沉淀条件对荧光级氧化钇中钙含量的影响

Effect of Precipitation Conditions on the Calcium Content in Fluorescent Grade Yttrium Oxide

研究了用草酸沉淀钇制备荧光级氧化钇时加料速度、加料比、反应温度、搅拌强度和加料方式对荧光级氧化钇中钙含量的影响。结果表明:温度是影响产品中钙含量的决定性因素,实际生产中应该确保体系温度大于60℃。与此同时,荧光级氧化钇产品中的钙含量与氯化钇料液中的钙含量相关,其Ca/RE建议控制在10×10-6g/g以下。当Ca/RE高于10×10-6g/g时,采用偏正同沉加料方式有利于降低氧化钇产品中的钙含量。

In the present paper, the effect of feed manner, feed rate, feed molar ratio, precipitation temperature and stir strength on the calcium content were studied using oxalate acid as precipitant of yttrium ion. The results show that the precipitation temperature is the dominating factor which influences the calcium content in product, it is necessary to ensure the operation temperature over 60℃ in the real production process. At the same time, the calcium in yttrium oxide is directly related to the content of calcium in yttrium chloride solution, it is proposed that the Ca/RE ratio in solution should be controlled below 10×10^(-6)g/g. However, when Ca/RE ratio is higher than 10×10^(-6)g/g, a synchronous feed manner with yttrium slightly overplus was found to be advantageous for the reduction of calcium content in yttrium oxide.