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:
Feb. 11, 1997
Filed:
Oct. 31, 1995
Donald L Ball, Castlegar, CA;
Richard S Varley, Trail, CA;
Cominco Ltd., Vancouver, CA;
Abstract
This invention is directed to a novel method for purifying calomel (Hg.sub.2 Cl.sub.2). More particularly, this invention pertains to a novel process for treating impure calomel (Hg.sub.2 Cl.sub.2) to produce a highly purified calomel product that passes American Chemical Society requirements for calomel assay and mercuric chloride contamination. A process for treating impure calomel to produce purified calomel comprising: (a) incorporating impure calomel into an aqueous slurry; (b) oxidizing the aqueous slurry with an oxidizing agent to form soluble mercuric chloride; (c) filtering the aqueous slurry containing soluble mercuric chloride into liquid and solid components; (d) heating the liquid component to greater than 70.degree. C; (e) treating the liquid component with a reducing agent to precipitate purified calomel; and (f) separating the precipitated purified calomel from the filtrate.