In order to compensate or improve the performance of refractory castable, it is necessary to add refractory particles or fine refractory powder (referred to as special additive materials or admixtures) with different main components to the material.
Generally, the materials added below 5% (mass fraction) and able to improve the performance and construction performance of basic constituent materials as required are called admixtures; If the content of added material is higher than 5%, it is called additive. In practical application, additives are also commonly known as admixtures. Admixtures mainly play a role in binding agents and basic materials. There are many varieties of them, and each variety has a certain scope of application. Therefore, additives should be determined and selected according to the performance requirements of refractory castables.
For example:
(1) For refractory castables with large re burning shrinkage, a certain amount of expansive materials in the ingredients shall be used to compensate for its volume shrinkage, ensure its volume stability, and inhibit the spalling and damage of the structure.
(2) When it is necessary to further improve or enhance the thermal shock resistance of refractory castables, an appropriate amount of toughening materials should be added to the ingredients to give them non-linear performance and improve their thermal shock stability.
(3) When it is necessary to further improve and enhance the impermeability of refractory castables, a certain amount of components with high impermeability can be added to the ingredients to inhibit the penetration of the slag into its interior.
(4) To further improve the corrosion resistance of refractory castables, a certain amount of materials that can improve the corrosion resistance of the refractory castables or materials that can increase the viscosity of the slag can be added to the ingredients.
(5) In general, the composite refractory castable should be added with antioxidant to inhibit the oxidation damage of the material and prolong its service life.
High performance refractory castables generally use composite admixtures, that is, several admixtures are used together to ensure the normal temperature index and high temperature performance of materials.
Post time: Oct-24-2022