熔融法制样-X射线荧光光谱法测定锌精矿中主、次组分含量

应用X射线荧光光谱法测定了锌精矿中主次量组分(包括锌、硫、铁、硅、铅、铜、砷、银、镉、锡及锑)。锌精矿样品(0.6g)与6.3g四硼酸锂和3.2g硝酸锂置于铂-金坩埚中拌匀,先在500℃随即升至700℃灼烧10min,使样品中的硫离子预氧化为硫酸盐。硝酸锂与四硼酸锂生成四硼酸锂和偏硼酸锂混合物熔剂,在1 030℃熔融样品10min,将熔化的样品倒入样模中,冷却后脱模所得熔块用于X射线荧光光谱分析。对在预氧化及熔融过程中由于样品组成变化及质量的增加所造成的基体干扰,采用基于Sherman方程的可变理论α影响系数法进行校正。在所测定的元素中,锌和硫的校准曲线范围依次为27%～62%和10%～35%,两者的标准偏差均小于0.2%。应用所提出的方法分析了2个CRM(GBW 07168和SRM 113b),所得测定值与认定值一致。

XRFS Determination of Major and Minor Components in Zinc Concentrates with Fusion Sample Preparation

Major and minor componental elements(i.e.,Zn,S,Fe,Si,Pb,Cu,As,Ag,Cd,Sn and Sb) in zinc concentrates were determined by XRFS.The sample(0.6 g) was mixed with 6.3 g of Li2B4O7 and 3.2 g of LiNO3 in a Pt-Au crucible and heated firstly at 500 ℃ and then at 700 ℃ for 10 min to pre-oxidize S2-in the sample to SO42-.A flux mixture of Li2B4O7 and LiBO2 was formed during the course of preoxidation and acted as flux to fuse the sample at 1 030 ℃ for 10 min.The molten melt was transferred into the sample mould,and after cooling,the melt was unloaded from the mould,and used for XRFS analysis.To eliminate the interferences arised from alteration of composition and increase of mass during preoxidation and fusion of sample,the method of variable α influential coefficient based on sherman equation was used in the correction.The ranges of calibration curves were found to cover from 27% to 62% for Zn and from 10% to 35% for S with values of standard deviation less than 0.2% for both Zn and S.In the analysis of 2 CRM′s(GBW 07168 and SRM 113b) by this method,results obtained were in consistency with the certified values.