Refractory raw materials are the cornerstone of refractories, regardless of how technology advances. The material evolution also directly affect refractory quality. The support is essential to the development of all new refractory materials for cement kilns.
For instance, such as magnesia-alumina spinel, iron-aluminum spinel, and magnesia-iron spinel are all inseparable from magnesia-aluminum spinel, iron-aluminum spinel, and magnesia-iron spinel bricks. As another illustration, zircon, silicon carbide, andalusite, and kyanite are inseparable from special high-alumina bricks such as anti-stripping bricks and silica bricks. Additionally, practically all high-grade monolithic refractory materials cannot be separated from one another.
1、Spinel made of magnesium and aluminum
A refractory raw material with a high melting point, a low thermal expansion coefficient, a low thermal conductivity, good thermal shock stability, and strong corrosion resistance is magnesium-aluminum spinel. It can be split into sintered magnesia-aluminum spinel and fused magnesia-alumina spinel based on the various synthesis methods.
Magnesium-aluminum spinel has strong thermal shock stability, corrosion resistance, and abrasion resistance. Its two most significant uses are: first, the replacement of magnesia-chrome sand in the production of magnesia-aluminum spinel bricks for cement rotary kilns, which not only prevent chromium pollution but also have good spalling resistance; and second, the production of ladle castables, which significantly enhances steel lining corrosion resistance. It is extensively utilized in steelmaking refractory materials. The creation of premium pre-synthesized spinel offers fresh raw materials.
2. Silicon carbide
Silicon carbide is widely used in abrasives, heating elements, refractory materials and structural ceramics due to its high hardness, electrical conductivity, high temperature resistance and high strength. Commercially available silicon carbide is divided into black and green. Black silicon carbide is mostly used in refractory raw materials.
Silicon carbide has good high temperature resistance. Under normal pressure, the inconsistent melting temperature of silicon carbide is 2760°C, silicon carbide has high strength, and the flexural strength can reach 625MPa. Silicon carbide has good thermal shock resistance, thanks to its moderately low thermal expansion coefficient (4.7×10-6K-1) and high thermal conductivity [84W/(m·K)]. Therefore, silicon carbide is widely used to make various ceramics and refractory raw materials.
3、Zircon
Zircon sand has low thermal expansion, high thermal conductivity, and strong chemical stability, and is mainly used in the production of refractory raw materials: zirconium refractory materials, such as zirconium corundum bricks, zirconium refractory fibers.
It can be used to make zircon bricks for glass kilns, zircon bricks for steel drums, ramming materials and castables; it can be added to other materials to improve its performance, such as adding zircon sand to synthetic cordierite, which can widen cordierite The sintering range without affecting its thermal shock stability; zircon sand is added to high alumina bricks to manufacture anti-stripping high alumina bricks, and the thermal shock stability is greatly improved; it can also be used to extract ZrO2.
