弓长岭磁铁矿拉曼光谱特征及意义  

Micro-Raman Spectral Characteristics and Implication of Magnetite in Gongchangling Iron Mine

作　　者：刘静 姚玉增[1] 付建飞[1] 李梓宁 侯婷婷 张永利[1] LIU Jing;YAO Yu-zeng;FU Jian-fei;LI Zi-ning;HOU Ting-ting;ZHANG Yong-li(School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004

出　　处：《光谱学与光谱分析》2024年第6期1697-1702,共6页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2022YFC2903701)资助。

摘　　要：弓长岭铁矿床是我国最大的沉积变质型磁铁富矿,诸多学者对其开展了大量研究工作,但磁铁矿拉曼光谱方面的研究较少。采用HORIBA XploRA PLUS显微拉曼光谱仪对弓长岭铁矿床典型贫铁矿石和富铁矿石中的磁铁矿进行了拉曼光谱测试,结果表明,贫铁矿石中磁铁矿在300、550和670 cm^(-1)处的拉曼峰位向高波数偏移,应与其中磁铁矿的铁平均氧化态升高及微量元素类质同象取代导致矿物晶格尺寸减小有关;富铁矿石中磁铁矿的拉曼峰强明显升高,应为富铁矿形成过程中磁铁矿重结晶致使其内部微量元素整体含量降低而铁离子含量相对升高所致。贫铁矿石中部分磁铁矿出现了微弱的赤铁矿拉曼光谱特征,可能与磁铁矿形成后的表生氧化有关。X射线衍射(XRD)分析表明,富矿中铁氧化物主要为磁铁矿,而贫铁矿石中的磁铁矿有向镁磁铁矿转变的趋势。扫描电镜能谱分析结果表明,富矿中磁铁矿相较于贫矿中的微量元素含量降低,即由贫矿到富矿,磁铁矿经历了“纯化”,与前面拉曼结果研究相一致。本次研究表明,拉曼光谱测试具有快速、简单、可重复且无损伤的特点,可有效估计磁铁矿中微量元素含量并可用以鉴别鞍本地区贫、富两类铁矿石。Gongchangling iron mine is the largest BIF-hosted high-grademagnetite ore deposit in China,various scholars have carried out many researches,however few studies are related to Raman spectra of magnetite.This paper measured the Raman spectra of magnetite in typical BIF ore and high-grade iron ore of Gongchangling by HORIBA XploRAPLUS micro-Raman spectrometer.The results show that the peaks of magnetite in BIF at 300,550 and 670 cm^(-1) shift to high wavenumber,which should be related to the increase of the average oxidation state of magnetite in BIF and the decrease of miner allattice size caused by the isomorphic substitution of trace elements.The Raman peak intensities of magnetite in high-grade iron ore increase obviously,probably due to the decrease of the overall content of trace elements and,correspondingly,the relative increase of iron ion content in magnetite.Some magnetites in BIF ore show weak Raman spectral features of hematite,which may be related to the epigenetic oxidation after the formation of magnetite.X-ray diffraction(XRD)analysis shows that the main iron mineral in the high-grade ore is magnetite,whereas the magnetite in the BIF ore is more similar to magnesioferrite.The results of SEM-EDS suggest that the contents of trace elements in the magnetite from high-grade iron ore are lower than those from BIF ore,i.e.,experiencing the process of“purification”,which is consistent with the abovementioned conclusion.The research indicates that Raman spectra measurement is proven to be a fast,simple,reproducible and non-destructive method and can be used to estimate the overall content of trace elements of magnetite and further distinguish the magnetite both in BIF and high-grade iron ores of Anshan-Benxi area.

关 键 词：磁铁矿 拉曼光谱 弓长岭富铁矿 

分 类 号：P62[天文地球—地质矿产勘探]