What are the key steps in the manufacturing process of insulating refractory bricks

Insulating refractory bricks are a key material that can maintain structural stability and thermal insulation performance under extremely high temperature environments. They are widely used in many industrial fields such as metallurgy, building materials, and chemicals. Its manufacturing process is complex and delicate, and each link directly affects the quality and performance of the final product.

In the production process, the preparation and sorting of raw materials are the first steps. High-quality raw materials are the basis for manufacturing high-quality insulating refractory bricks. The main raw materials include silica, alumina, and clay. The selection of raw materials depends on the required refractoriness and thermal insulation performance. They must be strictly sorted and crushed to ensure uniform particle size, which is convenient for subsequent processing. Especially for siliceous insulating refractory bricks, the SiO2 content must not be less than 91% to ensure the excellent performance of the product.

Next, powder fine grinding and aggregate screening are key links. The sorted raw materials need to be finely ground by equipment such as ball mills or air flow mills to grind the raw materials into fine powder, thereby enhancing the bonding force between particles and improving the density of the product. At the same time, aggregates (larger particles) need to be screened to ensure that particles of different sizes can be reasonably matched in subsequent formulas to form a stable structure.

The manufacturing process enters a critical link in the formulation and uniform mixing stage. This stage determines the performance of the final product. The proportion of various raw materials is accurately calculated based on the required refractoriness, thermal insulation performance and specific requirements of the customer. After the ingredients are mixed, all raw materials are evenly mixed in the mixer. This process requires strict control of the amount of water added and the mixing time to ensure the uniformity and plasticity of the mud.

The molding process is the process of converting the evenly mixed mud into a blank of the desired shape. There are various molding methods for insulating refractory bricks, including grouting molding, plastic molding (extrusion molding), and machine pressing molding. Grouting molding is suitable for thin-walled hollow products, such as thermocouple sleeves; plastic molding is often used for the production of blanks such as tubes; and machine pressing molding has become the most widely used molding method in the current production of refractory materials due to its dense blank structure, high strength, and easy size control.

The formed blank needs to be dried to remove excess moisture and prevent cracks due to excessive evaporation of moisture during the firing process. The dried blank enters the kiln for high-temperature firing. During this process, the mineral components in the raw materials undergo a series of physical and chemical changes to form a stable crystal structure, which gives the insulating refractory bricks excellent fire resistance and thermal insulation properties. Strict control of firing temperature and time is the key to ensuring product quality and performance.

Finally, the fired insulating refractory bricks need to be polished to remove surface flaws and burrs, thereby improving the product's aesthetics and performance. The finished products are strictly selected to remove bricks that do not meet quality standards, ensuring that every insulating refractory brick shipped meets industry standards and customer requirements.