What is the difference between fused refractory and sintered refractory?
Date:2019-12-25 15:50 From:Zhengzhou Sunrise Refractory Author:admin
The fused refractory is different from the sintered refractory. The sintered refractory is mainly a solid-phase reaction during firing, while the various raw materials of the fused refractory are completely liquid-phase reactions. The melt in the electric furnace is completely liquid and solidified. The post-composition phase is completely determined by the composition. This is not possible with sintered refractories. For example, sintered high-alumina bricks are composed of cristobalite and corundum. Since both exist in the form of particles, only mullite is formed at the interface between the two during firing. Therefore, the brick body is easily eroded from the high SO2 composition in use.
It is difficult to obtain complete mullite crystals from this brick. However, this problem does not exist in fused refractory materials. In the liquid phase, various chemical components are fully mixed and uniformly mixed in units of molecules, and finally recrystallized. The crystals develop well and the crystal form can be seen with the naked eye. The crystal of sintered refractory is very small, and it is generally invisible to the naked eye.
It is difficult to obtain complete mullite crystals from this brick. However, this problem does not exist in fused refractory materials. In the liquid phase, various chemical components are fully mixed and uniformly mixed in units of molecules, and finally recrystallized. The crystals develop well and the crystal form can be seen with the naked eye. The crystal of sintered refractory is very small, and it is generally invisible to the naked eye.
In this way, the crystal surface area of the fused refractory material is small in the same weight crystal, so the resistance to the etchant is good. Because the fused refractory is solidified in the liquid phase, the structure is very dense. This is also difficult to achieve with sintered refractories. In addition to the cast hole cavity caused by shrinkage, the porosity of other parts of the fused refractory is very small, which can theoretically reach the following, and it is a closed-mouth pore, so the erosion agent is not easy to penetrate.
In the case of sintered refractory materials using the same chemical composition of raw materials, because of their different crystal phases, the quality of crystallization is very different, so the selection of sintered refractory materials is very important. This problem does not exist with fused refractory materials. As long as the raw materials have the same chemical composition, the final product can get the same crystal phase, which makes quality control much easier. However, fused refractory materials have high power consumption and complicated production technology.