Critical metal recovering method from waste/discarded printed circuit boards

• Main Authors: KIM HYUN JUNG, SRIVASTAVA RAJIV RANJAN, ILYAS SADIA
• Format: Patent
• Language: English; Korean
• Published: 22.04.2021
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTIONOF COMPOUNDS OR NON-METALS; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention relates to a critical metal recovery method from waste printed circuit boards. More specifically, the present invention relates to a critical metal recovery method from waste printed circuit boards, which comprises: a step (S1) of pre-processing pieces of waste printed circuit boards, and separating deposits including tin and lead; a step (S2) of grinding the pieces of the printed circuit boards pre-processed by the step (S1), and acquiring metal fractions by using a difference in the density; a step (S3) of processing microorganisms on the metal fractions, and separating liquid including copper, nickel, and zinc by the bioleaching; a step (S4) of acquiring a leaching solution including gold by electro-chlorinating solid residues, which remains after the liquid is separated by the step (S3), in an electrolytic bath; and a step (S5) of processing an organic solvent on the leaching solution of the step (S4) and recovering gold. Accordingly, the present invention is able to recover various types of metal from the waste printed circuit boards, and to specifically recover gold which is a precious metal. 본 발명은 폐인쇄회로기판의 중요 금속을 회수하는 방법에 관한 것으로, 보다 상세하게는 폐인쇄회로기판 조각을 전처리하여 주석 및 납을 포함하는 침전을 분리하는 단계(S1); 상기 S1 단계에서 전처리된 폐인쇄회로기판 조각을 분쇄하고, 밀도 차를 이용하여 금속 분획을 수득하는 단계(S2); 상기 금속 분획에 미생물을 처리하여, 바이오 침출에 의해 구리, 니켈, 및 아연을 포함하는 액체를 분리하는 단계(S3); 상기 S3 단계에서 액체가 분리되고 남은 고체 잔류물을 전해조에서 전기-염소화하여 금을 포함하는 침출액을 수득하는 단계(S4); 및 상기 S4 단계의 침출액에 유기용매를 처리하여 금을 회수하는 단계(S5)를 통해, 폐인쇄회로기판부터 여러 금속을 회수할 수 있고, 특히 귀금속인 금을 회수할 수 있다.