石英-胶磷矿体系中浮选表面化学研究

The research mainly studied to solve the problem that quartz and collophane in sedimentary silicon calcium phosphate ores and flotation tailings from Guizhou province are difficult to separate from each other with the flotation method.The relationships between mineral chemical crystal, mineral surface properties and flotability.Chemical crystal calculation was studied by using Pouling Rule and Valence Bond Theory. Surface charge and exposed element characteristics of collophane and quartz was studied by Zeta Potential Analysis and XPS. Pure mineral floatation was applied to study the floatation rate.This paper introduced a system experimental investigation about the effect of metal cations and inorganic anions and deformer on surface properties and flotability. A effective solution condition and reasonable reagent system was taken to separate collophane and quartz. It is verified by laboratory floatation test. it is not only supply theoretical supports and technical supports for the effective flotation process of separate quartz and collophane, but also supply theoretical guidances for the production of low magnesium phosphate concentrates and high-purity phosphorus.

主要针对贵州沉积型硅钙质磷矿石中石英和胶磷矿难以有效浮选分离的特点，拟对矿物晶体化学特性、矿物表面特性与可浮性的关系进行研究。采用鲍林规则及价键理论对矿物进行晶体化学计算，通过ξ电位测定和光电子能谱（XPS）分析，系统研究胶磷矿和石英矿物的表面电位及解离后表面暴露元素的性质，通过纯矿物浮选试验考察矿物的可浮性差异。系统地考察金属阳离子、无机阴离子、消泡剂对胶磷矿和石英表面特性、可浮性的影响，找出胶磷矿和石英有效分离的溶液条件和药剂制度，并通过小型浮选试验对以上理论研究成果进行验证，为有效分选石英和胶磷矿的浮选工艺提供理论和技术支持。

（1）对贵州典型硅钙质磷矿石取样进行了工艺矿物学特性分析，矿石为低品位磷矿。矿石中的磷酸盐矿物为胶磷矿，以氟磷灰石为主；碳酸盐矿物主要为白云石和镁方解石；硅质矿物为石英；属于低品位硅质及硅酸盐型磷块岩，隐晶质结构。石英粒度微细，分散分布于胶磷矿和碳酸盐类矿物之间，解离难度大。从贵州典型硅钙质磷矿石中挑选石英纯矿物，试样属于α-石英，纯度高，结晶度高，晶粒比较粗大。扫描电镜及X射线能谱分析表明石英表面存在一定量的Mg、Al和Ca等杂质元素，这些杂质元素类质同象替代Si原子，与O2-结合化学键弱，易解离，在石英表面留下SiOH和Si-O-负电荷活性区域使阳离子捕收剂更易吸附。.（2）自然条件下新型捕收剂AY对石英作用效果更好，HAY对石英和胶磷矿均有较好的浮选效果。添加新型调整剂ZB和磷酸混合调整剂后可增大石英和胶磷矿的上浮率差异，说明新型调整剂ZB和磷酸混合调整剂对胶磷矿和石英浮选分离有促进作用。.（3）当矿浆中无难免离子时，HAY与石英表面硅氧键的氧主要以静电力形式结合发生物理吸附，而HAY与胶磷矿表面的钙离子发生络合而产生化学吸附；当矿浆中难免离子浓度较低时，石英和胶磷矿的可浮性无明显变化；当矿浆中难免离子浓度较高时，而石英的可浮性变化较大，金属阳离子对石英浮选的影响大小为：Fe3+＞Fe2+＞Al3+＞Ca2+＞Mg2+,无机阴离子对石英浮选的影响大小为：SO42-＞SiO32-＞F-＞CO32-＞PO43-。.（4）通过表面HAY吸附量测定、Zeta-电位测试、金属离子溶液化学计算、红外光谱分析、分子模拟等方法，对矿物浮选过程进行机理研究，研究结果与纯矿物浮选试验结果相一致。Ca2+、Mg2+可提高石英表面吸附活性点，提高石英浮选回收率；Fe3+、Fe2+与HAY能形成稳定螯合物，降低石英浮选回收率；Al3+吸附于石英Stern层，改变石英表面电性，使HAY难以吸附于石英表面，降低石英浮选回收率；SiO32-吸附在石英表面，降低表面吸附活性点，降低石英浮选回收率；F-与HAY发生络合，降低HAY浓度，降低表面疏水性，降低石英浮选回收率；SO42-、CO32-、PO43-能与带正电的HAY发生结合，降低石英表面HAY吸附量，降低石英浮选回收率。