熔融制样-X射线荧光光谱法测定钒钛磁铁矿中12种组分

钒钛磁铁矿中的铁和伴生组分是制造钢铁、合金的主要材料,以往采用多方法结合测定其主次元素,测量周期长,成本高。实验采用混合熔剂熔融制样后,使用X射线荧光光谱法(XRF)测定钒钛磁铁矿中TFe、TiO₂、SiO₂、Al₂O₃、CaO、MgO、V₂O₅、Cr₂O₃、MnO、K₂O、Na₂O、P等12种主次组分。为了防止试样对铂-金坩埚的腐蚀,采用预先烧失量处理。称量0.3000g样品与6.000g混合熔剂(m(Li₂B₄O₇)∶m(LiBO₂)=67∶33)于1050℃熔融,在熔样过程中添加溴化锂作为脱模剂。选用标准样品绘制校准曲线,采用理论α系数进行计算,校准曲线回归精度(SEE)小于0.3;方法中各组分检出限小于100μg/g。选取同一个样品进行熔融制样,并采用XRF测定其中TFe、TiO₂、SiO₂、Al₂O₃、CaO、MgO、V₂O₅、Cr₂O₃、MnO、K₂O、Na₂O、P等组分,测定结果的相对标准偏差(RSD,n=5)符合DZ/T 0130—2006《地质矿产实验室测试质量管理规范》要求。选取4个样品,分别按照实验方法和其他方法(分别采用滴定法、电感耦合等离子体原子发射光谱法、分光光度法等)对上述12种组分进行测定,两种方法所得测定结果差值均符合DZG 93—07《岩石和矿石分析规程》中《钒钛磁铁矿石分析规程》所要求的允许误差范围。

Determination of twelve compoments in vanadium-titanium magnetite ore by X-ray fluorescence spectrometry with fusion sample preparation

Iron and associated components in vanadium-titanium magnetite ore are the main materials to manufacture steel and alloys. In the past, the major and minor elements are usually determined by the combination of multiple methods. However, the measurement period is long and the cost is high. The sample was prepared by fusion method with mixed flux. Twelve major and minor components in vanadium-titanium magnetite ore (including TFe, TiO₂, SiO₂, Al₂O₃, CaO, MgO, V₂O₅, Cr₂O₃, MnO, K₂O, Na₂O and P) were determined by X-ray fluorescence spectrometry (XRF). In order to prevent the corrosion of platinum-gold crucible by sample, the pretreatment of loss on ignition was adopted. 0.3000g of sample and 6.000g mixed flux (m(Li₂B₄O₇)∶m(LiBO₂)=67∶33) were melted at 1050℃. The lithium bromide was added in sample melting process as the releasing reagent. The calibration curve was drawn using the standard sample. The theoretical α coefficient was used for calculation. The regression precision of calibration curve was less than 0.3. The detection limits of components of this method were less than 100μg/g. One same sample was used for fusion sample preparation, and the contents of TFe, TiO₂, SiO₂, Al₂O₃, CaO, MgO, V₂O₅, Cr₂O₃, MnO, K₂O, Na₂O and P were determined by XRF. The relative standard deviations (RSD, n=5) of determination results could meet the requirements in DZ/T 0130-2006 Geological and Mineral Laboratory Test Management Specification. Four samples were selected and twelve components above were determined according to the experimental method and other methods (i.e., titrimetry, inductively coupled plasma atomic emission spectrometry and spectrophotometry). The difference of measurement results was within the allowable error range required by Analysis Procedure of Vanadium-titanium Magnetite Ore in DZG 93-07 Analysis Procedures of Rocks and Ores.