Large scale plant for roasting iron ore pellets - where travelling grate furnace feeds number of shaft furnaces

摘要

Bulk material, esp. iron ore pellets are treated by (a) drying; (b) preheating; (c) prebaking; (d) final baking; and (e) cooling. At least steps (a,b) are undertaken on travelling grates in a belt furnace (x); and at least step (d) is carried out in a shaft furnace(y). Furnace (x) is pref. used for steps (a,B,C) and furnace (y) for steps (d,e), esp. where gas flows in counter current to the pellets and part of the gas used in step (a) is fed into step (e) for cooling. The pref. plant consists of a belt furnace contg. travelling grates for steps (a,b,c) and feeding the shaft furnace. Gas is fed in direction (e,d,c,b,a); and one furnace (x) pref. supplies three to six, e.g. five, shaft furnaces arranged in a circular row round the outlet of furnace (x). A flexible plant suitable for baking various types of iron ore pellets, with an extremely high output and reasonable investment- and operating-costs.