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:
May. 22, 1979
Filed:
May. 15, 1978
William W Carlin, Portland, TX (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
Disclosed is a method of electrolyzing alkali metal chloride brine. The method comprises feeding fortified brine to an electrolytic cell, passing an electrical current through the cell, and withdrawing depleted brine from the cell. Hydrochloric acid is added to the depleted brine to dechlorinate it; and the depleted, dechlorinated brine is then contacted with solid salt to refortify the brine. The solid brine is a source of heavy metal impurities. Sodium carbonate and barium carbonate are added to the refortified brine in order to precipitate calcium and sulfate ions therefrom. The precipitate is then separated from the refortified brine in order to obtain a refortified, purified brine. According to the disclosed method, ferrous ion and sufficient hydroxyl ion are added to the dechlorinated, depleted brine prior to its refortification in order to maintain the pH thereof above about 7 during fortification. After refortification, the pH is adjusted to pH 7 by the addition of hydrochloric acid and heavy metal impurities, such as vanadium, are flocculated therefrom. According to an alternate method, the pH can be adjusted to pH 2 by the addition of HCl and then to pH 7 by the addition of NaOH.