熔融制样-X射线荧光光谱法测定铁矿石中主次成分

Determination of main and minor components in iron ores by X-ray fluorescence spectrometry with fusion sampling

采用硝酸铵作为氧化剂,于600℃进行样品预氧化处理,然后以Li2B4O7和LiBO2[m(Li2B4O7):m(LiBO2)=67:33]为熔剂,采用1:15熔剂稀释比,于1050℃熔融制成玻璃熔片,用X射线荧光光谱分析仪对熔片中Fe,Si,P,Al,As,K,Na,Cu,Zn,Pb,Ca,Mg,V,Ti,Mn等元素进行同时测定。由于样品采用预氧化处理和大的熔剂稀释比进行高温熔融,有效提高了K,Na,As等元素的X射线荧光强度,消除了复杂矿物结构效应,降低共存元素间基体效应影响,提高了分析结果的准确度和精密度。本测定方法用于铁矿石标样分析,各组分的测定值与认定值相符。

The samples were pre-oxidized at 600 ℃ with ammonium nitrate as oxidant, and was then made into a glass melting piece at 1 050 ℃with Li2B4O7 and LiBO2 as flux [m（Li2B4O7） ： m（LiBO2） =67 ： 33] at a dilution ratio of 1 ： 15. The elements including Fe, Si, P, Al, As, K, Na, Cu, Zn, Pb, Ca, Mg, V, Ti and Mn in the melting piece were simultaneously determined by X-ray fluorescence spectrometry. The pre-oxidation treatment of samples and high-temperature melting at high dilution ratio of flux effectively enhanced the X-ray fluorescence intensities of K, Na and As, and eliminated the structure effect of complex ores and reduced the matrix effect of coexisting ions, resulting in better accuracy and precision of analytical results. The proposed method was applied to the analysis of standard samples of iron ore. The determination results were consistent with the certified values.