RARE EARTH ELEMENTS IN BROWN COALS FROM THE AZEYSK DEPOSIT OF THE IRKUTSK COAL BASIN

An efficient procedure for sample preparation and determination of rare earth elements (REE) in the brown coals of the Azeysk by a highly sensitive method, mass spectrometry with inductively coupled argon plasma, has been developed. The relative standard deviations in REE determination by the semi-quantitative and quantitative methods do not exceed 15 and 8 wt%, respectively. The total content of rare earth elements is 0.92±0.07 kg/t of coal, which was verified by an independent spectrophotometric method with аrsenazo III.