Method for Producing Ti or Ti Alloy Through Reduction by Ca

Abstract

A mixed molten salt containing CaCl 2 and NaCl is held in the reactor cell 1 at a temperature not more than 600° C. TiCl 4 which is of a Ti raw material is introduced into the reactor cell 1 while Na is introduced into the reactor cell 1 . Na introduced into the reactor cell 1 is replaced by Ca, Ca is dissolved in the molten salt, Ca reduces TiCl 4 introduced into the reactor cell 1 , and thereby Ti particles are generated. The generated Ti particles are introduced to a separation cell 2 along with the molten salt, and the Ti particles and Na are separated from the molten salt. The residual molten salt is introduced to an electrolytic cell 3 to generate Na by high-temperature electrolysis at the temperature more than 600° C. The generated Na is returned to the reactor cell 1 to replenish Na consumed in the reactor cell 1 . The highly reactive Ca is not directly handled, and Na which is easy to handle is used in a circulating manner. Therefore, the Ti or Ti alloy can economically be produced by Ca reduction.

1 . A method for producing Ti or Ti alloys through reduction by Ca, comprising: 
 a Ca generation step by Na introduction, in which Ca is generated by introducing Na into molten salt containing CaCl 2 , the molten salt being kept at temperatures of not more than 600° C.;    a Ti generation step by a reducing reaction, in which Ti or a Ti alloy is generated in said molten salt by supplying metallic chloride containing TiCl 4  into said molten salt to cause the metallic chloride to react with Ca generated in said molten salt; and    a Ti separation step in which said Ti or Ti alloy generated in said molten salt is separated from said molten salt.    
     
     
         2 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , wherein the Ca generation step by Na introduction and the Ti generation step by the reducing reaction are performed in the same reactor apparatus.  
     
     
         3 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , further comprising an electrolytic step in which Na is generated by electrolyzing the molten salt containing NaCl, wherein Na generated in the electrolytic step is introduced into said molten salt.  
     
     
         4 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 3 , wherein the molten salt is held at temperatures of more than 600° C. in said electrolytic step.  
     
     
         5 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 3 , wherein the molten salt separated from said Ti or Ti alloy is supplied to said electrolytic step.  
     
     
         6 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 3 , further comprising a chlorination step in which TiCl 4  is generated by causing a Cl 2  gas to react with TiO 2 , the Cl 2  gas being of by-product in association with said electrolysis, wherein TiCl 4  generated in the chlorination step is used for the generation reaction of said Ti or Ti alloy.  
     
     
         7 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 5 , further comprising a Na separation step, in which a temperature of the molten salt separated from said Ti or Ti alloy is increased to be more than 600° C. to generate Na before the molten salt is supplied to said electrolytic step, and said molten salt is introduced to the electrolytic step after the generated Na is separated and removed.  
     
     
         8 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 7 , wherein the Na separation step also doubles as said Ti separation step.  
     
     
         9 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , wherein said molten salt containing CaCl 2  is a mixed molten salt containing CaCl 2  and NaCl at a ratio in which a melting point becomes not more than 600° C.  
     
     
         10 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 9 , wherein said mixed molten salt is a mixed molten salt containing at least one of KCl, LiCl, and CaF 2  at a ratio in which a melting point becomes not more than 600° C.  
     
     
         11 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , wherein said metallic chloride containing TiCl 4  is a mixture containing TiCl 4  and another metallic chloride.  
     
     
         12 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , wherein the generated Ti or Ti alloy is particulate whose particle diameter ranges 0.5 to 50 μm on an average.  
     
     
         13 . The method for producing Ti or Ti alloys through reduction by Ca according to  claim 1 , wherein a Ca concentration is managed to be not lower than 0.01% in the molten salt used in said Ti generation step.