METHOD OF RECOVERY OF THE SPENT SOLUTIONS OF THE HYDROCHLORIC ACID Russian patent published in 2007 - IPC C23G1/36 

FIELD: chemical industry; metallurgy industry; other industries; methods of recovery of the spent solutions of the hydrochloric acid.

SUBSTANCE: the invention is pertaining to the methods of recovery of the spent solutions of the hydrochloric acid from the spent pickling solutions (SPS) containing the non-used hydrochloric acid and the salts of iron and may be used in the galvanic productions, in the metallurgy and other industries. The method includes the azeotropic distillation, before which they admix the distillation residue gained at the distillation of the flashed waters with the spent hydrochloric acid. The vapors liberated during the azeotropic distillation of the mixture are used for preheating up of the spent hydrochloric acid. The produced condensate is corrected according to the contents of the acid and is sent back into the process bosh. The part of the residue of the process of the azeotropic distillation is directed into the tank supplied with the refrigerator. For withdrawal of the chlorides of iron and other metals which have transferred into the hydrochloric acid at the pickling by chilling of the solution and the crystallization of the part of the dissolved salts of iron. The vapors gained at the flashing waters distillation are used for heating, and the produced condensate also is sent back into the production cycle for realization of the flashing operations. The technical result of the invention consists in creation of the closed cycles for the technological solutions - for the hydrochloric acid and for the flashing waters.

EFFECT: the invention ensures creation of the closed cycles for the technological solutions - for the hydrochloric acid and for the flashing waters.

1 ex, 1 dwg