Castable Refractory

Castable refractory is a monolithic refractory that is mixed with water and poured, cast, gunned, rammed or pumped in place instead of being laid as bricks. It is used for furnace roofs and walls, ladles, tundishes, kiln nose rings and burner blocks, and for complex hot-face shapes where bricklaying is not practical. Once set and fired it forms a jointless lining.

Castable refractory is available for maximum service temperatures from 1000°C up to 1800°C, depending on the grade. The limit is set mainly by the alumina content and the type of castable: insulating castables sit at the lower end, while high alumina and low cement grades with higher Al2O3 cover the upper end. Choose a grade rated above your actual hot-face temperature.

Castable refractory is supplied with 42%, 60%, 70%, 80% or 90% Al2O3, in Low Cement Castable (LCC), High Alumina Castable and Insulating Castable types. Higher alumina generally suits higher temperatures and more severe slag or abrasion service, while insulating castable is used where lower heat loss and lighter weight matter more than strength. Share your temperature and operating conditions and we will suggest a grade.

Castable refractory typically needs 6% to 9% water by weight, depending on the grade, with initial set in 20 to 40 minutes and final set in 4 to 8 hours. Adding more water than specified weakens the lining and increases porosity, so measure water accurately and mix only what can be placed within the working time.

Castable refractory reaches a cold crushing strength of 400 to 900 kg/cm² after firing, depending on the grade. Dense LCC and high alumina grades sit toward the upper end, while insulating castables trade strength for lower density and heat loss. Correct water addition, compaction and curing are needed to reach the rated strength on site.

Yes, a new castable refractory lining needs curing followed by a controlled first heat-up, or dry-out, before full operating temperature. Heating too quickly can turn trapped moisture into steam and cause spalling or cracking. Anchors are normally used to hold wall and roof linings, and Insulating Fire Bricks (IFB) or Ceramic Fiber Blanket & Board can be used as backup insulation behind the castable.

Castable refractory in this catalogue is referenced to ASTM C401 and IS 6913. ASTM C401 is the standard classification for alumina and alumina-silicate castable refractories. If your specification calls for specific test reports for an order, mention it in your enquiry and we will confirm what can be provided with the quotation.

Castable refractory is shipped under HS code 38160000, which covers refractory cements, mortars, concretes and similar compositions. The same heading is used for Refractory Mortar and Ramming Mass, so refractory monolithics can be declared consistently when they travel together in one export shipment.

Castable refractory is packed in 25 kg or 40 kg HDPE-lined paper bags, which help protect the cement-bonded powder from moisture during sea freight. Bags can be shipped in FCL 20′, 40′ or 40′HC containers or as LCL from Nhava Sheva (JNPT) or Mumbai, and can be combined with bricks, mortar and insulation in one container. Tell us the grade and tonnage in your enquiry.