Our high temperature magnesia crucibles are formulated to offer maximum density in severe basic melting situations. Although the resistance to thermal shock is not a high as alumina, the magnesia crucible does offer a slightly higher temperature limit. Combining the basic characteristics of magnesia and minimizing the thermal cycling makes this crucible an excellent choice.
Magnesia crucibles have a higher propensity for thermal expansion. Although the magnesia crucibles have a higher temperature limit than alumina, holding the crucible for long periods at tap temperature can still promote saturation below the melt line and play a part in the degradation of the crucible. Since the refractory has higher thermal expansion, minimizing the thermal cycling will be beneficial. The magnesia is basic in chemistry and the compatibility of the metal should be known or it will lead to erosion of the body and a potential source of failure. Fluid and aggressive slags can cause destruction of the bonding of the crucible and can lead to either build up or erosion on the walls and eventual failure of the crucible
Properly installed crucibles, with special attention given to ramming the bottoms and sidewalls, will help to ensure longer crucible life. Installation procedures should closely follow that of ram linings with proper venting and drying of the top cap. This will help to minimize top cap separation, keep the crucible in compression and minimize cracking.
These magnesia crucibles are manufactured in standard sizes up to 1000 lbs. but can be tailored to your specific shape.
Please call (203) 265-7112 or fill out the form to the right and someone will assist you with your order or questions.