METHOD OF TREATMENT OF MOTHER LIQUID OBTAINED AT THE ISOLATION OF MEDICINAL ASCORBIC ACID Russian patent published in 1996 - IPC

FIELD: chemical technology. SUBSTANCE: method involves the treatment of ascorbic acid mother liquids with equimolar quantity of NaHCO₃ or Na₂CO₃, concentration of obtained sodium ascorbate solution up to 68-70 wt.-% by the following treatment at 66-72 C: firstly, with Trilon B (0.2-0.4 wt.-%), then with activated carbon (3-4 wt.-%) followed by isolation of sodium ascorbate from a mixture H₂O:C₂H₅OH, addition of C₂H₅OH heated up to 38 C (not below) to an aqueous solution by two steps: at the first step - 1/3 of total required alcohol quantity measured by the formula V = where V - alcohol volume, l; G - parental ascorbic acid quantity, kg; C - concentration of evaporated aqueous solution, wt.-%, followed by seeding addition as an ascorbic acid powder at the reaction mass temperature 38-45 C; at the second step the remained alcohol quantity is added at the rate ≅ 0.02 l/min per 1 kg parental ascorbic acid, temperature of reaction mass is maintained at 30 C (not below) followed by cooling to 0-10 C, separation of sodium ascorbate crystals, washing with ethanol and drying. EFFECT: improved method of treatment. 1 tbl