摘要
铬铁矿属难熔矿物,目前对铬铁矿的分析以化学分析为主,方法成熟,但操作复杂且步骤繁琐;而应用X射线荧光光谱法进行分析测定,一般都采用较高稀释比熔融制样,不利于低含量元素的测定。本文选用四硼酸锂+偏硼酸锂作为混合熔剂,与样品以20∶1的稀释比熔融制样,利用波长色散X射线荧光光谱测定铬铁矿中多种元素(Cr、Si、Al、TFe、Mg、Ca、Mn)的方法。采用多种铬铁矿标准物质和人工配制标准样品制作工作曲线,理论α系数及康普顿散射内标法校正元素间的吸收-增强效应,方法精密度(RSD,n=10)为0.2%～5.3%。方法检出限低,如锰元素的检出限可低至60μg/g;镁元素的检出限为225μg/g,比文献采用高稀释比XRF测定的方法检出限(250μg/g)要低。本方法通过选择有效的熔剂和较低的稀释比解决了铬铁矿的制样问题,熔剂的用量减少,称样量增加,提高了低含量元素分析的准确度,相应地降低了分析成本。
Chromite analysis is dominated by chemical analysis,which is a wel-established but complicated procedure.Chromite can also be analysed by X-ray Fluorescence Spectrometry （XRF）,however,a high-dilution fusion is not conducive to low content elements.In this paper,a method is reported for the determination of multielements （Cr,Si,Al,TFe,Mg,Ca and Mn） in chromite by Wavelength Dispersive X-ray Fluorescence Spectrometry with a low-dilution fusion for Li2B4O7 and LiBO2-mixed flux （20 ∶ 1 reagent to sample）.Also discussed in this paper is the effective flux of molten chromite.The working curve was established by a variety of chromite standard substances and manual preparation of standard materials.The inter-element effect was corrected by using the theoretical alpha coefficient with Compton scattered radiation.The results are consistent with the certified values and RSD （n =10） range from 0.2％ to 5.3％.The detection limit of Mn is 60 μg/g.The detection limit of Mn by this method is as low as 225 μg/g which is lower than the previous reported limit of 250 μg/g reported elsewhere.By selecting the effective flux and low dilution ratio,the problem of chromite sample preparation has been solved,which reduces the amount of flux,increases the sample weight,improves the analysis accuracy for low content elements and reduces the cost of analysis.
出处
《岩矿测试》
CAS
CSCD
北大核心
2013年第6期915-919,共5页
Rock and Mineral Analysis
关键词
铬铁矿
X射线荧光光谱法
熔融制样
20∶1稀释比
chromite
X-ray Fluorescence Spectrometry
fusion sampling
20 ∶ 1 of dilution ratio
