铜渣在CO2-CO混合气体中焙烧实验研究

摘要

铜渣是极有价值的冶金二次资源,铜渣的主要矿物成分是铁橄榄石、磁铁矿、铜锍及一些脉石组成的无定形玻璃体.实验基于热力学分析,用CO2和CO混合气体来控制体系内的氧势来焙烧铜渣样品.在600~900 ℃时,焙烧产物为单质铁,此时是混合气体起还原作用.在1000 ℃,焙烧渣中重新出现了FeO,说明CO2-CO混合气体体系中产生的氧起了作用.在1100 ℃时,焙烧4 h,焙烧渣中产生了Fe3O4,此时焙烧铜渣磁选后全铁含量94.35 %,铁的回收率达到了90.8 %.在600~1100 ℃,适当条件下焙烧时,铁橄榄石的物相变化为:2FeO·SiO2→FeO+SiO2→Fe→FeO→Fe3O4,铁的回收率随着温度的升高而升高.在适当范围内,延长焙烧时间、增大分压比都有利于Fe3O4的生成.%Copper slag is very valuable secondary resource for metallurgy. The main mineral composition of the slag is fayalite, magnetite,copper matte and some amorphous vitreous.This experiment was based on thermodynamic analysis in which CO2 and CO mixed gas was used to control the oxygen potential.The samples were reduced to elemental iron by the mixed gas when roasted at 600~900 ℃.At 1 000 ℃, the presence of FeO in the slag appeared due to the effects of oxygen in the mixed gas system.Fe3O4 was produced in the slag when the slag was calcined for 4 hat 1 100℃.The total iron content was 94.35 %,iron recovery rate reaching 90.8 %. The change of the fayalite phase at 600~1 100 ℃ was 2FeO·SiO2→FeO+SiO2→Fe→FeO→Fe3O4, and the recovery rate of iron rose with the temperature increasing in the roasting slag.It is beneficial for the formation of Fe3O4 when the roasting time is extended and the partial pressure ratio is increased within the proper range.