FIELD: production or regeneration of acids; hydrofluoric acid, hydrochloric acid and nitric acid in particular from metal-containing solutions of these acids. SUBSTANCE: metal-containing solution are evaporated through heat exchange with medium of at least one absorption column or condensation column, after which this medium is returned to column. After evaporation, solution is subjected to pyrohydrolysis. Gases formed during pyrohydrolysis are subjected to absorption in aqueous absorption solution and condensation in columns. Device used for realization of this method includes solution supply pipe line, reactor for purohydrolysis and at least one absorption and condensation column which is connected with waste gas discharge pipe line; device is also provided with alkali scrubber, plant for catalytic reduction of NOx, condenser and unit for preliminary evaporation and increase of concentration of solution which includes heat exchanger connected with loop of at least one absorption or condensation column or with loop of condenser. EFFECT: reduced power requirements. 8 cl, 2 dwg
