PURPOSE: To prevent a splash of a molten metal and scattering of fumes, and to elevate yield of a graphite spheroidizing agent, by pouring a molten metal to a treatment ladle to which the graphite spheroidizing agent has been charged, through two upper and lower molten metal receiving vessels, which have been placed so as to tightly close its opening part.

CONSTITUTION: Into a recessed part 2 provided on one side of the bottom part of a spheroidizing treatment ladle 1, a graphite spheroidizing agent 3 consisting of Fe-Si-Mg, etc., which has covered its surface with a suitable coverign agent 4 in advance is charged. In order to tightly close the opening part of this ladle 1, 2 molten metal receiving vessels 6, 7 having pouring ports 8, 9 at alternate positions are placed on the upper and lower stages. A cast iron molten metal injected to the upper stage molten metal receiving vessel 6 is injected to the lower stage molten metal receiving vessel 7 through the pouring port 8, also is injected to the treatment ladle 1 through the pouring port 9, and reacts to a graphite spheroidizing agent 2. In said molten metal receiving vessels 6, 7, the poured quantity is adjusted so that the pouring ports 8, 9 are always filled with a molten metal 5.