熔融制样-X射线荧光光谱法测定渣铁中主次成分

渣铁成分复杂,含铁量较高,其中的铁、钙、镁具有回收价值,但硅、铝、磷对渣铁回收有一定的影响,这些元素含量是渣铁回收利用的重要参数。实验利用熔融制样-X射线荧光光谱法(XRF)测定渣铁中全铁、氧化硅、氧化钙、氧化镁、氧化铝和磷含量,解决了传统方法检测渣铁中这些组分耗时长、步骤多、污染环境等问题,提高了检测效率。渣铁样品预先经过1000℃高温灼烧1h,除去其中水分、碳及易挥发成分,氧化其中还原性物质;然后以四硼酸锂作为熔剂,按稀释比1∶10与灼烧后被测样品混合,先800℃预熔融2min,然后于1150℃熔融12min,将样品制成均匀的玻璃融片。选用13种不同质量分数与渣铁成分类似的标准物质绘制校准曲线,仪器参数经过优化后,建立了X射线荧光光谱法快速检测渣铁中全铁、氧化硅、氧化钙、氧化镁、氧化铝、磷的方法。方法对平炉渣YSBC13838-96、转炉渣QD12-183、钒渣YSBC19809-2000标准样品的准确度试验结果表明:全铁、氧化硅、氧化钙、氧化镁、氧化铝、磷测定结果的相对标准偏差(RSD,n=7)为0.22%~4.2%;测定值与认定值一致。渣铁实际样品的测定值与国家标准方法检测值吻合,满足实验室日常质量监控要求。

Determination of major and minor components in slag iron by X-ray fluorescence spectrometry with fusion sample preparation

The composition of slag iron is complex and the content of iron is high. The elements including iron, calcium and magnesium in slag iron have recycling value. However, silicon, aluminum and phosphorus have a certain influence on the recycling, and the content of these elements is an important parameter for recycling and reuse of slag iron. The contents of total iron, silicon oxide, calcium oxide, magnesium oxide, aluminum oxide and phosphorus in slag iron were determined by X-ray fluorescence spectrometry (XRF) with fusion sample preparation. It solved the problems of traditional methods such as time-consuming, long procedures and the pollution of environment. Moreover, the detection efficiency was improved. The slag iron samples were pre-heated at 1000℃ for 1h to remove the moisture, carbon and other volatile components. Meanwhile, the reducing substances were oxidized. Then lithium tetraborate was used as the flux to mix with the burned sample at a dilution ratio of 1∶10. The mixture was pre-melted at 800℃ for 2min followed by melting at 1150℃ for 12min to prepare the uniform glass melt. The calibration curves were established with 13 standard samples with different composition and similar components to the slag iron. The instrument parameters were optimized. The rapid determination method of total iron, silicon oxide, calcium oxide, magnesium oxide, aluminum oxide and phosphorus in slag iron by X-ray fluorescence spectrometry was established. The accuracy tests were conducted using standard samples including open-hearth furnace slag YSBC13838-96, converter slag QD12-183 and vanadium slag YSBC19809-2000. The results showed that the relative standard deviations (RSD, n=7) of determination results of total iron, silicon oxide, calcium oxide, magnesium oxide, aluminum oxide and phosphorus were 0.22%-4.2%. The found results were consistent with the certified values. The determination results of actual slag iron sample were consistent with those obtained by national standard method, which could meet the daily quality control requirements of the laboratory.