METHOD AND DEVICE FOR DIRECTLY REDUCING PARTICULATE OXIDE-CONTAINING ORES

摘要

The invention relates to a method for directly reducing particulate oxide-containing ores, especially iron-oxide containing material, by way of a fluidized bed method, at a pressure of 5 bar. According to the inventive method, the ore is heated up in a fluidized bed reactor (1) that is configured as a pre-heating stage (7) using a reducing gas produced from natural gas. Optionally, the ore is also pre-reduced, and is then reduced to sponge iron in at least one fluidized bed reactor (2, 3) that is configured as a reduction stage (8, 9). The reducing gas is guided via a reducing gas pipe (15) in a counter-current to the material to be reduced which is guided from stage to stage from the reduction stage (8, 9) to the pre-heating stage (7). The reducing gas is removed as top gas and is returned to the reduction stage (8, 9) after purification. Heat is supplied to the reduction stage (8, 9) and/or pre-heating stage (7) by combustion of an external fuel gas, especially natural gas, together with oxygen and/or air.