What are the steps of monolithic refractories casting

In the refractory industry, monolithic refractories have attracted wide attention due to their excellent fire resistance, corrosion resistance and flexibility. Casting, as a major molding process for monolithic refractories, is widely used in various high-temperature industrial equipment and has become an important way to achieve high-performance refractories.

Raw material preparation
The first step in casting is the preparation of raw materials, which involves the reasonable ratio of refractory aggregates, binders and water. Refractory aggregates are granular substances that constitute the main body of refractory materials, and common ones include alumina, magnesium oxide and silica. Binders are key materials that bind refractory aggregate particles together, usually including water glass, phosphates and aluminates. The addition of water is intended to adjust the fluidity and viscosity of the slurry to ensure the smooth progress of the casting process.
In the raw material preparation stage, it is crucial to strictly control the proportion and particle size distribution of each component to ensure the performance and quality of the final product. In addition, the drying and pretreatment of raw materials are also important links that cannot be ignored to avoid bubbles and cracks during the casting process and ensure the integrity and durability of the product.

Slurry preparation
After mixing the prepared raw materials in a specific proportion, add an appropriate amount of water for stirring to form a flowable slurry. During the slurry preparation process, the control of stirring speed and time is crucial to ensure that the components are evenly mixed. In addition, the viscosity and fluidity of the slurry should be adjusted according to the specific application scenario to meet different construction requirements.
In the slurry preparation process, it is equally important to remove bubbles in the slurry. The presence of bubbles will not only affect the density and strength of the final product, but may even cause cracks and fall off during use. Therefore, effective methods such as vacuum degassing or ultrasonic degassing can significantly improve the quality of the slurry.

Mold preparation and casting
The mold plays a vital role in the casting process. According to the shape and size of the required product, select a suitable mold for preparation. The material and precision of the mold directly affect the quality and performance of the final product.
After the mold is prepared, carefully pour the prepared slurry into the mold. During the casting process, the flow rate and flow rate of the slurry need to be controlled to avoid bubbles and cracks. At the same time, ensure the sealing of the mold to prevent the slurry from leaking during the casting process.

Vibration and curing
To further improve the density and strength of the product, the mold needs to be vibrated after pouring. Vibration can make the particles in the slurry more closely arranged, thereby reducing porosity and improving the density of the product.
After the vibration treatment is completed, the mold is moved to the curing room for curing. The purpose of curing is to gradually evaporate and solidify the water in the slurry to form a solid refractory layer. The curing time and temperature need to be adjusted accordingly according to the specific product type and performance requirements to ensure the final quality of the product.

Demolding and subsequent processing
After curing, open the mold and carefully remove the product. During the demoulding process, be careful to avoid damage to the product. After demoulding, the product usually requires further post-processing, including surface finishing and quality inspection to ensure that it meets the expected use standards and technical requirements.