Kinetic Analysis of Blast Furnace Dust Recycling with Flash Reduction Process at High Temperature

摘要

The kinetics study of blast furnace dust (BFD) recycling with flash reduction process at high temperature has been carried out using a high temperature drop tube furnace in laboratory scale. A combination characterization methods of chemical titration and SEM-EDS were used to track the reduction kinetics. The experiments using CO and CO_2 mixtures with range of CO/CO_2 (1:0, 1:1) at different temperature (1623-1723 K) and at different reduction time (1560-2340 ms) were conducted. It was found that the reduction degree increases with the increase of temperature and reduction time as well as CO concentration. The carbon contained in the original BFD has weak influence on the reduction potential in the form of gasification. The unreacted core model was adopted based on the observation of the cross section and the measurement of iron element content, the effective diffusion coefficient and reaction rate constant were determined and the rate controlling step was also analyzed.