熔融制样-X射线荧光光谱法测定酸溶性钛渣中主次量成分

酸溶性钛渣是优质的钛白生产原料,产品中的主次成分含量直接影响到后续钛白产品质量。针对酸溶性钛渣中含有低价物的特点,试验了粉末压片法制备样品的X射线荧光光谱法分析效果,并建立了熔融玻璃片制备方法:采用Li₂B₄O₇和Li₂CO₃作为熔剂,NH₄NO₃作为氧化剂,在石墨垫底瓷坩埚中先将酸溶性钛渣预氧化,再将熔球转入铂黄金坩埚,解决了样品中低价物对铂黄金坩埚腐蚀的难题。实验采用理论α影响系数法进行基体效应和谱线重叠干扰校正,进而通过对熔融条件及各待测元素测量条件的优化,以及采用金红石、钛渣、钛精矿等标准样品及人工合成校准样品绘制校准曲线,建立了X射线荧光光谱法(XRF)同时测定酸溶性钛渣中TiO₂、SiO₂、Al₂O₃、MnO、CaO、MgO、TFe、V₂O₅、ZrO₂等主次量成分的方法。将实验方法应用于酸溶性钛渣实际样品分析,所测组分测定结果的相对标准偏差(RSD,n=11)均小于1.5%。采用实验方法测定酸溶性钛渣中主次量成分,分析结果与化学湿法结果吻合。

Determination of major and minor components in acid-soluble titanium slag by X-ray fluorescence spectrometry with fusion sample preparation

The acid-soluble titanium slag is a high-quality raw material for the production of titanium dioxide. The content of major and minor components in acid-soluble titanium slag will directly affect the quality of subsequent titanium dioxide products. According to the characteristic that the acid-soluble titanium slag contained low-valence substances, the sample was prepared by pressed powder pellet for the analysis by X-ray fluorescence spectrometry (XRF). The preparation method of fusion glass pellet was also established as below: Li₂B₄O₇ and Li₂CO₃ were selected as the flux, and NH₄NO₃ was selected as the oxidizer; the acid-soluble titanium slag was pre-oxidized in porcelain crucible with graphite on the bottom; then the melt pellet was transferred into platinum-gold crucible, solving the corrosion problems by low-valence substances in sample. In experiments, the theoretical α coefficient method was used to correct matrix effect and spectral overlapping interference. The melting conditions of sample and determination conditions of testing elements were optimized. The calibration curves were plotted using the standard samples of rutile, titanium slag and titanium concentrate as well as some artificially synthesized samples. The method for the simultaneous determination of major and minor components in acid-soluble titanium slag (including TiO₂, SiO₂, Al₂O₃, MnO, CaO, MgO, TFe, V₂O₅ and ZrO₂) by X-ray fluorescence spectrometry (XRF) was established. The experimental method was applied for the analysis of actual sample of acid-soluble titanium slag. The relative standard deviations (RSD, n=11) of found results were all less than 1.5%. The contents of major and minor components in acid-soluble titanium slag were determined according to the experimental method, and the analytical results were consistent with those obtained by the wet chemical method.