Brief description of the treatment of water coming from the rinsing of the metal pieces having undergone a decapage by means of a strong acid (reference tied)

摘要

1. Treatment process for water that has been used for rinsing ferrous metal parts which have undergone pickling with strong acid, comprising the following stages : a) the said rinsing water is put in contact with a cationic resin ; b) the charged resin is eluted with a minimum 4N solution of the strong acid used for pickling ; characterised by the fact that the said concentrated acid, used in stage (b) is a used pickling solution and contains 40 to 150 grams of iron per litre, the ratio between the metallic ion concentration and the strong acid concentration, expressed in gram-equivalents, being one-third at the most.