Refractory castables and refractory plastics belong to amorphous refractory materials, which are made of refractory aggregates, powders, binders, etc., in addition to the different construction methods, refractory castables are refractory plastics with different uses.
1。 Refractory castables
Many properties of refractory castables depend to an appropriate extent on the variety and quantity of binders. In terms of strength, except for those made of light particles, the strength of the granular material is generally higher than the strength of the hardened body of the binder and the bond between it and the particles, so the strength of the castable actually depends on the binding strength of the binder.
The fluidity of refractory castables is generally higher than that of refractory ramming materials, therefore, most refractory castables can be placed tightly and covered with models only by pouring or then vibrating. After the castable is formed, it is necessary to adopt appropriate methods to promote hardening according to the hardening characteristics of the binder. For example, cement should be protected under appropriate wet conditions. For some metals, inorganic salts are dried and baked.
The high-temperature properties of refractory castables are also closely related to the variety and dosage of binders. If the granular and powdery materials selected have excellent fire resistance, and the melting point of the binder is both high and does not react with the refractory material to form a low melt, then the refractory castable must have an appropriately high fire resistance. If the lining of the granular and powdery materials used must be certain, the fire resistance of the refractory castable is controlled by the binder to an appropriate extent, because most or most or even all of the fusible components in the pouring made of general aluminate cement are always contained in the cement stone, so the amount of cement has a very significant impact on the high-temperature properties of the refractory castable.
2。 Refractory plastic
Refractory plastic (plastic refractory) is a kind of amorphous refractory material with high plasticity over a long period of time and is in the form of soft mud paste. It is composed of refractory particles and fine dressing, binders, plasticizers and moisture. Particles and fines can be used in a variety of materials for noise resistance: material preparation, but now widely used is aluminum silicate refractories. In order to improve the drying strength of plastics, a certain amount of cementing materials such as water glass, phosphoric acid, aluminum sulfate and so on are generally added to the plastic. Aluminium silicate can be plastic, and is now widely used in the ramming lining of various industrial furnaces and as part of the repair of the lining of thermal equipment.