微波消解-电感耦合等离子体原子发射光谱法测定钒铁中7种杂质元素

Determination of 7 impurity elements in ferrovanadium alloy by inductively coupled plasma atomic emission spectrometry with microwave digestion

利用X射线衍射法对钒铁酸溶前后的物相进行对比分析,发现酸溶残渣的主要成分为硅铝氧化物,因此可以使用混酸、在高压下提高反应温度的微波消解技术处理样品。采用硝酸、盐酸、氢氟酸混合酸并使用微波消解两步升温法处理样品,选择Si 251.611nm、Al394.401nm、Mn 257.610nm、P 178.284nm、As 189.042nm、Cu 324.754nm、Ni231.604nm为分析谱线,采用基体匹配法绘制校准曲线消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定硅、铝、锰、磷、砷、铜、镍,从而建立了钒铁中硅、铝、锰、磷、砷、铜、镍等杂质元素的分析方法。各待测元素校准曲线的线性相关系数r均大于0.999 5;方法中各元素检出限为0.000 1%~0.001 3%(质量分数)。方法应用于两个钒铁标准样品中硅、铝、锰、磷、砷、铜、镍测定,结果的相对标准偏差(RSD,n=8)不大于4%,测定值与认定值相符合。

The phases in ferrovanadium before and after acid dissolution were analyzed and compared by Xray diffraction.It was found that the main composition of residues after acid dissolution was silicon-aluminum oxide.Therefore,the sample could be treated with mixed acid by microwave digestion technology to increase the reaction temperature at high pressure.In this study,the sample was dissolved with nitric acidhydrochloric acid-hydrofluoric acid mixture and treated by microwave digestion with tow-step temperature rising.Si 251.611 nm, Al 394.401 nm, Mn 257.610 nm, P 178.284 nm, As 189.042 nm, Cu324.754 nm and Ni 231.604 nm were selected as the analytical line.The calibration curve was prepared by matrix matching method to eliminate the influence of matrix effect.The simultaneous determination of silicon,aluminum,manganese,phosphorus,arsenic,copper and nickel impurities in ferrovanadium by inductively coupled plasma atomic emission spectrometry(ICP-AES)with microwave digestion was established.The linear correlation coefficients(r)of calibration curves for testing elements were all higher than 0.9995.The detection limits of elements in this method were in range of 0.000 1%-0.001 3%(mass fraction).The proposed method was applied for the determination of silicon,aluminum,manganese,phosphorus,arsenic,copper and nickel in two ferrovanadium standard samples.The relative standard deviations(RSD,n=8)of determination results were less than 4%,and the found results were consistent with the certified values.