Granular sodium carbonate obtained by fluid-bed spray granulation and a process for its production

US7041267B2 · kind B2 · utility

Assignee

• Degussa AG · DE

Inventors

• Harald Jakob · Hasselroth, DE
• Birgit Bertsch-Frank · Rheinfelden (Baden), DE

Key dates

• Filing date: Sep 25, 2001
• Grant date: May 9, 2006
• Expiry date: Jan 12, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B15/106
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the production, by fluid-bed spray granulation, of granular sodium percarbonate having a low TAM value. According to the invention, in the fluid-bed spray granulation, an Mg compound in a quantity of 50 to 2,000 ppm, in particular 100 to 1,000 ppm, or/and a complexing agent from among the hydroxycarboxylic acids, aminocarboxylic acids, aminophosphonic acids and phosphonocarboxylic acids, hydroxyphosphonic acids and their alkali metal salts, ammonium salts or Mg salts, in a quantity of 50 to 2,000 ppm, in particular 200 to 1,000 ppm, are added as stabilisers to the soda solution and/or H2O2 solution. Preferably a combination of an Mg compound in a quantity of 100 to 1,000 ppm Mg2+ and waterglass in a quantity of 0.1 to 1 wt. %, in particular 0.1 to 0.5 wt. %, is used, and in this case granules having a TAM value of about or below 6 μW/g and simultaneously a short dissolving time, are obtainable.