High Alumina Bricks

High alumina bricks are refractory bricks containing 45 to 90% alumina (Al2O3), used where temperatures and slag or abrasion are too severe for fire clay. The higher alumina content raises refractoriness and strength. Typical uses include reheating furnaces, cement kilns, glass furnaces and ladles, where they line the hot face exposed to the most demanding conditions.

High alumina bricks have a maximum service temperature of 1500°C to 1750°C, depending on the alumina grade, and a refractoriness under load above 1500°C. Higher-alumina grades sit at the upper end of this range. The actual limit in service also depends on atmosphere, slag chemistry and load, so the grade should be selected for the specific furnace zone.

High alumina bricks are available in 45%, 60%, 70%, 80% and 90% Al2O3 grades, all in the standard 230 x 114 x 75 mm size. Lower grades suit general high-duty linings; higher grades are chosen for hotter zones and stronger slag or abrasion. Selection should be based on operating temperature, slag type and cost, so share these details in your enquiry.

Use High Alumina Bricks instead of Fire Clay Bricks when the lining operates above about 1400°C or faces slag and abrasion that would wear fire clay quickly. High alumina bricks serve up to 1500°C to 1750°C with cold crushing strength of 400 to 700 kg/cm², versus 250 to 400 kg/cm² for fire clay.

High alumina bricks have a bulk density of 2.3 to 2.9 g/cm³, cold crushing strength of 400 to 700 kg/cm², apparent porosity of 16 to 22% and refractoriness under load above 1500°C. The lower porosity and higher density compared with fire clay reduce slag penetration and improve abrasion resistance in high-duty furnaces.

High alumina bricks are laid with a matching high-alumina Refractory Mortar in thin, staggered joints, with expansion allowances as per the furnace design. The mortar should be compatible with the brick chemistry to avoid weak joints. After installation, the lining needs a controlled heat-up schedule, and backup insulation such as Insulating Fire Bricks (IFB) is commonly used behind the hot face.

High alumina bricks are made to IS 6, the Indian standard for high alumina refractory bricks, and ASTM C27, which classifies fireclay and high-alumina refractory brick. Both standards group bricks by alumina content and related properties. State the grade and standard your specification calls for in the enquiry so it can be confirmed with the quotation.

High alumina bricks are exported from India under HS code 69022020, refractory bricks and shapes of high alumina. This falls under heading 6902, which covers refractory bricks, blocks and tiles, with alumina content determining the subheading. The importing country assigns its own national digits and duty, so verify the code with your customs broker.

High alumina bricks are shipped on wooden pallets, shrink-wrapped, from Nhava Sheva or Mumbai in FCL or LCL loads. They are dense, so container loads are limited by weight rather than volume. In your enquiry, give the alumina grade, shapes and quantities, any matching mortar, destination port and Incoterm; lead time and price are confirmed with the quotation.