高铝高硅褐铁矿钠化焙烧-磁选试验研究

针对某高铝高硅难选褐铁矿(Al₂O₃含量26.11%、SiO₂含量13.88%)进行了钠化焙烧-磁选试验研究。通过单因素试验和正交试验探讨了钠盐种类、钠盐用量、焙烧时间、焙烧温度、磁选粒度、磁选强度对选别指标的影响, 结果表明, 在焙烧温度1 050 ℃、焙烧时间40 min、Na₂CO₃用量12%、煤粉用量20%、磨矿细度-0.038 mm粒级占98.86%、磁场强度200 kA/m条件下可获得铁品位57.91%、铁回收率97.50%的铁精矿。钠化焙烧后产品再经阶段磨矿、阶段磁选可获得铁品位62.04%、铁回收率60.90%的铁精矿。

Experimental Study on Sodium Roasting-Magnetic Separation for High-alumina and High-silicon Limonite

A sort of refractory limonite (containing 26.11% of Al₂O₃ and 13.88% of SiO₂) was taken as a sample for the tests on the process of sodium roasting-magnetic separation. Single factor test and orthogonal test were conducted to explore effects of species, dosage of sodium salts, roasting temperature and time, particle size and magnetic intensity for magnetic separation on the separation efficiency. It was found that iron concentrate grading 57.91% Fe at the recovery of 97.50% could be obtained after roasting process at a temperature of 1 050 ℃ for 40 min with the following conditions including dosage of Na₂CO₃ and coal dust at 12% and 20% respectively, grinding fineness of -0.038 mm 98.86%, magnetic field intensity of 200 kA/m. The obtained product was subjected to the following staged grinding and staged magnetic separation, resulting in the iron concentrate grading 62.04% Fe at the recovery of 60.90%.