Factors affecting the price of high alumina bricks
It depends on the specific aluminum content of the high-alumina bricks, because the aluminum content is different and the price is different. In high alumina materials such as alumina, mullite and corundum, adding kyanite, andalusite or sillimanite (three stones), or adding a compound of these minerals, can significantly improve the microstructure of the product , So as to improve and enhance the quality of traditional refractory products, or develop new varieties. In addition to sillimanite bricks for blast furnaces and low-creep bricks for hot blast stoves, the new varieties mainly include: high-load softening temperature it high thermal shock high alumina bricks, micro-expansion high alumina bricks, cement kilns and electric furnaces Phosphate the for top use.
(1) When kyanite concentrate is added to high-alumina materials, a large amount of mullite is formed at 1300°C. This mullite is primary mullite. After that, the two samples of KDKC (alumina + kyanite) and KCC (corundum + kyanite) both increased greatly with the increase of the calcination temperature. This indicates that the SiO2 produced by the decomposition and transformation of kyanite reacts with alumina or corundum to form mullite, which is secondary mullite.
The two samples (KDKC and KCC) completed the secondary mullite at different temperatures. From the analysis of the generated mullite content, the KDKC sample has a mullite content of 86% at 1500°C, indicating that the secondary mulliteization has been completed at this temperature. In the KCC sample, at 1500℃, the mullite content is 67%, indicating that at this temperature, the secondary mulliteization has not been completed. Even if the temperature reaches 1600℃, the mullite formation is only 77%, and there is still 14% corundum. , Has not yet completed the second mullite petrochemical. The corundum + kyanite sample completed the secondary mulliteization only when the temperature was greater than 1600°C.
The above discussion shows that there is a difference in the completion temperature of secondary mullite for bauxite + kyanite and corundum + kyanite, the former is easy, the latter is more difficult. The reason is that bauxite has a smaller particle size than corundum, and because bauxite clinker contains a large amount of impurities such as TiO2 and Fe2O3, it is easier to react.
