表面溶解对钛铁矿物浮选分离的影响及其调控机制研究

Titanium is an important strategic metal. Over 90% of titanium resources in China are present in vanadium-titano magnetite deposits. The titanium–minerals (e.g. ilmenite, titanaugite, and olivine) are easy to dissolve in the pulp, which leads to several challenging problems including difficulty in effective regulation of surface properties and poor selectivity of the flotation reagents. In view of these flotation separation problems, this project mainly carries on the following aspects of research. First, to reveal the law of surface dissolution behavior of ilmenite-minerals and to explore the influence mechanism of surface dissolution on mineral surface properties through the systematically studying the surface dissolution behavior of ilmenite-minerals and its influence on the surface properties of minerals. Secondly, to establish the intrinsic mechanism and correlation of mineral surface dissolution and adsorption flotation agents, as well as to reveal the interaction law of surface dissolution on flotation separation by investigating the effect of surface dissolution on the adsorption of flotation reagent and flotation behavior of titanium–minerals. Thirdly, to regulate the selective migration and transformation behavior of dissolved ions on the surface of ilmenite minerals, as well as to establish a mechanism for controlling the enhanced flotation separation based on the surface dissolution of ilmenite through strengthening measures such as the change of grinding conditions, the assembly of multiple flotation reagent molecules, and the addition of external forces field. Finally, to develop a high-efficiency processing of enhanced flotation separation for ilmenite based on surface dissolution regulation providing theoretical and technical basis for efficient recovery of refractory ilmenite in Panxi area by combing actual ore experiment of enhanced flotation separation.

钛是重要的战略金属，我国90%以上的钛资源赋存在钒钛磁铁矿矿床中。针对钛铁矿物（钛铁矿、钛辉石和橄榄石等）在矿浆溶液中易发生表面溶解、表面性质难以有效调控、浮选药剂作用选择性差等浮选难题，本项目通过系统研究钛铁矿物表面溶解行为及其对矿物表面性质的影响，揭示矿物表面溶解行为规律，探明表面溶解对矿物表面性质的影响机制；再通过研究表面溶解对钛铁矿物吸附浮选药剂和浮选行为的影响，建立矿物表面溶解与吸附浮选剂的内在机制与关联性，揭示表面溶解对矿物浮选分离的交互影响规律；然后通过磨矿环境条件的改变、多元浮选剂分子的组装以及外力场的添加等强化措施对钛铁矿物表面溶解离子的选择性迁移和转化行为进行调控，建立基于钛铁矿物表面溶解的强化浮选分离调控机制；最后结合实际矿石强化浮选分离工艺实验，开发出以表面溶解调控为基础的钛铁矿高效强化浮选分离工艺，为我国攀西地区难选钛铁矿的高效浮选回收提供理论与技术基础。

钛是重要的战略金属，我国90%以上的钛资源赋存在钒钛磁铁矿矿床中。针对钛铁矿物（钛铁矿、钛辉石）在矿浆溶液中易发生表面溶解、表面性质难以有效调控、浮选药剂作用选择性差等浮选难题。本项目系统了研究钛铁矿物表面溶解行为及其对矿物表面性质的影响，揭示矿物表面溶解行为规律，探明表面溶解对矿物表面性质的影响机制；添加外力场精准调控钛铁矿与钛辉石的表面溶解行为，构建钛铁矿与钛辉石差异化表面，之后，通过差异化表面与浮选捕收剂选择性作用进而实现对浮选行为的精准调控；以矿物表面溶解行为导致的差异化表面为切入点，开发了新型组合捕收剂强化钛铁矿的浮选分离，建立了基于钛铁矿物表面溶解的强化浮选分离调控机制；最后结合实际矿石强化浮选分离工艺实验，开发出以表面溶解调控为基础的钛铁矿高效强化浮选分离工艺，为我国攀西地区难选钛铁矿的高效浮选回收提供理论与技术基础。重要研究发现及结论如下：.1、常规钛铁矿浮选pH条件下（pH=6），镁和钙是钛铁矿物体系的主要溶出离子。相比钙离子和镁离子，矿物表面的铁较难溶出。在矿浆环境中Ca、Mg、Fe2+均为离子态形式存在，Fe3+以氢氧化物沉淀形式存在。.2、外力场（微波、超声）通过调控矿物表面溶解，使得矿物表面选择性溶出钙、镁，同时保留钛铁矿表面的铁活性位点，并且在外力场的作用下，钛铁表面的铁物种大多被转化为更有利于油酸钠（NaOL）吸附的三价铁。.3、钛铁矿与钛辉石在矿浆中的溶解行为导致的表面元素组成差异，是导致组合捕收剂与矿物表面发生选择性吸的主要原因，具体来说，组合捕收剂更易与钛铁矿表面铁活性位点作用，而较难与辉石表面大量钙、镁活性位点作用。.4、新型组合捕收剂在矿物/水接触面的界面组装机制研究表明：组合捕收剂之间通过氢键相连，以特定的先后顺序吸附到矿物表面，该吸附顺序间接与钛铁矿物溶解行为有关。.5、使用铅基多配体络合捕收剂Pb–BHA–NaOL，采用“一粗四精一扫”的浮选流程，可以获得TiO2品位为44.80%、回收率为78.11%的钛铁矿精矿。.