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The sintered AZS brick is a product made of zircon and alumina as main materials and using pre-synthetic aggregate as aggregate. Because the blank is infertile, it is not effective to increase the density of the product only by increasing the molding pressure. The increase in the number of times of pressing of large products will also lead to the phenomenon of spalling and uneven density. It is necessary to adjust the critical particle size composition, add a composite binder and a small amount of TiO2. , MgO sintering aid and strengthening sintering to achieve the purpose of dense sintering.

 

Its production principle is based on the solid-phase reaction between ZrSiO4-AI2O3:

3AI2O3 + 2ZrSiO4- + 3AI2O3-2SiO2 + 2ZrO2 This reaction is irreversible and is also called "in situ reaction". Due to the large volume effect produced in the reaction sintering process, which causes the body to deform and crack, only zircon mullite aggregates can be pre-synthesized, and sintered or fused corundum raw materials can be used to produce mullite, zirconia and corundum three-phase Materials are superior to two-phase materials in terms of strength and thermal shock resistance. The microstructure of sintered AZS bricks is mainly characterized by the uniform distribution of fine zirconia particles between the main crystalline phases mullite and corundum.

Electrofusion recombination AZS bricks are made by melting AZS clinker, scraps or recycled residual bricks (removing adhered glass) as raw materials, and adding a small amount of kaolin or alumina as a binder. When heated to high temperature, the fused AZS aggregate exudates the glass phase and the binder forms mullite, which promotes the product to sinter. The peritectic reaction of the glass and crystal phases in the fused AZS aggregate will also form mullite. At this time, mullite and ZrO2 are in the form of encapsulation and encapsulation. The "self-sinterability" of fused AZS aggregate is the basic principle for the production and recombination of AZS bricks.

 

The microstructural changes of high-temperature firing electrofusion combined with AZS bricks are mainly:

①. The coarse-grained glass phase exudates to the surface of the particles and reacts with AI2O3, forming a mullite shell to close the exudation channel so that the peritectic reaction proceeds inside the particles;

②. The glass phase of fused AZS powder reacts with active AI2O3, and the matrix is mullite. The microstructure of the combined AZS brick has the structural characteristics of dense combination of mullite and corundum zirconia eutectic.