Numerical Study of the Influence of Burden Batch Weight on Blast Furnace Performance

Abstract

Burden batch weight is a critical operating parameter in the blast furnace (BF) system. It directly affects solid distribution such as coke-layer and ore-layer thickness and thus gas permeability and thermal–chemical conditions inside a BF. However, in the open literature, few quantitative studies have been reported on the influence of burden batch weight on BF performance, such as cohesive zone (CZ) shape and location, reducing gas evolution, and iron oxide reduction behaviors. In this study, a multi-fluid BF model is used to investigate the BF performance with different burden batch weights systematically. This model features the layered burden structure with respective chemical reactions in respective coke and ore layers and a burden batch weight sub-model. The results show that, under the given simulation conditions, with the increased burden batch weight from 112 to 140 tons, the average gas velocity in central regions is significantly suppressed by ~ 1 m/s; the average gas and solid temperatures are decreased by ~ 160 K and the position of CZ decreased by ~ 7 m near the BF center; moreover, the gas utilization efficiency is improved by ~ 2.5 pct; the reduction load of the BF becomes heavier, particularly by ~ 0.05 near the BF center; the fuel rate is decreased by ~ 2.5 kg/thm, meaning a higher furnace efficiency. This study provides theoretical support for batch weight selection and optimization in BF ironmaking practice.