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题名	煤系高岭土表面改性的实验研究
作者	王绪海
学位类别	硕士
答辩日期	2004
授予单位	中国科学院过程工程研究所
授予地点	中国科学院过程工程研究所
导师	卢旭晨
关键词	煤系高岭土 超细化 表面包覆 锻烧
其他题名	Study on Surface Modification of Coal-measure Kaolin
学位专业	化学工艺
中文摘要	煤系高岭土是我国特有的矿产资源，伴生于煤系地层中，纯度高，杂质少，但白 度较低，极大地限制了其应用领域。本文研究了煤系高岭土的精细加工过程，包括煤 系高岭土原矿的超细化、锻烧和表面包覆TiO2，获得了白度高、遮盖性能较好的表 面改性产品，拓宽了产品的应用领域。在超细化过程中，煤系高岭土料浆的粘度随磨矿时间的延长而升高，即矿浆浓度 一定时颗粒的粒径越小，料浆的粘度越大。料浆呈现非牛顿流体的特性，切应力随切 变速率的增大而升高，而粘度则下降。分散剂可以吸附于煤系高岭土的表面上，赋予 颗粒间相互排斥作用，从而达到分散效果。煤系锻烧高岭土料，浆的粘度较小，不需要 添加分散剂也能在高固相浓度（70％（wt）下超细化。超细颗粒在锻烧过程中迅速脱去碳和有机物，使白度提高。颗粒大小、锻烧时间、 锻烧温度等因素，都影响锻烧产品的白度。采用溶胶一凝胶法在煤系高岭土表面包覆 TiO2，可使包覆产品的白度由煤系锻烧高岭土的82.2％提高到92.7％，遮盖力由煤系 锻烧高岭土的138.0g／m2变为55.5g／m2，产品性能提高。本文采用TiCl4-（CH3）2CHOH-H2O溶胶一凝胶体系制得TiO2前驱物溶胶，加入超 细煤系高岭土，进行表面包覆改性。包覆改性后Ti元素主要分布于煤系高岭土的表 面，当Ti元素的添加量为123％时，表面包覆后样品的能谱分析表明，煤系高岭土 表面Ti元素含量提高到21.6％～31.5％。X射线衍射分析表明，煤系高岭土表面的TiO2 以锐钛矿的形式存在，锐钦型TiO2的折射系数较低，光学性能较金红石型TiO2差。 为了促进金红石型TiO2的生成，需加入晶型转化剂，1％的MgF2就能有效地促进TioZ 晶型的转化。对包覆层TiO2用A12（SiO3）3进行处理，可以降低TiO2表面的微孔、改 变表面电荷、增强颜料在不同介质中的分散性，在造纸领域应用时，附着性增强。
英文摘要	The coal-measure kaolin is a unique mineral resource associated in coal stratum in our country. Although characterized by high purity, its application was limited by low whiteness. The present work has studied the main processing steps for producing the high grade kaolin from coal-measure kaolin, including ultrafine grinding, calcination of the raw kaolin and surface coating with TiO2 for the raw and calcined kaolin. The increased whiteness and the strengthened hiding power could broaden its application fields. In the ultrafine grinding process, the viscosity of coal-measure kaolin slurry gradually rises with the grinding time. In another words, the viscosity of the slurry could increase with the particle size decreasing. As a non-Newtonian fluid, the shear stress of the slurry increases with the shear rate elevating, while its viscosity drops. The dispersant agent may adsorb on the surface of particles, which endues with repulsive interaction because of the electric charge, thus leading to good dispersive effect. The slurry viscosity of the calcined coal-measure kaolin is low, and hence can be grinded at relatively high concentration(70%(wt)) without dispersant. The carbon and organic compound in the fine kaolin can be removed immediately by calcination, resulting in the increased whiteness of the coal-measure kaolin. Particle sizes, calcination time and calcination temperature affect the product quality. The performance of the product was improved through the technology of the surface coating with TiO2 gel by chemical synthesis. The whiteness and hiding power of the surface-coated product could increase from 82.2% and 138.0g/m2 before coating to 92.7% and 55.5 g/m2, respectively. The preceding product of TiO2 is obtained from the sol-gel system of TiCl4-(CH3)2CHOH-H2O. The process of surface coating carries on when the ultrafine coal-measure kaolin particles are added. The Ti element rests mainly on the surface of coal-measure kaolin. When the amount of Ti element is 12.3%, the superficial power spectrum analysis indicated that the mount of Ti element increased greatly on the surface, from 21.6% to 31.5%. X-ray diffraction analysis indicated that TiCh on the surface is in the type of anatase. As the refraction index of anatase is smaller than rutile, in order to promote the rutile TiC>2 production, it is important to introduce crystal transformation catalyzer. 1% of crystal transformation catalyzer of MgF2 can effectively promote the crystal transformation. Furthermore, to enhance the application fields of the product, it is needed to reprocess the particles coated with TiC>2. The reprocess technology with Al2(SiC>3)3 can reduce the pore of TiO2 on the coal-measure kaolin's surface, change surface electric charge and strengthen the dispersibility in different medium. The reprocess can increase the attaching power of the product when used as pigment, such as in the papermaking field.
语种	中文
公开日期	2013-09-16
页码	66
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1436]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	王绪海. 煤系高岭土表面改性的实验研究[D]. 中国科学院过程工程研究所. 中国科学院过程工程研究所. 2004.

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