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:
Oct. 19, 1993
Filed:
Aug. 03, 1992
Applicant:
Inventor:
Curtis L Knudson, Grand Forks, ND (US);
Primary Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ; B01D / ;
U.S. Cl.
CPC ...
502432 ; 42324401 ; 502416 ; 502437 ; 95129 ; 95137 ;
Abstract
A process of preparing lignite (low rank) coal filter material, suitable for use in lieu of more expensive activated carbon filter materials, is disclosed. The process comprises size reducing Leonardite coal material to a suitable filtering effective size, and thereafter heating the size reduced Leonardite preferably to at least 750.degree. C. in the presence of a flow of an inert gas.