某低品位高磷赤铁矿磁化焙烧-磁选-酸浸脱磷工艺研究

摘要

采用磁化焙烧⁃磁选⁃酸浸脱磷工艺对某低品位高磷赤铁矿石进行了试验研究，在焙烧温度800℃，焙烧时间30 min，配煤量20％条件下得到焙烧矿，再经过两段弱磁选得到铁品位55．03％、铁回收率55．49％、磷含量0．54％的粗精矿。采用硫酸酸浸对粗精矿进行脱磷，最终铁品位达到57．88％，全流程铁回收率53．47％，磷含量降到0．20％。通过酸浸脱磷正交实验，发现浓硫酸用量对脱磷率、铁回收率影响显著。使用高压辊磨处理，增加磁选粗精矿的比表面积，能有效提高酸浸脱磷率，当粗精矿比表面积由589 cm2／g提高到1865 cm2／g时，铁精矿磷含量由0．20％降到0．08％。%The technique of magnetizing roasting⁃magnetic separation⁃acid leaching for dephosphorization was adopted to treat the low⁃grade and high⁃phosphorous hematite ore in the experimental study. The calcine obtained after roasting process at 800 ℃ for 30 min with 20% coal, was then subjected to two stages of weak⁃intensity magnetic separation, resulted in a rough iron concentrate assaying 55. 03% Fe at 55. 49% recovery and 0. 54% P . After that, acid leaching with sulfuric acid was used for dephosphorizing the rough concentrate, leading to a final iron concentrate assaying 57�88% Fe at the total recovery of 53.47% and 0.20% P. Orthogonal test of acid leaching for dephosphorization showed that the dosage of concentrated sulfuric acid had a remarkable effect on the dephosphorization and iron recovery. An increased specific surface area of the rough magnetic concentrate in the treatment with high pressure grinding roller can improve dephosphorization by the acid leaching. The P content in the iron concentrate reduced from 0. 20% to 0. 08%when specific surface area of rough concontrate increased from 589 cm2/g to 1 865 cm2/g.