Refractory Bricks, Mortar and Castable for Reheating Furnace Lining

17-Jun-2023

Reheating Furnaces serve the purpose of heating various intermediate products of Steel like- ingots, blooms or billets before rolling to give them different shapes of angles, channels, bars, slabs, rods & wires etc 

Read: What are Reheating Furnaces Area wise specifications of Refractory Bricks and Castables or Blocks which can be used for lining of reheating furnaces and the quality of Refractory Mortar which can be used for laying the bricks are given hereunder -

Reheating Furnace Hearth

1. Dense high alumina bricks with low iron content. Alumina (Al₂O₃) 88-90%, Iron (Fe₂O₃) 1.8% (max), Bulk Density (BD) 3-3.2 gm/cc, Apparent Porosity (AP) 16-18%, CCS(kg/cm²) 800 (min), RUL(ta^OC) around 1550-1600, PLC at 1600^OC/2hrs (+/-) 0.2% (max).

2. Basic Magnesia, Mag-chrome bricks. MgO around 55-60%, Chrome (Cr₂O₃) around 12-15%, Silica (SiO₂) 8% (max), AP 18-20%, CCS (kg/cm²) around 450-500, RUL (ta^OC) 1600 (min), PLC at 1600^OC/2hrs (+/-) 0.5% (max).

Furnace Roof

Alumina (Al₂O₃) around 70%, Iron (Fe₂O₃) around 2.5-2.8%, BD 2.6-2.7 gm/cc, AP 21-23%, CCS (kg/cm²) 500 (min), RUL (ta^OC) around 1450-1500, PLC at 1500^OC/2hrs (+/-) 2.5% (max).

Furnace Side-Wall and for General purpose

1. Low porosity dense bricks. Alumina (Al₂O₃) 45%, Iron (Fe₂O₃) 1.6-1.8%, BD around 2.2 gm/cc, AP around 16%, CCS (kg/cm²) around 500, RUL (ta^OC) 1500 (min).
2. Alumina (Al₂O₃) 40%, Iron (Fe₂O₃) 2.0-2.2%, BD 2.1 gm/cc (min), AP 22% (max), CCS (kg/cm²) around 350, RUL (ta^OC) 1400 (min).

Furnace Bottom, Blocks (Burner Block, Well Block, Seating Block, Seating Well Block) and Castables

1. Medium purity Low Cement Castable (LCC). Alumina (Al₂O₃) around 90%, Iron (Fe₂O₃) 1.0-1.5%, BD 2.7-2.9 gm/cc, PCE 37 Orton (min), CCS (kg/cm²) at 110^OC/24hrs 600 (min), at 1500^OC/3hrs 550 (min), PLC at 1500^OC/2hrs (+/-) 1.0% (max).
2. Medium purity Castable conventional type. Alumina (Al₂O₃) around 60%, Iron (Fe₂O₃) 1.8% (max), BD 2.1 gm/cc (min), PCE 36 Orton (min), CCS (kg/cm²) at 110^OC/24hrs 350 (min), at 1500^OC/3hrs 450 (min), PLC at 1500^OC/3hrs (+/-) 1.5% (max).

Furnace Door, Flue Stack, Heaters

Insulating Castables. Iron 1% (max), BD 1.0-1.2 gm/cc, CCS (kg/cm²) at 110^OC/24hrs around 12-15.

Mortars

Have to be compatible with the laying brick quality (chemical spec).

All the data given above are tentative and should not be considered as ‘Typical Specification Data’. 

Methods of installation (Read: Refractory Installation Procedure and Heating Schedule to be followed after starting a Furnace) may be provided by the refractory supplier.