MgCl_(2)-YCl_(3)熔盐中Mg直接脱除钛废料中固溶氧研究

Study on the Direct Deoxidation of Solid Dissolved Oxygen with Titanium Scraps Using Mg in MgCl_(2)-YCl_(3)Flux

针对现有钛废料脱氧方法存在效率低、金属与熔盐分离困难等问题,提出了一种脱氧新方法,即在MgCl_(2)-YCl_(3)熔盐中,采用Mg为脱氧剂,借助YOCl的生成,有效促进Mg快速高效脱除钛废料中的固溶氧。热力学研究结果表明,在温度为1200 K时,采用Mg做脱氧剂,要使Ti中的氧含量降低至10^(-3)以下,脱氧产物MgO的活度必须降低至0.05以下;通过建立lgp(O_(2))—lgp(Cl_(2))优势区图可知,在Mg/MgCl_(2)/YOCl/YCl_(3)平衡下的理论脱氧极限为1.6×10^(-5)。在理论研究基础上,在MgCl_(2)-YCl_(3)熔盐体系中开展Mg脱氧实验研究。结果证实,YOCl的生成有效降低了脱氧副产物MgO的活度,进而促进了镁深度脱氧,Ti中氧含量可降低至10^(-3)以下;另外,随着YCl_(3)的活度逐渐增大,Ti中氧含量逐渐降低,当YCl_(3)的活度为0.9时,氧含量可降至6×10^(-4)左右。

Aim to solve the problems of low efficiency and difficulty in metal/molten salt separation for titanium scrap deoxidation,a new method was proposed to effectively reduce the dissolved oxygen in titanium scrap by using Mg as deoxidant in MgCl_(2)-YCl_(3)flux through the generation of YOCl in this study.To reduce oxygen contents in Ti to less than 10^(-3) by using magnesium(Mg)as a deoxidant at 1200 K,the activity of the deoxidation product MgO,in the system must be reduced to less than 0.05 from a thermodynamic study result.The theoretical deoxidation limit at Mg/MgCl_(2)/YOCl/YCl_(3)equilibrium was 1.6×10^(-5),through thermodynamic calculation using a lgp(O_(2))-lgp(Cl_(2))diagram.Based on theoretical research,the titanium deoxidization experiment with Mg as deoxidizer was carried out in the MgCl_(2)-YCl_(3)molten salt system.The results confirmed that the oxygen content in Ti is reduced to less than 10^(-3),because the activity of the deoxidized byproduct MgO is reduced to a lower level through the generation of YOCl,which promoted the deep deoxidization of magnesium.In addition,the oxygen content in Ti decreases gradually with the increasing activity of YCl_(3),which the oxygen content can be reduced to about 6×10^(-4) with the activity of YCl_(3)is 0.9.