熔融制样-X射线荧光光谱法测定石灰石和白云石中8种组分

采用四硼酸锂-偏硼酸锂混合熔剂[m(Li₂B₄O₇)∶m(LiBO₂)=67∶33],稀释比为8∶1,脱模剂为10滴300 g/L碘化铵溶液,预氧化温度和时间分别是600 ℃和200 s,熔融温度和时间分别为1 050 ℃和7.5 min的熔样条件,实现了熔融制样-X射线荧光光谱法(XRF)对石灰石和白云石中CaO、MgO、SiO₂、Al₂O₃、Fe₂O₃、MnO、K₂O、P₂O₅等组分的准确测定。选择石灰石、白云石标准样品及由标准样品人工合成的校准样品进行校准曲线的绘制,各组分的相关系数均可达到0.99以上。采用OXSAS软件提供的AC+MC综合模式进行谱线重叠干扰校正和基体校正,效果良好。选择标准样品进行精密度考察,各组分测定结果的相对标准偏差(RSD,n=12)均小于3%。石灰石、白云石标准样品和实际样品的测定结果与认定值或其他方法测定值进行比较,结果基本相符。

Determination of eight components in limestone and dolomite by X-ray fluorescence spectrometry with fusion sample preparation

The sample fusion conditions were as follows: the mixed flux of lithium tetraborate-lithium metaborate [m(Li₂B₄O₇)∶m(LiBO₂)=67∶33] was used; the dilution ratio was 8∶1; the release reagent was 10 drops of 300 g/L ammonium iodide solution; the pre-oxidization temperature and time was 600 ℃ and 200 s, respectively; the fusion temperature and time was 1 050 ℃ and 7.5 min, respectively. The accurate determination of components in limestone and dolomite (including CaO, MgO, SiO₂, Al₂O₃, Fe₂O₃, MnO, K₂O and P₂O₅) by X-ray fluorescence spectrometry (XRF) with fusion sample preparation method was realized. The calibration curve was prepared using the standard samples of limestone and dolomite as well as the artificially synthesized calibration samples. The correlation coefficient of each component was higher than 0.99. The spectral overlapping interference and matrix interference were corrected by the AC+MC integrated model of OXSAS software, and the effect was good. The precision was investigated using the standard samples. The relative standard deviations (RSD, n=12) of determination results were less than 3%. The determination results of standard samples and actual samples of limestone and dolomite were basically consistent with the certified values or those obtained by other methods.