Anti Spalling High Alumina Brick Introduction
Anti spalling high alumina brick, referred to as anti spalling brick or anti spalling refractory brick. It uses high alumina clinker as the main raw material, introduces a small amount of ZrO2 (due to the phase transition between monoclinic and tetragonal ZrO2, the thermal shock stability of refractory bricks can be improved), and adds a certain amount of composite binder and additives. By controlling the particle gradation of mud, it is prepared by molding and high temperature sintering.
| Parameters | Specifications |
|---|---|
| Refractoriness | Up to 1850℃ |
| Compressive strength | ≥120MPa |
| Flexural strength | ≥50MPa |
| Peeling rate | ＜0.3% (at 1000℃) |
| Chemical stability | Excellent |
| Product stability | Superior |
Anti Spalling High Alumina Brick Specifications
The standard size of the anti spalling high alumina brick is 230*114*65mm, and other sizes can be customized according to the drawings.
Anti Spalling High Alumina Brick Performance Principle
After the introduction of ZrO2, its microstructure determines its anti spalling performance.
(1) There are obvious microcracks around the ZrO2 aggregate, and there is obvious gap peeling between the aggregate and the surrounding corundum and mullite.
(2) Well developed ZrO2 aggregates are columnar and form layered distribution in space. There are small slits between ZrO2 with a size of only 1 ~ 5 microns, forming a channel structure. This kind of structure is disorderly and tortuous, which is conducive to stress transmission and dispersion.
(3) Mullite is well developed and fibrous, and exists in space with ZrO2 and corundum to form a composite reinforced structure. ZrSiO4 reacts with surrounding A12O3 during high temperature decomposition to form ZrO2 and mullite. The existence of ZrO2 crystal prevents the growth of fibrous mullite crystal and plate columnar corundum and is wrapped by it. Therefore, it is in a disordered state around ZrO2.
(4) Petrographic analysis shows that corundum and mullite structure are staggered, ZrO2 is intercalated, there are microcracks around, and there are radial microcracks in and around the larger ZrO2 crystal.
Advantages and Characteristics of Anti Spalling High Alumina Brick
(1) High fire resistance temperature.
(2) The softening temperature under 0.2MPa load is greater than 1500 ℃.
(3) Excellent thermal shock resistance.
(4) High compressive strength at room temperature, greater than 60MPa.
(5) Low apparent porosity and stable volume at high temperature.
(6) Excellent spalling resistance.
(7) Good chemical resistance.
Application of Anti Spalling High Alumina Brick
Anti spalling high alumina bricks are widely used in new dry process kilns, LIBOR kilns and wet process kilns. The parts used include kiln door cover, rising flue, cooling belt, decomposition belt, safety belt, transition belt, coolant rear wall and side wall and beam bending top.
