金刚石氮缺陷定量模型及其找矿意义

Diamond is a rare and valuable mineral resource, has unique physical properties, and is an important strategic resource for new industries. China has less proven reserves of diamond and are therefore less pursued for development and exploitation. Diamond is identified as a new important industrial mineral resource in The Strategic Action of breakthrough prospecting. Therefore, the application of novel concepts and new methods to enhance the studies on diamond genesis and prospecting mineralogy, are urgently required to assist in prospecting. The physical properties of diamond crystals, such as morphology and optics, are often used as the standard features of deposits. These properties are closely related to the content of diamond defects and their forms of occurrence. In China and abroad usually people use infrared spectroscopy to quantify nitrogen content and its form of occurrence. Although this method has been successfully applied in prospecting, due to the complex characteristics of different nitrogen defects in the mid-infrared region, and because the method of analysis in infrared spectrum is limited, the results from infrared spectroscopy of quantitative nitrogen defects are plagued with up to 25% error in. Thus, precise characterization of quantitative nitrogen deficiency is an important challenge. This proposal attempts to develop a quantitative model based on the characteristics of diamond nitrogen by using the convolution curve and the second-order partial derivative to analyses the infrared spectrum and to precisely quantify the standard feature of nitrogen defect, and to explain the diamond genesis from standard micro-characteristics. The results from this study would be useful for prospecting.

金刚石是稀有的、贵重的矿物资源,有优异的物理性能，是新型产业重要战略资源。我国金刚石探明储量少，可供开发利用不足。找矿突破战略行动已经将金刚石确定为重要新兴产业矿种。因此，急需用新思维、新方法增强金刚石成因与找矿矿物学研究，指导找矿。金刚石晶体的形态、光学等物理特性常被用作矿床的标型特征，而与这些物理特性密切相关的是金刚石结构缺陷的含量及其赋存形式，其中以氮缺陷为主。国内外通常采用红外光谱图定量氮含量及其赋存形式。虽然用这一方法取得了很多找矿成果，但是，由于不同氮缺陷在中红外区的特征复杂，加上对红外光谱图解析手段有限，造成通过红外光谱图定量氮缺陷存在25%的误差。因此，如何精准氮缺陷定量被提上了日程。本文通过使用卷积曲线和二阶偏导解析红外光谱图，精准氮缺陷标型特征，从其自身的微观标型特征解释金刚石成因，建立基于金刚石氮指示特征的定量模型，这对指导找矿具有重要意义。

金刚石为找矿突破战略行动中的重要新兴产业矿种。本项目以山东省蒙阴临沂地区金刚石地区为研究对象，对矿区的成矿地质背景、成矿时代、成因类型及矿化类型进行基于大数据的分析研究，初步建立找矿模型的概念。在此基础上，研究了蒙阴胜利1号岩管的金刚石晶体形貌和金伯利岩岩性，阐明了金刚石的氮含量与形貌的关系，发现了氮缺陷是在金刚石结晶过程中被摄取的，并建立了较为可信的找矿概念模型，为以后矿区深部（1000m以下）的预测工作提供了参考。