Thixotropic behavior of clay colloid enhance green density of ceramic body = Thixotropic behavior of clay colloid enhance green density of ceramic body

다국어 초록 (Multilingual Abstract)

Traditionally, ceramic products have been created using raw materials that require high firing temperature and energy intensive processing. The fast increase of ceramic tille production in the world has lead to a fast decrease of the available raw materials and energy sources, and also generate huge amount of the waste tils. These may also contain harmful materials as the heavy metal elements that can contaminate the soil. Therefore alternative ways to reuse of these kinds of waste materials have been studied for reducing environmental issues. The present work aims at developing a new process for fabricating extra large scaled tiles with uniform packing density using rheology of colloidal suspension. To prepare the vibrated casting slurries, colloids of the waste tiles were added as a binder materials, and a thixotropic agent to avoid segregation between large and fine grains. The plasticity of the slurries may be governed by the rheology of colloids of the waste tile. To give thixotropic behavior, the dispersion and coagulation behavior of the colloidal suspension of will be investigated by zeta potentiometer. The blending of discrete sized to achieve a high packing density is essential in formulating batches, which may cause a little dimensional change during sintering. To get the maximum green density, four different particle sizes were mixed as the case of refractories. To give thixotropic behavior, the dispersion and coagulation behavior of the colloidal suspension were investigated by the zeta potentiometer. The point of zero charge of the suspension was shown sear pH 5 and maximum zeta potential was -55[mV] near pH 11. Maximum agglomerate particles were appeared near to the point of zero charge. The bending strength and water absorption of sintered bodies were more than 8.35kgf/cm2, and less than 5.0% above 1100℃ respectively. In addition, crystalline phase of sintered bodies were quarts and mullite. The micro-structure of the sintered body has a uniform pore size and distribution.