PURPOSE: To produce a high-purity copper ingot contg. Fe and Si at extremely low ratios by using a carbon crucible, nozzle and casting mold.
CONSTITUTION: This method comprises producing the high-purity copper ingot by melting a high-purity copper raw material, such as electric copper, by using the carbon crucible and passing the resulted high-purity copper melt through the carbon nozzle into the carbon casting mold, thereby casting the ingot. The carbon crucible, the carbon nozzle and the carbon casting mold are previously heat treated under a condition of holding at 800 to 1120°C in a non-oxidizing atmosphere before the high-purity copper raw material is melted and cast. The high-purity copper ingot is produced by using the heat treated carbon crucible, the carbon nozzle and the carbon casting mold.
YAJIMA KENJI
ISHIDA TOKUKAZU
IKENOTANI HIDEYUKI
