用磁化焙烧-磁选工艺从粗铌精矿中回收铁富集铌的试验研究

Recovering Iron and beneficiating Niobium From Rough Niobium Concentrate by Magnetization Roast-Magnetic Separation Process

针对粗铌精矿铁含量较高的特点,提出了采用还原磁化焙烧-酸浸工艺从粗铌精矿中回收铁、富集铌。以活性炭为还原剂进行磁化焙烧,用XCGS磁选管进行磁选,考察了还原温度、还原时间和激磁电流对磁选铁精矿指标的影响。结果表明,在750℃下还原45min,粗铌精矿中的绝大部分赤铁矿被还原成磁铁矿,还原度接近理论值;还原矿在1.2A激磁电流下磁选得到铁精矿,铁品位为60.80%,收率为98.81%;磁选尾矿酸洗后,79.36%的铌留在尾矿中,Nb2O5品位达到12.46%。

Aim at high iron content in rough niobium concentrate,a process including reduction magnetization roast, magnetic separation and acid washing was used for recover iron and enriching niobium. Active carbon was used as reductant for magnetizing hematite to magnetite under higher temperature, and magnetic separation were carried out in a XCGS magnetic tube. The magnetic separation tailings were washed using hydrochloric acid for removing those soluble components. The influence of calcination temperature and time as well as excitation current on quality of iron concentrate were investigated. The results showed that after the concentrate was calcinated for 45 min at 750 ℃, most of hematite in rough niobium concentrate was reduced to magnetite with a reduction degree approaching the theoretical value. When magnetic separation was performed under an excitation current of 1.2 A, the iron concentrate with Fe content of 60. 80% and the recovery of 98. 81% were obtained, also the niobium content of 79.36% in rough niobium concentrate was left in the tailings, by acid washed,the Nb2O5 was enriched to 12.46%.