FIELD: mining industry. SUBSTANCE: invention relates to isolation of rare-earth elements from naturally occurring phosphorus-containing concentrates. Monazite concentrate is treated on heating with sulfuric acid in amounts 110-150% of its stoichiometrically required amount. Resultant cake is treated with water in presence of oxalic acid at 60-80 C, acidity 1-2 N, and solids-to- liquid ratio 1:(4-5). Rare-earth element oxalate precipitate is separated and treated with alkali to convert oxalates into hydroxides. Yield of the reaches 90%. EFFECT: increased degree of rare-earth elements' recovery, simplified process, and reduced amount of reagents and effluent volume. 2 cl, 3 ex
