胺类捕收剂在铁精矿脱硅反浮选中的作用机制

Mechanism of Amine Collector in Reverse Flotation De-silicates Process of Iron Concentrates

从理论上分析了铁精矿和硅质矿物的表面电性与矿浆pH的关系,以及胺类捕收剂在矿浆中的水解行为。在此基础上,通过试验研究了胺类捕收剂在铁精矿脱硅反浮选过程中的作用机制。结果表明:强碱性条件下,胺类捕收剂主要以RNH2形式存在,不能有效地与硅质矿物作用,达不到降硅的目的;酸性过强时,矿浆中胺阳离子(RNH+3)浓度过高,胺阳离子之间通过氢键相互作用,减少甚至失去与矿物颗粒的吸附作用,同样不能取得好的分选效果。因此,铁精矿反浮选脱硅时,应根据矿石性质控制pH值,使矿浆中保持适当的胺阳离子浓度。

This paper analyzed the relationship of the surface electricity of iron concentrate and silicate minerals with pH values of ore pulp, and the hydrolysis behavior of amine collector in ore pulps. On this basis, experiment is made to research the mechanism of amine collector in reverse flotation de-silicates process of iron concentrates. The results showed that the amine-collector in RNH2 does not act with the silicate minerals and could not reduce silicon under strong alkaline; Under strong acid condition, high content of amine-cation （ RNH3^＋ ） in ore pulps acting with each other reduce or even lose the adsorption on mineral particles, and can not reach the good separation effect either. Hence, in reverse flotation de-silicates process of iron concentrates, an appropriate amine-action concentration should be kept by adjusting the pH values according to the ore property.