Abstract
The dolomite refractory brick, highly resistive to spalling and also to errosion by slag, was used in the melting zone of cupola.
The dolomite refractory brick is an unburned brick having the chemical composition of 12∼13% SiO2, 9∼11% Fe2O3, 40∼42% CaO, 30∼32% MgO and the refractorieness of SK37 and 22.3% Porosity.
The first test
The dolomite refractory brick was heated at the temperatures between 1450°∼1500°C for about 8 hours for test. The surface of the brick was somewhat melted and the thickness of the brick was decreased by 30∼40mm., but any spalling tendency was not observed.
The second test
The brick was heated at the temperatures between 1450∼1500°C for one hour, and then cooled to room temperature, and again the brick was heated at the temperatures between 1450∼1500°C for one hour and cooled again to room temperature, thus the brick was tested four times in the same way, No spalling tendency was observed substantially, and the resistance for errosion was much better than that of the slag contains less Fe2O3 and more MgO compared with the ordinary one, and the melted iron was thus obtained by using the conventional brick.
