Corundum Mullite Ultra-low Cement Prefabricated Blocks

Corundum-mullite ultra-low cement prefabricated blocks:

Amorphous refractory prefabricated blocks are mainly made of refractory castables and refractory plastic materials. They are classified into castable prefabricated blocks and plastic prefabricated blocks; there are prefabricated blocks with binders such as aluminate cement, water glass, phosphoric acid and aluminum phosphate, clay bond and low cement; according to the type of aggregate, they are divided into high-aluminum, clay, silica and corundum prefabricated blocks; according to the molding method, they are divided into vibration molding, vibration pressure molding and ramming molding prefabricated blocks; the mass of prefabricated blocks ranges from tens of kilograms to several tons, so they are divided into large, medium and small prefabricated blocks; prefabricated blocks are equipped with steel bars and anchors, so they are divided into ordinary prefabricated blocks, steel bar prefabricated blocks and anchor prefabricated blocks.

The setting and hardening mechanism of ultra-low cement refractory castables is that coagulation and bonding play a leading role, while cement plays the role of a delayed coagulant. For example, when SiO2 ultrafine powder is added, it forms colloidal particles after encountering water, and adsorbs Al+3 and Ca2+ ions that are slowly dissolved during the hydration of calcium aluminate, causing its zeta potential to drop. When the "isoelectric point" is reached, setting and hardening occurs. In addition, silanol groups can be formed on the surface of active SiO2, which dehydrate and bridge to form a siloxane network structure during the drying process, and adsorb Al3+, Ca2+ and Na+ ions brought by electrolytes, which can also produce setting and hardening effects.