Selection Of Raw Materials And Particle Size For Low Creep Refractory Bricks

Selection of raw materials and particle size for low creep refractory bricks

1. Raw materials
In the AL2O3-SiO2 material system, mullite and corundum are important raw materials, and there are many varieties of raw materials, taking mullite as an example. How to choose raw materials?
Selection criteria:
1. Characteristics of each raw material;
2. Appropriate price. Generally speaking, the development of fused mullite crystals is better than that of sintered mullite crystals, and the framework formed by the interlocking of mullite crystals is relatively firm; Fewer grain boundaries reduce grain boundary slip, which is beneficial for creep resistance. So when making low creep refractory bricks, * * choose fused mullite. The quality of sintered mullite from various brands, including alumina based mullite, is superior to the corresponding alumina based mullite; Compared with the corresponding brands of alumina based mullite, the "three stones" quality mullite has a higher content of mullite and better crystal development in the former. The wet process obtains mullite with better quality than the corresponding brands of mullite obtained by the semi dry process due to sufficient material homogenization. In the selection of "three stones" in standardized products, more choices are made for composite raw materials of sillimanite and rhodochrosite.
2. Granularity

When developing new products, attention should be paid to particle size distribution. Different particle size distributions affect the performance of the product. The traditional three-level ingredients of coarse, medium, and fine are no longer suitable. In today's world where nanotechnology has been applied to technology and daily life, the ingredients for refractory materials should be selected in multiple stages, in accordance with the principle of tight packing as much as possible, to obtain a dense body. The minimum requirement for grading is four levels: coarse, medium, fine, and fine. At the same time, the particle size of the raw materials should be continuous, with each particle size range covered, and try to comply with the principle of tight packing.

3. Temperature

The selection of calcination temperature is very important to ensure a tight bond between the matrix and the aggregate. There are still many characteristics of "San Shi" that need to be further explored and utilized, such as thermal shock resistance, CO resistance, electrical insulation, etc. In summary, this is the author's experience in the development and application of "Three Stones". With further understanding of "Three Stones", it will have greater development and role in the future, and the market prospects will be broader.