Title: Process for production or recovery of acids from metalliferous solutims of such acid
Application Number: 88103731 Application Date: 1988.06.16
Publication Number: 1023184 Publication Date: 1988.12.28
Approval Pub. Date: 1993.03.31 Granted Pub. Date: 1993.03.31
International Classifi-cation: C23F1/36
Applicant(s) Name: Maschinenfabrik Andritz Actiengesellschaft Address:
Inventor(s) Name: Heinz Krivanec;Wilheim Karner
Attorney & Agent: YU YANSHENG
Abstract:
    In the pickling, etching, chemical milling etc. of steels, stainless steels, special alloys and special metals and also when dissolving these metals, metalliferous solutions of the acids used arise in the course of these processes, and these must either be disposed of by neutralisation or used in expensive processes in order to recover the acids and metals. Nitric acid or a nitric acid/hydrofluoric acid mixture are obtained or recovered according to the invention by spray-roasting the solutions at temperatures from 200 to 500 DEG C in a reactor (1) followed by absorption and condensation of the resulting gases in columns (7, 8) at temperatures from 0 to 70 DEG C.
Time: 7