含锑烟尘氧化焙烧处理后CO-CO2混合气体中锑资源的还原焙烧法回收

摘要

This paper mainly investigated the antimony recovery from antimony-bearing dusts through reduction roasting process after the dust firstly oxidation roasted. CO-CO2 mixture gas was used as reducing agent, and the antimony-containing phase was reduced into Sb4O6, volatilized into smoke, and finally recovered through the cooling cylinder. The antimony recovery rate increased from 66.00 wt％ to 73.81 wt％ in temperature range of 650 to 800 ℃, and decreased with temperature increased further to 900 ℃ due to the reduction of Sb4O6 to the nonvolatile Sb. Similarly, the CO partial pressure also played a double role in this test. Under optimized conditions of roasting temperature of 800 ℃, CO partial pressure of 7.5 vol％ and roasting time of 120 min, 98.40 wt％ of arsenic removal rate and 80.40 wt％ antimony recovery rate could be obtained. In addition, the "As2O3" product could be used for preparing ferric arsenate which realized the harmless treatment of it.%研究主要针对含锑烟尘经氧化焙烧处理后CO-CO2混合气体中锑资源的还原焙烧法回收进行了探讨.以CO-CO2混合气体作为还原剂,过程中锑物相还原为Sb4O6并进入气相,最后通过冷凝收尘方式实现其回收.温度由650℃升高至800℃时,锑回收率从66.00 wt％增至73.81 wt％,当温度进一步升高到900℃时,Sb4O6被进一步还原为非挥发性金属锑,锑回收率降低.同样,CO分压对锑的挥发回收亦起双重作用.在最优焙烧条件下,即焙烧温度800℃、CO分压7.5 vol％及焙烧时间120 min时,锑烟尘中砷挥发率可达98.40 wt％,同时锑回收率亦可达80.40 wt％.此外,挥发脱除的"As2O3"烟尘可用于制备砷酸铁,以实现其无害化处理.