湖北某低品位铌钽矿选矿工艺试验研究

Experimental Research on Beneficiation Technology of a Low-grade Niobium-Tantalum Ore in Hubei

针对湖北某花岗伟晶岩型铌钽矿进行了选矿试验研究,确定了重磁粗选—粗精矿浮选—酸化焙烧、浸出—萃取、反萃—磁选尾矿浮选分离长石、石英的联合选矿工艺流程。试验获得的铌钽精矿产品中Nb2O5品位53.96%、Ta2O5品位21.33%,Nb2O5回收率63.48%、Ta2O5回收率53.05%。其中,在重磁粗选阶段通过粗磨分级—摇床工艺,考察了磨矿细度和磁场强度对铌钽预富集的影响,试验得到产率9.47%,可工业应用的一级绢云母产品;针对强磁精矿进行浮选,考察了捕收剂种类对浮选效果的影响,在苯乙烯膦酸与正辛醇用量比4︰1、药剂用量1500g/t的条件下进行两次精选,获得Nb2O5品位为10.578%、Ta2O5品位为4.753%的浮选精矿;在纯硫酸体系下对浮选精矿产品进行了酸化焙烧浸出试验研究,铌钽分解液在低酸条件下采用甲基异丁基甲酮(MIBK)萃取钽、在高酸条件下采用磷酸三丁酯(TBP)萃取铌,萃取液均采用纯水进行反萃,反萃后的铌、钽液用氨水沉淀后焙烧,得到高纯Nb2O5和Ta2O5产品;对磁选尾矿进行浮选获得可工业利用的长石精矿和石英精矿。试验对绝大部分有用矿物实现了富集,高效富集铌钽的同时实现了伴生矿物的综合回收。

An experimental study on the beneficiation of a granitic pegmatite type Nb-Ta ore in Hubei province was carried out,and a combined beneficiation flowsheet was determined,which consisted of gravity and magnetic roughing,flotation of rough concentrate,acidification roasting,leaching,extraction and stripping,and flotation of feldspar and quartz from magnetic tailings.The Nb,Os and Ta2O,grade of the Nb-Ta concentrate was 53.96%and 21.33%,respectively,and the recovery of Nb,O,was 63.48%and 53.05%,respectively.The effects of grinding fineness and magnetic field intensity on the preconcentration of Nb and Ta were investigated in the roughing stage of gravity-magnetic separation.A sericite product of first-class with a yield of 9.47%was obtained.The influence of collector types on the flotation performance of the high intensity magnetic concentrate was investigated.Under the conditions of styrene phosphonic acid to n-octanol dosage ratio of 4:1 and reagent dosage of 1500 g/t,the flotation concentrate with Nb,O,grade of 10.578%and TazO,grade of 4.753%was obtained by twice cleanings.Acidic roasting-leaching test of the flotation concentrate products in pure sulfuric acid system was carried out,tantalum was extracted by methyl isobutyl ketone(MIBK)under low acid condition,niobium was extracted by tributyl phosphate(TBP)under high acid condition,the extract was stripped by pure water,and the stripped niobium and tantalum solution was precipitated by ammonia water and roasted.In this way a high-purity Nb,O,and TazOs product was obtained.The feldspar concentrate and quartz concentrate which can be industrially utilized were obtained by flotation of the magnetic separation tailings.Most of the useful minerals were enriched in the test,and the associated minerals were comprehensively recovered and utilized while efficiently enriching Nb and Ta.