钇直接脱除钛废料中固溶氧新技术

New Technology on Direct Removal of Oxygen from Titanium Scrap by Yttrium

钛加工过程90%以上的钛成为废屑残料,钛与氧的亲和力较强,且高温下氧在钛中的溶解度高,清洁深度脱除钛废料中的有害杂质元素氧对废料回收意义重大。针对现有钛脱氧方法存在固溶氧脱除困难、脱氧效率低等问题提出一种用稀土金属钇(Y)作脱氧剂,在Y/YOCl/YCl_(3)平衡下直接脱除钛废料中固溶氧的新方法。热力学计算结果表明:在1200 K下,利用Y/YOCl/YCl_(3)平衡可将钛中的氧含量降低至10^(-5)以下。在热力学分析结果的基础上,开展在YCl_(3)和YCl_(3)-NaCl-KCl熔盐体系中钇直接脱氧的试验研究。结果表明:钛中氧含量可降低至3×10^(-5),远远低于海绵钛中的氧含量(约5×10^(-4));以Y作脱氧剂,在Y/YOCl/YCl_(3)平衡下可深度脱除钛中的固溶氧。

More than 90%of titanium in the titanium processing process becomes scrap.Titanium has a strong affinity with oxygen,and oxygen has a high solubility in titanium at high temperature.It is significant to remove harmful impurity element oxygen from titanium waste in depth of cleaning for scrap recycling.The existing deoxidation method have disadvantage such as difficult removal of solid solution oxygen and low deoxidation efficiency.Aiming at the problems of difficulty in removing solid dissolved oxygen and low deoxidation efficiency in the existing titanium deoxidation methods,a new method is proposed to directly remove solid dissolved oxygen from titanium waste under Y/YOCl/YCl_(3) equilibrium using rare earth metal yttrium(Y)as deoxidizer.Thermodynamic calculations show that the oxygen content in titanium can be reduced to less than 10^(-5) by using the Y/YOCl/YCl_(3) equilibrium at 1200 K.On the basis of thermodynamic analysis results,the experimental study of yttrium deoxidation in YCl_(3) and YCl_(3)-NaCl-KCl molten salt system was carried out.The experimental results show that the oxygen content in titanium can be reduced to 3×10^(-4),which is much lower than the oxygen content in titanium sponge(about 5×10^(-4)).The solid solution oxygen in titanium can be deeply removed under the equilibrium of Y/YOCl/YCl_(3) with Y as deoxidizer.