铁锰矿低温固相法制备尖晶石型铁酸锰及其分解CO2的基础研究

尖晶石型铁酸盐分解CO2为碳的研究是近年来CO2减量化和资源化领域的研究热点。申请人在铁锰矿资源综合利用的前期研究中发现，还原焙烧气氛下锰、铁氧化物易发生晶格取代，生成强磁性、难还原的锰铁尖晶石，导致锰铁组分不能彻底分离和回收。本项目巧妙地利用这一特性，创新性提出“通过控制焙烧气氛和添加剂调控铁锰矿中主要组分性能，使锰、铁氧化物定向转化为强磁性的铁酸锰，而添加剂则与脉石组分优先反应生成无磁性的化合物（或可溶性盐），磁选回收高纯铁酸锰后用于分解CO2”的技术思路。系统研究不同焙烧气氛下铁锰矿中主要组分间的反应行为，查明添加剂存在时脉石组分对铁酸锰生成、结构和性能的影响规律，揭示金属离子掺杂对铁酸锰晶体结构和分解CO2性能的影响机制，最终构建铁锰矿低温固相制备锰系铁酸盐及其用于分解CO2的理论基础和技术原型。本项目的开展和实施，旨在为CO2的资源化利用和铁锰矿的增值化加工提供新途径。

Investigation on the decomposition of CO2 to carbon by the spinel-type ferrites has been the hotspot in the fields of CO2 emission reduction and recycling in recent years. In our previous researches, it’s found that the spinel-type manganese ferrite was easily formed due to the mutal substitution of manganese and iron oxides during the reduction roasting process of the iron-manganese (Fe-Mn) ores for the purpose of separation and recovery of iron and manganese, resulting in the incomplete separation and recovery of iron and manganese. However, the.applicant takes the advantage of this feature, and put forward an innovative approach and technical route in this proposal, in which the directional regulation of the properties of the main components in the Fe-Mn ores was firstly performed by using chemical additives during the controlled atmosphere roasting process. During the process, iron and manganese components are directionally converted into magnetic spinel-type manganese ferrites, while the impurities are superior to react with the additives to form the non-magnetic compounds (or soluble salts). Then, after the high-purity manganese ferrites are recovered by magnetic separation, they are used to decompose CO2. In current project, the reaction behaviors of the main components in the Fe-Mn ores roasted under different atmospheres are firstly investigated, and then the effects of impurity components on the formation, crystal structure and performances of the synthetic manganese ferrites are studied in the presence of additives. Afterwards, the influence mechanisms of doping metal ions in the manganese ferrites on the crystal structure and performance of CO2 decomposition are revealed. Eventually, the theoretical basis and technology scheme of the preparation of manganese ferrites from Fe-Mn ores by low-temperature solid phase reaction method and decomposion behavior of CO2 by the synthetic ferrites are established. The main purpose of this project is to provide a new route for utilizing CO2 resource as well as processing the Fe-Mn ores in a value-added way without separating iron and manganese components in advance.