光谱学与光谱分析, 2019, 39 (9): 2929, 网络出版: 2019-09-28  

大宝山多金属矿床氧化微粒的X射线衍射和近红外光谱分析及其意义

XRD and NIR Analysis of Oxidation Particles in Dabashan Polymetallic Deposit and Its Significance
作者单位
1 中山大学地球科学与工程学院, 广东 广州 510275
2 广东省地质过程与矿产资源探查重点实验室, 广东 广州 510275
摘要
利用XRD和NIR技术对大宝山东岗岭组下亚组氧化矿中7个氧化物样品微粒进行分析, 其中前4个样品为同一标高, 后3个样品为不同标高。 XRD, NIR研究结果表明随着氧化程度的加深(04-2→04-3→04-4), Al—OH矿物吸收峰位所对应的波长不断加大(2 16072→2 16305→2 20036 nm), 说明矿物中的阳离子Al被取代, 产生贫Al现象; 且对应的峰的强度从708×10-4, 783×10-3到666×10-2, 说明Al—OH矿物的含量不断上升; 另外SO2-4矿物所对应的吸收峰位(1 93880→1 94694→1 92647 nm)的强度从5635×10-2, 182×10-2到1668×10-2, 说明随着氧化的进行, SO2-4矿物的含量不断下降, 结合前人研究, 我们可以推测出早期形成的铜多金属硫化物矿床在后期发生强烈氧化作用, 使得硫化矿体氧化, 其中的硫经氧化形成强酸性硫酸溶液, 围岩受到硫酸溶液的腐蚀, 转变成松散的黏土; 在04-2, 04-3, 13-1号样品中发现钠明矾石和钾明矾石, 矾类矿物的大量发现说明该矿区的氧化淋滤作用仍在进行; 通过XRD与NIR技术发现了石英、 绢云母、 方解石、 绿帘石、 角闪石、 透闪石、 金云母、 绿泥石、 高岭土等矿物, 很好的反映出蚀变类型, 且与此区域的地质特征相吻合, 目前近红外已开始用于矿床勘查中的蚀变填图。 通过光谱分析发现了矿床深部氧化过程与阳离子取代间的关系, 并以光谱学的视角验证了前人对于大宝山矿床成因的解释。 研究表明一方面XRD和NIR可以有效的分析土壤和岩石的矿物成分, 从而为该地区矿床矿石研究提供服务; 另一方面NIR可以波长的迁移情况反映离子交代, 峰的尖锐程度反映结晶程度, 峰的强度反映矿物含量, 这些独具的优势使其可以从微观角度研究矿物的氧化。 不过有一点需要指出来, 和近红外与X射线衍射在其他领域的研究相比, 这两种技术在地质学的应用需要进一步加深, 包括地质学应用的理论基础研究和光谱的分析解释手段, 以尽量做到不仅可以通过光谱技术分析出所对应的矿物类型还能快速分析出不同矿物的含量及同一矿物的不同构型。
Abstract
XRD and NIR techniques were used to analyze the seven oxide sample particles in the lower sub-group oxidized ore of the Dabaoshan dong Gangling Formation. The first four samples were of the same elevation and the latter three samples were of different elevations. XRD and NIR results show that as the degree of oxidation deepens (04-2→04-3→04-4), the wavelength corresponding to the absorption peak of Al—OH mineral increases continuously (2 16072→2 16305→2 20036 nm). It is indicated that the cationic Al in the mineral is substituted, resulting in an Al-poor phenomenon; and the corresponding peak intensity is from 708×10-4, 783×10-3 to 666×10-2, which indicates that the content of Al—OH minerals is increasing; in addition, the intensity of the absorption peak corresponding to SO2-4 mineral (1 93880→1 94694→1 92647 nm) is from 5635×10-2, 182×10-2 to 1668×10-2. It is indicated that the content of SO2-4 minerals decreases with the progress of oxidation. Combined with previous studies, we can speculate that the early formation of copper polymetallic sulphide deposits will undergo strong oxidation in the later stage, causing the sulfide ore bodies to oxidize. Oxidation forms a strongly acidic sulfuric acid solution, and the surrounding rock is corroded by a sulfuric acid solution to convert it into loose clay; Sodiumalumite and potassium alumite were found in samples 04-2, 04-3, 13-1. A large number of strontium minerals indicate that the oxidative leaching of the ore is still ongoing; Minerals such as quartz, sericite, calcite, epidote, hornblende, tremolite, phlogopite, chlorite, kaolin, etc. have been discovered by XRD and NIR techniques, which reflect the type of alteration, and the geological features of the area are consistent. At present, near-infrared spectroscopy has been used for alteration mapping in mineral deposit exploration. In this paper, the relationship between the deep oxidation process of the deposit and the cation substitution was discovered by means of spectroscopy, and the interpretation of the genesis of the Dabaoshan deposit was verified by the spectroscopy. The results of this paper show that on the one hand, XRD and NIR can effectively analyze the mineral composition of soil and rock, and provide services for the ore deposit research in this area. On the other hand, NIR can reflect the ion transfer and the sharpness of the peak reflects the crystallization. The intensity of the peak reflects the mineral content, and these unique advantages make it possible to study the oxidation of minerals from a microscopic point of view. However, there is one point that needs to be pointed out. Compared with the research of NIR and X-ray diffraction in other fields, the application of these two technologies in geology needs to be further deepened, including the theoretical basis for the application to geology research and analysis and interpretation of the spectrum, in order to not only analyze the corresponding mineral types by spectroscopy, but also quickly analyze the content of different minerals and different configurations of the same mineral.

邓永康, 曹建劲, 党万强, 王国强, 刘翔, 李德伟. 大宝山多金属矿床氧化微粒的X射线衍射和近红外光谱分析及其意义[J]. 光谱学与光谱分析, 2019, 39(9): 2929. DENG Yong-kang, CAO Jian-jin, DANG Wan-qiang, WANG Guo-qiang, LIU Xiang, LI De-wei. XRD and NIR Analysis of Oxidation Particles in Dabashan Polymetallic Deposit and Its Significance[J]. Spectroscopy and Spectral Analysis, 2019, 39(9): 2929.

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!