Toward sustainable electroplating of decorative silver for SMEs in Indonesia

Abstract

Decorative silver electroplating has been a long time conducted by small and medium enterprises (SMEs) in Indonesia. Environmental pollution associated with the electroplating SMEs activities has created serious problems. For example SMEs of silver electroplating has contaminated groundwater which is no longer fit for domestic consumption due to its high level of cyanide contamination. Inefficient process and the use of high concentration of cyanide based electrolyte have been claimed to be the root cause. Therefore, the process of decorative silver electrodeposition in SMEs would be improved by developing an electrolyte with low cyanide concentration, determining onset potential and current densities, and modifying the process and the electrochemical cell so that the process would be more efficient and sustainable. A new electrolyte composed of AgNO3 and KCN with a ratio of 5:39 were chosen for the experimentation. For this electrolyte, silver would possibly be electrodeposited at potentials ranging from -2.2 V to -2.8 V. Corresponding current densities for silver electrodeposition would be between -2 and 7 mA/cm2. To improve the process, a new design of electrochemical reactor has been developed which ensure improvement of the observed electrochemical parameters i.e. the uniform current density distribution, the larger area of anode, and the stability of electrodes distance and position.