오종기 김성규 이화영 2024-01-21T19:39:36Z 2024-01-21T19:39:36Z 2022-01-10 1996-03 https://pubs.kist.re.kr/handle/201004/144511 Technology for removal of iron impurities from clay resources 점토광물의 탈철기술 Article 3 광업진흥, v.60, pp.118 - 127 광업진흥 60 118 127 clay mineral