镍火法熔炼高钙低硅渣提取铁的研究

Iron Extraction Research on Slag With Higher Calcium and Lower Silicate in Nickel Smelting Process

镍火法冶炼的高硅酸铁渣在综合利用中还原提取铁比较困难,通过在镍熔炼渣中适当增加CaO含量、减少SiO2含量以改善后续还原提取铁的热力学条件。在对所确定的新渣型对镍锍进行分离试验后,对熔炼终渣进行物相分析和还原提取铁试验,探讨了原渣和高钙低硅新渣型还原提取铁的不同。研究结果表明,高钙低硅新渣型终渣中铁主要以Ca(Fe,Mg)Si2O6以及MgFe2O4形式存在,50%以上的Fe以MgFe2O4的形式存在,其磁性以及还原性都比原渣中的(Fe,Mg)2SiO4要好,有利于其还原。与原渣的还原性相比,在试验条件下,当wCaO/wSiO2为0.80时,其还原率由48.53%提高到了57.45%。

Due to the difficulty of iron reduction extraction in high fayalite residue comprehensive utilization produced by nickel smelting process, optimized research on the existing high silicate slag was investigated through increasing the content of CaO and lowering SiO2 in proportion to improve the thermodynamic condition for iron reducing subsequently. Separation test between nickel mattes and the new determined slag were investigated followed by phase analysis of the final slags. And then, iron extraction experiments on the new smelted slag as well as on the current high-iron residue were studied to explore the different influencing rules of iron reduction. The results show that it is Ca（Fe, Mg）Si2 06 and MgFe2O4 which mainly exist in the new slag with higher calcium and lower silicate. And more than 50% existing Fe are in the form of MgFe2O4 with better magnetic and reducing than （Fe,Mg）2 SiO4, as a result benefit to its reduction. Compared with the current high fayalite original salg, the iron extraction ability of new slag can be enhanced from 48.53% to 57.45% when wCaO/wSiO2 are set as 0.80.