Anti spalling high alumina brick

Anti-stripping high-alumina brick with high-alumina bauxite as the main raw material, introduce a small amount of ZrOz (due to the phase transition between monoclinic crystal system and tequad ZrO2, can improve the thermal shock stability of the product), add a certain amount of composite binder and additives, through the control of mud particle size, through the molding and high temperature fired refractory brick become anti-stripping high-alumina brick.

Advantages

Strong resistance to spalling, thermal shock resistance, low thermal conductivity, excellent anti-erosion performance.

Principle of properties of high alumina brick against spalling

After the introduction of ZrO2, its microstructure determines its spalling resistance.

(1) There are obvious micro-cracks around the ZrO2 aggregate, and the aggregate has obvious gap spalling with the surrounding corundum and mullite.

(2) Well-developed ZrO2 aggregates are columnar and stratified in space. ZrO2 has a small slit between the size of only 1~5 microns, forming a channel structure. This structure is disordered and tortuous, which is conducive to stress transfer and dispersion.

(3) Mullite is well developed and fibrous, and exists in the space with ZrO2 and corundum, forming a composite reinforced structure. ZrSiO4 reacts with surrounding A12O3 to form ZrO2 and mullite during high-temperature decomposition. The presence of ZrO2 crystals prevents the growth and coating of fibrous mullite crystals and lamellar corundum. So, it's out of order around ZrO2.

(4) Petrographic analysis shows that corundum and mullite are interleaved, ZrO2 intercalated and surrounded by microcracks. The larger ZrO2 crystals have radial microcracks in and around them.

Application

Anti - spalling high alumina brick is widely used in new dry kiln, LIBOR kiln and wet kiln. Cement kiln preheating area, calciner lining, large cooler bottom area.