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. 29, 1991
Filed:
Aug. 02, 1989
Glenn M Mason, Laramie, WY (US);
Gerald Gardner, Laramie, WY (US);
Western Research Institute, Laramie, WY (US);
Abstract
Lead or other heavy metals are rendered immobile for sanitary disposal by vitrifying the silica-based soil or other medium in which the lead or heavy metal is contained. The silica sand or other soil contaminated with lead is heated to the melting point of the silica. A melt accelerator or fluxing agent is added to lower the melting point of the silica. A reducing agent is added to cause a separation of the metallic phases from the glass. The glass formed retains a portion of the lead, with excess metals, e.g., gold, silver, and platinum, separating. These metals may be recovered at any time after this point in the process. In the case of a silica-poor medium, such as a soil that does not contain sufficient quartz to perform the process successfully, additional quartz sand or scrap glass is added to the process in quantity sufficient to ensure the formation of the glass slag. The slag formed by the process of the present invention is extremely impervious to leaching by groundwater, therefore removing the contaiminate from the environment.