青海上庄磷-稀土矿床矿物组成及稀土元素的赋存状态研究

Mineral Composition and Occurrence State of Rare Earth Elements in Shangzhuang Phosphorus-rare Earth Ore Deposit,Qinghai Province

为实现与超镁铁质岩有关磷-稀土矿床中伴生低品位稀土元素的有效提取,通过全岩化学分析、显微镜下鉴定、扫描电镜分析(SEM)及矿物自动定量分析(AMICS),查明了上庄磷-稀土矿床的矿石物质组成和稀土元素赋存状态。矿石中TREO品位为0.08%~0.17%,主要矿物组成为透辉石、黑云母、磁铁矿、磷灰石、方解石及榍石等,矿石中含稀土矿物主要为磷灰石(TREO=1.00%)和榍石(TREO=2.57%),含量分别为6.40%和1.94%。矿石LRE_(2)O_(3)含量为0.07%~0.15%,HRE_(2)O_(3)含量为0.01%~0.02%。稀土元素在磷灰石和榍石中分布率分别为53.33%和41.54%。含稀土矿物磷灰石的粒径主要分布于32μm~106μm、榍石的粒径主要介于6.8μm~38μm;矿物单体解离度较高,磷灰石占46.59%、榍石占25.84%。该矿床为与超镁铁质岩相关的岩浆型稀土矿床,稀土主要以类质同象形式赋存于载体矿物磷灰石和榍石中,可直接通过富集磷灰石、榍石精矿达到回收稀土的目的。

Through whole rock chemical analysis,microscopic identification,scanning electron microscope analysis(SEM)and mineral automatic quantitative analysis(AMICS),the ore material composition and rare earth element occurrence state of Shangzhuang phosphorus-rare earth deposit were identified.The TREO grade of the ore is 0.08% to 0.17%.The main mineral compositions are diopside,biotite,magnetite,apatite,calcite and sphene.The rare earth minerals in the ore are mainly apatite(TREO=1.00%)and sphene(TREO=2.57%),with contents of 6.40% and 1.94%,respectively.The ore contains 0.07% to 0.15%LRE_(2)O_(3) and 0.01% to 0.02%HRE_(2)O_(3).The distribution rates of rare earth elements in apatite and sphene are 53.33% and 41.54%,respectively.The particle size of apatite containing rare earth minerals is mainly distributed in 32μm to 106μm,and the particle size of sphene is mainly between 6.8μm and 38μm.The dissociation degree of mineral monomer is high,apatite accounts for 46.59% and sphene accounts for 25.84%.The deposit is a magmatic rare earth deposit related to ultramafic rocks.Rare earth mainly occurs in the carrier minerals apatite and sphene in the form of isomorphism,which can be directly recovered by enriching apatite and sphene concentrate.