Method for preparing polymeric ferric aluminum by utilizing metal chlorohydric acid pickling waste liquor

The invention discloses a method for preparing polymeric ferric aluminum by utilizing metal chlorohydric acid picking waste liquor. At present, the commonly used method for treating acid pickling waste liquor easily causes secondary pollution and has higher requirement on treatment equipment and is higher in treatment cost. The method comprises the following steps: firstly adding H2O2 into chlorohydric acid pickling waste liquor, oxidizing ferrous ions into ferric ions; adding calcium aluminate powder into the chlorohydric acid pickling waste liquor subjected to H2O2 treatment under the stirring condition, and carrying out acid soluble and polymerization reaction; filtering the obtain liquor with qualitative filter paper, collecting filtrate, standing and curing for 24h, thereby obtaining liquid-state polymeric aluminum-ferric chloride products. The method has the advantages of being simple in production technique, less in investment and fast in effect, solves the pollution problem of metal acid pickling waste liquor, polymeric aluminum-ferric chloride flocculating agent can be widely used industrially, the purposes of using waste to treat waste, being energy-saving and emission-reduction can be achieved, and the environment values and the economic values can be achieved.