Method of producing hot metal using solid-reducing furnace and submerged arc furnace

A method of producing hot metal, the method comprising:

• an iron ore preparation process (A) comprising a process (A-1) of preparing first iron ore pellets produced from low-grade iron ore having a total Fe content of 63 mass % or less, an optional process (A-2) of preparing second iron ore pellets produced from high-grade iron ore having a total Fe content exceeding 63 mass %, and an optional process (A-3) of preparing lump ore;
• a reduced iron preparation process (B) comprising a process (B-1) of producing first reduced iron from the first iron ore pellets, an optional process (B-2) of producing second reduced iron from the second iron ore pellets, an optional process (B-3) of producing third reduced iron from the lump ore, and an optional process (B-4) of preparing a pre-produced fourth reduced iron;
• and
• a melting process (C) of melting the first reduced iron and optionally any of the second reduced iron, the third reduced iron, and the fourth reduced iron in a submerged arc furnace to obtain hot metal, while adding flux to adjust basicity of molten slag formed on the hot metal, wherein the following Expression (1) is satisfied,
• 150.
• ≤
• S
• ⁢
• 1
• ×
• W
• ⁢
• 1
• +
• S
• ⁢
• 2
• ×
• W
• ⁢
• 2
• +
• S
• ⁢
• 3
• ≤
• 400.
• (
• 1
• )
• where
• S1 is slag ratio, in kg/t, of the first reduced iron,
• W1 is mix ratio of the first reduced iron,
• S2 is average slag ratio, in kg/t, of the second, third, and fourth reduced iron,
• W2 is total mix ratio of the second, third, and fourth reduced iron, and
• S3 is amount of the flux, in kg/t, added in the melting process (C).