the leaching residue is up to 90%,while the arsenic content is only 0.2%.Thus,the preliminary separation of arsenic and antimony in high-arsenic and antimony dust is realized.Using stannous chloride two-stage reduction process,and under the conditions of acidity of 12 mol/L,temperature of 90 ℃,mole ratio of n(NaCl)/n(As)=3,reductant coefficient of 1 and reaction time of 4 h,the reduction rate of arsenic can reach 99.75%,the concentration of antimony in the reaction solution is 6.72 g/L and the concentration of arsenic is only 0.17 g/L.The secondary separation of arsenic and antimony is realized.