Method for manufacturing molten pig iron

A method for manufacturing molten pig iron comprising:

• forming a packed bed of coke in a vertical furnace having a charging port in an upper portion thereof for charging raw materials and discharging gases, one or more primary tuyeres in a lower portion of a wall of the furnace, one or more secondary tuyeres in a wall of the furnace at a level above the primary tuyere, a tapping port for molten pig iron formed in a lower portion of the furnace, a slag discharge port formed in a wall of the furnace at a level above the tapping port, and a tilting mechanism for tilting the furnace, the packed bed of coke extending higher than the level of the primary tuyere;
• forming a packed bed of scrap and iron ore atop the packed bed of coke to a level which extends at least to the secondary tuyere;
• blowing an oxidizing gas through the primary tuyere;
• blowing an oxidizing gas through the secondary tuyere;
• and
• discharging molten pig iron and slag which have formed in the furnace and separated from one another by natural separation via the tapping port and the slag discharge port, respectively.

A method for manufacturing molten pig iron comprising:

• forming molten pig iron containing partially melted solids in a vertical furnace having a charging port for charging raw materials and discharging gases in its upper portion, one or more primary tuyeres in a lower portion of a wall of the furnace, one or more secondary tuyeres in a wall of the furnace at a level above the primary tuyere, and a tapping port for molten pig iron in the bottom of the furnace;
• blowing an oxygen-containing oxidizing gas and a carbon-containing fuel through the primary tuyere;
• blowing an oxygen-containing oxidizing gas through the secondary tuyere;
• and
• adjusting the amount of carbon-containing fuel which is blown through the primary tuyere such that the amount of carbon which is blown into the furnace is more than the stoichiometric amount necessary to combine with the oxygen in the carbon-containing fuel and the oxygen in the oxygen-containing oxidizing gas which is blown through the primary tuyere to form carbon monoxide.

A method for manufacturing molten pig iron comprising the steps of:

• (a) forming a packed bed of coke in a vertical furnace having a charging port in an upper portion thereof for charging raw materials and discharging gases, one or more primary tuyeres in its lower portion, and one or more secondary tuyeres in a wall of the furnace at a level above the primary tuyere, the packed bed of coke extending from the furnace bottom to higher than the level of the primary tuyere;
• (b) forming a packed bed of scrap and iron ore atop the packed bed of coke to a level which extends above the secondary tuyere;
• (c) blowing an oxidizing gas through the primary tuyere and the secondary tuyere to melt and reduce the scrap and iron ore;
• (d) forming a new packed bed of scrap and iron ore atop partially melted scrap and partially melted iron ore which were partially melted in step (c);
• (e) blowing an oxygen-containing oxidizing gas and a carbon-containing fuel through the primary tuyere into the partially melted scrap and partially melted iron ore, blowing an oxygen-containing oxidizing gas through the secondary tuyere into the new packed bed of scrap and iron ore, and adjusting the amount of carbon-containing fuel which is blown through the primary tuyere such that the amount of carbon which is blown into the furnace is more than the stoichiometric amount necessary to combine with the oxygen in the carbon-containing fuel and the oxygen in the oxygen-containing oxidizing gas which is blown through the primary tuyere to form carbon monoxide;
• (f) discharging molten pig iron and slag through the tapping port while leaving partially melted scrap and partially melted iron ore in the furnace when the top of the new packed bed of scrap and iron ore falls to a prescribed level above the primary tuyere;
• and
• (g) repeatedly performing steps (d) through (f).