Synthesis and production of aluminum-magnesium spinel in refractory castable
Release time：2026-03-08
page views：
Refractory castables also contain a wide variety of raw materials and aggregates. Today, our editor will summarize the synthesis and production methods of spinel from aluminum-magnesium spinel.
1. The commonly used production methods for spinel refractory castables are as follows:
(1) In magnesia (sintered or fused), raw materials containing Al2O3 (such as bauxite raw materials or industrial alumina) are blended to allow the green body to directly form spinel during the firing process. Research indicates that spinel formation begins at 950~1000℃, intensifies at 1400℃, and tends to be complete at 1500℃. However, the recrystallization ability of spinel is very weak. At the same time, due to the reaction MgO + α-Al2O3 → MgO·Al2O3, which itself has a volume shrinkage of 6.9%, sintering the brick body is quite difficult, making it challenging to obtain dense spinel products. To obtain directly separated spinel products, the maximum firing temperature should be above 1700℃.
(2) Add pre-synthesized spinel powder to magnesia (sintered or fused).
2. There are several types of synthetic spinels:
(1) Electrofusion spinel. Its product features well-developed grains, uniform texture, dense structure, high strength, and strong corrosion resistance. It is produced by mixing industrial alumina (or high-alumina bauxite raw material) with magnesia (or magnesite, magnesia powder), condensing and cooling the mixture in an electric furnace, and then crushing to obtain the electrofusion spinel product.
(2) Sintered spinel sand. This product is more economical than fused spinel and can serve as a substitute for fused spinel in many applications. It is obtained through the blending, balling, and high-temperature sintering of lightly burned A, G, and MgO. To achieve a dense spinel crystal, sintering is typically intensified at 1800℃ to 1900℃. This is highly beneficial for enhancing the strength of castables
The above is about the synthesis and production of aluminum-magnesium spinel in refractory castables. I hope it can be of some help to you
