X射线荧光光谱法测定磷矿石中11种主次组分

建立了X射线荧光光谱法测定磷矿石中SiO₂、Al₂O₃、Fe₂O₃、CaO、MgO、P₂O₅、Na₂O、K₂O、SrO、TiO₂、F等主次成分的分析方法。选择熔融制样作为样品前处理手段，通过比较P、Ca两元素响应值与观察实验现象以优化实验参数，确定取样量为0.7000g，稀释比为8∶1，预氧化时间为4min，熔样温度为1050℃，熔样摆动时间为5min。混合磷矿石标准物质以配制具有浓度梯度的校准样品序列，以熔融制样方法处理，保证校准曲线工作范围涵盖磷矿石精、中、尾矿中各成分含量分布，测定样品灼烧减量并手动输入进行归一化补偿。方法检出限为63(SiO₂)、141(Al₂O₃)、35(Fe₂O₃)、198(CaO)、67(MgO)、275(P₂O₅)、39(Na₂O)、46(K₂O)、2(SrO₂)、42(TiO₂)、102(F)μg/g。方法应用于3个混合标样的多次测定，实测值与理论值相符，结果的相对标准偏差(n=10)在0.066%~5.3%之间。

Determination of eleven major and minor components in phosphate ores by X-ray fluorescence spectrometry

A method was developed for determination of silica, aluminum oxide, ferric oxide, calcium oxide, magnesium oxide, phosphorus pentoxide, sodium oxide, potassium oxide, strontium oxide, titanium oxide, fluoride in phosphate ores by X-ray fluorescence spectrometry. Fusion method was selected for sample pretreatment, while the experimental parameters were optimized by comparing the response value of phosphorus and calcium and observing experimental phenomena. The final experimental conditions were as follows: sampling amount of 0.700 0 g, dilution ratio of 8∶1, pre-oxidization time of 4 min, sample melting temperature of 1 050 ℃ and sample oscillation time of 5 min. The calibration sample series with concentration gradient, which were prepared by mixing phosphate ore reference materials, were treated by fusion preparation. The working range of calibration curve could cover the content distribution of components in phosphate concentrate, middlings and tailings. The ignition loss of sample was measured and then manually input for normalization compensation. The detection limit of method was as follows: 63 (SiO₂), 141 (Al₂O₃), 35 (Fe₂O₃), 198 (CaO), 67 (MgO), 275 (P₂O₅), 39 (Na₂O), 46 (K₂O), 2(SrO₂), 42 (TiO₂) and 102 (F) μg/g. The proposed method was applied to the determination of three mixed reference samples. The results were consistent with the theoretical values, and the relative standard deviation (RSD, n=10) was between 0.066% and 5.3%.