Process for removing impurities from iron chloride solutions
View Patent ↗The disclosure provides a process for removing dissolved niobium, titanium, and zirconium impurities from an iron chloride solution having an iron concentration of about 50 to about 250 grams/liter comprising: (a) heating the iron chloride solution comprising a compound selected from the group consisting of a niobium compound, titanium compound, zirconium compound, and mixtures thereof, in a vessel, at a temperature of about 120° C. to about 300° C., and at least autogenous pressure, to precipitate the compound as a solid; and (b) separating the solid from the iron chloride solution. The separation of the solid is accomplished by filtration, settling, or centrifugation. In one embodiment, the iron chloride solution is a byproduct of the chlorination process for making titanium dioxide.
1. A process for removing dissolved niobium, titanium, and zirconium impurities from an iron chloride solution having an iron concentration of about 50 to about 250 grams/liter comprising:
(a) heating the iron chloride solution comprising a compound selected from the group consisting of a niobium compound, titanium compound, zirconium compound, and mixtures thereof, in a vessel, at a temperature of about 120° C. to about 300° C., and at least autogenous pressure, to precipitate the compound as a solid; and
(b) separating the solid from the iron chloride solution.
2. The process of claim 1 wherein the separating of the solid is accomplished by filtration, settling, or centrifugation.
3. The process of claim 1 wherein the heating is conducted at a temperature of about 200° C. to about 250° C.
4. The process of claim 1 wherein the at least autogenous pressure is about 200 to about 1400 psig.
5. The process of claim 1 wherein the at least autogenous pressure is about 500 to about 800 psig.
6. The process of claim 1 wherein the iron chloride solution is heated to precipitate the compound as a solid for about 1 to about 120 minutes.
7. The process of claim 6 wherein the iron chloride solution is heated to precipitate the compound as a solid for about 3 to about 30 minutes.
8. The process of claim 1 wherein the vessel is a pipeline reactor.
9. A process for removing dissolved niobium, titanium, and zirconium impurities from an iron chloride solution having an iron concentration of about 50 to about 250 grams/liter comprising:
(a) reacting ore comprising metal oxides with a chlorine and a carbon compound at a temperature of about 900° C. to about 1300° C. to form a gaseous stream comprising chlorides of the metal and off gases comprising carbon oxides;
(b) cooling the gaseous stream to form iron chloride solids along with solids of a compound selected from the group consisting of a niobium compound, titanium compound, zirconium compound, and mixtures thereof;
(c) quenching the solids formed in step (b) to form an iron chloride solution having an iron concentration of about 50 to about 250 grams/liter and a compound selected from the group consisting of a niobium compound, titanium compound, zirconium compound, and mixtures thereof;
(d) heating the iron chloride solution in a vessel, at a temperature of about 120° C. to about 300° C., and at least autogenous pressure, to precipitate the compound as a solid; and
(e) separating the solid from the iron chloride solution.
10. The process of claim 9 wherein the carbon compound is coke.
11. The process of claim 9 wherein the solids are separated using a spray condenser or a cyclone.
12. The process of claim 9 wherein the quenching is accomplished by mixing dilute hydrochloric acid or water with the solids.
13. The process of claim 9 wherein the separating of the solid in step (e) is accomplished by filtration, settling, or centrifugation.
14. The process of claim 9 wherein the heating is conducted at a temperature of about 200° C. to about 250° C.
15. The process of claim 9 wherein the at least autogenous pressure is about 200 to about 1400 psig.
16. The process of claim 9 wherein the at least autogenous pressure is about 500 to about 800 psig.
17. The process of claim 9 wherein the iron chloride solution is heated to precipitate the compound as a solid for about 1 to about 120 minutes.
18. The process of claim 17 wherein the iron chloride solution is heated to precipitate the compound as a solid for about 3 to about 30 minutes.
19. The process of claim 9 wherein the vessel is an autoclave or pipeline reactor.
20. The process of claim 9 wherein the gaseous stream further comprises entrained solids and, said entrained solids are removed before step (d).