近红外矿物光谱技术研究及其在德兴斑岩铜矿的应用.doc

近红外矿物光谱技术研究及其在德兴斑岩铜矿的应用 【中文摘要】本文在中国地质调查局地质大调查项目No.1212010660604的资助下,以南京地质矿产研究所和南京中地仪器公司共同研制的便携式近红外矿物分析仪为测试工具,开展矿物光谱特征的测试与分析、矿物光谱变异性分析、矿物光谱库的建立和德兴铜矿的应用四个方面的研究,重点分析了白云母、蒙脱石、高岭石、绿泥石等矿物和Al-OH、Mg-OH、-OH等化学键的光谱特征,从混合光谱、类质同象和同质多象等方面进手研究了矿物混合、化学成分、结构以及粒度等因素对光谱造成的影响,建立了一个小型的光谱库并与国外光谱库进行了对比,对德兴铜厂铜矿的钻孔岩芯和剖面样品进行了光谱测试,分析了光谱的反射率、Al-OH特征谱带的强度和位置、Fe-OH特征谱带的强度、Al-OH/OH比值等参数与矿化的关系,得出了以下一些结论1、不同的矿物都有着自己独特的光谱特征,Al-OH化学键在2200nm四周有单一的强谱带,Mg-OH化学键在2300nm四周有单一或两条强谱带,碳酸盐矿物则在2350nm四周有单一的强谱带,而光谱中1400和1900nm处-OH的谱带可以指示存在于矿物中水的赋存状态;2、粒度等外在因素并不会对光谱的特征谱带位置造成影响,对光谱的影响主要体现在光谱反射率上,而化学成分、结构等内在因素,对光谱特征起着决定性作用,矿物的混合将使混合光谱变得复杂,矿物的相互影响会使特征谱带的位置发生漂移,混合矿物中一方矿物的含量达到一定数目,其光谱特征谱带就能在混合光谱中体现出来,并且暗色矿物的特征谱带更轻易被识别。3、本文建立的近50条矿物光谱的小型光谱库可以进行检索和识别,并且矿物识别的结果与国外光谱库基本一致。4、在铜厂矿区绢云母蚀变广泛,原先的蚀变分带被后期蚀变严重破坏,所以从蚀变矿物上来判定矿化的位置相当困难,但是产于矿化和非矿化部位的绢云母在结构和成份上可能存在微细差别,这可以帮助确定矿化位置矿化部位的绢云母的结晶度相对稍低,而含水量则稍高于非矿化部位的绢云母。; 【Abstract】 This *** was supported by the great geological survey projects No.1212010660604 of China Geological Survey . In this ***, the Near-infrared mineral spectrum analyzer which was jointly developed by Nanjing Institute of Geology and Mineral Resources and Nanjing Zhong Di Instrument Company was taken as testing tool, and the researches about the testing and analysis of Mineral spectrum characteristics, the analysis of mineral spectrum changeability, the establishment of mineral spectrum database, and the application in DeXing porphyry copper deposit were carried out. The key contents of these researches are analysing the spectrum characteristics of muscovite, montmorillonite, kaolinite, chlorite and other altered minerals and Al-OH, Mg-OH, -OH and other molecule group; studying the influences resulted from mineral mixture, component, structure and granularity to spectrum, starting with mix spectrum, isomorphism and polymorphism; building a small spectrum database and being contrasted to foreign spectrum database; testing the drill cores and section samples in field, and discussing the relation between the spectral reflectivity, intensity and position of Al-OH band and Fe-OH band, Al-OH/OH and mineralization. The resultes are followed1. The spectrum characteristics are different from mineral to mineral. The spectral band of Al-OH lay around 2200nm, which is single and strong; In 2300nm, Mg-OH’s spectral band is single or double strong bands; Corbonate mineral has single strong spectral band in 2350nm; the–OH bands which are in 1400nm and 1900nm can indicate the occurrence status of water in minerals.2. Granularity just influence the spectral reflectivity, mineral spectrum characteristics are determined by component and structure, mineral mixture make the mixspectrum complex.3. The small spectrum database is consistent with foreign sepctrum database in mineral recognition.4. Sericite alteration is widespread in the ore district, the original alteration zone is destroyed seriously by the later period alteration, therefore it is quite difficult to estimate the mineralize position from the altered mineral, but there are tinily differences in the structure and component between the mineralization sericites and the non-mineralization seritcites The crystallinity of mineralization seritcites is relatively slightly low, but the water content is slightly higher than the non-mineralization seritcites.