炼钢用钙铁包芯线主次元素测定方法的试验研究

EXPERIMENTAL STUDY ON DETERMINATION METHOD OF PRIMARY AND SECONDARY ELEMENTS OF CALCIUM IRON CORED WIRE FOR STEELMAKING

炼钢连铸开浇之前采用喂线机将钙铁线喂入进行终脱氧,在炼钢企业广泛使用。准确测定钙铁线中钙、铁和杂质元素的含量对提高钢水的纯净度、降低成品钢中氧含量具有重要意义。本实验方法采用盐酸(1+4)及少量双氧水溶解样品,制成母液。分取适量母液,利用络合反应,用EDTA标准溶液滴定钙离子。利用氧化还原反应原理,以重铬酸钾标准溶液滴定Fe^(2+)。按选定的仪器测量条件,用电感耦合等离子体原子发射光谱法测定Al、Cr.P、Ti、Si、Mn等杂质元素含量。基体干扰试验发现,基体对Al元素测定结果基本没有影响;随着基体含量的增加,P、Ti测得值逐渐升高;Cr、Si、Mn由于基体的存在,测定结果偏低。在仪器最佳工作条件下,各元素校准曲线线性相关系数均不小于0.9995。测定结果的相对标准偏差(RSD,n=10)为0.6%~3.7%.加标回收率为92%~109%,该试验方法对钙铁线的检测结果与认定值基本相符。

Before steel casting and continuous casting,a wire feeding machine is used to feed calcium iron wire for final deoxidation,which is widely used in steel making enterprises.Accurate determination of the content of calcium,iron and impurity elements in calcium-iron wire is of great significance for improving the purity of molten steel and reducing the oxygen content in finished steel.Methods Hydrochloric acid(1+4)and a small amount of hydrogen peroxide were used to dissolve the sample to make mother liquor.Separately take appropriate amount of mother liquor,use complexation reaction,and titrate calcium ion with EDTA standard solution.Using the principle of redox reaction,titrate Fe2+with potassium dichromate standard solution.According to the measurement conditions of the selected instrument,the content of impurity elements such as Al,Cr,P,Ti,Si,Mn and the like is determined by inductively coupled plasma atomic emission spectrometry.The matrix interference test found that the matrix had basically no effect on the Al measurement results.The measured values of P and Ti gradually increased with the increase of the matrix content.The measurement results of Cr,Si and Mn were low due to the presence of the matrix.Under the best working conditions of the instrument,the linear correlation coefficient of the calibration curve of each element is not less than 0.9995.The relative standard deviation(RSD,n=10)of the measurement results is 0.6%~3.7%,and the recovery rate of the spike is 92%~109%.The test results of the calcium iron wire are basically consistent with the certified values.