The main factors affect the performance of magnesia carbon bricks include MgO/CaO ratio, chemical purity and density etc.
The MgO/CaO ratio of magnesia carbon brick can increase high temperature resistance, chemical erosion resistance of slag, high temperature corrosion resistance and hydration resistance. But it will decrease the performance of magnesia carbon brick, as spalling resistance, resistance to the slag penetration and molten steel purification performance.
Adding some additives in the production of magnesia carbon brick can improve some performances of the magnesia carbon brick.
Add appropriate amount of ZrO2 can improve the performance of spalling resistance, high temperature corrosion resistance and hydration resistance of the magnesia carbon brick. ZrO2 is called the "multi-functional" additives of magnesia carbon brick.
At Abroad, eye refractory bricks of AOD furnace generally use high-purity, high density sintered magnesia dolomite brick with 1% content of ZrO2 with favorable results.