FIELD: milk industry. SUBSTANCE: method involves subjecting liquid substance of milk origin to electric deionization in apparatus comprising dilution chamber having layer of ion-exchange resin positioned between cation-permeable and anion-permeable membranes, anion and cation concentration chambers as well as electrodes for creating electric field; directing substrate through layer of ion-exchange resin placed in dilution chamber. Electric field created by electrodes directs cations from dilution chamber through cation-permeable membrane into cation concentration chamber and directs anions from dilution chamber through anion-permeable membrane into anion concentration chamber. Method further involves passing washing solution into and through anion concentration chamber and cation concentration chamber for removal of anions and cations from concentration chambers; collecting treated product from dilution chamber; passing liquid milk substance through layer of resin in dilution chamber containing pellets of high cation-exchange resin; maintaining pH of washing solution at such level that acidity of solution in anion and cation concentration chambers be less than 5. Liquid substance of milk origin is selected from group comprising sore whey, separated milk microfiltration or ultrafiltration permeate, sore whey ultrafiltration permeate and sweet whey microfiltration permeate. Resin layer may comprise pellets of high cation-exchange resin. Washing solution may be passed through concentration chambers free of ion-exchange resin. Resin layers may be selected from group comprising mixed layer and stratified layer. According to other version, method involves passing liquid substance through resin layer in dilution chamber comprising pellets of cation-exchange resin and low anion exchange resin. EFFECT: increased efficiency by intensified demineralization process and improved quality of milk products and derivatives thereof. 30 cl, 1 dwg, 3 tbl, 6 ex
