基于赤泥构筑类水滑石及其结构分析与催化炭化性质研究

Red mud, which has caused serious environmental pollution, is the largest industrial hazardous solid waste produced in domestic nonferrous metal processing. Until now, there are no feasible methods to utilize large-scale red mud in practice. This issue becomes a bottleneck that especially restricts rapid development in aluminum industries in China. In this project, hydrotalcite-like compounds will be prepared by reorganizing the structure of red mud with divalent metals via physical, chemical, and thermodynamic methods. The products will be characterized on their structures and compositions. The reaction principle will be thoroughly understood from the investigation on the roles of reactive properties and reaction conditions in the structure formation of the compounds. Based on the study, the optimal processing parameters of the preparation method of the compounds will be justified accordingly. Flame retardant hydrotalcite/polymer composites, as the final products, will be developed from this controllable preparation method, consuming red mud as raw materials. The flame retardancy and thermal degradation behavior of the composite will be studied, focusing on the catalytic carbonization behavior of the composites. The goal of the study is to clarify the underlying relationship of the structure, composition, and morphology of the compounds v.s. flame retardant properties and the structure of burning char residue of the composites. The catalytic carbonization mechanism of the hydrotalcite-like compounds will be thoroghly discussed. This project aims to facilitate the feasibility of preparing hydrotalcite-like compounds using bulky red mud, bringing this industrial waste high value in the field of halogen-free flame retardants. It is hoped that the red-mud based preparation route and catalytic carbonization mechanism of the compounds in this research would provide theoretical and technical understanding for the utilization of red mud.

赤泥是我国有色金属行业产量最大的工业有害固体废物，已造成了严重的环境污染。目前世界上还没有找到大规模利用赤泥的有效途径，该问题己成为制约我国铝工业发展的瓶颈。本项目拟采用物理、化学、热力学方法，通过二价金属对赤泥的结构进行改变和重组，构筑类水滑石，对其结构和组成进行表征；通过研究反应物性质、反应条件对类水滑石结构的影响，提出反应原理，确定最佳的类水滑石制备方法和工艺，实现以赤泥为原料的类水滑石阻燃剂的可控制备。通过类水滑石阻燃聚合物材料的阻燃性能和热降解行为的研究，尤其是类水滑石阻燃剂催化炭化作用的研究，建立类水滑石阻燃剂结构、组成、形貌与阻燃复合材料组成结构、阻燃性能、燃烧炭化物结构之间的本质联系，深入探讨催化炭化机理。本项目旨在研究以大宗工业赤泥为原料制备类水滑石的方法，并阐明其制备原理和催化炭化机理，实现赤泥在无卤阻燃领域的高值化利用，为赤泥综合利用提供理论和技术支撑。

赤泥是我国有色金属行业产量最大的工业有害固体废物，已造成了严重的环境污染。目前世界上还没有找到大规模利用赤泥的有效途径，该问题己成为制约我国铝工业发展的瓶颈。本项目以赤泥为基本原料，通过引入二价金属，以焙烧还原法及共沉淀法制备了多种二元、三元类水滑石，并对其结构、组成、热稳定性等进行表征，研究发现合成的类水滑石晶形规整、热稳定性高，确定了最佳的类水滑石制备方法和工艺，实现了以赤泥为原料的类水滑石阻燃剂的可控制备；通过熔融共混的方法制备了类水滑石阻燃聚合物材料，并对复合材料的阻燃性能和热降解行为进行了研究，研究结果发现这类复合材料具有良好的阻燃性能，部分材料的阻燃等级稳定维持在UL 94 V-0级、极限氧指数可达30%、且燃烧过程中的滴融现象及产烟量都得到了不同程度的改善，建立了类水滑石阻燃剂结构、组成、形貌与阻燃复合材料组成结构、阻燃性能、燃烧炭化物结构之间的本质联系，深入探讨了阻燃、抑烟机理，其中以不可燃气体的产生及催化炭化为主；通过对类水滑石改性及与协效阻燃剂的复配进一步提升了阻燃材料的性能，研究发现表面活性剂及硅烷偶联剂有助于类水滑石在基体材料中分散性能的提升，而协效阻燃剂如部分磷系（红磷、聚磷酸铵）、氮系（三聚氰胺）、硼系（硼酸锌）及硅系（气相白炭黑）阻燃剂均可与类水滑石产生协同阻燃、抑烟作用。本项目以大宗工业赤泥为原料制备了多种类水滑石并详细研究了其阻燃性能，阐明了其制备原理和催化炭化机理，通过对其改性与协效复配，进一步提升了阻燃复合材料的性能，为实现赤泥在无卤阻燃领域的高值化利用提供了可靠的技术路线，为赤泥综合、高效利用提供了理论和技术支撑，有望解决赤泥的环境问题。