Fuel consumption and reduction kinetics in blast furnaces

Abstract

Statistical analysis of blast-furnace performance at NLMK between 2009 and 2014 reveals the thermodynamic and kinetic behavior of the reduction process. A method is developed for calculating the reducing potential of the hearth gas and for quantitative estimation of its utilization and the reaction rate. With the attainable productivity of 2.4–2.9 t/m day and fuel consumption 400–420 kg/t (in terms of total carbon), the properties of the hearth gases are sufficient to ensure near-optimal (around 70%) indirect reduction of Fe, but insufficient for batch heating in the shaft to the temperatures required for intense reduction.