The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 1994
Filed:
Sep. 09, 1991
Morio Watanabe, Hyogo, JP;
Solex Research Corporation of Japan, Tokyo, JP;
Abstract
A process for producing titanium dioxide which discharges no waste is disclosed. In a first step, a sulfuric acid solution containing titanium ion with one or more kinds of metal ions is contacted with a first organic solvent to extract the titanium ion as a sulfuric acid complex. The organic solvent containing the extracted titanium as a sulfuric acid complex (titanyl sulfate) is contacted with an aqueous liquid to strip the titanium into the aqueous liquid and regenerate the first organic solvent. In a second step, the aqueous liquid containing the titanium is subjected to hydrolysis to form insoluble titanium hydroxide, and the titanium hydroxide is washed with dilute sulfuric acid and/or clear water. In a third step, the raffinate of extraction in the first step is contacted with a second organic solvent to extract the titanium ion and the organic solvent containing extracted titanium is contacted with water, dilute sulfuric acid solution or a dilute titanyl sulfate solution to strip the titanium, and regenerate the organic solvent.