(1. 江西理工大学 材料冶金化学学部，赣州 341000；
2. 赣州市绿色冶金与过程强化工程技术研究中心，赣州 341000)
摘 要: 氧化钇是一种重要的稀土氧化物，广泛应用于多个领域，而碳酸钇作为生产氧化钇的重要前驱体，其对氧化钇的制备和产品性能有重要影响。本文采用CO2碳化法制备晶型碳酸钇，通过XRD、SEM、TEM等方法对碳化过程进行表征，研究了碳酸钇晶体成核生长过程形貌结构演变机制及CO2流速、搅拌转速、YCl3浓度对结晶性能的影响。结果表明：在pH为5.0，体系温度为35 ℃的条件下可获得由大量针状晶体交织成的片状晶型二水碳酸钇，其生长是一个定向附着(OA)和奥斯特瓦尔德熟化(OR)机制并存的过程；在确定温度和pH后，碳化过程搅拌速率、CO2流速及YCl3浓度等对碳酸钇的结晶影响较小。CO2碳化法具有环保、操作简单、条件温和、易于工业化等优点，可为绿色高效制备其他晶型碳酸稀土提供借鉴。
关键字: 二氧化碳；碳化；碳酸钇；结晶机理；定向附着；奥斯特瓦尔德熟化
（1. Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. Ganzhou Engineering Technology Research Center of Green Metallurgy and Process Intensification, Ganzhou 341000, China）
Abstract:Yttrium oxide is an important rare earth oxide, which is widely used in many fields, and yttrium carbonate, as an important precursor for the production of yttrium oxide, has an important influence on the preparation and product performance of yttrium oxide. In this paper, CO2 carbonization method was used to prepare crystalline yttrium carbonate, and the carbonization process was explored by XRD, SEM, TEM. The morphology and structure evolution mechanism of yttrium carbonate crystal during nucleation and growth process, and the effects of CO2 flow rate, stirring speed, and YCl3 concentration on the crystallization performance were studied. The results show that a large number of needle-like crystals intertwined flake crystal yttrium carbonate dihydrate can be obtained under the conditions of pH 5.0 and system temperature of 35 ℃, and its growth is a coexistence process of Oriented attachment (OA) and Ostwald ripening (OR) mechanisms. Moreover, after determining the temperature and pH, the stirring rate, CO2 flow rate and the concentration of YCl3 during the carbonization process have little effect on the crystallization of yttrium carbonate. The CO2 carbonization method has the advantages of environmental protection, simple operation, mild conditions and easy industrialization, the method can provide a reference for the green and efficient preparation of other crystalline rare earth carbonates.
Key words: carbon dioxide; carbonization; yttrium carbonate; crystallization mechanism; oriented attachment; Ostwald ripening
