(中南大学 冶金与环境学院,长沙 410083)
摘 要: 对脆硫铅锑精矿富氧直接熔炼过程Fe元素行为进行研究,利用X射线衍射、扫描电镜能谱、光学显微镜、电子探针、化学物相分析等手段对熔炼过程Fe元素走向及各相中赋存状态进行表征。结果表明:熔炼中间过程Fe主要富集于精矿颗粒外围FexSbyS复杂硫化物相,少量Fe以FeSb和FeS形式赋存于颗粒中心合金相;随反应进行,Fe不断向颗粒外围迁移,熔炼终产物粗铅锑合金中Fe以FeSb和FeSb2形式存在,绝大部分Fe氧化造渣以硅酸铁(60.04%)和赤褐铁矿(Fe2O3,37.34%,质量分数)形式进入熔炼终渣。中间产物FexSbyS化合物的形成抑制锑硫化物氧化和挥发,其直接分解是铅锑合金中存在Fe-Sb合金相的主要原因。
关键字: 脆硫铅锑精矿;富氧;直接熔炼;铅锑合金;Fe;赋存状态
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract:Fe element behavior of jamesonite concentrate during the oxygen-enriched direct smelting was studied. The trend of iron in the smelting process and occurrence state in each phase were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, electron probe and chemical phase analysis. The results show that the intermediate, partially oxidized jamesonite concentrate particle, is consisted of inner metal phase and outer FexSbyS sulfide phase. The oxidation and volatilization of antimony compounds is inhibited by the formation of FexSbyS phase. The iron is mainly enriched in the FexSbyS phase, while a little of FeS and FeSb alloy exist in the inner metal phase. As reactions proceeded, the iron is gradually transferred into the outer sulfide phase. And the iron was presented as FeSb and FeSb2 in the lead-antimony alloy. Most of the iron are presented in the form of 2FeO·SiO2 and Fe2O3 within the smelting slag. The presence of FeSb and FeSb2 phases in the lead-antimony alloy are mainly originated from the direct decomposition of FexSbyS phase.
Key words: jamesonite concentrate; oxygen-enriched; direct smelting; lead-antimony alloy; Fe; occurrence state