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. 21, 1998
Filed:
Nov. 16, 1995
Randall D Peterson, Salt Lake City, UT (US);
Other;
Abstract
A mining process that consists of a combination of surface mining and underground mining techniques carried out in a novel extraction sequence. The coal seam is first mined by surface-mining stripping methods to produce a highwall. Roadways to a predetermined distance underground from the surface highwall are then developed using continuous mining equipment, so that a panel of coal with a minable underground face or wall is blocked out. A longwall is then set up at the face and the panel is mined in retreat toward the surface highwall to a safety barrier determined by the highwall slope. Adjacent panels are successively developed and extracted by longwall mining, thereby permitting the recovery of substantially all coal reserves between the surface highwall and the predetermined distance at which the underground wall was set up.