Method for preparing metallic titanium by electrolyzing molten salt with titanium circulation

Abstract

The present invention provides a method for preparing metallic titanium by electrolyzing molten salt with titanium circulation. The method mainly comprises reducing titanium tetrachloride (TiCl 4 ) to at least one of titanium trichloride (TiCl 3 ) and titanium dichloride (TiCl 2 ) in chloride molten salt by metallic titanium (Ti), and electrolyzing the at least one of TiCl 3 and TiCl 2 in the chloride molten salt to form metallic titanium. According to the method for preparing metallic titanium of the present invention, TiCl 2 , and/or TiCl 3 are prepared and electrolyzed continuously without changing the surrounding medium, thereby simplifying process flow, reducing power consumption, and realizing industrialization.

1 . A method for preparing metallic titanium by electrolyzing molten salt with titanium circulation, comprising:
 i) reducing titanium tetrachloride (TiCl 4 ) to at least one of titanium trichloride (TiCl 3 ) and titanium dichloride (TiCl 2 ) in chloride molten salt by metallic titanium (Ti); and   ii) electrolyzing the at least one of TiCl 3  and TiCl 2  in the chloride molten salt to form metallic titanium.   
     
     
         2 . The method of  claim 1 , wherein the metallic titanium used in the step i) is a portion of metallic titanium obtained by electrolyzing at least one of TiCl 3  and TiCl 2 . 
     
     
         3 . The method of  claim 1 , wherein a mole ratio of the metallic titanium for reducing to TiCl 4  is 1:1 to 1:3. 
     
     
         4 . The method of  claim 1 , wherein the chloride molten salt is formed by melting two or more of LiCl, NaCl, KCl, MgCl 2 , CaCl 2 , SrCl 2  and BaCl 2 . 
     
     
         5 . The method of  claim 4 , wherein the chloride molten salt is at a temperature higher than the eutectic temperature of the chloride molten salt and lower than vaporization temperatures and decomposition temperatures of salts for forming the chloride molten salt. 
     
     
         6 . The method of  claim 5 , wherein the chloride molten salt is at a temperature of 400° C. to 850° C. 
     
     
         7 . The method of  claim 1 , wherein a small amount of sponge titanium, titanium powder or titanium scrap is added as a titanium source before electrolyzing so as to react with TiCl 4 , thereby obtaining TiCl 2 , TiCl 3 , or a mixture of TiCl 2  and TiCl 3  as electrolyte to induce electrolysis. 
     
     
         8 . The method of  claim 1 , further comprising: collecting Cl 2  liberated from an anode in the step ii).