黑沟铁矿石粉矿(-15mm)棒磨磨矿工艺试验

黑沟铁矿石粉矿(-15 mm)铁品位为37.35%,铁主要以赤褐铁矿形式存在,铁在赤褐铁矿中分布率为85.35%。现场采用球磨机磨矿后强磁选工艺回收粉矿,球磨机磨矿时泥化现象严重,细粒级铁矿物无法通过强磁选有效回收。为减轻粉矿磨矿过程的过粉碎现象,优化磨矿产品粒度组成,对破碎至-2 mm的粉矿,预选筛分出产率为33.30%的-120μm粒级,对+120μm粒级进行棒磨机磨矿试验。在棒径分别为18、20、22 mm的钢棒为磨矿介质,且其质量比为4∶3∶3、介质充填率为30%、料棒比为1.0、磨矿浓度为70%、磨矿时间为62 s条件下闭路磨矿,合格粒级(38~120μm)占-120μm粒级比例达57.55%。降低分级粒度能够有效减少微细粒级的产生,减少过磨。采用棒磨工艺可以减少过磨,优化磨矿产品的粒度组成。

Research on Rod-grinding Technology of Heigou Iron Ore Fines (-15 mm)

Iron grade of fines (-15 mm) iron ore from Heigou is 37.35 ％.Iron mainly exists in form of hematite-limonite and the distribution rate is 85.35％.The fines iron ore was recovered by high intensity magnetic separation after ball milling in on-site process,while sliming phenomenon in grinding operation is serious,the fines iron ore can't be recovered by high intensi ty magnetic separation.In order to relieve over crushing phenomenon during grinding and optimize size composition of grinding products.The fines were crushed to-2 mm,Pre-screened-120 μm size fraction with the rate of 33.30％.Rod milling experiments were implemented for + 120 μm size fraction.Closed-circuit grinding was carried out with the conditions that grinding medium of rod diameter 18,20,22 mm with mass ratio of 4 ∶ 3 ∶ 3,medium filling ratio of 30％,rod to powder ratio 1.0,grinding concentration 70％ and grinding for 62 s,and it can obtain qualified size fraction (38 ～ 120 μm) accounts for 57.55％ of -120 μm size fraction.Decreasing classification particle size can reduce production of fine particle effectively and over grinding.It has a significant reference to reducing over grinding and optimize the size composition of grinding products by rod milling technology.