Process of providing titanium dioxide and/or vanadium oxide

Abstract

The present invention relates to a process of providing titanium dioxide and/or vanadium oxide from feedstocks comprising minerals and/or slags comprising titanium and/or vanadium.

1 . A process of providing titanium dioxide and/or vanadium oxide, the process comprising:
 (a) providing a feedstock, the feedstock comprising at least one of
 (I) a mineral comprising titanium and/or vanadium, and 
 (II) a slag comprising titanium and/or vanadium, 
   (b) adding an alkaline material to the feedstock to provide a modified feedstock, wherein the alkaline material has a pH of less than 9.0,   (c) roasting at least a portion of the modified feedstock at a temperature in the range of 600° C. to 900° C. to provide a roasted calcine,   (d) optionally leaching at least a portion of the roasted calcine under acidic conditions to provide a pre-cure leach solid and a pre-cure leach liquor,   (e) optionally obtaining vanadium oxide from at least a portion of the pre-cure leach liquor via solvent extraction and/or precipitation,   (f) adding sulphuric acid and/or hydrochloric acid to at least a portion of the roasted calcine or at least a portion of the pre-cure leach solid to provide a first acidic solid;   (g) curing at least a portion of the first acidic solid at a temperature in the range of 100° C. to 300° C. to provide a cured first acidic solid,   (h) leaching at least a portion of the cured first acidic solid to provide a post-cure leach solid and a post-cure leach liquor,   (i) hydrolysing at least a portion of the post-cure leach liquor to provide titanium dioxide, and/or   (j) obtaining vanadium oxide from at least a portion of the post-cure leach liquor via solvent extraction and/or precipitation.   
     
     
         2 . The process of  claim 1 , wherein the alkaline material has a pH of less than 8.0. 
     
     
         3 . The process of  claim 1 or claim 2 , wherein the alkaline material comprises borax. 
     
     
         4 . The process of  any one of the preceding claims , wherein the alkaline material is added to the feedstock in an amount of 3 to 20 wt %, based on the total weight of the feedstock, preferably wherein the alkaline material is added to the feedstock in an amount of 5 to 15 wt %, based on the total weight of the feedstock. 
     
     
         5 . The process of  any one of the preceding claims , wherein the roasting in step (c) is at a temperature in the range of 600° C. to 800° C. 
     
     
         6 . The process of  any one of the preceding claims , wherein the roasting in step (c) is for 0.5 hours to 4 hours. 
     
     
         7 . The process of  any one of the preceding claims , wherein the roasted calcine has a pH of less than 9.0, preferably wherein the roasted calcine has a pH in the range of 6.0 to 8.0. 
     
     
         8 . The process of  any one of the preceding claims , wherein the process comprises
 (d) leaching at least a portion of the roasted calcine under acidic conditions to provide a pre-cure leach solid and a pre-cure leach liquor; and   (f) adding sulphuric acid and/or hydrochloric acid to at least a portion of the pre-cure leach solid to provide a first acidic solid.   
     
     
         9 . The process of  claim 8 , wherein the leaching of the at least a portion of the roasted calcine in step (d) is at a pH of 1.0 to 3.0, preferably 1.0 to 2.0. 
     
     
         10 . The process of  claim 8 or claim 9 , wherein the process comprises separating the pre-cure leach solid and the pre-cure leach liquor, preferably via filtration. 
     
     
         11 . The process of  any one of the preceding claims , wherein the process comprises (e) obtaining vanadium oxide from at least a portion of the pre-cure leach liquor via solvent extraction and/or precipitation. 
     
     
         12 . The process of  any one of the preceding claims , wherein the feedstock further comprises aluminium, and where the process further comprises obtaining aluminium oxide from at least a portion of the pre-cure leach liquor via precipitation. 
     
     
         13 . The process of  any one of the preceding claims , wherein the process further comprises pelletizing the first acidic solid before curing step (g). 
     
     
         14 . The process of  claim 13 , wherein the first acidic solid is pelletized into pellets having an average diameter in the range of 5 to 80 mm 
     
     
         15 . The process of  any one of the preceding claims , wherein the curing in step (g) is at a temperature in the range of 100° C. to 200° C. 
     
     
         16 . The process of  any one of the preceding claims , further comprising pulverizing the at least a portion of the cured first acidic solid before leaching step (h). 
     
     
         17 . The process of  any one of the preceding claims , wherein the leaching of the at least a portion of the cured first acidic solid in step (h) is at a pH of less than 3.0. 
     
     
         18 . The process of  any one of the preceding claims , wherein the leaching of the at least a portion of the cured first acidic solid in step (h) is at a pH of less than 2.0. 
     
     
         19 . The process of  any one of the preceding claims , wherein the process comprises separating the post-cure leach solid and the post-cure leach liquor, preferably via filtration. 
     
     
         20 . The process of  any one of the preceding claims , wherein the hydrolysing at least a portion of the post-cure leach liquor in step (i) is at a temperature in the range of 50° C. to 80° C., preferably wherein the hydrolysing at least a portion of the post-cure leach liquor in step (i) is at a temperature in the range of 50° C. to 70° C. 
     
     
         21 . The process of  any one of the preceding claims , wherein the feedstock further comprises manganese, iron, chromium, and/or nickel, and wherein the process further comprises obtaining manganese, iron, chromium, and/or nickel from at least a portion of the post-cure leach liquor via solvent extraction and/or precipitation. 
     
     
         22 . The process of  claim 21 , wherein the feedstock further comprises manganese, iron, chromium, and nickel, and wherein the process further comprises obtaining manganese, iron, chromium, and nickel from at least a portion of the post-cure leach liquor via solvent extraction and/or precipitation; and wherein the process further comprises melting the obtained manganese, iron, chromium, and nickel to provide an alloy comprising manganese, iron, chromium, and nickel. 
     
     
         23 . The process of  any one of the preceding claims , wherein the feedstock comprises a slag comprising titanium and/or vanadium, or wherein the feedstock comprises one or more of the group consisting of ilmenite, leucoxene, rutile, and complex calcium magnesium aluminium silicates. 
     
     
         24 . The process of  any one of the preceding claims , wherein the feedstock comprises 0.3 to 5.0 wt % vanadium and/or 5.0 to 85.0 wt % titanium dioxide, based on the total weight of the feedstock. 
     
     
         25 . The process of  any one of the preceding claims , wherein the process is a process of providing titanium dioxide and vanadium oxide, and wherein the process comprises
 (i) hydrolysing at least a portion of the post-cure leach liquor to provide titanium dioxide, and   (j) obtaining vanadium oxide from at least a portion of the post-cure leach liquor via solvent extraction and/or precipitation.   
     
     
         26 . The process of  any one of the preceding claims , wherein step (f) further comprises adding water to at least a portion of the roasted calcine or at least a portion of the pre-cure leach solid. 
     
     
         27 . The process of  any one of the preceding claims , wherein the process further comprises
 (f′) adding sulphuric acid and/or hydrochloric acid to at least a portion of the post-cure leach solid to provide a second acidic solid;   (g′) curing at least a portion of the second acidic solid at a temperature in the range of 100° C. to 300° C. to provide a cured second acidic solid;   (h′) leaching at least a portion of the cured second acidic solid to provide a post-cure second leach solid and a post-cure second leach liquor;   (i′) hydrolysing at least a portion of the post-cure second leach liquor to provide titanium dioxide, and/or   (j′) obtaining vanadium oxide from at least a portion of the post-cure second leach liquor via solvent extraction and/or precipitation.