司家营综合尾矿预富集—悬浮磁化焙烧试验研究

Experimental Study on Pre-enrichment-Suspension Magnetization Roasting of Comprehensive Tailings in Sijiaying

尾矿持续堆存导致了一系列的安全和生态环境问题,提高尾矿综合利用率,实现尾矿规模化消纳成为矿山企业绿色发展的必然要求。司家营铁矿综合尾矿的铁品位为9.84%,铁主要以赤褐铁矿和磁铁矿的形式存在。针对尾矿铁品位低的问题,提出了预富集—悬浮磁化焙烧—弱磁选的工艺流程。结果表明:原矿经过弱磁选—强磁选—磨矿(-0.038 mm占95%)—弱磁选—强磁选工艺,获得了铁品位20.94%、回收率64.08%的预富集精矿。预富集精矿在焙烧温度540℃、CO浓度20%、还原时间15 min、总气量350 mL/min的条件下焙烧,焙烧产品磨细至-0.025 mm占70%经弱磁选分离可得到铁品位65.61%、回收率53.68%的磁选精矿。

The continuous stockpiling of tailings has led to a series of safety and ecological environment problems.Improving the comprehensive utilization rate of tailings and realizing the large-scale consumption of tailings have become the inevitable requirements for the green development of mining enterprises.The iron grade of the comprehensive tailings of Sijiaying iron mine is 9.84%,and the iron mainly exists in the form of hematite-limonite and magnetite.Aiming at the problem of low iron grade in tailings,a process flow of pre-enrichment-suspension magnetization roasting-low intensity magnetic separation is proposed.The results showed that the pre-concentrated concentrate with iron grade of 20.94%and recovery of 64.08%is obtained by the process of low intensity magnetic separation-high intensity magnetic separation grinding(-0.038 mm accounted for 95%)-low intensity magnetic separation-high intensity magnetic separation.The pre-concentrated concentrate is roasted under the conditions of roasting temperature of 540℃,CO concentration of 20%,reduction time of 15 min and total gas flow of 350 mL/min.The roasted product is ground to-0.025 mm accounted for 70%,separated by low-intensity magnetic separation to obtain a magnetic concentrate with iron grade of 65.61%and recovery of 53.68%.