Process for the preparation of coarse-particle dicalcium phosphate dihydrate

US4755367A · kind A · utility

Assignee

• Benckiser-Knapsack GmbH · DE

Inventors

• Gerold Brachtel · Mannheim, DE
• Guenter Raab · Hemsbach, DE
• Detlev Schober · Bischofswerda, DE

Key dates

• Filing date: Apr 21, 1986
• Grant date: Jul 5, 1988
• Expiry date: Apr 21, 2006

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B25/322
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for the preparation of coarse-particle dicalcium phosphate dihydrate having a virtually spherical crystal shape and a particle size range between about 63 and 450 .mu.m, preferably between about 90 and 300 .mu.m, by reacting pure aqueous phosphoric acid with aqueous suspensions of precipitated chalks, wherein an amount of suspension corresponding to the reaction product formed is removed continuously or semicontinuously and the dicalcium phosphate dihydrate is separated off, washed and dried. Also disclosed is coarse-particle dicalcium phosphate dihydrate produced by the above process.