Can silicate cement be used as a binder for refractory castables?

Silicate cement can generally be used as a binder for refractory castables, but there are certain limitations. The specific analysis is as follows:

Reasons why silicate cement can be used as a binder

1•Good gelling property: silicate cement can form a slurry with certain viscosity and strength after adding water, which can firmly bond refractory aggregates, powders and other particles together, so that the refractory castable can quickly solidify and form after construction, which is convenient for subsequent construction operations and use.

2•Wide sources and low costs: silicate cement has a mature production process, is easy to obtain in the market, and is relatively cheap. When used as a binder for refractory castables, it can reduce the production cost of refractory castables to a certain extent and improve its economy.

3•Certain early strength: Refractory castables using silicate cement as a binder can quickly obtain certain early strength under normal temperature curing conditions, which is conducive to speeding up construction progress and improving construction efficiency.

Limitations of Portland Cement

1• Limited refractoriness: The main components of Portland cement will undergo a series of physical and chemical changes at high temperatures. Generally, its refractoriness is relatively low, usually around 1200℃ - 1300℃. When used in higher temperature environments, problems such as strength loss and structural damage will occur, affecting the performance and service life of refractory castables.

2• Poor high-temperature volume stability: At high temperatures, Portland cement will produce a large volume shrinkage or expansion, resulting in stress inside the refractory castable, prone to cracks, spalling and other phenomena, reducing the overall stability and thermal shock resistance of the refractory castable.

3• Insufficient chemical stability: In some high-temperature environments containing corrosive media, some components in Portland cement may react chemically with the corrosive media, thereby reducing the corrosion resistance of the refractory castable and shortening its service life.