Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Separation Leaching Behaviors of Cobalt(Co) and Tungsten(W) from Tungsten Carbide Sludge by Sulfuric Acid Solutions

황산용액을 이용한 초경합금 슬러지로부터 코발트 및 텅스텐의 분리 침출 거동

  • Jonggwan Ahn (Dept. of Fire prevention and Safety, Jungwon University) ;
  • Jin-Young Lee (Mineral & Materials Processing Div., Korea Institute of Geoscience and Mineral Resources)
  • 안종관 (중원대학교 소방안전학과) ;
  • 이진영 (한국지질자원연구원 자원활용연구본부)
  • Received : 2023.08.25
  • Accepted : 2023.09.20
  • Published : 2023.10.31
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Abstract

Cemented carbide is an important material in strategic materials, and nd the development of recycling technologies for valuable metals such as cobalt(Co) and tungsten(W) is urgently needed to ensure sufficient domestic raw material supply, supply chain stability, and high-tech industrialization. In this study, an experiment was conducted to leach Co and W from roasted WC-Co cemented carbide sludge by sulfuric-acid leaching. From this experiments, the optimal conditions for Co leaching included a sludge/leachate solid-liquid ratio of 1:20, Co/sulfuric acid molar ratio of 1/5.8, leaching temperature of 80℃, and leaching time of 7 h. Under these conditions, the leaching rate was calculated to be approximately 72.6%. In addition, up to 83% Co can be recovered when two-stage leaching is applied. By contrast, the leaching rate of W was less than 5%. The results of this experiment demonstrate the possibility of separating and recovering Co from W in cemented carbide sludge by sulfuric-acid leaching.

초경 합금은 전략 소재 금속 가공공정에서 중요한 소재이며, 국내의 원료 수급, 공급망 안정 및 첨단 산업화를 위하여 코발트나 텅스텐 등 관련 유가 금속의 재활용 기술개발이 시급한 실정이다. 이에, 본 연구에서는 WC-Co계 초경합금 슬러지와 배소한 각각의 시료를 황산 침출법을 이용하여 코발트(Co) 및 텅스텐(W)을 침출하는 실험을 수행하였다. 실험 결과, Co 침출의 최적 조건은 슬러지와 침출액과의 고액비(Solid-Liquid ratio)의 경우 1:20, Co와 황산의 몰비는 5.8, 침출온도는 80℃, 침출시간은 7시간이며, 이 때 침출율은 약 72.6%로 산출되었다. 추가적으로, 2단 침출을 적용된다면 최대 83%의 Co가 회수될 수 있는 것으로 보인다. 이에 반해 텅스텐의 침출율은 5% 이하였다. 본 실험결과에서 제시된 황산 침출 공정을 통하여 초경합금 슬러지로부터 코발트 및 텅스텐을 분리 회수할 수 있을 것으로 기대된다.

Keywords

Acknowledgement

이 논문은 산업자원통상부 / 한국에너지기술평가원(순환자원 이용 희소금속 회수 공통 활용기술개발사업)의 지원으로 수행되었습니다(과제명: 저품위 공정 폐액으로부터 희소금속 회수 공통 핵심(농축 , 분리회수) 공정 플랫폼 구축 및 소재화 기술 개발, 과제번호: 20217510100020).

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