Senior Industiral Insider Tell You What Are Low Cement Castables?

Jul 6, 2023

Low cement castables are a type of refractory castable that contains a lower amount of cement in the mix. They typically contain around 5-10% cement by weight. This lower cement content makes low cement castables more thermally insulating and refractory compared to traditional concrete mixes that contain higher amounts of cement.

low-cement castables represents an effective middle ground between high cement concrete mixes that offer good strength but lower insulation and refractory single burnt bricks which have superior insulation and refractoriness but are more expensive and difficult to repair. By utilizing a balance of cement, aggregate and additives.

cement castable

Low Cement Castables Uses And Applications

Due to their high insulating properties and refractoriness, low cement castables are primarily used for lining furnaces and kilns where temperatures range from 1,500°F to 3,000°F. Common applications for low cement castable insulation include:

• Ladle and tundish linings in steel plants
Low cement castable mixes are used to line ladles and tundishes which contain and channel molten steel and slag. They provide excellent resistance to corrosion from the molten metals and slag at high operating temperatures up to 3,000°F.

• Incinerator and waste heat boiler linings
The ability of low cement castables to withstand high temperatures and abrasion makes them suitable for lining industrial incinerators and waste heat boilers that operate at intense heat levels.

• Reformer furnace linings
Reformer furnace linings require materials that can withstand high temperatures up to 2,300°F and provide resistance to corrosion from carbon and hydrogen sulfide gases. Low cement castable is well suited for this application.

• Cement kiln linings
Cement kilns operate at very high temperatures up to 2,800°F, requiring linings that have good insulation and refractoriness. Low cement castables are often used to line rotary cement kilns.

Properties Of Low Cement Castables

The lower cement content of low cement castables contributes to the following properties:

• Higher refractoriness – Due to decreased cement content, low cement castables can remain solid and stable at temperatures up to 3,000°F. The cement acts as a binder which set, hardening the mix. However, higher amounts of cement begin to break down at lower temperatures.
• Improved insulation – Less cement means more space between the larger aggregate particles in the mix, resulting in more air pockets that trap heat and increase thermal resistance. This makes low cement castables more thermally insulating compared to regular concretes.
• Higher resistance to corrosion – The lower pH of low cement castables makes them more resistant to chemical attack. And also makes them corrosion from hot gases, metals and slags. These are because of less cement content.
• Increased abrasion resistance – Low cement castables generally contain larger sized aggregate particles which lock together well and provide more resistance to wear and erosion from rapid material movement and slag pellets.
• Higher flexibility – The lower cement content allows low cement castables to exhibit more flexibility and plasticity during placement and compaction, resulting in a more durable lining after curing.