高均匀度纳米稀土氧化物的碳化法调控机制研究

项目名称： 高均匀度纳米稀土氧化物的碳化法调控机制研究

项目编号： No.51504034

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 矿业工程

项目作者： 冯宗玉

作者单位： 有研工程技术研究院有限公司

项目金额： 21万元

中文摘要： 随着稀土高新材料的快速发展与苛刻需求，亟需规模化制备高均匀度纳米稀土氧化物，但是传统的固相法和沉淀法生产难以将粒度细和分布范围窄有机统一，而溶胶-凝胶法等新型方法则难以规模低成本制备。鉴于碳酸盐沉淀体系和均相沉淀法的优势，本项目提出采用二氧化碳碳化法均相合成纳米稀土氧化物的新思路。通过双膜理论研究碳化法沉淀过程的类均相沉淀机制，使CO2气体扩散、离解以均匀提供HCO3-或CO32-沉淀离子，从而有效控制过饱和度在适当范围内，达到控制晶粒生长速度的目的；揭示前驱体的成核生长机理，以对颗粒的微观形态进行控制；探索碳化法沉淀前驱体过程中在微观级别、气泡液级别、设备级别等多尺度上表现的不同规律，以确定高均匀度纳米稀土氧化物的碳化法调控机制；阐明前驱体热分解制备纳米稀土氧化物的反应机理与继承性。最终建立二氧化碳碳化法合成纳米稀土氧化物的基础理论，对于国内突破高均匀度纳米稀土氧化物具有科学意义。

中文关键词： 纳米稀土氧化物；碳化法；类均相沉淀；多尺度；二氧化碳

英文摘要： With the rapid development and strict demand of rare earth high-tech material, high uniformity nanocrystalline rare earth oxide was needed large-scale preparation. However, it was difficult to unify the fine particle size and narrow distribution range for industrial production with traditional solid phase and precipitation methods, and new methods including sol-gel method were difficult to realize large-scale and low-cost preparation. Based on the advantages of carbonate precipitation system and homogeneous precipitation method, the project put forward a new idea that nanocrystalline rare earth oxide can be homogeneous synthesized by carbon dioxide carbonization. An analogous homogeneous precipitation mechanism of CO2 carbonization precipitation process was proposed and researched by double-film theory, to supply HCO3- or CO32- precipitant evenly through CO2 gas diffusion and dissociation process, thereby controlling the degree of supersaturation in a proper range to achieve the purpose of controlling the particle growth rate. The nucleation and growth mechanism of nanocrystalline rare earth oxide precursor was revealed, in order to control the morphology of particles. The different rules of multi-scale including micro level, the bubble-liquid level and equipment level in carbonization precipitation process of nanocrystalline rare earth oxide precursor were explored, in order to determine the carbonization mechanism of high uniformity nanocrystalline rare earth oxide. The reaction mechanism and inheritance of nanocrystalline rare earth oxide prepared by precursor through thermal decomposition process were clarified. Finally, based on the above data and mechanism, the basic theory of nanocrystalline rare earth oxide prepared by carbon dioxide carbonization is established. It will have great scientific significance for domestic breakthrough high uniformity nanocrystalline rare earth oxide.

英文关键词： nanocrystalline rare earth oxide;carbonization;analogous homogeneous precipitation;multi-scale; carbon dioxide