Assessing The Role of Type of Colloidal Silica and Deflocculantes on Properties of Refractory Concrete Free Cement

Abstract

Refractories used for construction the kilns. Refractory concrete is one of the most important types of refractories used for linings furnaces in cement, petrochemical industries and nuclear power plants. Refractory concrete is consisting of refractory aggregate and bonding material which is hydraulic, clay or phosphate bonds. Because of dehydration at high temperature which accompanied with reduction in compressive strength, new trend appears in type of bonding materials.This research aims to study the combined effect of type, percentage of colloidal silica and deflocculantes type in some properties of refractory concrete free cement. Two types of colloidal silica used ( densified and undensified) with (2,4,6,7,8,9)% of aggregate weight and two types deflocculantes ( sodium silicate and aluminum fluoride ) with 0.1% of aggregate weight are used . Results show the compressive strength increase 183.6% and the bulk density increases 18.4% when undensified colloidal silica increases from 2% to 9% using aluminum fluoride as deflocculantes. But when using densified colloidal silica compressive strength increase 92 .2% and the bulk density increases 9.3%.