Abstract
In this study, scarp of PCB containing copper and precious metals was manufactured as an anode, and electrorefining experiments were conducted on change of $H_2SO_4$ concentration and current density. Through electrolytic refining experiments, the concentration of Cu and slime recovered from each electrode was analyzed, element behavior was confirmed, and current efficiency was also calculated. As the $H_2SO_4$ concentration was increased, the current efficiency and the purity of Cu decreased, but the precious metals in the anode slime were maximally concentrated with 2.0 M $H_2SO_4$. In addition, as the current density was increased, the current efficiency decreased and the purity of Cu showed a tendency to increase, and the precious metals in the anode slime were maximally concentrated with $300A/m^2$. As a result of the pilot scale experiments, the Au content was 8,705 mg/kg, the Ag content was 35,092 mg/kg in the anode slime. As compared with the initial content, Au was concentrated 16 times and Ag concentrated 14 times.
본 연구에서는 구리와 귀금속이 함유된 PCB 스크랩을 양극동으로 사용하여 $H_2SO_4$농도, 전류밀도 변화에 대하여 전해정련 실험을 수행하였다. 전해정련 실험을 통해 각 전극에서 회수된 Cu와 slime에 대하여 농도 분석을 하고 원소들의 거동을 확인하였으며, 전류효율도 계산하였다. $H_2SO_4$ 농도가 증가할수록 전류효율과 Cu의 순도는 감소하였지만 양극 슬라임 내에 귀금속은 2.0 M $H_2SO_4$ 조건에서 최대로 농축되었다. 또한 전류밀도가 증가할수록 전류효율은 감소하였고 Cu의 순도는 증가하는 경향을 나타내었으며 양극 슬라임 내에 귀금속은 $300A/m^2$ 조건에서 최대로 농축되었다. Pilot scale 실험 결과, 양극 슬라임에 Au 함량은 8,705 mg/kg, Ag 함량은 35,092 mg/kg으로 나타났고, 초기의 함량과 비교했을 때 Au는 약 16배, Ag는 약 14배 농축이 가능하였다.
