Poster (EARTH)

[PE1-030] Separation of electric and electronic components from wasted printed circuit boards by HCl leaching with Sn⁴⁺

○MOONCHUL JUNG¹, Kyoungkeun YOO¹ (1. Korea Maritime and Ocean University)

Keywords:printed circuit boards, electric and electronic components, dismantling, stannic chloride, hydrochloric acid leaching

In this paper, a study for PCB dismantling was conducted using hydrochloric acid with stannic chloride under the following conditions; HCl concentration of 1 M, agitation speed of 100-300 rpm, temperature of 30-90 °C, and concentration of Sn⁴⁺ of 7,000-13,000 mg/L. The use of HCl solution with Sn⁴⁺ ions dissolves tin (Sn)-alloy solder that holds EECs on bare board, which allows the EECs to be detached from PCB. Sample was retrieved from the leaching solution at a desired time interval and quantitative analysis was performed to calculate the dismantling ratio using the number of EECs detached from the PCB. Lastly, metallic contents on each dismantled component were investigated to figure out the feasibility of enriching valuable metals into the separated components. The result of the experiments shows that dismantling ratio increased to 100 % within 8 hours under the all experiment conditions. Increasing temperature and concentration of Sn⁴⁺ had a significant effect to decrease the dismantling time whereas the effect of agitation speed was negligible. The dismantling of PCB was completed within 30 min under the following leaching condition: HCl concentration, 1 M; agitation speed; 300 rpm, temperature; 90 °C, Sn⁴⁺ concentration; 13,000 mg/L. Each metal was enriched after dismantling process; e.g. the content of Ag increased from 0.016 % in PCB to 3.118 % in registor. It was expected that efficient PCB recycling process could be designed to recover metals from EECs with higher concentrated metals.