青海某低品位磷矿石综合利用研究

摘要

青海上庄磷矿石主要组成矿物为透辉石、黑云母、(氟)磷灰石和磁铁矿,还有少量的长石、榍石和方解石.矿石P2O5、TFe和K2O品位分别为3.52%、9.08%和3.77%.黑云母主要呈不规则片状或片状分布,结晶粒度较粗,磷灰石多分布在透辉石、黑云母和磁铁矿的粒间,一般在0.3~1.5 mm,易于单体解离.透辉石和黑云母的矿物结晶粒度较粗,但是在矿石中相互包裹现象比较普遍.为给该矿石的开发利用提供参考,进行了实验室选矿流程试验.结果表明:采用棒磨粗磨(-0.35 mm占78.22%)分级(d=0.35 mm)、粗粒级摇床重选黑云母、细粒级棒磨再磨(-74 μm占50.90%)1粗2精1扫浮选磷灰石、浮选尾矿3段磁选磁铁矿(一段磁选精矿磨细至-74 μm占94.00%)、磁选尾矿分级(d=45 μm)脱泥后浮选分离透辉石和细云母的联合流程,获得了P2O5品位为32.01%、P2O5回收率为92.85%的磷精矿,K2O品位为9.58%、K2O回收率为20.80%的粗云母精矿和 K2O品位为8.38%、K2O回收率为37.38%的细云母精矿,云母总回收率为58.18%;此外,还可获得TFe品位为64.35%、回收率为33.62%的铁精矿.实验室试验获得了满意的选矿指标,试验在保证磷灰石和磁铁矿回收率的情况下,综合回收了云母和透辉石矿物,实现了矿石的综合回收.%Main mineral composition of Shangzhuang phosphate ore in Qinghai is diopside,biotite,(fluorine) apatite and magnetite,and a small amount of feldspar,titanite and calcite.The grades of P2O5,TFe and K2O are 3.52%,9.08% and 3.77% respectively.The biotite is irregular flake,coarse grain,apatite mostly distributed among diopside,biotite and magne-tite,the particle size generally between 0.3 ~1.5 mm,and is easy to be separated.Biotite and diopside grain size relatively coarse,while parcel phenomenon is common in the ore.In order to provide reference for the development and utilization of the ore,mineral processing experiment of laboratory was carried out.The results indicated that,via rod rough grinding (78.22%-0.35 mm) grading (d= 0.35 mm),gravity separation on coarse grained biotite,fine-grain rod regrinding (50.90% -74 μm) and thebn one roughing two cleaning one scavenging flotation recovery of apatite,three stage magnetic separation recovery magnetite from flotation tailings(first stage magnetic concentrate ground to 94.00% -74 μm),flotation separation diopside and fine-grained biotite from magnetic tailings after classification (d=45 μm) desilting.P2O5grade and recovery of phosphorus concentrate is 32.01% and 92.85%;K2O grade and recovery of coarse-grained biotite concentrate is 9.58% and 20.80%, K2O grade and recovery of fine-grained biotite concentrate is 8.38% and 37.38%;total recovery rate of biotite is 58.18%,be-sides,TFe grade and recovery of iron concentrate is 62.35% and 33.62%.Satisfactory results were obtained in laboratory ex-periments,in the case of ensuring the recovery indicators of apatite and magnetite,mica and diopside were comprehensive re-covered,realized useful minerals effectively recovered.