Phosphate refractory bricks are a type of refractory material that is widely used in high-temperature industrial furnaces. It is a non-metallic material composed of a certain proportion of phosphate bonded refractory materials. Phosphate refractory bricks have superior thermal shock resistance, abrasion resistance, and corrosion resistance compared to other refractory materials.
Phosphate refractory bricks can be classified into three grades according to their phosphate content:
1. High phosphate bricks: The phosphate content is ≥80%.
2. Medium phosphate bricks: The phosphate content is between 70-80%.
3. Low phosphate bricks: The phosphate content is ≤70%.
Technical Parameters:
1. High-temperature strength: The compressive strength of the phosphate refractory brick should be above 70MPa at 1400℃.
2. Linear shrinkage: The linear shrinkage rate should not exceed 0.5% at 1400℃.
3. Refractoriness: The refractoriness of the phosphate refractory brick should be above 1780℃.
The production process of phosphate refractory brick can be divided into three steps:
1. Raw materials preparation: According to the different grades of phosphate refractory bricks, different raw materials are required. Generally, high-quality phosphate rock, high-alumina bauxite, and other additives are mixed according to a certain proportion, and then crushed, screened, and mixed evenly to form a dry powder.
2. Molding: The dry powder is wetted with a certain amount of water to make mud, and then the mud is sent to a pressure molding machine for extrusion molding.
3. Firing: The molded bricks are dried and fired in a tunnel kiln or shuttle kiln at a high temperature of 1400-1500℃ for a certain period of time to form a dense brick body with complete mineralization.
In conclusion, phosphate refractory bricks are essential materials for high-temperature industrial furnaces. With their superior performance and quality, they are widely used in steelmaking, nonferrous metal smelting, chemical industry, and other industrial fields. The production process is complex but has been constantly improved to improve efficiency and quality. The development of phosphate refractory bricks will continue to promote the progress of the refractory industry.
