Original Article

Characteristics of the tuyere coke in a blast furnace

¹ State Key Laboratory of Metallic Materials for Marine Equipment and Applications, Liaoning, Anshan 114021, PR China
² Ansteel Iron & Steel Research Institutes, Liaoning, Anshan 114021, PR China
³ Angang Steel Co., Ltd. Coking Plant, Liaoning, Anshan 114021, PR China
⁴ General Ironmaking Plant of Angang Steel Co., Ltd., Anshan 114021, PR China

^* e-mail: yileqiannian@126.com

Received: 24 February 2025
Accepted: 20 May 2025

Abstract

This study investigates the particle size, chemical composition, mechanical strength, microstructure, and graphitization of tuyere coke sampled from radial zones in a 3200 m³ blast furnace. Results indicate that the average particle size of tuyere coke diminishes progressively (<19 mm) with increasing distance from the tuyere, reflecting cumulative degradation. Coke proximate to the furnace core exhibits elevated ash content and graphitization due to intensified erosion by molten slag and iron. A negative correlation is observed between sulfur, volatile matter, fixed carbon content and distance from the tuyere. Compressive strength declines near the core, attributed to alkali metal enrichment and advanced graphitization. SEM-EDS analysis reveals severe deterioration of pore walls, with adherent slag and iron particles disrupting the coke’s internal architecture. These findings elucidate the spatial heterogeneity of coke degradation mechanisms and provide actionable insights for optimizing coke quality and blast furnace performance.