Pickling wastewater is wastewater produced when acid washes such as sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, and phosphoric acid are used to remove metal surface oxides. Most of the wastewater comes from iron and steel plants or electroplating plants. The pH value is generally below 1.5 (free acid 0.5-2%). Magnesium oxide and so on.
In general, the thin plate and rolling process of steel mills use the sulfuric acid flow method to clean the surface just now. Medium-sized enterprises produce 1000-1500 tons of waste water washing liquid each year, among which the main components of the waste acid discharged from the steel rolling process are: FeSO4-100g/L, free acid -20%. Any treatment of this kind of pickling liquid is directly discharged into the river, causing river water pollution and ecological damage, so it is imperative to treat it.
Pickling waste liquid is a kind of usable resource, and comprehensive treatment of it, turning harm into profit, and turning waste into treasure is a powerful measure to benefit the factory and society. According to the actual situation of general steel mills, it is appropriate to eliminate environmental pollution, resources can be reused, no secondary pollution occurs, one-time investment is small, the process is simple, and management is convenient.