熔融制样-X射线荧光光谱法测定除尘灰中10种组分

由于除尘灰组分复杂,逐一分析难度较大,因此,采用熔融制样-X射线荧光光谱法(XRF)测定除尘灰中多种组分。实验采用在950℃除C,选择质量比为2∶1的Li₂B₄O₇-LiBO₂为熔剂,LiNO₃为氧化剂,LiBr溶液为脱模剂进行熔融制样,采用铁矿石标样绘制校准曲线,并通过在含锌矿标样加入ZnO基准试剂的方法扩大了Zn的分析范围,以满足不同类型除尘灰中Zn含量差别的要求。各组分校准曲线的线性相关系数为0.9981~0.9999。实验方法用于测定1个除尘灰中TFe、SiO₂、Al₂O₃、CaO、MgO、MnO、P、Na₂O、K₂O、Zn,各组分测定结果的相对标准偏差(RSD,n=10)为0.071%~1.7%;按照实验方法测定5个除尘灰样品(包括高炉除尘灰、转炉除尘灰和污泥等)中10种组分,并与化学湿法进行比较,测定结果相符。

Determination of ten components in dust ash by X-ray fluorescence spectrometry with fusion sample preparation

Since the composition of dust ash is complex, the one-by-one analysis is difficult. A variety of components in precipitator dust were determined by X-ray fluorescence spectrometry (XRF) with fusion sample preparation. Carbon was firstly removed at 950℃ in experiments. The sample was prepared by fusion method using Li₂B₄O₇-LiBO₂ (mass ratio of 2∶1) as flux, LiNO₃ as oxidizer and LiBr solution as release reagent. The calibration curve was plotted using standard sample of iron ore. The reference reagent of ZnO was added into zinc-containing standard sample to enlarge the analysis range of Zn, thus to meet the determination requirements of Zn in various types of dust ash. The linear correlation coefficient of calibration curves of components were between 0.9981 and 0.9999. The proposed method was applied for the determination of TFe, SiO₂, Al₂O₃, CaO, MgO, MnO, P, Na₂O, K₂O and Zn in one dust ash sample. The relative standard deviation (RSD, n=10) of determination results were between 0.071% and 1.7%. Ten components in five dust ash samples (including blast furnace dust, converter dust and sludge, etc) were determined according to the experimental method. The found results were consistent with those obtained by wet chemical method.