RUTHENIUM CONCENTRATION METHOD Russian patent published in 2004 - IPC

FIELD: inorganic compounds technology. SUBSTANCE: invention relates to liquid extraction-mediated isolation of ruthenium from solution and, more particularly, consists in that ruthenium is extracted from nitrite anion-containing solution with phosphoric acid tributyl ester. After extraction, organic phase is washed with sodium nitrite solution having 250 g/l salt content and reextracted with sodium hydroxide solution having 10-100 g/l alkali content. As nitrite anion-containing solution, mother liquor remaining after precipitation rhodiumand/or iridium-ammonium hexanitrite. Purity of ruthenium product is at least 95%, 99% of which is recovered being concentrated by a factor of 18-20. EFFECT: increased purity and degree of recovery of desired product. 2 cl, 2 tbl