Regeneration of spent hydrofluoric acid esp. pickling acid

摘要

Regeneration of a spent process soln. (I) contg. HF acid and metal fluorides and/or metal oxides comprises: (i) passing (I) into a reactor, where it is subjected to pyrohydrolysis at 200-1000 deg C; (ii) completely recovering the metals as mixed oxide; (iii) removing dust from the reactor waste gas contg. HF and cooling to 60-100 deg C; and (iv) the removing HF by scrubbing with water in an absorber and discharging the resultant recovered HF acid.