微细粒钛铁矿磁选回收率低原因分析

为查明攀西微细粒钛铁矿在磁选过程损失的原因,制备了4个粒级的钛铁矿、钛辉石单矿物样品,在不同外加磁场强度条件下,各粒级钛铁矿的比磁化率趋近于1.40×10-6~1.50×10-6 m3/kg、钛辉石趋近于0.32×10-6~0.43×10-6 m3/kg。不同粒级混合矿的磁选试验结果表明,磁选精矿中钛铁矿的含量主要受钛辉石粒度的影响,而钛铁矿的回收率主要受其自身粒度的影响;颗粒在磁选中的受力计算结果表明,微细粒钛铁矿磁选回收所需要的磁场力大幅增大,而常规高梯度强磁选机不能达到此要求,这是造成微细粒钛铁矿磁选回收率低的主要原因。实现微细粒钛铁矿高效回收的措施是进行分级磁选、磁絮凝,而避免钛铁矿在选铁流程中的过磨、泥化是提高钛铁矿回收率的根本途径。

Loss mechanism of fine-grained ilmenite in magnetic separation

In order to investigate the loss mechanism of fine-grained ilmenite during magnetic separation process of the titanium beneficiation plant in Pan-Xi region, four size fractions of ilmenite and titanaugite minerals were prepared. It was shown that with the increase of applied magnetic field strength, the magnetic susceptibilities of each ilmenite fractions converged to 1.40~1.50×10-6 m3/kg, while those of titanaugite converged to 0.32~0.43×10-6 m3/kg. Results of magnetic separation experiments of mixed ores indicated that the content of ilmenite in concentrate mainly were influenced by the size of titanaugite and its recovery was predominantly affected by the size of itself. The required applied magnetic force of ultrafine ilmenite increased substantially compared to that of coarse fractions, and it could not offer by normal high intensity magnetic separator, which resulted in the loss of ultrafine ilmenite. Therefore, to collect the coarse and the fine of ilmenite in corresponding magnetic separators which can offer customized magnetic field forces, or to enlarge ilmenite clusters, can beneficiate the fine-grained ilmenite efficiently. Moreover, to avoid overgrinding and slimming ilmenite in iron beneficiation process is the basic way to increase the recovery of ilmenite.