| 摘要 |
A preparation method of crystallized sugar from an aqueous solution containing one or several sugars, multivalent cations, monovalent metal cations, monovalent anions and multivalent inorganic anions and/or organic acid anions comprising the following steps: (a) replacement of at least a part of the multivalent cations and/or the multivalent inorganic anionsand organic acid anions by monovalent metal cations and/or monovalent anions, respectively, in order to obtain an aqueous solution depleted in multivalent cations and/or multivalent inorganic anions and organic acid anions, and containing the monovalent metal cations and monovalent anions; (b) nanofiltration of the solution resulting from step (a) in order to obtain as a retentate, a sugar aqueous juice enriched in sugars, in multivalent cations and in multivalent inorganic anions and/or in organic acid anions, and as a permeate, an aqueous effluent enriched in monovalent metal cations; and (c) crystallization of least part of the retentate resulting from step (b), in order to obtain crystallized sugar and a mother liquor enriched in monovalent anions and monovalent metal cations. Also described is a use of the above method for the purification of a whey, of a permeate resulting from the ultrafiltration of a whey or a juice of sugar beetroot, sugarcane, chicory or Jerusalem Artichokes. The whey, permeate or juice comprises Ca2+ and Mg2+ ions Cl- anions, Na+ or K+ cations and anions selected mainly in the group consisting of phosphate and sulfate anions, anions from organic acids and their mixtures. |
