Process for the preparation of titaniun concentrates from iron-containing titanium ores

Claim 2

A process according to claim 1, said removing of water being effected by conducting the vapors boiled from said mixture into a condensation zone and fractionally condensing in said zone and returning as condensate into said mixture the azeotropic HC1 content of said vapors while passing the remaining water vapor content of said vapors through said zone and away from said mixture.

Claim 3

A process according to claim 1, said washing being effected first with hydrochloric acid of said azeotropic concentration and then with water.

Claim 4

A process according to claim 1, and regenerating from said separated liquid hydrochloric acid for reuse in the process.

Claim 5

A process for the production of a titanium dioxide concentrate form iron-containing titanium ore, whereby the speed of deferrization of the ore is kept high, which comprises forming a reaction mixture consisting essentially of a quantity of said ore and an aqueous solution of hydrochloric acid having a concentration approximating the azeotropic HC1 concentration of 20.24 percent by weight, the amount of said acid solution being at least twice that theoretically required to transform the iron oxide content of said ore quantity into iron chloride, during an initial reaction period of not longer than 3 hours boiling said mixture and condensing and returning thereinto as condensate substantially all the vapors being boiled therefrom, then during a substantially longer reaction period boiling the reaction mixture and maintaining the hydrochloric acid therein at substantially said azeotropic concentration by fractionally condensing and returning as condensate into said mixture only the azeotropic HC1 content of the vapors being boiled therefrom while passing the remaining water vapor content of said vapors away from said mixture, to selectively dissolve the iron content of the ore until 90 to 97 percent of said iron oxide content has been extracted into the liquid phase of said mixture, and then adding water into said mixture in an amount sufficient to precipitate by hydrolysis titanium that has dissolved in said liquid phase and continuing the boiling of the mixture during a relatively short final reaction period while again condensing and returning as condensate into said mixture substantially all the vapors being boiled therefrom, and upon the end of said boiling period cooling the reaction material, separating the liquid thereof from the solids therein and washing the separated solids, thus recovering them as a solid titanium dioxide concentrate that contains from 90 to 97 percent of Ti02 by weight when dried and calcined.

Claim 6

A process according to claim 6, and condensing and collecting as an acidic distillate said water vapor content passed away from said mixture and effecting said adding of water into the reaction mixture by introducing said distillate thereinto.

Claim 7

A process according to claim 6, said initial reaction period being of approximately 1 1/2 hours, said longer reaction period being of approximately 10 hours, and said final reaction period being of approximately one-half to 1 hour.

Claim 8

A process according to claim 6, and at the end of said final reaction period cooling the reaction material, regenerating from the separated liquid hydrochloric acid for reuse in the process.