火焰原子吸收光谱法测定拜耳法生产氧化铝赤泥中钠

Flame atomic absorption spectrometric determination of sodium in red mud derived from aluminum oxide production by Bayer process

用氢氧化钾熔融赤泥样品后再用HCl(1+1)溶解,选择Na 588.99nm谱线作为分析线,以氯化钾为电离抑制剂,火焰原子吸收光谱法测定拜尔法赤泥中钠含量。实验采用标准加入法消除共存离子的干扰,通过优化火焰原子吸收光谱的燃助比、光谱通带宽度和抑制剂加入量等参数,确定了最佳实验条件。钠的质量浓度在0.01～2.0mg/L范围内与吸光度呈良好线性关系,方法检出限为0.005 1μg/mL。对赤泥样品中钠进行测定,相对标准偏差(RSD)小于2.3%,回收率在97%～103%范围内。

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 0.01-2.0 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 %.