The process of melting cast iron in a gas furnace includes six aspects:
(1) Furnace lining preheating: the burner is ignited and the furnace lining is preheated to 800~1000℃.
(2) Feeding: After the furnace lining is preheated, the furnace body is tilted, and the charge is added to the furnace through the hydraulic chute, and the furnace body is leveled after the charge.
(3) Charge preheating: The burner ignites again to start heating the charge. During the charge preheating, the furnace body rotates intermittently and slowly in the forward and reverse directions. The charge gradually softened and initially melted during this period.
(4) Overheating of molten iron: Soon after the initial melting of the charge, the furnace enters the overheating stage of molten iron. During the overheating of molten iron, the burner is heated with high power, and the furnace body rotates rapidly in a single direction.
(5) Liquid iron test: When the temperature of the molten iron meets the requirements for tapping, use a thermocouple or infrared thermometer to measure the temperature of the molten iron, and use a triangle test piece or a furnace front thermal analyzer to measure the composition of the molten iron.
(6) Tapping and pouring: If the temperature and composition of the molten iron meet the requirements, open the tap hole for tapping and pouring the casting.