Process and apparatus for the direct reduction of iron oxides in an electrothermal fluidized bed and resultant product

摘要

A method and an apparatus ( 50 ) for producing direct reduced iron ( 37 ) from dry pellets ( 25 ) composed of iron oxide and carbonaceous material. A mixture of pellets ( 25 ) and free coke particles ( 38 ) with weight relation from 3:1 to 5:1 is fed into the top of an electrothermal fluidized bed ( 32 ) that is fluidized by nitrogen. By exposing pellets ( 25 ) in the electrothermal fluidized bed ( 32 ) to temperatures of between approximately 850-1,100° C. for an average period of between approximately 15-60 minutes, the volatiles are removed and the pellets ( 25 ) metallized. Reduced pellets ( 37 ) mixed with free coke ( 38 ) are discharged from the bottom of fluidized bed ( 32 ) and cooled. The reduced iron pellets ( 37 ) are physically separated from any free coke ( 38 ) and the free coke ( 38 ) is recycled back into the fluidized bed ( 32 ).