| 摘要 |
A method for pickling products in a metal alloy containing iron, and products in titanium and alloys thereof, in the absence of nitric acid as an oxidizing agent, and for the recovery of the exhausted solutions, characterized in that the recovery of the exhausted solutions deriving from pickling comprises the following steps: sending of the pickling solution, both as catholyte and as anolyte, in an electro-chemical cell optionally of the membrane type to separate the Fe2+ (or Ti2+) ions to be disposed of, from the Fe3+ (or of the Ti3+ and Ti4+) ions to be recovered, obtained by reduction at the cathode of the Fe3+ ions which are in the catholyte to Fe2+ (or of the Ti3+ and Ti4+ ions to Ti2+) and of oxidation at the anode Fe2+ (or Ti2+) ions which are in the anolyte to Fe3+ (to Ti3+ and Ti4+); treating the catholytic solution coming out of the cell and enriched in Fe2+ (or Ti2+) ions as to allow the separation in two phases, a first phase containing the metal canions Fe2+, Cr3+, Ni2+ (or Ti2+) to be disposed of and a second liquid phase deprived of said metal cations to be sent in the pickling bath; and sending the anolytic solution, coming out of the cell and enriched in Fe3+ ions (or Ti3+ or Ti4+), in the pickling bath. It is also the object of the present invention an apparatus thereof. |
