长石-锂辉石型伟晶岩硅酸盐矿物浮选体系中组合药剂的界面作用研究

In view of pegmatite silicate minerals having complex crystal structures, similar surface properties and poor selectivity with flotation reagents，spodumene, feldspar, mica and quartz in feldspar-spodumene pegmatite silicate minerals flotation system are taken as the object of study. Firstly, the correlation between mineral flotation behavior and crystal strcucture as well as surface properties is investigated by applying tools based on theories of crystal chemistry and density functional theory. Secondly, dissolution equilibrium of dissolved components from mineral surface, flotation solution chemistry behavior of reagents, complex interface reactions between mineral and reagents and combination regularity of using reagents are studied by adopting the surface analysis methods such as X-ray photoelectron spectroscopy(XPS), infrared spectroscopic(FTIR) and solution chemistry calculations, which leads to interface regulation mechanism of feldspar-spodumene pegmatite silicate minerals flotation system. Meanwhile, the efficient combined flotation reagents are screened by combining with ore flotation practice. Lastly, the competitive adsorption of mixed regulators along with the synergistic effect and the adsorption of mixed collectors are investigated through zeta potential measurements, reversed phase high-performance liquid chromatography (RP-HPLC), pyrene fluo-rescence tests and Molecular dynamics (MD) simulations to reveal assembly mechanism and behavior of combined flotation reagents on the surface of minerals. All of above is to provide the theoretical foundation to combined flotation reagents separation of pegmatite silicate minerals from other ones. Hence,it is of important practical value for efficient flotation of pegmatite silicate minerals and improving the recovery of valuable mineral from this type of ore. At the same time, it can enrich the theories of combined flotation reagents.

本研究针对伟晶岩硅酸盐矿物晶体结构复杂、表面性质相似、与浮选药剂作用选择性差的特点，以锂辉石、长石、云母、石英等矿物为研究对象，运用晶体化学、密度泛函理论等工具，研究矿物晶体结构、表面性质与浮选行为的关系；通过浮选溶液化学计算、XPS、红外光谱测试等手段，研究矿物表面组分溶解平衡、浮选剂浮选溶液化学行为、复杂界面相互作用以及组合用药规律，从而形成伟晶岩硅酸盐矿物浮选体系界面调控机制，再结合浮选实践筛选出高效组合药剂；采用动电位测试、反相高效液相色谱分析、荧光探针技术及分子动力学模拟等方法研究组合调整剂的竞争吸附、组合捕收剂在矿物表面的吸附特性及组合药剂的协同作用机制，揭示组合药剂在矿物表面的界面组装机制与行为，为组合药剂浮选分离伟晶岩硅酸盐矿物提供理论基础。该研究对于高效分选伟晶岩硅酸盐矿物和提高长石-锂辉石型伟晶岩矿产资源综合利用率等具有重要的实际意义，同时可以丰富浮选组合药剂使用理论。

本项目以长石-锂辉石型伟晶岩硅酸盐矿物晶体结构特征为切入点，系统研究阴阳离子组合捕收剂与伟晶岩硅酸矿物的界面组装作用机制；开发出高效的阴阳离子组合捕收剂来强化浮选分离伟晶岩硅酸矿物；成果应用于川西伟晶岩型锂辉石矿，一定程度上实现了的综合回收云母、锂辉石和长石等矿物的目的。研究成果对进一步提高我国锂等稀有金属资源的保障程度和综合利用率，有重要的理论意义和实际指导价值。同时在一定程度上可以丰富浮选晶体化学和浮选界面化学理论。重要结论和发现如下：. a. 阴阳离子组合捕收剂可以强化浮选分离伟晶岩硅酸矿物。阴阳离子组合捕收剂油酸钠/十二胺在浮选伟晶岩型铝硅酸盐矿物的性能上优于单一捕收剂油酸钠和十二胺。组合捕收剂在浮选分离锂辉石和长石方面表现出一定的选择性，当油酸钠与十二胺混合的摩尔比为6:1~10:1，对锂辉石浮选效果很好，而对长石浮选效果不好。锂辉石和钠长石对组合捕收剂组装形成的离子-分子缔合物选择性吸附是选择性浮选分离的根本原因。. b. 组合捕收剂油酸钠/十二胺在气-液界面上组装具有正协同效应。同时，组合捕收剂在白云母矿物表面上组装也具有正协同作用，研究表明阴阳离子组合捕收剂通过适当组装方式达到“1+1>2”的正协同效应。阴阳离子之间的组装吸附不仅降低了相同分子之间的静电斥力，而且两种异电性分子间的强静电引力使捕收剂之间的距离缩短，从而在单位面积上排布更多的药剂分子。. c. 通过“组合捕收剂强化浮选分离”选别工艺综合回收云母、锂辉石和长石的新技术，可分别获得产率为5.26%的云母精矿；Li2O品位高达5.81%，Li2O回收率为79.52%的锂辉石精矿；K2O+Na2O含量为11.33%，K2O+Na2O作业回收率为85.77%，Fe2O3含量只为0.21%的长石精矿，实现了此类难选伟晶岩型锂辉石矿一定程度的综合利用，其选矿指标有显著提高，较目前现场选厂Li2O回收率提高了几个百分点，同时药剂消耗减半。. d. 发表有本基金号标注的学术论文20篇，其中SCI收录论文11篇，EI收录论文3篇，北大中文核心期刊6篇，申请专利1个，1部专著在出版中。