Patent ID: 8690987

Claim:
A method for producing carbon iron composite comprising: providing a carbonization furnace having a top portion, a carbonization zone in an upper portion, and a cooling zone in a lower portion; feeding a formed product of a carbon-containing substance and an iron-containing substance into the carbonization furnace; carbonizing the formed product in the carbonization zone to produce carbon iron composite; blowing a coolant gas into the furnace through a coolant-gas-blowing tuyere disposed in the cooling zone to cool the carbon iron composite; exhausting a furnace gas through an outlet in the top portion; and discharging the carbon iron composite through the lower portion of the cooling zone, wherein the carbonization comprises: forming the coolant gas from the furnace gas in a gas cooler, heating the coolant gas to form a cooling gas, and supplying heated coolant gas to the carbonization zone after cooling the carbon iron composite in the cooling zone, forming the coolant gas from the furnace gas in a gas cooler and supplying heated coolant gas to the carbonization zone after cooling the carbon iron composite in the cooling zone, blowing a high-temperature gas into the furnace through a high-temperature-gas-blowing tuyere disposed in a lower portion of the carbonization zone, and blowing a low-temperature gas into the furnace through a low-temperature-gas-blowing tuyere disposed in an intermediate portion of the carbonization zone.