Analysis of anti-stripping mechanism of anti-stripping high alumina brick
2018-05-23
The use of high alumina bauxite as the main clinker, the introduction of a small amount of ZrO2 (because ZrO2 is a phase transition between monoclinic and tetragonal, can improve the product's resistance to thermal shock stability), add a certain amount of composite binder and additives, through control The particle size distribution of the mud, and the refractory products obtained by shaping and high-temperature firing become anti-stripping high-alumina bricks.
The anti-stripping mechanism is due to the fact that the microstructure characteristics of ZrO2 have been determined to have anti-stripping properties.
(1) There were obvious micro-cracks around the ZrO2 aggregates. The aggregates had obvious clearance and peeling from the surrounding corundum and mullite.
(2) The well-developed ZrO2 aggregates are columnar and form a layered distribution in space. There are small slits between ZrO2 and their size is only 1~5um, forming a channel structure. This kind of structure is superimposed on one another, with twists and turns, which is conducive to stress transmission and dispersion.
(3) Mullite is well developed and fibrous, and it intersperses with ZrO2 and corundum in space, forming a conforming structure. Obviously, ZrSiO4 reacts with surrounding Al2O3 when decomposed at high temperature to form ZrO2 and mullite. The presence of ZrO2 crystals prevents the growth of fibrous mullite crystals and plate-shaped corundum and is wrapped by it. Therefore, it is present around ZrO2. Chaotic state.
(4) The lithofacies analysis shows that the structure of corundum and mullite is interlaced and ZrO2 is intercalated. There are micro-cracks in the surroundings, and there are radial micro-cracks in the larger ZrO2 crystal itself and around it.
The above-mentioned structure of the anti-stripping high-alumina brick will have energy dissipation when subjected to stress, and improve the effect of thermal stability and high-temperature strength
