Castable refractories are characterized by several key specifications including maximum service temperature, bulk density, cold crushing strength, and thermal conductivity. These properties vary depending on the type of castable (e.g., conventional, low cement, insulating) and its intended application. Understanding these specifications is crucial for selecting the right castable for a specific high-temperature or corrosive environment.
Key Properties and Specifications:
Maximum Service Temperature:
This indicates the highest temperature a castable can withstand without significant degradation. It can range from 1200°C to 1800°C for standard castables, with some high-performance options reaching 3000°C.
Bulk Density:
Measured in grams per cubic centimeter (g/cm³), it reflects the density of the castable. Heavy castables have a density greater than 2.0 g/cm³, while insulating castables can be as low as 0.4-1.0 g/cm³.
Cold Crushing Strength (CCS):
Measured in kg/cm², this indicates the castable’s ability to withstand compressive forces at room temperature. Higher CCS values indicate greater strength.
Thermal Conductivity:
Measures the rate at which heat passes through the material. Insulating castables have low thermal conductivity, making them effective for heat retention.
Permanent Linear Change (PLC):
Represents the dimensional change of the castable after heating, which is important for maintaining the integrity of the lining.