磁流体强化弱磁性矿物按磁化率高效分选及其机理

Efficient separation of weakly magnetic minerals based on susceptibility enhanced by magnetic fluid and its mechanism

为了兼顾弱磁性矿物高梯度磁选的品位和回收率,提出一种新的高梯度磁选方法—磁流体耦合高梯度磁选,该方法将顺磁性磁流体引入到高梯度磁选中产生磁排斥力来扩大有用磁性矿物和磁性脉石矿物的受力差异,减少进而消除二者之间的竞争捕集,大幅提高分选的选择性。以攀西钛铁矿为试验对象,MnCl_(2)溶液为磁流体,开展磁流体耦合高梯度磁选试验和相关机理研究。研究结果表明:磁流体能显著提高钛铁矿的选择性,经一次分选后磁性产物TiO_(2)品位达到39.70%,远比工业常规高梯度磁选获得的TiO_(2)品位高;磁性矿物和磁性脉石的受力差异由磁流体的磁化率调控,与磁场力HgradH无关,能够实现品位和回收率的双向同步强化,最佳的磁流体磁化率应接近磁性脉石的磁化率;磁流体耦合高梯度磁选能够强化弱磁性矿物按磁化率精细分离,突破传统高梯度磁选无法兼顾品位和回收率的技术瓶颈,具有广阔的应用前景。

To obtain the balance in concentrate grade and recovery in high gradient magnetic separation(HGMS)of the weakly magnetic minerals,a novel separation method termed high gradient magnetic separation coupling with magnetic fluid(HGMSCMF)was put forward.Paramagnetic fluid was introduced into HGMS to generate magnetic repulsive force and enlarge the force difference between magnetic valuable minerals and gangue minerals,reducing or eliminating competing capture and significantly improving separation selectivity.Systematical experimental and theoretical study on HGMSCMF was conducted with ilmenite in Panzhihua and MnCl_(2)paramagnetic solutions.The results show that the selectivity of ilmenite can be significantly improved with HGMSCMF,concentrate with TiO_(2)grade up to 39.74%is obtained with only one-stage HGMSCMF,which is much higher than that in industrial production.The force difference between valuable weakly magnetic minerals and weakly gangue minerals is regulated by the susceptibility of magnetic fluid and is independent of magnetic field force HgradH,and the grade and recovery of magnetic products can be simultaneously improved.Optimal susceptibility of magnetic fluid should be approaching that of magnetic gangue minerals.HGMSCMF can enhance the separation of weakly magnetic minerals based on susceptibility and break through the bottleneck of balance between concentrate grade and recovery in conventional HGMS,exhibiting great potential in the processing of complex weakly magnetic materials.