Glass Phase Of Fused Cast AZS Brick
2015-10-16
The composition of fused cast AZS brick are baddeleyite, corundum, mullite, glass phase and pores. In order to reduce and eliminate residual thermal stress, products need to have a certain amount of glass phase which is as the absorbent for the thermal stress. However, glass phase of fused cast AZS brick is the weak link to resist erosion of glass liquid, during the process of erosion, first is the exudation of glass phase, then replace with high temperature glass liquid, and then accelerate the erosion of the crystal phase. The segregation of fused cast AZS brick is also reflected in the glass phase. As to fused cast AZS brick 33#,36#,41#, the content of glass phase is 20%-14%, so the effect of the characteristics of the electric melting brick can not be ignored.
In theory, there is no glass phase of AZS which represents alumina, zircon, and silica, even if there is a small amount of impurities, glass phase is also rare when no alkaline oxide is added. In production due to the introduction of basic oxides (Na2O) which lead to most silica into glass phase. The sodium oxide and silicon oxide and alumina together constitute the backbone of composition of glass phase. If the content of sodium oxide in raw material reduces from 1.37% to 0.65%, the glass phase number was significantly reduced from 21.5% to 12%. However, increasing sodium content obviously reduces the viscosity of the glass phase, so it is an ideal range when the content of sodium is less than 1%.
From the view of pollution to glass liquid and improvement of glass phase, iron oxide, titanium, calcium, magnesium and other impurities, the less the better. These increases in the number will increase the number of glass phase, while reducing the viscosity of the glass, which is not only pollute the glass products and affect the product service life. Iron oxide, titanium content is controlled at less than 0.2%.
In a word, the good quality fused cast AZS brick is that has the lowest level pollution to glass liquid and longest service life.
