Influence of multiple factors on the alkali metal enrichment in blast furnaces by a thermodynamic model

Alkali metal circulation enrichment occurs in blast furnaces, which is harmful to the blast furnace. The amount of enrichment helps to quantify the effect of alkali metals on blast furnace production, but it is not possible to directly measure the actual alkali metal enrichment in blast furnaces for technical reasons. On the basis of a thermodynamic model, FactSage was used to calculate the effects of alkali loading, slag basicity, MgO content in the slag and Al2O3 content in the slag on the alkali metal enrichment in the blast furnace. Quantitative relationships among various factors and the enrichment were obtained, and the degree of influence of various factors on the amount of enrichment was determined. The basicity B-2 of the slag was the key factor for enrichment. With an increase in the slag basicity of 0.1, the enrichment of K and Na increased by 5.3 and 1.6 kg/tHM, respectively.