ICP-AES Determination of 6 Rare Earth Elements in Red Mud

0.25 g of red mud sample was melted with 3 g of NaOH for 20 min and then was extracted with hot water and 20 mL of HCl (1+1) solution. Finally the solution was diluted to 250 mL with water. The 6 rare earth elements, i.e. La, Ce, Pr, Nd, Sc and Y in the solution were determined by ICP-AES. Linear relationships between values of emission intensity and mass concentration of the 6 rare earth elements were kept in the same range within 2.00 mg·L^-1, with detection limits of the method (3s) in the range of 0.001 8-0.042 mg·L^-1. The proposed method was applied to the analysis of red mud sample, giving values of recovery and RSD's (n=6) in the ranges of 85.0%-105% and 0.24%-0.70% respectively.