Method for preparing metallic titanium by molten salt electrolysis reduction of titanium dioxide

Abstract

The present application relates to a method for preparing metallic titanium by molten salt electrolysis reduction of titanium dioxide, the method includes: constructing an electrochemical system, including an anode chamber filled with an anodic molten salt electrolyte and inserted with an anode, and a cathode chamber filled with a cathodic molten salt electrolyte and inserted with a cathode, where the anodic molten salt electrolyte and the cathodic molten salt electrolyte are connected through a liquid alloy accommodated at an inner bottom of the electrolytic cell without contacting with each other; and adding titanium dioxide to the anode chamber, and energizing for electrolysis to obtain metallic titanium at the cathode. The method of the present application has advantages such as low requirements for the titanium dioxide raw material, simple process flow, low energy consumption, environmental friendliness, and direct acquisition of high-purity metallic titanium.

What is claimed is: 
     
         1 . A method for preparing metallic titanium by molten salt electrolysis reduction of titanium dioxide, wherein
 the method is implemented with an electrolytic cell; the electrolytic cell comprises an anode chamber and a cathode chamber, the anode chamber is filled with an anodic molten salt electrolyte and inserted with an anode, the cathode chamber is filled with a cathodic molten salt electrolyte and inserted with a cathode, and a liquid alloy is accommodated at an inner bottom of the electrolytic cell; the anodic molten salt electrolyte and the cathodic molten salt electrolyte are connected through the liquid alloy without contacting with each other; and   the method comprises: adding titanium dioxide to the anode chamber and powering on the electrolytic cell, the titanium dioxide in the anode chamber is reduced into titanium atoms at an interface between the anodic molten salt electrolyte and the liquid alloy and dissolved in the liquid alloy, the titanium atoms in the liquid alloy are oxidized into titanium ions at an interface between the liquid alloy and the cathodic molten salt electrolyte and enter the cathodic molten salt electrolyte, and the titanium ions to be reduced into titanium atoms on a surface of the cathode, thereby forming the metallic titanium.   
     
     
         2 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 1 , wherein the anodic molten salt electrolyte and the cathodic molten salt electrolyte both are halide molten salts. 
     
     
         3 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 2 , wherein the anodic molten salt electrolyte comprises one or more selected from the group consisting of CaCl 2 , BaCl 2 , LiCl, NaCl, KCl, CsCl, LiF, NaF, and KF. 
     
     
         4 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 2 , wherein the cathodic molten salt electrolyte comprises TiCl 2  and/or TiCl 3 , and one or more selected from the group consisting of LiCl, NaCl, KCl, CaCl 2 , and MgCl 2 . 
     
     
         5 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 1 , wherein the anode is graphite, and the cathode is a stainless steel, tungsten, or molybdenum cathode. 
     
     
         6 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 1 , wherein the liquid alloy is formed from a solute metal Ti and a matrix metal; the matrix metal has a lower metal activity than the titanium, and is mixed with the titanium to produce an alloy with a low melting point of lower than 1,000° C.; and preferably, the matrix metal is one or more selected from the group consisting of Cu, Sn, Sb, Zn, Pb, Bi, and Ni. 
     
     
         7 . The method for preparing metallic titanium through molten salt electrolysis reduction of titanium dioxide according to  claim 1 , wherein an area of the cathode is 1 to 20 times an area of the anode; and when the electrolytic cell operates normally, an anode current density is 0.05 A/cm 2  to 2.0 A/cm 2  and a temperature is 400° C. to 1,000° C.