章村南部伊利石粘土岩及其伊_蒙混层矿物特征研究.doc

章村南部伊利石粘土岩及其伊/蒙混层矿物特征研究 【中文摘要】伊利石是一种重要的无机非金属矿产,被广泛应用于造纸、化妆品、塑料、橡胶、油漆、陶瓷、线缆尽缘材料等产业领域,但自然产出的纯伊利石粘土岩比较少见,伊利石在一定条件下可转化为蒙脱石,在转化过程中首先形成伊/蒙混层矿物这一过渡矿物。伊/蒙混层矿物的存在将会影响到伊利石的矿物特性和工艺性能,限制其产业应用范围。本文主要研究了章村南部二叠纪地层中伊利石粘土岩的赋存层位、矿物学特征、化学成分特征及微量元素特征;通过X-射线衍射XRD、红外光谱IR、扫描电镜SEM等仪器分析,具体研究了伊利石粘土岩中伊/蒙混层矿物的含量及其在不同混层比条件下的矿物学特征。研究发现研究区内叠系地层中具有产业开采价值的伊利石矿共有7层,各层伊利石的SiO_2/Al_2O_3值在1.71-2.75之间,Fe_2O_3含量总体偏高,微量元素含量多数低于或接近地壳中元素的丰度值。X-射线衍射测试结果显示伊利石粘土岩中主要的粘土矿物有伊利石、伊/蒙混层矿物、叶腊石、蛇纹石等。红外光谱测试结果主要呈现四种类型的IR图谱①伊利石伊/蒙混层型;②伊利石-蛇纹石型;③叶腊石-蛇纹石型;④伊利石-叶腊石-蛇纹石型。扫描电镜下各类粘土矿物的单体形态多呈大小各异的片状,集合体形态相差较大。利用伊/蒙混层矿物的结构随混层比的变化而变化的特点,研究了不同混层比条件下伊/蒙混层矿物的矿物学特征。XRD分析结果显示随着混层比的增加,伊/蒙混层矿物XRD图谱中的10特征衍射峰将向高角度移动,峰值逐渐变小。分析了混层比分别为5,10,15,20,25,30的伊/蒙混层矿物的IR图谱,结果表明随着混层比的变化,IR图谱变化较为明显的有三个区域3625cm-1,1200-1000 cm-1,850-700 cm-1。由此可推断出混层矿物IR图谱的外形受Al3对四面体中Si4的置换程度的控制;扫描电子显微镜测试结果显示含膨胀性晶层的伊/蒙混层矿物层状结构明显,边界清楚;含非膨胀性晶层的伊/蒙混层矿物的层状结构不明显,单体外形轮廓不明显,边沿破碎,呈丝缕状,集合体具有玻屑假象。; 【Abstract】 Illite is an important inorganic non-metallic mineral.It is widely used in the industrial fields especially in the ceramic and rubber,*** industry and ****** and so on. But pure illite clay rocks are relatively rare in the nature.Illite can be transed into montmorillonite under certain conditions and be transed firstly into I/S mixed-layer minerals which will affect the minerals properties and process properties of illite.The aim of this *** was to explore occurrence horizon,mineralogical characteristics,chemical composition and characteristics of trace elements of the illite clay rocks in Permian system of study area by using X-ray diffractionXRD,infrared spectroscopyIR,scanning electron microscopySEM and so on.The mineralogical characters of I/S mixed-layer minerals with different mixed-layer ratio were studied in detail.Seven stratums illite rocks having industrial exploitation value were found by combining with both field observation including field investigations,sampling,sample hand observation and laboratory analysis including XRD,IR,SEM.The ratio of SIO_2/Al_2O_3 of seven stratums was 1.71-2.75;The contents of Fe_2O_3 were overall high in the whole and the content of trace elements were close to the abundance value of elements in crust.The results of XRD test showed that the major clay minerals in illite clay rocks were illite,I/S mixed-layer minerals,pyrophyllite,serpentine,etc...The IR patterns of illite clay include four types①illiteI/S mixed-layer type;②illite-serpentine type;③pyrophyllite- serpentine type;④illite-pyrophyllite-serpentine type.The SEM results showed that the shape of various clay minerals monomer was flake with different sizes, the aggregates were different with each other.The mineralogical characteristics of I/S mixed-layer minerals with different mixed-layer ratio were studied by using XRD,IR and SEM.The XRD patterns showed that the character peak with 10 value moved to a higher angle with increase of mixed-layer ratio and became smaller thanl0 value.The IR spectrums of I/S mixed-layer minerals with mixed-layer ratio of 5,10,15,20,25and 30 were analyzed and the results showed that three regions including 3625 cm-1, 1200-1000 cm-1,850-700 cm-1 in all spectrums had taken place great change regularly. It was confirmed that the shape of IR spectrum was controlled by the replacement degree of Al3 on Sl4.The SEM pictures showed that I/S mixed-layer minerals with expansible crystal layer had obvious layered structure with clear border.In the contract, the layer structure of I/S with non-expansible crystal layer was not obvious and its\ monomer was in the shape of broken edge appeared as fili and the aggregate appeared as glass litter illusion.