(1. 江西理工大學 材料冶金化學學部，贛州 341000；
2. 贛州市綠色冶金與過程強化工程技術研究中心，贛州 341000)
摘 要: 氧化釔是一種重要的稀土氧化物，廣泛應用于多個領域，而碳酸釔作為生產氧化釔的重要前驅體，其對氧化釔的制備和產品性能有重要影響。本文采用CO2碳化法制備晶型碳酸釔，通過XRD、SEM、TEM等方法對碳化過程進行表征，研究了碳酸釔晶體成核生長過程形貌結構演變機制及CO2流速、攪拌轉速、YCl3濃度對結晶性能的影響。結果表明：在pH為5.0，體系溫度為35 ℃的條件下可獲得由大量針狀晶體交織成的片狀晶型二水碳酸釔，其生長是一個定向附著(OA)和奧斯特瓦爾德熟化(OR)機制并存的過程；在確定溫度和pH后，碳化過程攪拌速率、CO2流速及YCl3濃度等對碳酸釔的結晶影響較小。CO2碳化法具有環(huán)保、操作簡單、條件溫和、易于工業(yè)化等優(yōu)點，可為綠色高效制備其他晶型碳酸稀土提供借鑒。
關鍵字: 二氧化碳；碳化；碳酸釔；結晶機理；定向附著；奧斯特瓦爾德熟化
（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
