*2.3. Electrochemical Process Description*

The installation used for lead electroextraction consisted of a storage tank of the processed solution, connected in series with a divided electrochemical reactor (ER), operated in galvanostatic mode. Recirculation of the solution between the storage tank and ER was performed with a peristaltic pump. The cathode was made of stainless-steel plates and the anode was made of graphite. Two Ag/AgCl/KClsat reference electrodes were used to measure the cathodic and anodic potentials. All tests were performed at 22 ◦C for two hours using a 150 mL of electrolyte containing 9.25 g/L Pb2+, 3.91 g/L Mg(CH3COO)2 and 7.24 g/L Ca(CH3COO)2 which correspond to the final composition of the leaching solution. The experiments were performed at different flow rates (15, 30 and 45 mL/min) and current densities (4, 8 and 12 mA/cm2). Experiments also involved the use of a computer-controlled DC power supply, and LabVIEW software for process control and data acquisition. The obtained Pb deposit was dissolved in concentrated HNO3 to determine the amount and purity of lead deposited. The concentration of lead in the solutions at the end of the experiment was determined using an atomic absorption spectrophotometer.
