Abstract:The existing deoxidation method has such disadvantage as low efficiency, and difficulty in separation of molten salt from metal etc. This study proposes a new method to directly remove solid solution oxygen from the titanium scrap by using Ho as a deoxidizer under the equilibrium of Ho/Ho2O3 and Ho/HoOCl/HoCl3.The thermodynamic calculation results show that the deoxidation limit of Ho/Ho2O3 and Ho/HoOCl/HoCl3 equilibrium is 280 ppm O and 12 ppm O at 1200K. The experimental results show that the deoxidation limit under the equilibrium of Ho/Ho2O3 is 420 ppm O at 1200 K. As the content of Ho2O3 decreases, the deoxidation limit decreases; at the same temperature, the deoxidation limit under the equilibrium of Ho/HoOCl/HoCl3 is 180 ppm O , much lower than the deoxidation limit of the Ho/Ho2O3 equilibrium. The decrease of HoOCl content reduces the deoxidation limit, indicating that the formation of HoOCl (2/3 Ho (s) + O(inβ -Ti, 1 wt %)+1/3 HoCl3(l) = HoOCl (s)) effectively promotes the deep deoxidation by Ho metal. Theoretical and experimental results prove that the use of Ho as a deoxidizer can effectively remove the solid dissolved oxygen in the titanium scrap with the help of the generation of HoOCl. Based on the above research results, this study proposes a new green and efficient deoxidation process.

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