Investigation of clay content and sintering temperature on attrition resistance of highly porous diatomite based material
Investigation of clay content and sintering temperature on attrition resistance of highly porous diatomite based material
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DOI：
10.1016/j.clay.2011.02.008
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发表时间：
2011-04-01
影响因子：
5.6
通讯作者：
Graule, Thomas
中科院分区：
文献类型：
--
作者：
van Garderen, Noemie;Clemens, Frank J.;Graule, Thomas
直径为500 μ m的硅藻土基颗粒通过挤出生产，加入16、28和48体积%的高岭土和有机粘合剂，以优化流动性能。研究了粘土含量和烧结温度对陶瓷微观结构和耐磨性的影响。在800 ℃下通过压汞孔隙率测定法获得双峰孔径分布。小于250 nm的孔径被认为是源于多孔结构，而较大的孔径主要来自颗粒间孔隙度。硅藻的中孔和大孔在1100摄氏度下趋于闭合，并且由于在较高温度下的聚结，出现单峰大孔尺寸分布。在1100和1300摄氏度之间的温度范围内的孔径的增加与粘土和粘土之间的不同的烧结行为。此外，在1100至1300摄氏度之间的烧结温度下观察到α-方石英结晶。通过研磨试验和一种新的分析方法来评估不同磨损行为的材料，以确定耐磨损性。新的分析方法使用从耐磨性行为与转数获得的指数的绝对值。高粘土含量和高烧结温度可使材料发生莫来石和方石英相转变，从而提高材料的耐磨性。(C)2011 Elsevier B. V.保留所有权利。
Diatomite based granulates with a diameter of 500 mu m were produced by extrusion with the addition of 16,28 and 48 vol.% kaolin and organic binder in order to optimise the flow behaviour. The influences of clay content and sintering temperature on the microstructure and attrition resistance were investigated. Bimodal pore size distribution was obtained by mercury intrusion porosimetry at 800 degrees C. Pore sizes smaller than 250 nm were assumed to originate from the diatomite porous structure and the larger ones mainly from the interparticle porosity. Meso and macropores of diatoms tend to close at 1100 degrees C and due to coalescence at higher temperature a unimodal macro pore size distribution occurs. An increase of the pore size in temperature range between 1100 and 1300 degrees C was associated with a different sintering behaviour between diatomite and clay. Additionally alpha-cristobalite crystallization was observed at sintering temperatures between 1100 and 1300 degrees C. Attrition resistance was determined by a grinding test and a new analysis method to evaluate different attrition behaviour materials. The new analysis method uses the absolute value of the exponent obtained from attrition resistance behaviour versus the number of revolutions. High clay content in diatomite based materials and high sintering temperature lead to an increase of attrition resistance of the material due to phase transformations of the materials into mullite and cristobalite. (C) 2011 Elsevier B.V. All rights reserved.