Analysis on Magnesia Calcium Brick Used for AOD Lining

According to the effects of AOD smelting on refractories and the high required standard about molten stainless steel, the selected refractories should meet the following requirements.

1.) Excellent resistance to high temperature.

2.) Excellent corrosion resistance to slag.

3.) Excellent thermal and vibration stability.

4.) Excellent volume stability.

5.) Can purify molten steel.

Magnesia calcium brick, mainly made from magnesium sand and synthesized magnesium dolomite sand, is a kind of alkaline refractories and contains CaO. The melting points of MgO and CaO in synthesized sand are both high, it’s 2825℃ and 2620℃, their eutectic point is as high as 2370℃. When chemical reactions happen between CaO and slag, a compound with high molten point will be easily produced, such as dicalcium silicate whose molten point is 2130℃, and whose molten point is 1900℃. Those minerals with high molten points make magnesia calcium brick possess excellent resistance to high temperature.

CaO in magnesia calcium brick has good thermodynamic property stability; CaO has good resistance to acid slag. Therefore magnesia calcium brick not only has excellent resistance to high alkaline slag but also has excellent resistance to acid slag.

Magnesia calciumrefractories are the best choice for desulfurization and dephosphorization of molten steel.