Magnesia brick is an alkaline refractory material with magnesite as the main crystalline phase and magnesia-carbon brick with magnesium oxide content above 90%. Generally it can be divided into two categories: sintered magnesia bricks (also known as fired magnesia bricks) and chemically bonded magnesia bricks (also known as non-fired magnesia bricks). Magnesia bricks with high purity and firing temperature are called direct bonded magnesium bricks because of direct contact of the periclase grains; bricks made of fused magnesia are called fused and bonded magnesium bricks, which are suitable for various Large and medium-sized lime kiln such as rotary kiln, sleeve kiln and shaft kiln. Magnesia brick has the advantages of strong resistance to alkaline erosion, strong erosion resistance, good thermal stability, high compressive strength, and high load softening temperature. The fired magnesia brick uses high-quality sintered magnesia as the main raw material and pulp as the binding agent. After mixing and high-pressure forming, it is fired in a high-temperature tunnel kiln above 1550 ° C. Has good thermal stability, resistance to erosion and spalling. It is widely used in industrial furnaces such as converters and electric arc furnaces as furnace lining refractories.
Fused magnesia brick has a dense brick structure and high mechanical strength.
It has the advantages of low impurity content, etc. It is mainly used in large-scale glass kiln heat-resistant dense refractory bricks with a certain shape and size of refractory materials. The unit weight and density are large, indicating that the compactness is good, and the strength may be high. Temperature, called the reburning line change or residual line change, refers to the volume expansion and contraction changes in the same temperature change each time, high temperature resistance, about 1800 degrees, the load softening temperature is 1620-1640, the thermal expansion coefficient is small.