某低品位铌钽矿磁选试验研究

Experimental Study on Magnetic Separation of Nb-Ta Ore

铌钽矿类型多、组成复杂且嵌布粒度不均匀,导致分选困难。针对某低品位铌钽矿开展了磁选预分选试验。在对矿石进行筛析和磨矿细度试验的基础上,通过调整磨矿时间和磁场强度,最终在磨矿16 min(-0.074 mm占98.02%)、磁场强度1800 kA/m的条件下获得铌钽粗精矿,Nb 2O 5、Ta 2O 5品位分别为0.89%、0.39%,富集比分别为78.11,86.38。Nb 2O 5、Ta 2O 5回收率分别为94.02%、96.23%。磁选预分选结果表明,磁选能够抛除绝大多数尾矿,获得铌钽粗精矿,为后续进一步分选富集铌钽精矿提供了基础。采用MLA对磁选粗精矿进行了工艺矿物学分析,结果表明,粗精矿中的铌钽铁矿已经大部分单体解离,但嵌布粒度较细,脉石矿物以硅质和硅酸盐矿物为主,可采用抑制硅质或硅酸盐矿物,活化浮选铌钽铁矿的浮选方法,进一步富集铌和钽。

Because of its various type,complex composition and uneven particle size distribution,niobium-tantalum ore is difficult to separate.In this paper,magnetic pre-separation tests were conducted to concentrate a low grade niobium-tantalum ore.On the basis of sieving analysis and grinding fineness tests of the ore,through adjusting grinding time and magnetic field intensity,crude concentrate with 0.89%Nb 2O 5 and 0.39%Ta 2O 5(78.11 and 86.38 times enrichment ratio respectively)was obtained at 16 min grinding(-0.074 mm,98.02%)and 1800 kA/m magnetic field intensity,and the yield was 1.51%;the recovery of Nb 2O 5 and Ta 2O 5 was 94.02%and 96.23%respectively.Magnetic separation was able to remove most of the tailings and obtain the crude concentrate,providing a basis for further separation and enrichment of niobium and tantalum.MLA was used to analyze the process mineralogy of the crude concentrate.The results showed that most of the niobium-tantalite in the crude concentrate have been dissociated,but the particle size is fine.In addition,the gangue minerals are mainly composed of siliceous and silicate.As a result,the flotation method of depressing siliceous or silicate minerals and activating niobium-tantalite was suggested to further enrich niobium and tantalum.