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:
May. 12, 1998
Filed:
Mar. 07, 1997
Abstract
A novel method is proposed for the preparation of a calcium silicate powder particularly useful as a filter aid in the filtration of an acidic aqueous liquid by virtue of the extremely high acid resistance of the calcium silicate powder. The inventive method comprises a hydrothermal reaction of a blend of a silica-containing material and calcium oxide or hydroxide in a specified molar ratio under specified reaction conditions to form calcium silicate, which is then subjected to a heat treatment at 800.degree.-1200.degree. C. for 0.5-2 hours. An improvement can be obtained in the clarity of the filtrate obtained by the filtration using the calcium silicate powder prepared by the inventive method as a filter aid when the hydrothermal reaction for the preparation thereof is conducted in an aqueous solution of potassium hydroxide in a specified concentration.