(1) 110Kg vitamin C, 8.8Kg anhydrous calcium chloride, 110Kg deionized water were added into 500L reactor with the temperature at -10, stirred for 2 hours, and then added 30% aqueous sodium hydroxide solution dropwise, adjusted the PH as 5, and then 110Kg sodium trimetaphosphate was added, kept the temperature at 25, and reacted for 2 hours, and the obtained reactant was calcium vitamin C ester;< /p>
(2) add calcium vitamin C ester into 500L drum washer with water, and then adjust the PH with sulfuric acid to 1.5, the obtained reactant is vitamin C phosphate;
(3) the vitamin C phosphate through the rolled-type nano-filtration membrane filter for nanofiltration membrane filtration, the temperature of the rolled-type nano-filtration membrane filter inlet is 120 , rolled-type nano-filtration membrane filter exit temperature is 30C; the nanofiltration membrane has nanoscale pore size, the molecular weight cutoff of the nanofiltration membrane is 500, and the coil type nanofiltration membrane filter has a high removal rate of inorganic salts, and the removal rate is 90%;
(4) the filtrate obtained by filtration in step (3) was added to a 500L reactor, and eluted by weakly alkaline anion-exchange resin with 0.05M hydrochloric acid and 0.5M hydrochloric acid in turn, and the elution portion was collected. The eluted portion was adjusted to pH 7 with magnesium oxide under constant stirring, and the obtained reactant was magnesium vitamin C phosphate;
(5) the magnesium vitamin C phosphate was filtered through activated charcoal filter to remove the precipitation, and the filtrate was concentrated at 30 under reduced pressure to one-fifth of the original volume, and ethanol with a volume of three times the volume of concentrated filtrate and content of 95% was added, and then it was dried by spray dryer, and the drying temperature was 140 , and the drying time was 30 . 140 , drying time of 30min, that is, the white vitamin C magnesium phosphate 79.85KG, vitamin C magnesium phosphate content of 97.75%.
