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:
Sep. 14, 1976
Filed:
Nov. 20, 1975
Frank R Foulkes, Toronto, CA;
Huron Chemicals Limited, Kingston, CA;
Abstract
The present invention relates to removal of chromate from an aqueous solution of an alkali metal chlorate and chloride, particularly sodium chlorate and sodium chloride in a selected ratio which has been obtained by the electrolysis of an aqueous solution of alkali metal chloride containing chromate in which the essentially chromate free aqueous solution of alkali metal chlorate and chloride contains the chlorate and chloride in essentially the same selected ratio. In the process the chromate containing aqueous solution of alkali metal chlorate and chloride is acidified with hydrochloric acid to a pH value not smaller than 0.5 and passed through an anionic ion exchange resin bed which has previously been saturated with alkali metal chlorate and chloride. The bed is then regenerated by passing an aqueous solution of an alkali metal hydroxide and alkali metal chloride therethrough to remove chromate therefrom. An acidified aqueous solution of alkali metal chloride is then passed through the bed to convert the resin to an acid form and an aqueous solution of essentially chromate free alkali metal chlorate and chloride acidified with hydrochloric acid to a low pH value but not smaller than 0.5 is passed through the bed to saturate the resin with the alkali metal chlorate. The effluents from the regeneration stages may then be used as feedstock for the electrolysis to produce the aqueous solution of alkali metal chlorate and chloride, after suitable additions of chromate and chloride solutions.