Recovery of antimony from antimony-bearing dusts through reduction roasting process under CO—CO₂ mixture gas atmosphere after firstly oxidation roasted

Abstract

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 °C, and decreased with temperature increased further to 900 °C 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 °C, 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.

摘要

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 °C 升高至800 °C 时,锑回收率从66.00 wt%增至73.81 wt%,当温度进 一步升高到900 °C 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 °C、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。