湖南某贫赤铁矿石还原焙烧—弱磁选试验

湖南祁东某贫铁矿石铁品位为31.77%,矿石中铁主要以赤铁矿形式存在,赤铁矿多呈微细粒嵌布。为开发利用该矿石,采用还原焙烧—弱磁选工艺进行了选矿试验。结果表明,制备还原球团时,添加内配煤可以改善小球内部的还原气氛,外配煤与内配煤协同使用,可使小球还原更加充分、均匀;在添加剂用量为3%、m(C)∶m(Fe)为0.3时制成直径3~5 mm的小球,小球干燥后在外配煤用量为20%、还原温度为960℃、还原时间为35 min时进行焙烧可以得到铁金属化率为86.15%的焙烧产品,焙烧产品在磨矿细度为-0.045 mm占95%、磁场强度为183 k A/m条件下弱磁选,获得了铁品位为80.23%、Si O2含量为9.48%、铁回收率为80.78%的铁精矿,实现了该铁矿资源的高效回收。

Reduction Roasting-Low Intensity Magnetic Separation of Lean Hematite in Hunan

There is 31.77% iron in a refractory iron ore in Qidong，Hunan Province.Iron mainly exists in form of hematite.For the development and utilization of the ore，the reduction roasting-low intensity magnetic separation method was used for dressing experiment.The results showed that adding coal pellets can improve the reducing atmosphere inside of the ball，iron can be fully reduced by using coal both inside and outside of the pellets；With additive dosage of 3%，m（C）∶m（Fe） is 0.3，small pellets with diameter of 3~5 mm,after dired the pellets,the dosage of the blending coal is 20%，the reduction temperature of 960 ℃，the reduction time of 35 min，iron metallization rate of 86.15% for roasted products will be obtained，by ground the roasted products to 95% passing 0.045 mm，magnetic field intensity of 183 kA/m for low intensity magnetic separation，the iron concentrate with iron grade of 80.23%，9.48% content of SiO₂，iron recovery of 80.78% was obtained，realized high effective recovery of the iron ore resources.