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. 15, 1997
Filed:
Oct. 12, 1995
Applicant:
Inventors:
Assignees:
Kurita Water Industries Ltd., Tokyo, JP;
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210641 ; 210650 ; 210651 ; 134 10 ;
Abstract
A method for recovering abrasive particles of, in particular, colloidal silica, in a simple manner from a spent abrasive suspension, which requires subjecting the spent abrasive slurry (5) containing colloidal silica used for polishing a semiconductor substrate in a microfilter (1) to thereby concentrate coarse particulate impurities for being removed out of the system, subjecting the slurry (6) which has permeated through the microfilter to an ultrafiltration in an ultrafilter (2) to concentrate the retained abrasive particles and recovering this concentrate in order to recover the colloidal silica.