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:
Jul. 14, 1981
Filed:
Sep. 08, 1978
Chakra J Santhanam, Lexington, MA (US);
Ravindra M Nadkarni, Arlington, MA (US);
Arthur D. Little, Inc., Cambridge, MA (US);
Abstract
Method and apparatus for removing heavy metals as sulfides from aqueous liquids. The aqueous liquid is introduced into a circulating liquid loop wherein there are established a mixing zone, a controlled precipitation initiating zone, a crystal growing zone and a crystal settling zone. The aqueous feed liquid containing H.sub.2 S dissolved therein and at a pH below that at which the sulfide is precipitated is mixed in the loop with a pH-adjusting liquid; and the degree of supersaturation with respect to the metal sulfide is maintained within the controlled precipitation initiating and crystal growing zones in the metastable condition so that the growth rate of the metal sulfide crystals remains greater than under uncontrolled conditions vis-a-vis the nucleation rate to effect the production of metal sulfide crystals of a character which makes it possible to separate them through clarification and filtration.