| 摘要 |
Process for the preparation of calcium ascorbate and in particular a process for the aqueous reaction of calcium carbonate with ascorbic acid and the preparation of crystalline calcium ascorbate. Depending on solvent extraction, crystal seed technique or combinations of these processes, previously known processes yield crystalline calcium ascorbate dihydrate in essentially pure form by use of an excess of ascorbic acid in the seed material; they are slow and complicated. The invention works with excess calcium carbonate which is added during the entire reaction, and at elevated temperature which is kept so low that the product does not decompose. The process of the invention is simpler than the known processes, calcium ascorbate oxidate having advantageous properties being formed as a by-product. The oxidate yield is controlled via the addition of calcium carbonate, a carbon dioxide saturation of the reaction participants being maintained and the reaction zone being protected with foam.
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