Process for increasing pulp brightness with zeolites and easily decomposable organic chelating agents

US5227022A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Wolfgang Leonhardt · Frankfurt, DE
• Kurt Schmidt · Hammersbach, DE
• Hans U. Suess · Langenselbold, DE
• Holger Glaum · Maintal, DE

Key dates

• Filing date: May 19, 1992
• Grant date: Jul 13, 1993
• Expiry date: May 19, 2012

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D21C9/1042
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A process is disclosed for bleaching wood pulp, cellulose or used paper by treatment the fibre material to be bleached before the bleaching steps with a natural or synthetic zeolite or a layer lattice silicate and an easily decomposable organic complex forming agent, e.g. citric acid.