Clay for Manufacturing Refractory Bricks
On that note just a very brief description on how refractory bricks are manufactured. The Refractory Brick manufacturing needs good sound in usage of amount of mix to use. Plastic clay has to be used for preparation of chamotte and as a binder. Chamotte is prepared by burning the plastic clay to 1450C for about 24 hours. The Chamotte should then be crushed and grounded well. Grinded Chamotte is generally divided as the below mentioned fraction
Coarse – 1 to 6 mm
Medium – 0,2 to 1 mm
Fine – 0 to 0.2 mm
The grinded chamotte will be mixed with binder clay according to the plasticity factor in the following range of 50:50 or 70:30 or 80:20 of Chamotte:Clay. The addition of water to the clay is important for the forming process. Ideally it has to range in 6 to 9%. The green bricks are prepared by the semi-dry method using a hydraulic press and molding pressure of 50 N /mm2 . After molding and drying the bricks will be burned at 1250, 1300, 1350, 1400 and 1450C .
The fired bricks should then be tested for quality. Some lab test to note important properties such as specific gravity, bulk density, and resistance to temperature changes and compressive strength at room temperature.
