Process for the isolation of high-purity tri-calcium citrate from aqueous solutions containing citric acid

摘要

1. Method of isolating highly pure crystalline tricalciumcitrate-tetrahydrate by addition of a calcium-containing precipitant to citric-acid-containing aqueous solutions at elevated temperature, which method is characterised in that, after addition of about 25 to 30% of the stoichiometrically calculated amount of calcium-containing precipitant, to the aqueous solution, required for the formation of tricalcium-citrate, the further addition is continued at a reduced rate until the first appearance of cloudiness due to tricalcium-citrate-tetrahydrate precipitating by crystallisation, then is interrupted as long as crystallisation is substantially completed and the remaining portion of the calcium-containing precipitant is added upon expiration of that period of time.