Refractory Production Process

According to the density and shape of the product, there are sintering method, melting casting method and melt blowing method. The sintering method is to pre-burn some raw materials into clinker, crush and sieve, then mix with raw material according to a certain ratio, and then go through molding, drying and firing. The purpose of raw material pre-burning is to burn off the moisture, organic impurities, and sulfate decomposed gas, so as to reduce the firing shrinkage of the product and ensure the accuracy of the product's external dimension. Raw materials need to be sieved after crushing and grinding, because the billet is graded by powders of different particle sizes, which can ensure the most compact packing to obtain a dense green body.
In order to homogenize the ingredients and particles of various raw materials and clinkers, mixing is carried out, and a binder is added at the same time to enhance the bonding strength of the billet. For example, add combined clay to aluminum silicate billet, add sulfurous acid pulp waste liquid to magnesium billet, add lime milk to siliceous billet, etc. According to the moisture content of the billet, semi-dry molding (about 5% moisture), plastic molding (about 15% moisture) and grouting molding (about 40% moisture) can be used. It is then dried and fired. The melting and casting method is to melt the raw materials at high temperature through the processes of batching mixing and fine grinding, directly casting, cooling and crystallization, and annealing to become products. Such as fused mullite bricks, corundum bricks and magnesia bricks. Their green bodies are compact, high mechanical strength, high temperature structural strength, good slag resistance, and the scope of use is constantly expanding. The melt blowing method is to melt the ingredients and blow them with high-pressure air or superheated steam to disperse them into fibers or hollow balls. Products are mainly used as light refractory and heat insulation materials. In addition, it can also be made into powdery or granular unshaped refractory materials, which are cemented with binders such as tar, asphalt, cement, phosphate, sulfate or chloride, and used directly without molding and sintering.