Mechanism and Prevention of Agglomeration/Defluidization during Fluidized-Bed Reduction of Iron Ore

Abstract

The mechanisms of agglomeration and defluidization and fluidization characteristic of iron oxide particles were investigated based on the theory of surface diffusion, interface reaction, surface nano/microeffect, and phase transformation. Moreover, a mathematical model was developed to predict the high-temperature defluidization behavior by the force-balance and plastic-viscous flow mechanism, and the fluidization phase diagram was obtained. On these bases, a control method of defluidization and its inhibition mechanism were proposed. As a result, the theoretical system of agglomeration/defluidization in the gas-solid fluidization was developed, and thus afforded theory support and techno-logical bases for the solution of defluidization in industrial fluidized-bed reactors.