贵州某褐铁矿磁化焙烧—磁选试验

贵州某褐铁矿石为低硫磷褐铁矿石,铁品位为47.14%,铁矿物主要有褐铁矿,纤铁矿、硬锰矿、软锰矿、黄铁矿少量,褐铁矿呈不规则胶状、土状分布,与脉石矿物共生关系密切,磨矿过程不仅难以实现有用矿物与脉石矿物的有效分离,而且容易泥化,因而直接强磁选或重选均难以获得理想的分选指标。为解决该褐铁矿石资源的开发利用问题,采用磁化焙烧—磁选工艺对该矿石进行了选矿试验。结果表明,在无烟煤(2~0 mm)与矿样(3~0 mm)质量比为5%,焙烧温度为850℃,保温时间为40 min,焙烧产物的磨矿细度为-0.074 mm占97.5%,中磁选磁场强度为218.95 kA/m情况下,可获得铁品位为66.23%、铁回收率为97.53%的铁精矿。

Experiments on Magnetic Roasting-Magnetic Separation of a Limonite in Guizhou

A limonite ore in Guizhou is a kind of low-sulfur and low-phosphorus limonite ore with iron grade of 47.14%.Main iron minerals of the ore include limonite，lepidocrocite,psilomelane,pyrolusite and minor pyrite.Limonite was distributed in irregular colloidal and earthy states，and closely associated with gangue minerals.It′s difficult to effectively separate gangue minerals from valuable minerals through grinding process，and even easy to be slimed.Therefore ideal separation index can hardly achieved through direct high intensity magnetic separation or gravity concentration.In order to explore the limonite ore，beneficiation tests were carried out through the process of magnetic roasting-magnetic separation.The results showed that with the mass ratio of anthracite（2～0 mm） to coarse ore samples（3～0 mm）5%，iron concentrate with Fe grade of 66.23% and Fe recovery of 97.53% was obtained respectively at roasting temperature of 850 ℃ for 40 min，with the grinding fineness of the roasting products 97.5% 0.074mm，and magnetic intensity of mid-magnetic separation 218.95 kA/m.