Abstract

Processing of castable refractories is known generally as time and energy consuming treatment including both curing and drying.  Typically the process consists of casting into metal-frame, curing for 1 day (24h) at ambient temperature and drying by heating with gas-burners for 2 to 3 days after de-framing.  Among the castable refractories, a cement-free type has quite low productivity requiring several days for curing process.  As an environmentally-friendly process innovation by energy saving through shortening the castable processing, a microwave heating system has been introduced for drying of them used for lining of ladle and container for molten steel in some steel works so far.  In the heating system, the refractories are warmed-up quite efficiently with short time by heat generation from inside of material without depending on its thermal conduction.  In order to make use of the above described superior feature more progressively, the microwave heating was applied to shorten the total operation times for both curing and drying of the castable refractories.  Thus, precast block of refractories were fabricated by processing with the microwave heating. Comparing the properties of the material obtained from the block by the above described new process with those by the conventional process, the effectiveness of the new process was evaluated.