MgO-C refractories are a kind of refractory materials usually made of MgO (molecular sieve magnesium oxide) and carbon. Because of their excellent fire resistance and anti-corrosion properties, they are used in many industrial applications including furnaces, kilns, incinerators, electric arc furnaces and ladles.
MgO-C refractories can be made of sintering, which is a process in which powder particles are fused together by heat or pressure. The sintered MgO-C refractory materials have a high mechanical strength due to their enhanced bonding structure. In this process, a large quantity of micro pore size is generated, which further increases the mechanical strength. The microstructure of MgO-C refractory material is composed of a large amount of primary MgO particles and several secondary particles of various sizes. All the particles are adhered to each other through the process of sintering.
The microstructure of MgO-C refractory materials is very important for its characteristics. Generally, the microstructure of the material is determined by the chemical composition, particle size, and the sintering method adopted. The primary MgO particles form a network structure, while the secondary particles are attached to them at various locations. As a result, the material is highly resistant to wear and abrasion and also resistant to thermal shock.
The primary MgO particles have an irregular or rounded shape. The particle size of the secondary particles is much smaller than that of the primary particles. Generally, the particle size of the secondary particles ranges from 0.1 to 100 microns. The chemical composition of the MgO-C refractory includes carbon and other elements such as SiO2, CaO, MgO, Al2O3, Fe2O3, and Na2O. The addition of other elements significantly increases the strength, wear resistance, and corrosion resistance of the MgO-C refractory material.
Sintering is the most commonly used process to fabricate MgO-C refractories. In this process, a mixture of MgO and carbon is heated to very high temperatures in a vessel with airless conditions. The sintering temperature is usually above 1600 °C and it can be reduced by using various additives, such as silicon additives and aluminum additives. The sintering process results in a dense material with a homogenous microstructure.
The microstructure of the MgO-C refractories can be further studied by using Scanning Electron Microscopy (SEM). This process allows us to observe the size, shape, and distribution of the primary and secondary particles in the material. This can be helpful in understanding the strength, wear resistance, and corrosion resistance of the material.
In conclusion, MgO-C refractories are a popular and essential material for many industrial applications. Their excellent fire resistance and anti-corrosion properties make them an ideal choice for a variety of applications. The microstructure of MgO-C refractory materials can be studied by using Scanning Electron Microscopy, which helps us to understand the material and its properties.
