PURPOSE: To enhance casting material melting speed and thermal efficiency and make weighing automatic by heating cutting chips including cast iron cutting chips to a specified temp. or above in a non-oxidizing atmosphere; blending ferroalloy into the heated chips; compression-molding the blend; and charging the resulting briquettes into a melting furnace without cooling.

CONSTITUTION: Cast iron cutting chips are fed to conveying unit 4 through weighing unit 2, and oil adhered to the chips is baked in the presence of insufficient air together with heavy oil when the chips are passed through conveying unit 7 in primary combustion furnace 6. The baked oil is fired in rotary kiln 10 to heat the chips to a predetermined temp., and in secondary combustion furnace 12 the oil is perfectly burned. On the other hand, ferroalloy dusts are fed to conveying unit 21 through weighing units 17, 18 and mixed into the chips heated to the plasticizing temp. This mixt. is molded into briquettes of a predetermined size with compression molding machine 22 at a high temp. The briquettes are charged into low frequency induction furnaces 32a, 32b, 32c through conveying unit 30 and material charge basket 31 without cooling, and they are heat melted.