醚多胺胶磷矿反浮选脱硅过稳定泡沫的形成与调控的基础研究

There are still some technical problems as “large amount of over-stable foam" for the process of desilication in collophane flotation using cationic collector, and this brings the huge challenge to the industrial applications of cationic reverse flotation desilication process in our country. For the above reasons, the typical siliceous- calcareous phosphate ore was chose as research object. The bubble microscopic observation system and the bubble size measurement system were set up respectively. The effects and function mechanism of surface tension, interfacial elasticity, liquid viscosity on bubble generation, coalescence and foam stability were studied. The particle behavior of hydrophobic and hydrophilic minerals in froth was studied by the design of drainage experiments and Cyro-SEM analysis. The effects of the typical micro-fine particle in phosphate ore on the foam stability were studied systematically, and the relationship between slime composition, particle size, Zeta potential and foam stability was clarified using air recovery measurement. The three-phase foam stability physical model of cation - collophane is established, which providing fundamental basis for industrial applications of cationic reverse flotation desilication process in our country.

本课题针对我国胶磷矿阳离子反浮选脱硅泡沫量大、发粘，浮选效果因泡沫状况波动而变差，导致工业应用受到限制的难题，选取我国典型的硅钙质胶磷矿作为研究对象。通过构建高速显微摄像系统及泡沫大小测试系统，观测醚多胺为主体的组合药剂的泡沫形成–稳定–消泡全过程，研究表面张力、气液界面弹性、液相粘度对气泡产生、兼并及泡沫稳定性的影响规律和作用机制。运用冰冻—扫描电子显微镜对颗粒稳定的不同泡沫体系微观形貌进行表征，并结合三相泡沫析液试验，揭示了疏水颗粒和亲水颗粒在泡沫排液过程中作用机理。通过测试三相泡沫的气体回收率，研究胶磷矿组成中的微细粒颗粒对三相泡沫稳定性的影响，阐明胶磷矿中泥质矿物组分、粒度、Zeta电位对泡沫稳定性的作用规律。建立醚多胺—胶磷矿三相泡沫稳定性物理模型，得出醚多胺—胶磷矿体系过稳定泡沫形成的细泥和矿浆物理化学参数临界值，实现过稳定泡沫调控，为胶磷矿反浮选脱硅工艺工业应用提供理论基础。

随着高质量磷酸盐矿石的消耗殆尽，难选硅质胶磷矿的开发利用显得日益重要。浮选法是硅质磷矿脱硅的主要方法，包括阴离子正浮选法和阳离子反浮选法。前者技术成熟，指标稳定，却存在药剂制度复杂，加温成本高的问题。后者可常温浮选，药剂制度简单，却存在浮选泡沫过稳定，不易消泡的难题。因此，提出胶磷矿阳离子反浮选脱硅过稳定泡沫的形成及调控研究，主要取得以下研究成果：.（1）含有支链结构的烷基醚多胺形成泡沫的稳定性低于直链醚单胺所形成的泡沫。支链结构的烷基醚多胺在气液界面上的饱和吸附量最低、离子在气液界面的独占面积最大，离子在泡沫液膜上排列较为松散，导致液膜强度较低，气泡的兼并时间较短，导致其起泡能力弱和泡沫的稳定性低。.（2）矿物颗粒可以显著增强泡沫稳定性，且不同种类矿物颗粒稳定程度不同，四种矿物稳定泡沫的强弱顺序为：方解石>白云石>胶磷矿>石英。细粒级颗粒较粗粒级颗粒能够更加稳定泡沫。.（3）无机离子促进烷基醚多胺在气液界面的吸附，增加其饱和吸附量，使吸附层排列更为紧密，从而提高泡沫的稳定性。电解质对烷基醚多胺起泡能力影响强弱顺序为FeCl3>AlCl3>NaF>Na3PO4>CaCl2>Na2SO4>MgCl2>NaCl；对泡沫稳定性影响强弱顺序为AlCl3>FeCl3>Na2SO4>NaF> CaCl2> Na3PO4> MgCl2>NaCl。.（4）三相泡沫稳定性调控技术：开发了预先脱泥-浮选脱泥-阳离子反浮选脱硅工艺，可以有效调控胶磷矿反浮选脱硅泡沫稳定性。实践证明，预先脱泥-浮选脱泥-阳离子反浮选脱硅技术泡沫量适当，易于消泡，闭路实验可以获得P2O5品位为33.24%，回收率为69.63%优质磷精矿。