COPPER ELECTROWINNING USING A SPOUTED-BED ELECTROCHEMICAL REACTOR

摘要

In this work, copper electrowinning using a three-dimensional spouted-bed electrode (SBE) was studied in order to investigate the effects of current density (i), concentration of supporting electrolyte (Cs), pH, electrolyte temperature, and bed thickness on the process current efficiency (EC), energy consumption (CE) and space-time yield (Y). The results indicated that the SBE may be successfully used for the electrowinning of copper when the copper ion concentration is high and the pH is between 1 and 2. In this case, 100% CE, 2.7 kWh kg-1 EC and 118 kg L-1 h-1 Y can be achieved. It was verified that an increase in the electrolyte temperature caused a decrease in the electrodeposition rate (from 3.97 g L-1h-1 to 1.17 g L-1 h-1), indicating that, despite the solution conductivity enhancement, temperature promoted the increase in the anodic dissolution kinetics. The results also showed that EC depends on the applied current density, whereby greater EC values can be obtained using high current densities. Finally, the copper particles were analyzed by scanning electron microscopy and it was confirmed that a smooth, uniform and compact electrodeposit can be obtained without using any chemical additives.