Sterilising fresh or spent pickling brines - with iodine complex-bonded polyvinyl pyrrolidone or non-ionogenic surfactants

摘要

fresh but esp. spent pickling brines are sterilised and regenerated by mixing with 0.01-0.02% complex-bonded I2, precipitating insol. material, after some treatment-time, by reducing pH to about 4.2, filtering and raising pH, e.g. to 5-5.5. Iodophoric materials are pref. (A) polyvinyl pyrrolidone complex-bonded with I2 and contg. 1.6% active I2 and 2.1-2.2% total I2, combined with KI or HI, or (B) I2 bonded to non-ionogenic surfactants consisting of condensation prods. of C2H4O with C3H6O or alkyl phenols in various ratios, and contg. 1.7% free active I2.