Investigation of the Influence of Alkali Circulation on the Blast Furnace Operation

Abstract

This paper is concerned with the influence of alkali circulation on the degradation of coke and the blast furnaee operation.
The adsorption rates of potassium on coke and sinter were measured experimentally as follows.
υ_a, _c=9.07e^{-16 900/RT}. P_k (coke)
υ_a, _s= 0.68e^{-13 800/RT}. P_k (sinter)
where
υ_a, _c=adsorption rate on cokc (g/g-coke/min)
υ_a, _s=adsorption rate on sinter (g/g-sinter/min)
P_k=partial pressure of potassium (atm)
T = temperature (K)
R=gas constant (cal/K/mol)
Using these results, a mathematical model was developed with the assumption of the distribution of alkali in the blast furnace.
The effect of alkali circulation on the blast furnace operation was investigated by using this model. The main results are summarized as follows:
(1) Recycling alkali content increases as the slag basicity increases or the slag volume decreases.
(2) The adverse effect of alkali in the coke ash on the alkali circulation, gasification and degradation of coke properties can be lowerd by charging high quality coke.