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. 26, 1977
Filed:
Sep. 05, 1975
Mitchell A Lekas, Concord, CA (US);
Other;
Abstract
Subterranean carbonaceous deposits, such as oil shale or the like, that are located at or close to the surface, are prepared for retorting by drilling blast holes from the surface into the deposit, and blasting, creating a rubble pile that reaches the surface. The surface is sealed by suitable means, and the oil shale is retorted in place. Where a stratum of barren rock lies between the carbonaceous deposit and the surface, the blast holes are drilled and blasted in such a manner as to maximize the fragmentation of the carbonaceous deposit, and minimize the fragmentation of the overlying barren stratum. Where overburden conditions are not suitable for treatment by this method, the overburden is removed by strip mining methods, and the carbonaceous deposits are exposed for treatment by the method described above.