基于可见光-近红外光谱的BIF磁性率确定方法研究

铁矿中磁性率是评价铁矿床工业价值和划分矿石工业类型的重要指标。传统的磁性率测定法存在工作量大、效率低、周期长的缺陷，成为经济、合理、高效开采铁矿资源的瓶颈问题。采用便携式地物光谱测试仪对辽宁省鞍钢集团鞍千矿业有限责任公司的BIF实验样品进行可见光-近红外光谱测试，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磁性率相关性最显著的敏感波段及对应的相关系数值；优选出与样品磁性率相关性最显著的比值指数(RI)，构建实验样品磁性率的定量反演模型，并进行了验证。结果表明，三种光谱指数与样品磁性率敏感波段均位于935与1 050 nm，且该波段处的相关系数均达到0.9以上，其中比值指数与样品磁性率的相关性最高；基于比值指数构建的实验样品磁性率定量反演模型的预测误差为0.038，反演磁性率与实测磁性率的判定系数(R2)为0.964 5，预测结果比较理想。为确定BIF的磁性率提供了一种新方法，该方法具有工作强度小、经济、高效、便捷的优点，且对遥感找矿具有一定指导意义。

A FeO/TFe Determination Method of BIF Based on the Visible and Near-Infrared Spectrum

The FeO/TFe of iron ore is an important index to evaluate the industrial value of iron ore and classify the industrial type of ore. The conventional FeO/TFe measurements cost a lot of labor with low efficiency and long period, which are not benefit for the economical, reasonable and effective iron ore exploitation. Firstly, the visible and near-infrared spectrums of the BIF samples from Anqian mining area of Liaoning province were measured and the spectral features were analyzed. Then, three indexes of ration index (RI), difference index (DI) and normalized difference index (NDI) were put forward for analyzing the correlation relations between the indexes and FeO/TFe, and exploring the sensitive waveband. The experimental results showed that the sensitive waveband results of FeO/TFe from these three indexes are all located at 935 and 1 050 nm. All of these three correlation coefficients are larger than 0.9 at these two wavelength and the maximum value is 0.971 for the RI. Therefore, the inversion model for FeO/TFe according to RI results can be established and verified based on the laboratory report. The prediction error of FeO/TFe is 0.038 and the coefficient of determination (R2) is 0.964 5. The experimental results can provide a new economical and effective approach for determining the FeO/TFe of BIF and mine exploring via remote sensing.