Process for recovering titanium dioxide from titanium containing materials
AssigneeArgex Titanium Inc.
InventorsEric Larochelle, Carroll Moore, Tommee Larochelle, Richard A. Sixberry, Oumar Bashir, Steeve Lafontaine
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Abstract
A process operating at super-atmospheric pressure for leaching a titanium containing ore with an HCl and producing titanium dioxide with integrated steps of solvent extraction for removing iron from the leached ore and solvent extraction of a resulting titanium enriched raffinate to produce particles suitable for finishing into pigment grade TiO2. The process can integrate the recovery of HCl from both solvent recovery steps and the recovery of solvent. The process also produces commercial grade ferric chloride.
Claims19
A process for producing a titanium dioxide product using super-atmospheric pressure conditions, the process comprising:
- a. leaching a feed material in acidic leaching solution at high intensity and super atmospheric pressure to form a leaching slurry having a solids content of 20 wt % to 35 wt % on a total slurry basis, said titanium containing ore having a mean particle size below 100 microns and said an acidic leaching solution comprising water and HCl at an HCl concentration above 11N;
- b. separating the leaching slurry into a solid residue stream and a pregnant liquor comprising titanium and iron compounds and adding chlorine to the pregnant liquor to promote conversion of FeCl2 into FeCl3 to form a treated pregnant liquor;
- c. removing FeCl3 by solvent extraction at super-atmospheric conditions to provide a FeCl3 enriched stream and FeCl3 depleted stream;
- d. recovering titanium compounds from the FeCl3 depleted stream by solvent extraction at super-atmospheric conditions to produce a titanium enriched stream and a titanium depleted raffinate stream;
- e. recovering HCl from the FeCl3 enriched stream and the titanium depleted raffinate stream for reuse in the leaching of step a.;
- f. hydrolyzing the titanium enriched stream under plug flow conditions, super-atmospheric pressure, and a temperature of 110° C. to 125° C. to produce a hydrolysate stream comprising TiO2.H2O particles;
- g. drying the hydrolysate stream for 2 to 4 hours while maintaining the temperature in a range of 100° C. to 250° C. to remove interstitial water, to inhibit rupture of the TiO2.H2O particles, and to produce a dried hydrolysate stream;
- h. calcining the dried hydrolysate stream to convert TiO2.H2O to TiO2 and produce a calcined TiO2 material;
- and
- i. converting the calcined TiO2 material into a pigment grade titanium oxide product.
A process for producing a titanium oxide product using super-atmospheric pressure conditions, said process comprising:
- a. contacting a feed material comprising titanium containing ore having a mean particle size below 100 microns with an acidic leaching solution comprising water and HCl at an HCl concentration above 11 N and above the HCl azeotrope concentration in a high intensity leaching step at super-atmospheric pressure to form a leaching slurry having a solids content of 20 wt % to 35 wt % on a total slurry basis;
- b. separating the leaching slurry into a solid residue stream and a pregnant liquor comprising titanium and iron compounds and adding chlorine to the pregnant liquor to promote conversion of FeCl3 into FeCl3 to form a treated pregnant liquor;
- c. removing FeCl3 by solvent extraction at super-atmospheric conditions to provide a FeCl3 enriched stream and FeCl3 depleted stream;
- d. recovering titanium compounds from the FeCl3 depleted stream by solvent extraction at super-atmospheric conditions using the same solvent as that used in step c. to produce a titanium enriched stream and a titanium depleted raffinate stream;
- e. purifying the solvents in a single solvent purification zone to provide at least a portion of the solvent for steps c. and d.;
- f. recovering HCl from the FeCl3 enriched stream and the titanium depleted raffinate stream for reuse in the high intensity leaching;
- g. hydrolyzing the titanium enriched stream under plug flow conditions, super-atmospheric pressure and at a temperature of 110° C. to 125° C. to produce a hydrolysate stream comprising TiO2.H2O particles;
- h. drying the hydrolysate stream for 2 to 4 hours while maintaining the temperature in a range of from 100° C. to 250° C. to remove interstitial water and inhibit rupture of the TiO2.H2O particles, to produce a dried hydrolysate stream;
- i. calcining the dried hydrolysate stream to convert TiO2.H2O to TiO2 and producing a calcined TiO2 material;
- and
- j. converting the calcined TiO2 material into a pigment grade titanium oxide product.
A hydrolysis method for hydrolyzing a titanium rich stream to produce a hydrolysate stream comprising TiO2.H2O particles, the method comprising feeding the titanium rich stream into a plug flow reactor having a boustrophedonic reaction conduit operated under pressure conditions above atmospheric and at a temperature of from 110° C. to 125° C.
Dependencies are inferred from the claim text.