Dolomite is a magnesium limestone (CaMgCO3). It occurs in nature. Calcined dolomite brick particles are united with the help of silicate binders and water.
Mixture is then molded to bricks which are air dried and burnt to temperature ranging between 1200 to 1560oC for about one day which gives stabilized dolomite bricks. Such bricks are quite stable towards basic slag.
Dolomite is generally used as a repairing material rather than as a direct refractory because of its defects like porosity, shrinkage and softness. However stabilized dolomites are used in electric furnaces, Bessemer converters, open hearth furnaces etc, cheap substitute for magnesia bricks.
Dolomite Brick |
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AL2O3 | MIN 1 % |
Fe2O3 | Max 1.50 % |
SiO2 | Max 1 % |
CaO2 | Min 53 % |
MgO | Min 38 % |
Physical Properties
Bulk Density (Db.) | g/cm3 | min2.85 | |
Apparent Porosity (Po.) | Vol-% | max 8 | |
Cold Crushing Strength at 20(c.c.s) | kg/cm2 | min 150 | |
Total Carbon | % | 4-6 | |
Residual Crabon (after finig at 1000) | % | 1.5-4 | |
Storage Limit | days | 14-45 |