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:
Dec. 22, 1992
Filed:
Jul. 19, 1991
Costandi A Audeh, Princeton, NJ (US);
Mobil Oil Corporation, Fairfax, VA (US);
Abstract
A process for fixing elemental mercury (Hg.degree.) in a spent molecular sieve desiccant is disclosed. The process includes isolating gspent molecular sieve desiccant containing elemental mercury, and contacting the spent desiccant in a dilute aqueous solution of an alkaline metal salt. The reaction traps the mercury within the spent desiccant as an insoluble heavy metal salt. The alkaline metal salt can include, for example, sodium thiosulfate (Na.sub.2 S.sub.2 O.sub.3), sodium polysulfide (Na.sub.2 S.sub.x), or potassium peroxomonosulfate (KHSO.sub.5). The reaction with any of these aqueous solutions acts to fix the elemental mercury (Hg.degree.) as a mercury compound within the solid desiccant. If sodium thiosulfate or sodium polysulfide is utilized, then the process also includes introducing hydrochloric acid (HCl) in a suitable quantity to liberate sufficient elemental sulfur to react with the elemental mercury (Hg.degree.) to form an HgS salt. The formation of HgS fixes the elemental mercury (Hg.degree.) in the form of a heavy metal salt in the solid desiccant. If, however, an aqueous potassium peroxomonosulfate (KHSO.sub.5) solution is utilized, then HCl is not needed. The aqueous potassium peroxomonosulfate solution is used in a suitable concentration to convert the elemental mercury (Hg.degree.) in the spent desiccant to HgO, so that the elemental mercury (Hg.degree.) is fixed as an insoluble heavy metal oxide in the solid desiccant.