PULSED METHOD FOR ELECTROCHEMICAL EXTRACTION OF METALS AND THEIR COMPOSITIONS FROM SPENT ELECTROLYTES AND WASTE WATERS Russian patent published in 1995 - IPC

FIELD: metallurgy. SUBSTANCE: pulsed method for electrochemical extraction of metals and their hydroxides with clearing waste water includes operations of electrochemical extraction of metals using electrolysis. The electrolysis is carried out by imposing pulses of the same polarity on the constant component. Pulse amplitude is higher than d.c. magnitude, with potential of the constant component being within standard electrode potentials of any metal to be recovered at 0.5 - 2.5 Hz pulse-recurrence frequency. The process is carried out by successive extraction of all the metals in two stages for each metal. The first stage electrolysis is carried out by imposition of spike pulses described by l^KRt law. Electric treatment is carried out at the second stage at total quantity of electricity equal to total quantity of electricity in spike pulses with constant relations between their amplitudes. The first stage electrolysis is carried out using iridium as an anode, and titanium as a cathode. EFFECT: electrochemical precipitation of metals from aqueous solutions of metal salts, basically metal extraction and their compositions in the process of clearing up waste waters of galvanization and etching processes, mine waters, containing ions of nonferrous and heavy metals in small concentrations. 3 cl, 5 dwg, 3 tbl