FIRECLAY BRICKS

Fireclay bricks contain 25–45% Al₂O₃ and are rated to about 1400°C. High alumina bricks start at 45% Al₂O₃ and run up to 90%+, with service temperatures of 1550–1850°C. Fireclay is significantly cheaper and is the right choice for backup linings, boilers and general-duty furnaces. High alumina is needed for working linings exposed to slag, metal or temperatures above 1500°C.

Common grades are STD-30, STD-40, HFK-28, HFK-32 and HFK-36. The number broadly tracks Al₂O₃ percentage. STD-40 is the most-supplied grade for general industrial work. HFK grades are higher-quality fireclay with tighter tolerances. All comply with IS 8 (Indian Standard for fireclay refractories) and equivalents.

IS 8:2013 is the Indian Standard specifying fireclay refractory bricks by chemical composition, refractoriness, cold crushing strength, apparent porosity and dimensions. It defines four classes, Super Duty, High Duty, Medium Duty and Low Duty, based on Al₂O₃ content (40% down to 22%) and PCE (SK 35 down to SK 28). All Shanker Agencies fireclay supply complies with IS 8.

Avoid fireclay in working linings exposed to basic slags (steel converters, EAF, cement burning zone), they will react and fail rapidly. Also avoid them where temperatures consistently exceed 1400°C, in glass contact zones, or in atmospheres with high alkali content. For these, use high alumina, basic, magnesia spinel or fused-cast AZS depending on the duty.

Properly installed fireclay back walls in coal-fired industrial boilers typically run 5–8 years between full relines, with hot-spot patching every 12–18 months. Life depends on coal quality (alkali and chlorine content), boiler load cycling and dry-out discipline at first commissioning. Cycling-heavy boilers will see faster joint deterioration.

Yes, STD-40 and HFK-32 are stocked in standard sizes for same-day dispatch on quantities up to 5 MT from our Delhi warehouse. Larger orders, special shapes or higher Al₂O₃ grades typically dispatch in 2–7 working days. We deliver pan-India and handle full export documentation for GCC, ASEAN and African shipments.