The SiO2 content of iron is an essential index to control and measure the quality of iron ore .It is important to deter-mine the method of mineral processing and the process of ore blending .The traditional method of SiO2 content measurement has the defects of heavy workload ,complex operations and long period ,thus it is difficult to determine SiO2 content of iron quickly and efficiently .The thermal infrared spectrum data of Anshan-type iron experimental samples from Anqian mining area of Liaon-ing province was measured and collected by Turbo FT .The spectral characteristics of the experimental samples were analyzed . In addition ,the RI ,DI and NDI were established based on the spectrum data of the samples .The most sensitive waveband and correlation coefficient between spectral indexes and SiO2 content were determined .The NDI which had the most significant corre-lation with SiO2 content was selected out .Besides ,the model for predicting SiO2 content of experimental samples was established based on NDI .We tested and verified the practicality of the model .The results showed that the sensitive waveband of the three spectral indexes and SiO2 content were all located at 8.06 and 8.20 μm which was the left border of Reststrahlen Features .And the correlation coefficient of the three spectral indexes and SiO2 content were all above 0.9 .The correlation between NDI and SiO2 content was the best .Moreover ,the predictive residual of SiO2 content prediction model which was based on NDI was 3.57% .The prediction results of the model were ideal .We provide a new method for determining the SiO2 content of Anshan-type iron .The method has the advantages of low working strength ,simplicity ,efficiency and non-pollution nature .It has some certain guiding significance for remote sensing exploration .%SiO2含量是铁矿石质量控制的主要技术指标,亦是衡量铁矿石品质好坏的关键指标之一,对选矿方法、配矿流程的确定具有重要意义.传统的SiO2含量测定法虽然准确度高,但工作量大,操作繁琐,花费时间长,难以快速、高效确定铁矿石中SiO2含量.采用红外光谱辐射计T urbo FT对辽宁省鞍钢集团鞍千矿业有限责任公司的"鞍山式"铁矿样品进行热红外光谱测试,分析了光谱特征,构建了比值指数(RI) 、差值指数(DI)和归一化指数(NDI) ,并确定光谱指数与样品SiO2含量相关性最显著的敏感波段及对应的相关系数值;优选出与样品SiO2含量相关性最显著的归一化指数(NDI) ,构建样品SiO2含量的定量反演模型,并进行了验证.结果表明,三种光谱指数与样品SiO2含量的敏感波段均位于余辉带特征(RF)的左边界8.06与8. 2 μm处,相关系数均达到0.9以上,其中NDI与样品SiO2含量的相关性最高;基于NDI构建了实验样品SiO2含量的二次函数反演模型,预测误差为3.57%.该方法相对于传统的研磨化验法,具有工作强度小、便捷、快速、高效、无污染的优点,对遥感找矿也具有一定指导意义.
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