The invention relates to a method for producing high-purity pure iron. The method includes the following steps:
iron oxide is reduced in a layered-
control mode through a direct-reduction
system to manufacture
sponge iron; the
sponge iron is added into a medium-frequency or power-frequency
induction furnace for
smelting, and composite
slag forming constituents are added in batches; after
smelting and slagging-off are conducted, composite
slag forming constituents are added,
argon-
oxygen mixed gas bottom blowing is carried out on the medium-frequency or power-frequency
induction furnace through porous bricks at the bottom, blowing of the
mixed gas is stopped when the temperature of
molten steel reaches 1620 DEG C to 1650 DEG C, standing is carried out on the
molten steel for 25 minutes to 35 minutes, then slagging-off is conducted, a proper amount of aluminum is added into the
molten steel for 1 minute to 2 minutes,
argon bottom blowing is carried out through the air bricks at the bottom of the
induction furnace at the moment, and stopped when the temperature is continuously raised to range from 1640 DEG C to 1680 DEG C, horizontal
continuous casting or bottom
casting is conducted after standing is conducted on the molten steel for 15 minutes, and the low-
impurity pure iron with the
iron content larger than 99.9% is obtained, wherein the contents of more than twenty elements are all smaller than 0.01%. Meanwhile, the pure iron with the higher purity can be produced through vacuum refining or electroslag remelting. By means of the method, the flow path is short, devices are simple, and investment is saved.