X射线荧光光谱结合判别分析识别铁矿石产地及品牌：应用拓展

铁矿石是钢铁工业的重要原材料，我国是铁矿石进口需求型国家，是世界铁矿石消费第一大国。海关对进口铁矿石检验的主要目标是预防进口铁矿石中涉及安全、卫生、环保、欺诈等方面的风险。对进口铁矿石产地及品牌进行符合性验证，可以快速筛选掺杂、掺假、以次充好，支撑进口铁矿石的风险管理，保障贸易便利化。在前期研究基础上进行应用拓展，研究对象为澳大利亚、南非、巴西、哈萨克斯坦、印度5个国家、21个品牌的422份进口铁矿石样品。考察了波长色散-X射线荧光光谱无标样分析方法的准确度，对于测量过程中未检出的元素含量，选择了用检测限替代缺失值。对于测量过程中的异常值，使用基于剩余方差的F检验进行异常值的剔除，皮尔巴拉混合块、纽曼混合块铁矿、纽曼混合粉铁矿各有一组数据计算得出的F统计量大于F检验临界值（a=0.01），因此将这3组数据剔除。采用逐步判别法筛选出Fe，O，Si，Ca，Al，Mn，Ti，Mg，P，Na，Cr，K，Sr，S，Zn，V，Cu，Ba，Ni，Mo，Pb共21个元素的含量作为产地识别模型的特征变量，建立四维Fisher判别模型，实现了对铁矿石产地的识别；采用逐步判别法筛选出Fe，O，Si，Ca，Al，Mn，Ti，Mg，P，Na，Cr，K，Sr，S，Zr，Zn，V，Cu，Ba，Cl，Ni，Mo和Pb共23种元素含量作为品牌识别模型的特征变量，建立二十维Fisher判别模型，实现对21种品牌铁矿石的识别。考察了特征元素对分类识别模型的贡献，并分析了误判品牌铁矿石的元素特征。总结出进口铁矿石产地及品牌判别分析模型的整体数据处理流程。

X-Ray Fluorescence Spectroscopy Combined With Discriminant Analysis to Identify Imported Iron Ore Origin and Brand:Application Development

Iron ore is an important raw material for the iron and steel industry.China is an iron ore import-demand country and the world’s largest iron ore consumer.The main goal of the customs’inspection of imported iron ore is to prevent the risk of safety,health,environmental protection,fraud and other aspects of imported iron ore.The compliance verification of the origin and brand of imported iron ore can quickly screen the phenomena of adulteration,adulteration,and inferior charging,which support the risk management of imported iron ore and ensure trade facilitation.This article expands the application based on previous research.The research objects are 422 imported iron ore samples from 5 countries.In this paper,the accuracy of the non-standard sample analysis method of wavelength dispersive X-ray fluorescence spectrum is investigated.For the elements not detected in the measurement process,the detection limit was chosen to replace the missing values.For the outliers in the measurement process,F-test based on residual variance is used to eliminate the outliers.Each of the Pilbara Blend Lumps,Newman Blend Lumps,and Newman Blend Fines has one F statistic calculated from one set of data is greater than the F-test critical value(a=0.01),so these three sets of data are eliminated.The contents of Fe,O,Si,Ca,Al,Mn,Ti,Mg,P,Na,Cr,K,Sr,S,Zn,V,Cu,Ba,Ni,Mo,and Pb are selected by the stepwise discriminant method as the characteristic variable of the original identification model,and a four-dimensional Fisher discriminant model is established to identify the origin of the iron ore.The contents of Fe,O,Si,Ca,Al,Mn,Ti,Mg,P,Na,Cr,K,Sr,S,Zr,Zn,V,Cu,Ba,Cl,Ni,Mo,and Pb are selected by the stepwise discrimination method as the feature variables of the brand recognition model,and a 20-dimensional Fisher discriminant model is established to realize the recognition of 21 brand iron ores.The contribution of characteristic elements to the classification and recognition model is investigated,and the element characteristics of misidentified brand iron ore are analyzed.On this basis,the paper summarizes the whole data processing flow of the discrimination analysis model of the origin and brand of imported iron ore.