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:
Jan. 12, 2010
Filed:
May. 31, 2007
Thomas E. Higgins, Reston, VA (US);
Thomas E. Higgins, Reston, VA (US);
CH2M Hill, Inc., Englewood, CO (US);
Abstract
In methods for treatment of in ground chromium ore processing residue contamination, ferrous sulfide is provided as a substantially insoluble material in the residue deposit. The ferrous sulfide accordingly may remain substantially in place, in the pores of the soil or residue, even over long periods of time, regardless of underground water movement or diffusion. As a result, the ferrous sulfide may act continuously to chemically reduce and remove contamination. As hexavalent chromium diffuses from the soil or residue, it is reduced by the ferrous sulfide. The ferrous sulfide may be placed into the underground deposit by injecting a ferrous salt solution into the deposit, waiting for a precipitation to elapse, and then injecting a sulfide solution into the deposit.