METHOD OF PICKLING STEEL Russian patent published in 2002 - IPC

FIELD: pickling steel followed by regeneration of solution. SUBSTANCE: method of pickling stainless steel consists in using pickling solution containing HF and Fe³⁺ as main components; oxidation of Fe²⁺ formed in the course of pickling to Fe³⁺ in order to maintain concentration of Fe³⁺ at preset level is performed electrolytically through oxidation of pickling solution in electrolytic cell provided with diaphragm made from porous material or ion-exchange diaphragm, anode made from graphite or another carbon material and cathode made from iron-containing or carbon materials or from metal; this cell works on voltage of 1 to 8 V and density of anode current of 0.4 to 15 A/sq.dm. Overoxidized solution thus obtained is returned to pickling bath. EFFECT: possibility of performing continuous pickling process. 14 cl, 4 dwg