熔融制样-X射线荧光光谱法测定含铝铬锆耐火材料中主次成分

对含铝铬锆新型耐火材料的化学成分分析,目前行业内没有匹配的标准物质和合适的X射线荧光光谱(XRF)分析方法,而是仍沿用传统湿法,操作相对繁琐且低含量的次成分灵敏度低。实验利用日本产既有标准物质铝锆硅JRRM708、JRRM710、矾土JRRM310作基质,分别加氧化铬、氧化锆基准试剂混配出不同浓度梯度的9个校准样片系列,每个校准样片称样0.2 g,采用m(四硼酸锂)∶m(偏硼酸锂)∶m(氟化锂)=65∶25∶10配比的混合熔剂,1∶30的稀释比,熔融温度1 100 ℃,以200 g/L溴化铵溶液为脱模剂,45 kV-75 mA激发条件,建立了XRF测定含铝铬锆耐火材料中主次成分的方法。主成分相关系数均不小于0.999,次成分的检出限均不大于0.014%。精密度试验表明,除了较低含量氧化硅的相对标准偏差(RSD,n=6)为1.4%外,其他各成分均小于1%;对含铝铬锆耐火材料的常规试样进行分析,实验方法与化学湿法的一致性较好,满足含铝铬锆新型耐火材料对XRF的要求。

Determination of major and minor components in refractories containing aluminum,chromium and zirconium by X-ray fluorescence spectrometry with fusion sample preparation

For the analysis of chemical composition of new refractory materials containing aluminum, chromium and zirconium, there is currently no matching certified reference materials(CRMs) and suitable X-ray fluorescence spectrometry (XRF) analysis methods in the industry. The traditional wet method is still used, which is cumbersome to operate with poor sensitivity for minor components with low content. In experiments, nine calibration samples series with different concentration gradients were prepared based on existing CRMs of aluminum-zirconium-silicon (JRRM708, JRRM710) and vanadine (JRRM310) by adding primary reagents of chromium oxide and zirconium oxide. 0.2 g of each calibration sample was mixed with flux m(Li₂B₄O₇)∶m(LiBO₂)∶m(LiF)=65∶25∶10]. The dilution ratio was 1∶30. The melting temperature was 1 100℃. 200 g/L ammonium bromide solution was used as release agent. The analysis method of major and minor components in refractories containing aluminum, chromium and zirconium by XRF was established with 45 kV-75 mA as the excitation conditions. The correlation coefficients of major components were not less than 0.999. The limits of detection of minor components were not more than 0.014%. The precision test indicated that the relative standard deviations (RSD,n=6) of all components were less than 1% besides 1.4% for silica with low content. The conventional samples of refractories containing aluminum, chromium and zirconium were analyzed according to the experimental method, and the found results were consistent with those obtained by the chemical wet method. The proposed method could meet the XRF analysis requirements of new refractory materials containing aluminum, chromium and zirconium.