Patent ID: 8133299
Filing Date: 2012-03-13
Classification: C21B,F27D

Abstract:
1. A method of reducing an iron oxide source in a multiple moving hearth furnace comprising the steps of: a. providing a furnace housing having at least two moving hearths positioned laterally within the furnace housing, at least two of said hearths moving in opposite directions and each moving hearth capable of being charged with at least one layer of iron oxide source and carbon bearing material adjacent one end of the furnace housing, and being capable of discharging reduced material adjacent the other end of the furnace housing, b. positioning a heat insulating partition between adjacent moving hearths in at least portions of conversion zones at least partially separating the atmospheres adjacent opposite sides of the partition, c. charging removable hearth sections of each moving hearth with at least a layer of iron oxide and carbon bearing material, d. passing each moving hearth within the furnace housing sequentially through a drying/preheat zone providing an atmosphere capable of drying an iron oxide source and carbon bearing material, the conversion zone providing an atmosphere capable of fluidizing volatile material in the iron oxide source and at least partially reducing iron oxide, and, optionally, a cooling zone capable of providing a cooling atmosphere for cooling reduced material containing metallic iron on the moving hearth positioned within the furnace housing, and e. transferring fluid between the atmospheres of the conversion zones of moving hearths moving in opposite directions within the furnace housing.