XRF测定水泥中9种氧化物含量的短时稳定能力研究

Study on Short Term Stability Ability of XRF Determination of Nine Oxides in Cement

X射线荧光分析法(XRF)能够实现对硅酸盐水泥中氧化物的大范围线性检测,能够免除滴定法和分光光度法测量浓度较大样品会远离朗伯-比尔定律的问题,很好地实现了对水泥这一性质成分复杂的材料的良好测量。然而,实际检测中随检测时间的延长,发现XRF法对不同氧化物的检测短时稳定性存在差异。基于GB/T176中方法,短时内测得质量分数波动极差为0.02%~0.43%,且以CaO的质量分数波动极差最高,可达0.43%,TiO_(2)的质量分数波动极差最小,为0.02%。同时,单次检测各氧化物结果相对标准偏差最大值RSD_(MAX)以Na_(2)O最高,为5.20%,CaO最小,为0.10%。综合分析一般硅酸盐水泥中9种氧化物本身的质量分数范围,XRF法对水泥中Fe_(2)O_(3)、MgO、Al_(2)O_(3)、TiO_(2)的测量精确度和稳定性最佳。除此,特别需要关注碱含量测试结果稳定性,并使用标准样品检验结果准确性。

X-ray fluorescence analysis can achieve a wide range of linear detection of oxides in portlandcement,and can avoid the problem that the concentration of titration and spectrophotometry will be far away from Lambert Beer’s law when the concentration is large.However,with the continuation of the detection time in the actual detection,it is found that the short-term stability of the XRF method for detection of different oxides is different.Based on the method in GB/T176,the range of the mass fraction fluctuation range measured in a short time is between 0.02%~0.43%,and the mass fraction fluctuation range of CaO is as high as 0.43%,and the minimum fluctuation range of TiO_(2) is 0.02%.At the same time,the maximum value of RSDMAX of the results of a single test of each oxide is 5.20%for Na_(2)O and 0.10%for CaO.Through comprehensive analysis of the mass fraction range of the nine oxides in general portlandcement,it is found that the XRF method has the best measurement accuracy and stability for Fe_(2)O_(3),MgO,Al_(2)O_(3),and TiO_(2) in cement.In addition,it is particularly important to pay attention to the stability of the alkali content test results and use standard samples to verify the accuracy of the results.