Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Current Research Trends for Recovery of Rare Earth Elements Contained in Coal Ash

석탄재에 포함된 희토류 회수 연구동향

  • Kim, Young-Jin (Department of Research and Development, Korea Institute of Limestone and Advanced Materials) ;
  • Choi, Moon-Kwan (Department of Research and Development, Korea Institute of Limestone and Advanced Materials) ;
  • Seo, Jun-Hyung (Department of Research and Development, Korea Institute of Limestone and Advanced Materials) ;
  • Kim, Byung-Ryeol (Department of Research and Development, Korea Institute of Limestone and Advanced Materials) ;
  • Cho, Kye-Hong (Department of Research and Development, Korea Institute of Limestone and Advanced Materials)
  • 김영진 (한국석회석신소재연구소 연구개발부) ;
  • 최문관 (한국석회석신소재연구소 연구개발부) ;
  • 서준형 (한국석회석신소재연구소 연구개발부) ;
  • 김병렬 (한국석회석신소재연구소 연구개발부) ;
  • 조계홍 (한국석회석신소재연구소 연구개발부)
  • Received : 2020.11.18
  • Accepted : 2020.12.09
  • Published : 2020.12.30
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Abstract

This study aims to introduce and review on the recovery technologies of rare earth elements(REEs) from coal ash. Many researchers have been carried out by various beneficiation processes, such as particle size separation, magnetic separation, specific gravity, and flotation to recover rare earth elements from coal ash generated from Pulverized Coal(PC) boiler. Through the beneficiation process, it was confirmed that concentration of rare earth elements was much lower than the 4,700 ppm, and that additional enrichment treatment through wet process was needed for the products recovered after the beneficiation process. It was confirmed that the rare earth elements contained in coal ash were applied to the leaching process after pretreatment such as alkali-fusion to improve leaching efficiency. Although beneficiation and leaching methods have been studied, its optimum recovery technologies for rare earth elements not been confirmed up to now, research on the recovery of rare earth contained in coal ash is reported to continue. In case of Korea, the technology for the recovery of rare earth elements from coal ash and coal by-product could not been confirmed up to present. In these reasons, it is urgent to develop technologies such as beneficiation and leaching process continuously.

석탄재로부터 희토류 회수에 관한 연구 자료를 분석 및 검토하였다. 석탄재로부터 희토류 회수를 위해 적용된 선별 실험은 주로 PC 보일러로부터 발생된 석탄재를 대상으로 입도분리, 자력, 비중 및 부유선별법 등을 이용해 연구하였다. 선별 공정을 통해 희토류 성분의 농축 가능한 수준은 수 천 ppm 정도로 낮게 확인되었고, 선별 공정 이후 회수된 산물을 대상으로 습식 제련 공정을 통한 추가 농축 처리가 필요한 것으로 확인되었다. 침출 공정에서는 석탄재의 희토류 성분을 침출 향상을 위해 알칼리 용융과 같은 전처리 후, 침출공정에 적용하는 것이 효율적인 공정으로 확인되었다. 세계적 희토류 회수 시스템의 개발이 아직은 미흡한 것으로 확인되었으나, 석탄재에 포함된 희토류 회수 연구는 계속 진행될 것으로 보고되었다. 국내에서는 석탄재 중 희토류 회수를 위한 회수 기술이 매우 부족한 상황으로 선별, 침출 등의 기술 개발이 시급한 실정이다.

Keywords

Acknowledgement

본 연구는 2019년도 정부(과학기술정보통신부, 환경부, 산업통상자원부)의 재원으로 한국연구재단-탄소자원화 국가전략프로젝트사업의 지원을 받아 수행함(NRF-2019M3D8A2113444).

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