Which Type of Cement, Refractory Cement Or Ordinary Cement, Has Higher Strength?

1.Refractory Cement: Refractory cement, also known as special cement, is produced by blending high-quality bauxite and high-quality lime into a suitable raw material mixture in specific proportions. After sintering, the resulting clinker primarily composed of aluminate is finely ground to produce a refractory hydraulic binder. In simple terms, refractory cement, a type of special cement, is used for high-temperature applications such as furnaces and chimneys due to its ability to withstand high temperatures and resist chemical erosion.

2.Ordinary Cement: Ordinary cement refers to the six major types of silicate cement commonly seen in general construction and concrete structures.

3.Based on their respective purposes, refractory cement is used for high-temperature fire resistance rather than for enhancing the strength of concrete under normal conditions. Therefore, in general, ordinary cement would have higher strength and can reach strengths of up to 62.5 MPa.

Refractory mortar, also known as fire clay or joint material (powdered material), is used as joint material for refractory products. It consists of refractory powder and additives. Almost all refractory materials can be made into powders used to prepare refractory mortar.

Common refractory mortar, made by mixing refractory clinker powder with an appropriate amount of binder, has relatively low strength at room temperature, but it develops higher strength at high temperatures when it forms a ceramic bond. Refractory mortar can be classified into various types based on their refractoriness, including ordinary refractory mortar (580-1250°C), intermediate refractory mortar (1300-1770°C), high-grade refractory materials (1770-2000°C), and special-grade refractory materials (above 2000°C). They can also be classified according to their chemical properties as acidic, neutral, or alkaline refractory materials, with special refractory mortars used for specific applications.

Refractory cement, also known as aluminate cement, is made from bauxite and limestone, which are calcined to produce clinker primarily composed of calcium aluminate with an alumina content of approximately 50%. It is then finely ground to produce a hydraulic binder. Refractory cement is commonly yellow or brown, sometimes gray. Its main mineral components include calcium aluminate (CaO·Al2O3, abbreviated as CA) and other aluminates, as well as minor amounts of dicalcium silicate (2CaO·SiO2). Refractory cement is used to bond various refractory aggregates (such as corundum and calcined high-alumina bauxite) to produce refractory castables or concrete for lining industrial kilns. Under high temperatures, refractory cement forms low-melting compounds. Excessive use of refractory cement in refractory castables may reduce their high-temperature performance, and silica fume can be used to partially replace refractory cement in formulations.

The key difference between refractory mortar and refractory cement lies in their respective uses: refractory mortar is used as a joint material (mixed with water or other liquids) for laying refractory bricks, while refractory cement serves as a binder for various refractory aggregates to produce refractory castables used for lining kilns.