聚天冬氨酸对白钨矿和方解石浮选分离的影响及其作用机理

白钨矿中方解石等含钙脉石矿物的存在制约着白钨矿浮选技术的进步,开发选择性强的高效抑制剂是解决此类问题的关键。以铅离子-苯甲羟肟酸( Pb-BHA)配合物为捕收剂,通过浮选试验及 Zeta 电位测试、XPS 分析等手段研究了聚天冬氨酸(PASP)的抑制效果,并结合浮选溶液化学及晶体化学计算进一步分析作用机理。 纯矿物试验结果显示:当 cBHA = cPb = 2. 0×10-4 mol / L、cPASP = 2 mg / L、pH = 10 时,白钨矿与方解石的回收率之差可达 70%以上,表明 PASP 对方解石有选择性抑制作用。在此条件基础上开展人工混合矿试验,结果表明:PASP 能够在基本不影响回收率的前提下,大幅提高精矿 CaWO₄ 品位;当白钨矿与方解石的质量比为 1 ∶1 时,添加 2 mg / L 的 PASP 后精矿中CaWO ₄ 的回收率和品位分别达到 95. 2%和 85. 0%。 Zeta 电位测试及 XPS分析结果证实 PASP 在方解石表面发生了强烈的吸附作用,改变了方解石表面电性及化学环境。晶体化学分析显示:聚天冬氨酸官能团与方解石表面钙质点的匹配度明显优于其与白钨矿的匹配度,从而导致了聚天冬氨酸对方解石的选择性抑制作用。

Effect of Polyaspartic Acid on Flotation Separation of Scheelite and Calcite and Its Action Mechanism

Due to the existence of calcite and other calcium gangue minerals in scheelite ore,scheelite flotation technology was hindered,in which the key is to develop highly selective and efficient inhibitors. The inhibition effect of polyasparticacid (PASP) was studied by flotation test,Zeta potential test and XPS analysis,and the mechanism was further analyzed byflotation solution chemistry and crystal chemistry calculation with lead ion-benzohydroxamic acid (PB-BHA) complex as collector. The results of pure mineral test showed that the difference of recovery rate between scheelite and calcite could reachmore than 70% in the condition of cBHA = cPb = 2. 0×10-4 mol / L、cPASP = 2 mg / L and pH of 10,indicating that the selective inhibition effect of PASP on calcite. Then,the artificial ore mixing test was carried out based on the pure mineral test. The resultsshowed that PASP can greatly improve the CaWO₄ grade of concentrate without affecting the recovery rate. When the mass ratioof scheelite to calcite is 1 ∶1,the recovery rate and grade of CaWO₄ in concentrate with 2 mg / L PASP are 95. 2% and 85. 0%,respectively. The results of Zeta potential test and XPS analysis confirmed that PASP had strong adsorption on the calcite surface,which changed the electrical and chemical environment of the calcite surface. Crystal chemical analysis showed that thematching degree of polyaspartic acid functional groups with calcite surface calcareous points was obviously better than that ofscheelite,which resulted in the selective inhibition effect of polyaspartic acid on calcite.