Electrochemical studies of sulphides,II. Measurement of the galvanic currents in galena and the general mechanism of oxygen reduction and xanthate adsorption on sulphides in relation to flotation

Galvanic currents were measured by short circuiting two half cells; PbS  N₂ (g)  KNO₃ | KNO₃  O₂ (g) or H₂O₂  PbS, and then after adding xanthate to the l.h.s. cell. Such addition of xanthate resulted in a 10 fold (with O₂ in the r.h.s. cell) and 100 fold (with H₂O₂ in r.h.s. cell) increase in the short circuit and steady state currents and also lead to bubble attachment on galena in the l.h.s. cell, in nitrogen atmosphere. The results indicated a heterogeneous, two site electrochemical mechanism for the reduction of oxygen and oxidative adsorption of xanthate on galena.