煤飞灰中铬铁元素的形态分析研究

用连续提取法将煤飞灰中的铬、铁元素依结合态区分为水溶态,交换态,表面氧化物和碳酸结合态,铁锰氧化物结合态,金属有机物和硫化物结合态,磁性四氧化三铁结合态和硅铝酸盐矿物态,用原子吸收法及X-衍射分析进行测定。并对煤飞灰化学形态分布进行了讨论。

Differentiation on Species of Chromium and Iron Elements in Coal Fly Ash

A sequential extraction procedure was developed for fractionation of Cr and Fe in coal fly ash. Seven fractions were separated as soluble (redistilled water), exchangable (1 mol/1 NaAc.HAc,pH=5.0), bound to Fe-Mn oxides (0.04 mol/l NH_2OH.HCl, pH=2.0), bound to organic matter and sulfides (30% H_2O_2-3.2 mol/l NH4 Ac in 25% HAc), bound to iron oxide black (HF-HClO_4) and in primary and secondary minerals (HF-HClO_4). AAS and X-ray diffraction was used for determination. Based on the results obtained from the four samples of coal fly ash, the distribution of speciation of Cr and Fe was discussed.