Elecrokinetic separation of sulphate and lead from sludge of spent lead acid battery.

A novel electrokinetic (EK) technique is applied to separate lead and sulphate from the sludge of used/spent lead acid battery. XRD reveals that the sludge is a mixture of (PbO)(4) [Pb(SO(4))], Pb(2)O(3), PbSO(4), Pb(S(2)O(3)) and Pb(2)(SO(4)) which upon DC voltage application in a EK cell employing either titanium electrodes or titanium substrate insoluble anode as electrodes caused migration of sulphates and lead ions respectively into anode and cathode compartments, and accumulation of insoluble lead oxides at the central compartment. The insoluble lead oxides accumulated at the central compartment in the ratio 1:3, respectively for the high oxygen over-voltage Ti-anode (Ti-EK cell) and low oxygen over-voltage TSIA-anode (TSIA-EK cell) shows the superiority of Ti anode over TSIA anode. Also thermal investigation reveals Pb deposited at Ti-cathode is superior to that from TSIA cathode. This process does not release air/soil pollutants which are usually associated with high temperature pyrotechnic process.