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:
Nov. 14, 1995
Filed:
Aug. 11, 1993
Applicant:
Inventors:
William E Fristad, Santa Rosa, CA (US);
Jeffrey L Narum, Santa Rosa, CA (US);
Phillip L Mattison, Santa Rosa, CA (US);
Michael J Virnig, Santa Rosa, CA (US);
John Fast, Littleton, CO (US);
Assignee:
Cognis, Inc., Santa Rosa, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
C22B / ;
U.S. Cl.
CPC ...
423 98 ; 75725 ;
Abstract
The invention is a process and an apparatus for removing metal contamination from soil. In the method, the soil is treated to produce soil with a small particle size. The particulate soil is then separated into a coarse fraction and a fine fraction. The coarse fraction and the fine fraction are contacted with a leach solution in separate contacting zones to remove the metal contamination from the soil, the metal is removed from the leach solution and the leach solution recycled to the leaching zones.