选择性絮凝-磁种法在微细粒人工磁铁矿磁选中的团聚效应

对鄂西隐晶质鲕状赤铁矿进行磁化焙烧—阶段磨矿—磁选试验,得到TFe 57.73%、磷含量0.70%,铁回收率为90.41%的人工磁铁矿粗精矿。为继续提升精矿质量,对人工磁铁矿粗精矿进行细磨,磨矿细度-22μm含量80%时,单体解离度为84.63%。采用选择性絮凝—磁种法对细磨粗精矿磁选,进行了流程优化试验,得到了TFe 60.87%、磷品位0.41%的铁精矿,综合铁回收率提高了9.55%。机理分析表明,人工磁铁矿的磁性明显弱于天然磁铁矿,且随粒度减小,两者磁性差异进一步增大。在磁场强度70kA/m条件下,用作磁种的天然磁铁矿的比磁化系数是人工磁铁矿的2.4倍。在添加絮凝剂CMS后,FTIR分析表明絮凝剂CMS在磁铁矿表面产生了选择性吸附,使细磨粗精矿平均粒径或人工磁铁矿平均粒径均大幅度增大,而石英平均粒径增幅很小,从而增强了脉石与磁铁矿的分离效果,提高了铁的回收率。

Aggregation Effect of Selective Flocculation-Magnetic Seed Method in Magnetic Separation Process of Micro-fine Artificial Magnetite

A kind of cryptocrystalline oolitic hematite was dealt with by magnetization roasting - stage grinding - magnetic separation technology. The obtained crude iron concentrate grade was TFe57.73%, phosphorus content 0.70%, total iron recovery rate of 90.41%.Deep grinding of the artificial magnetite was carried out for better results. The degree of disintegration of the coarse concentrate was determined to be 79.6% under the grinding fineness below 0.022mm, and the degree of monomer dissociation was 84.63%. A selective flocculation - magnetic seed method was used to optimize the iron extraction process for fine grinding of coarse concentrate. Iron ore concentrate with a total iron grade of 60.87%, a phosphorus grade of 0.41%, and the total iron recovery was increased by 9.55%. It indicatesSon theSmechanismSanalysisSthat the magnetism of the artificial magnetite is obviously weaker than that of the natural magnetite,as grain size decreases, the magnetic difference between the two increases further. The specific magnetic susceptibility of the natural magnetic species used as magneticSseeds was 2.4 times of an artificial magnetite at a magnetic field strength of 70 kA/m. The test of the particle size before and after flocculation found that there are both large increase in weighted average grain size of the finely ground coarse concentrate or artificial magnetite, but the increasement of the grain size of the flocculation quartz is very small, Therefore, it was inferred that CMS has no flocculation effect on quartz. It was proved that CMS produced selective adsorption on the surface of artificial magnetite particles by FTIR analysis.