Extraction and refining of the rarer metals : a Symposium on Extraction Metallurgy of Some of the Less Common Metals / arranged by the Institution of Mining and Metallurgy, held on 22nd and 23rd March, 1956, at the Royal Society of Arts, John Adam Street, London. Institution of Mining and Metallurgy (Great Britain) Symposium on Extraction Metallurgy of Some of the Less Common Metals (1956 : London) Ore-dressing Societies, etc. Rare earth metals Metallurgy Congresses. TN500 .I44 1956 669.29 INF Includes bibliographies. London : Institution of Mining and Metallurgy, 1957. 1957. 1957 Text xiii, 444 p. : eng