Purification of Titanium Tetrachloride

Abstract

Disclosed is a process/system for the removal of metal chloride impurities from a titanium tetrachloride stream. The metal chloride impurities are removed through contact of the titanium tetrachloride stream with a sorbent material comprising a member selected from the group consisting of an alumino-silicate, activated alumina, ultrafine TiO2, and combinations thereof.

What is claimed is: 
     
         1 . A titanium tetrachloride purification process comprising the steps of:
 a) contacting a sorbent material with a feedstock comprising titanium tetrachloride and at least one impurity to form a product stream, wherein said sorbent material comprises a member selected from the group consisting of an alumino-silicate, activated alumina, ultrafine TiO2, and combinations thereof, and wherein said at least one impurity comprises a member selected from the group consisting of carbonyl sulfide, sulfur dioxide, phosgene, hydrogen sulfide, carbon disulfide, chlorides of: aluminum, carbon, gallium, indium, tin, thallium, lead, bismuth, polonium, boron, silicon, germanium, arsenic, antimony, tellurium, zirconium, hafnium, iron, chromium, copper, magnesium, vanadium, nickel, thorium, uranium, oxychlorides of: aluminum, bismuth, arsenic, antimony, zirconium, hafnium, chromium, vanadium, uranium; and combinations thereof; and   b) withdrawing said product stream.   
     
     
         2 . The process of  claim 1  wherein said sorbent material further comprises activated carbon. 
     
     
         3 . The process of  claim 1  wherein said member of said sorbent material comprises alumino-silicate and said sorbent material further comprises activated carbon. 
     
     
         4 . The process of  claim 1  wherein said feedstock comprises a vaporous form. 
     
     
         5 . The process of  claim 1  wherein said feedstock comprises a liquid form. 
     
     
         6 . The process of  claim 1  wherein said titanium tetrachloride comprises an anhydrous form. 
     
     
         7 . The process of  claim 1  wherein said titanium tetrachloride comprises an aqueous form. 
     
     
         8 . The process of  claim 1  wherein said feedstock comprises in the range of from about 0.1 to about 10,000 ppmw of said at least one impurity. 
     
     
         9 . The process of  claim 8  wherein said product stream contains less than about 80 weight % of said at least one impurity contained in said feedstock. 
     
     
         10 . The process of  claim 1  wherein said at least one impurity comprises a chloride of tin comprising tin dichloride; and wherein said feedstock comprises in the range of from about 1 to about 500 ppmw of combined chlorides of tin. 
     
     
         11 . The process of  claim 10  wherein said product stream contains less than about 20 weight % of the tin dichloride contained in said feedstock. 
     
     
         12 . The process of  claim 1  wherein said at least one impurity comprises a member selected from the group consisting of chlorides of arsenic, oxychlorides of arsenic, and combinations thereof; and wherein said feedstock comprises in the range of from about 0.1 to about 500 ppmw of combined chlorides of arsenic and oxychlorides of arsenic. 
     
     
         13 . The process of  claim 12  wherein said product stream contains less than about 20 weight % of the combined chlorides of arsenic, and oxychlorides of arsenic contained in said feedstock. 
     
     
         14 . The process of  claim 1  wherein said at least one impurity comprises a member selected from the group consisting of chlorides of antimony, oxychlorides of antimony, and combinations thereof; and wherein said feedstock comprises in the range of from about 0.1 to about 500 ppmw of combined chlorides of antimony and oxychlorides of antimony. 
     
     
         15 . The process of  claim 14  wherein said product stream contains less than about 20 weight % of the combined chlorides of antimony and oxychlorides of antimony contained in said feedstock. 
     
     
         16 . The process of  claim 1  wherein said at least one impurity comprises a member selected from the group consisting of chlorides of zirconium, oxychlorides of zirconium, and combinations thereof; and wherein said feedstock comprises in the range of from about 0.1 to about 100 ppmw of combined chlorides of zirconium and oxychlorides of zirconium. 
     
     
         17 . The process of  claim 16  wherein said product stream contains less than about 20 weight % of the combined chlorides of zirconium and oxychlorides of zirconium contained in said feedstock. 
     
     
         18 . The process of  claim 1  wherein contacting said sorbent material with said feedstock comprising titanium tetrachloride and at least one impurity comprises contacting said sorbent material with said feedstock in a single vessel; removing said sorbent material from said vessel; and disposing said sorbent material once spent. 
     
     
         19 . The process of  claim 1  wherein contacting said sorbent material with said feedstock comprising titanium tetrachloride and at least one impurity comprises i) contacting said sorbent material with said feedstock in a single vessel until said sorbent material is spent forming a spent sorbent material; stopping contact with said feedstock in step a) until said spent sorbent material is regenerated into a regenerated sorbent material; and iii) contacting the regenerated sorbent material with said feedstock. 
     
     
         20 . The process of  claim 1  wherein contacting said sorbent material with said feedstock comprising titanium tetrachloride and at least one impurity comprises contacting said sorbent material with said feedstock in a system containing multiple vessels, and wherein said contacting of said sorbent material with said feedstock comprises sequentially charging said feedstock to said vessels and regenerating said sorbent material in each of said vessels upon becoming spent. 
     
     
         21 . The process of  claim 1  further comprising chlorinating a titanium ore comprising titanium oxide, iron oxide, and at least 3 wt % of said at least one impurity to form said feedstock. 
     
     
         22 . The process of  claim 1 , further comprising reacting said product stream with oxygen to form pigmentary titanium dioxide. 
     
     
         23 . The process of  claim 1 , further comprising reacting said product stream with a metal selected from the group consisting of sodium, magnesium, or combinations thereof, to form titanium metal. 
     
     
         24 . A titanium tetrachloride purification process comprising the steps of:
 a) contacting a feedstock comprising titanium tetrachloride and at least one impurity with an alumino-silicate to form a product stream, wherein said at least one impurity comprises a member selected from the group consisting of carbonyl sulfide, sulfur dioxide, phosgene, hydrogen sulfide, carbon disulfide, and chlorides of: aluminum, carbon, gallium, indium, tin, thallium, lead, bismuth, polonium, boron, silicon, germanium, arsenic, antimony, tellurium, zirconium, hafnium, iron, chromium, copper, magnesium, vanadium, nickel, thorium, uranium, oxychlorides of: aluminum, bismuth, arsenic, antimony, zirconium, hafnium, chromium, vanadium, uranium; and combinations thereof; and   b) withdrawing said product stream.   
     
     
         25 . The process of  claim 24  wherein said alumino-silicate has a surface area greater than about 200 m 2 /g. 
     
     
         26 . The process of  claim 24  wherein said alumino-silicate has an average channel size in the range of from about 4.5 to about 9.5 Å. 
     
     
         27 . The process of  claim 24  wherein said alumino-silicate has an alkali content in the range of from about 0.02 to about 0.2 wt %. 
     
     
         28 . The process of  claim 24  wherein said alumino-silicate has a silica to alumina ratio in the range of from about 30 to about 100. 
     
     
         29 . The process of  claim 24  wherein said alumino-silicate comprises a zeolite. 
     
     
         30 . The process of  claim 29  wherein said zeolite comprises a faujasite zeolite.