Abstract： The red mud sample was melted with potassium hydroxide and then dissolved with HCl (1+1). The content of sodium in the red mud derived from aluminum oxide production by Bayer process was determined by flame atomic absorption spectrometry using Na 588.99 nm as analytical line and potassium chloride as ionization inhibitor. The interference of coexisting ions was eliminated by standard addition method. The optimal experiment conditions were obtained by optimizing the parameters such as the ratio of acetylene and air , the spectral band width and the addition amount of inhibitor. The mass concentration of sodium in the range of 0.012.0 mg/L showed good linear relationship with absorbance. The detection limit of method was 0.005 1 μg/mL. The proposed method was applied to the determination of sodium in red mud samples. The relative standard deviation (RSD) was smaller than 2.3 %, and the recovery was 97 %103 %.
