超导磁絮凝快速分离过程中微磁絮体生成结构及其运动轨迹研究

Magnetic seeding flocculation followed by Superconducting magnetic separation is an effective technology for aqueous pollutants removal. The capturing process of pollutants contained magnetic flocs in superconducting magnetic field is the key process of magnetic separation. Meanwhile, the structure changes and movement mechanism of magnetic floc in superconducting magnetic field controlled the aqueous pollutants separation. The project focused on the basic theory and mechanism in the magnetic seeding flocculation and superconducting magnetic separation process. The magnetic floc structure changes and movement mechanism in superconducting magnetic field will be measured and discussed in the project. The magnetic floc structure will be determined by modern analytical tools, the finite element analysis software will be used in magnetic and flow field simulation. At the meantime, image output system will be established in the superconducting magnetic field to observe the structure changes and movements of magnetic flocs. The starting point of this project is the comparison of magnetic floc structure in non-magnetic and magnetic circumstances. At the basis of research on magnetic floc structure changes, the components and the interactions among the components will be studied, therefore, the driving force of structure changes will be discussed. The effects of magnetic aggregation, fast movement and magnetic capture process on floc structure and trajectory changes will be discussed. Considering the magnetic flocs structure change in superconducting magnetic field, the project will discuss the movement mechanism of flocs by combining the simulation results of finite element analysis software and image output system. The research of this project will provide theoretical support for the magnetic seeding flocculation followed by superconducting magnetic separation technology.

超导磁絮凝分离技术是近年新兴发展的一种用于资源矿物分离提纯，水质净化处理技术领域的高新产业技术，在资源与环境领域具有广阔的应用前景，已成为近年来国内外技术研发的前沿与热点。磁絮体在超导磁场中的结构变化和运动规律是制约污染物与水分离过程的客观规律。本项目依据国内外最新研究进展，开展超导磁絮凝分离过程磁絮体结构特征及其运行轨迹等相关基础研究，采用现代絮体测试分析手段表征磁絮体结构，研究探讨磁絮体结构在超导磁场中的变化；利用有限元分析软件对磁场及流场环境进行模拟，推测磁絮体在超导磁场中的受力和聚集情况；构建超导磁场内影像系统，对磁絮体的结构变化和运动轨迹进行原位测定；探究超导磁场中磁团聚对磁絮体结构和运动轨迹的影响，磁絮体快速与水分离对絮体结构和运动轨迹的影响等关键基础科学问题。本项目对超导磁絮凝分离技术及其设备在资源和环境领域的应用具有重要科学意义和应用价值。

本研究关注超导磁絮凝分离技术中磁絮体组成结构对分离效率的影响。超导磁絮凝分离技术为超导磁分离与磁絮凝结合用于水处理的新兴高新技术，其利用超导磁体强磁场、大磁区域的特征，可实现集约化、大处理量水污染处理。磁絮凝为利用混凝剂结合磁种与污染物，进而可实现无磁污染物快速与水分离。本研究在口径102mm和600mm超导磁体的基础上，基于开梯度与高梯度磁分离理论，利用钢毛、钢棍、钢板、沉降槽等开发了多种超导磁絮凝分离器。本研究利用铝系和铁系絮凝剂开展了针对水中磷、氟、砷、重金属等的超导磁絮凝分离研究；利用显微镜、电镜、原位激光粒度仪等设备开展了铝系、铁系絮凝剂形成磁絮体的结构表征研究，比较了磁场内外磁絮体的结构变化；研究了开高梯度磁分离过程中，磁场、梯度介质、流场等对磁絮体结构的变化规律。本项目得到如下研究结果：1）磁种、絮凝剂和污染物可形成磁絮体，该磁絮体的粒度、分形维数等结构特征对污染物去除有影响，磁絮体在磁分离过程中可破碎，添加聚丙烯酰胺等助凝剂可显著降低絮体的破碎几率；2）磁场、流场、高梯度介质等磁分离过程关键参数对磁絮体分离有显著影响，高梯度介质一方面可显著降低磁絮体与水分离所需的水力停留时间，另一方面可能导致磁絮体发生破碎；3）铁系絮凝剂产生的絮体具微弱顺磁性，当铁盐絮体与磁种剥离后，大于2T的超导磁场可显著提高铁系絮体的去除率。本项目的研究成果具有如下科学意义：1）阐明了磁絮体在超导强磁场内的结构形态变化规律，为超导磁絮凝分离技术实际用于特殊场合集约化大处理量水处理奠定了絮凝前处理工艺的理论基础；2）研究了超导磁分离工艺参数对磁絮体与水分离的影响，为超导磁絮凝分离技术特种装备研发提供了理论指导；3）探索了微弱磁性水处理药剂在超导强磁场中的分离过程，拓展了环境领域磁材料的研究和应用范畴。