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. 12, 2000
Filed:
Jun. 29, 1999
Lyle H Howard, West Memphis, AR (US);
John A Bain, Hughes, AR (US);
Tetra Technologies, Inc., The Woodlands, TX (US);
Abstract
A method for producing zinc bromide from zinc hydroxide contaminated with iron and manganese compounds. The method comprises the step of mixing zinc hydroxide feedstock containing metal impurities with a hydrobromic acid comprising elemental bromine in the presence of a reducing agent to produce an impure zinc bromide solution. The metal impurities are removed from the zinc bromide solution in a two-stage process: the first stage comprises the steps of precipitating iron by maintaining the pH within a range of from about 3.6 to 4.15 and filtering out the insoluble iron compounds. The second stage comprises the steps of acidifying the zinc hydroxide solution and adjusting the pH to a range of 3.8 to 4.3 with a alkalinity source from metal oxide, hydroxide or carbonate to precipitate the manganese compounds. The resulting mixture is filtered and concentrated to form a solution comprising zinc bromide essentially free of iron and manganese compounds.