通过热力学计算,结合XRD和化学滴定分析,对选择性氧化法处理砷、锑烟尘过程中砷、锑的行为进行了实验研究.结果表明,烟尘中砷、锑挥发率均随焙烧系统中氧浓度升高而逐步降低,其中铁、铅等金属氧化物可将砷物相固定成稳定的Fe3(ASO4)2和Pb3(ASO4)2,从而影响砷的挥发脱除;影响砷脱除效果的主要因素为焙烧温度,O2环境下对砷、锑烟尘进行控制氧势两段焙烧法处理,温度973K,前期氧气流量30mL/min、时间30min,后期氧气流量40mL/min、时间60min时,砷脱除率达60.79%,锑挥发损失率为9.78%,实现了烟尘中砷、锑的有效分离.
Based on the thermodynamic analysis, behavior characteristics of As and Sb in the As and Sb contained smoke dust were studied. The results showed that the volatilization rates of As and Sb deceased with the increase of oxygen concentration in the roasting system. The arsenic phase was transformed into Fe3(AsO4)2 and Pb3(AsO4)2 with the existence of lead and iron oxides in the dust, which went against increasing of the As removal rate. The main influential factor on the As removal rate was roasting temperature. After treatment through the two-stage oxidizing roasting, the As removal rate reached 60.79% with the Sb loss rate of 9.78% in the conditions of roasting temperature of 973 K, oxygen flow rate of 30 mL/min and roasting time of 30 min for the first stage roasting, and oxygen flow rate of 40 mL/min and roasting time of 60 rain for the second stage roasting. As was effectively separated from the smoke dust.