GB826015A - Method for the manufacture of hydrogen peroxide solutions having a high electrical resistance - Google Patents

Abstract

Hydrogen peroxide solutions having a high electrical resistance are prepared by contacting industrial hydrogen peroxide solutions in a single bed with a mixture of an anion exchanger in hydroxyl form and a cation exchanger in hydrogen form at approximately 0 DEG C., e.g. -4 DEG to 7 DEG C., the quantity of anion exchanger having a breakthrough capacity equal to that equivalent to the quantity of anion impurities in the solution and the cation exchanger having a breakthrough capacity larger, preferably at least 5 times larger, than that equivalent to the cation impurities in the solution. The cation exchanger is water-washed, treated with dilute acid, and water-washed until acid free. The anion exchanger is treated in the same way and is then activated by treatment with alkali, and water - washing. The cation exchanger may be strongly acid resin containing free SO3H groups, and the anion exchanger may be strongly basic resin of the amine or quaternary ammonium types. The exchangers may be treated, after mixing in the column, with dilute hydrogen peroxide, e.g. 0.1-1.5% for 48 hours, and the exchanger mixture is filled with water before use. The solutions may be treated fractionally and the separate fractions collected. The exchanger mixture is regenerated by reverse washing with water, treating with alkali solution to reactivate the anion exchanger and exhaust surplus cation exchanger, reverse water-washing to separate the two resins as two layers, reactivating the cation exchanger with acid, water-washing and mixing the exchangers by air blowing during the the reverse washing. After a number of contacts the capacity of the anion exchanger may be decreased, when it should be subjected to the prolonged treatment with concentrated acid, e.g. 5N acid for 4 hours, before alkali reactivation.