超声场耦合下白钨矿/方解石/萤石表面特性及与药剂相互作用机制

Scheelite accounted for 70% of China's proven reserves of tungsten resource, and Scheelite and Ca-bearing minerals flotation separation problem is the key technology for scheelite resources development. Interaction between ultrasound and media will cause physical and chemical changes and give rise to ultrasonic effect. In this project, Ultrasound technology will adopt during flotation separation process of scheelite, calcite and fluorite. By doing so, four researches are to going to be achieved:1) The roles of ultrasonic treatment in film formation process of activation ion on the mineral surface are to be investigated using “kernel-cover”model in this project. Therefore, the combination of activation ion and microstructural unit will be identified by testing and analyzing the film microstructure on mineral surface.2) The effects of ultrasonic treatment in dissolution equilibrium, surface chemistry, surface microstructure and ζ potential of scheelite, calcite and fluorite will be studied. Thus, relationships of microstructures, chemical composition changes and surface solubility, surface electric potentials were discovered.3) The influences of ultrasound in solution properties of collectors, microstructure of self-assemblies and mutual transformation, the adsorption of reagent and mineral surface will be examined. Therefore, the relationships of solution properties and aggregate structure with ultrasonic parameters were identified, microstructural conditions of adsorption products producing collector and mineral interaction were found. 4) Effect of ultrasonic treatment on secondary beneficiation of forth foam was investigated, and flotation kinetics equations were established .The project will establish new theory and new technology of scheelite, calcite and fluorite flotation room separation based on ultrasonic and flotation reagents interaction, thus it is to provide the related theoretical guidance for flotation flowsheet design.

白钨占我国钨资源储量的70%，而白钨开发的关键技术瓶颈是白钨矿与含钙矿物的浮选分离问题。本项目利用超声波的物理化学效应，将超声波预处理引入到白钨矿与方解石、萤石的浮选中完成以下研究：1）采用“核-壳”模型研究超声波对活化离子在矿物表面成膜过程的作用，弄清活化离子与矿物表面敏感结构单元的联接方式；2）研究超声波对白钨矿、方解石和萤石的溶解平衡、表面化学、表面结构和表面电位的影响，探明矿物表面微观结构、化学成分变化与表面溶解、电位之间的作用关系；3）研究超声波对捕收剂溶液性质、自组装聚集结构及转化的影响，探明超声波参数变化与溶液性质和聚集体结构变化的关系；研究超声波对药剂在矿物表面选择性吸附与脱附的影响，弄清捕收剂与矿物表面作用的微观结构状态；4）研究超声波对浮选泡沫二次富集作用规律，建立浮选动力学方程。形成基于超声波与浮选药剂协同作用下白钨矿与方解石、萤石常温浮选分离的新理论与新技术原型。

白钨矿与含钙矿物具有相似的表面化学和溶解特征，导致其分离困难。超声波具有空化效应、机械力学效应、热效应等特征，可改变药剂溶液性质、微观结构和矿物表面性质。本项目利用超声波辅助合成了的白钨矿及Pb2+包覆的白钨矿、萤石及Pb2+包覆的萤石、方解石及Pb2+包覆的方解石，超声作用促进了合成矿物的结晶，使矿物纯度较高、形状单一均匀。研究了合成矿物在NaOH、Na2CO3、Na2SiO3、Na2CO3+Na2SiO3调整剂溶液中的溶解特性及超声波物理场对矿物溶解特性及结构的影响，研究表明超声波的空化效应有助于矿物的溶解，当超声功率≥600W时，白钨矿、方解石、萤石溶解的离子浓度均能达到最大值，超声波的空化效应能促进Pb2+包覆的白钨表面Ca2+的溶解，对方解石的溶解影响不大，探明了矿物在不同调整剂中的溶解微量热动力学，查明了油酸钠和水杨羟肟酸与矿物表面作用的微量热动力学，并且弄清楚了了Pb2+对矿物溶解行为的影响及活化的作用机制。同时，利用超声波对阴离子捕收剂（油酸钠、环烷酸）、阳离子捕收剂（十二胺、CTAB）、螯合捕收剂（苯甲羟肟酸、水杨羟肟酸）的溶液性质、微观结构进行调控，探明超声波对矿物与捕收剂的作用机理，结果表明，超声作用使捕收剂溶液电导率增大，表面张力与溶氧量减小，并且改变了其微观结构存在形态和聚集状态。通过单矿物、人工混合矿浮选，选取油酸钠、苯甲羟肟酸为浮选捕收剂，硅酸钠、栲胶为抑制剂，研究了超声波强度、作用时间白钨矿、方解石和萤石浮选速率的作用规律，探明超声作用方式对白钨矿、方解石和萤石浮选速率的影响规律。研究表明超声时间、超声功率及矿浆pH对白钨矿、萤石、方解石有较大影响，超声作用后均能有效提高矿物累计回收率。在白钨-萤石、白钨-方解石、白钨矿-萤石-方解石混合矿分离中，超声作用苯甲羟肟酸时混合矿中白钨矿对应品位和累计回收率均明显增大，并建立了超声作用下不同矿物的浮选动力学方程。