| 摘要 |
PURPOSE:To produce lump ore having an excellent high temp. characteristic at a good yield by adding a flux to pulverous iron ore having a specific grain size, subjecting the ore to primary pelletization, coating solid fuel on the pellets and subjecting the same to secondary pelletization to a specific grain size and calcining the pellets. CONSTITUTION:The pulverous iron ore having <=5mm grain size as the main grain size and flux are supplied from raw material tanks 1-5 and are mixed in a mixer 6 while water is added thereto. The mixture is put into an inside disk 70 of a two-stage type disk pelletizer 7, by which the mixture is subjected to primary pelletization. The primary pellets are transferred into an outside disk 71 by the rotation of the pelletizer 7. Quicklime, C.D.Q. powder coke are added thereto from raw material tanks 8, 9 and water is added to the mixture, then the mixture is subjected to the secondary pelletization to form the mini- pellets having 3-9mm grain size. The mini-pellets are then calcined by passing the same through the drying zone 100, ignition zone 101, calcining and cooling ozone 102 of a grate calcination furnace 10 and thereafter the calcined pellets are crushed by a crusher 106 and are screened by a screen 107, by which about >=3mm product lump ore is produced. |
