Low Temperature Sintering of Alumina Porous Refractory Products Containing Chromium Oxide

摘要

Molten steel tapped from a converter or an electric furnace is treated with a secondary refining furnace before casting. In the secondary refining, inert gas is injected into the molten steel through a porous refractory plug in order to disperse alloy additives uniformly. As for a porous refractory plug, in many cases, chromium oxide is mixed with alumina because it is a main raw material for improving corrosion and heat resistance. Chromium oxide added-refractories have excellent heat resistance but demand high temperatures of more than 1700°C. On the other hand, considering the environment where porous refractory plugs are actually used, the heat resistance to 1700°C assumed no to be necessary with some kinds of steel because inert gas is constantly blown into the molten steel. The decrease in firing temperature can be expected to reduce fuel costs and contribute to environmental problems by decreasing the amount of carbon dioxide emissions.