METHOD OF WATER PURIFICATION FROM METAL OXIDES OR SUSPENDED IMPURITIES Russian patent published in 1995 - IPC

FIELD: water purification. SUBSTANCE: recovery of ion-exchange resins by backwashing is accomplished at an increase of differential water pressure due to entrainment of suspended impurities in the mix within 0.2 to 0.8 kg/sq.cm, or at a content of iron oxide, trapped by the mix, exceeding 1 g/l of resin in terms of the amount of surface-precipitated iron, or at a concentration of suspended impurities at the outlet from the demineralized exceeding 1.5 particles per billion; and recovery of resins by passing of a chemical agent through the demineralizer is accomplished at a concentration of suspended impurities at the outlet from the demineralizer exceeding 1.5 particles per billion, or at a content of iron oxide sorbed on resins exceeding 9 g/l of resin in terms of the amount of matrix-diffuse iron. EFFECT: safe and economic water purification due to definite conditions of the process and, in particular, recovery of demineralizer by backwashing and passing of chemical compounds through it, and replacement of demineralizer. 4 cl, 6 dwg