X射线荧光光谱法测定海绵铁中TFe、SiO_2、P、CaO、MgO

Determination of TFe,SiO_2,P,CaO,MgO in sponge iron by X-ray fluorescence spectrometry

研究了熔融法制样,X射线荧光光谱法分析海绵铁的最佳熔融和测量条件,建立了X荧光光谱法分析海绵铁中TFe、SiO2、P、CaO、MgO的方法。本方法通过熔剂熔融挂壁制成熔剂坩埚和对试样的氧化预处理,使样品熔解更完全并保护了铂金坩埚。实验选择了硝酸钾和碳酸锂作为氧化剂,制样时加入Co元素作主成分TFe的内标,校正基体效应和烧失量(烧增量),采用铑靶LNN线的康普顿散射线作次量成分SiO2内标线,校正SiO2。在选定实验条件下,重复制样得到各元素的相对标准偏差均小于1.9%。本法已用于海绵铁试样中TFe、SiO2、P、CaO、MgO测定,结果与湿法测定值相符,能满足海绵铁的分析要求。

The optimal melting and measuring conditions for the determination of TFe,SiO2,P,CaO and MgO in sponge iron were studied by X-ray fluorescence spectrometry after sample preparation by fusion.The X-ray fluorescence analysis method of TFe,SiO2,P,CaO and MgO in sponge iron was established.In this method,the flux crucible was prepared by wall hanging of fused flux.Moreover,the sample was pretreated by oxidation.Therefore,the dissolution of sample was more complete and the platinum crucible was protected.In this study,potassium nitrate and lithium carbonate were used as oxidizing agent.Co was added as an internal standard of TFe（major component） in sample preparation to correct the matrix effect and burning loss（increment）.The Compton scattering line using LNN line of rhodium target was used as the internal standard line of SiO2（minor component） to correct SiO2.Under the selected experimental conditions,the relative standard deviations（RSD） were all less than 1.9 %.This method has been applied to the determination of TFe,SiO2,P,CaO and MgO in sponge iron sample.The results were consistent with those obtained by wet method.This method could meet the analytical requirements of sponge iron.