The invention belongs to the field of stainless steel
processing waste treatment, and relates to a stainless steel cold rolling waste acid purification
system. According to the present invention, in stainless steel cold rolling annealing
acid washing units,
strip steel is required to be subjected to an
acid washing treatment to remove
oxide scale on the surface of the
strip steel; resin adsorption is performed on waste acid generated from
acid washing to remove soluble
metal ions, wherein the acid washing adopts a mixing acid; the
free acid is recycled so as to reduce waste acid emission, reduce production cost, and improve quality of the acid washing product. The acid purification
system is an
ion exchange
system, wherein
filtration and resin adsorption are performed on the waste acid liquid to separate iron,
nickel and
chromium metal salts accumulated in the acid liquid from the acid washing liquid, such that the acid liquid can be reused for stainless steel acid washing. The process principle is the following acid purification system process: carrying out acid washing on the waste acid, adopting a circulation tank, adopting a swirling separator, adopting a
filtration unit, adopting a purification system (SAR), and purifying the acid. The waste acid from the acid washing line is filtered through the
filtration unit, and then directly enters the acid purification unit (SAR). The
free acid water absorbed by the resin
bed is substituted by water, and then returns to the acid washing line, and the waste acid enters a
wastewater treatment system.