The substance added to make the monolithic refractory bond and obtain initial strength even at room temperature is called the monolithic refractory binder.
Since the unshaped refractory material has not been fired at a high temperature before use, there is no ceramic bond or direct bond between the particles like ordinary sintered products, and they can only be bonded as a whole by the action of the binder, and the structure or The product has a certain initial strength. Particles basically maintain their original characteristics in the unshaped refractory material, but because the binder binds it into a structure or product, the performance of the product is largely affected by the binder. Therefore, the binder is an important component in the monolithic refractories. In unshaped refractory materials, the bonding performance and other beneficial effects of the binder should be fully utilized, while the adverse effects of the binder on the high temperature properties of the material should be minimized and avoided.
Therefore, not all substances can be used as binders for monolithic refractory materials.
1. Binder Selection Requirements
As a binder for monolithic refractories, the following conditions must be met:
1. It can harden at room temperature and make structures or products produce sufficient strength. Generally, it is required that the compressive strength after drying at 110°C is greater than 15MPa;
2. The volume change during hardening is small, and the volume change rate is less than 1%;
3. A certain strength can be guaranteed even at high temperature;
4. The performance of monolithic refractories cannot be significantly reduced;
5. No harm to human body and environment;
6. Low cost;
7. You can purchase goods stably from the market.
2. Common unshaped refractory binders
According to different bonding methods, binders for monolithic refractory materials can be divided into hydration bonding, chemical bonding, ceramic bonding, adhesive bonding, coagulation bonding, etc.