Effect of coaxial oxygen enrichment on three different coals and their blends

ABSTRACT

Mathematical models appear as very attractive alternatives in blast furnace studies. Therefore, a three-dimensional model is described and validated to simulate the flow and combustion of binary coal blends under simplified blast furnace conditions. The present article aims to analyse the performance of different coals and their blends for conventional and coaxial oxygen enrichment methods. Among the simulated coals, Coal C, which combines one of the smallest particle sizes with one of the highest volatile matter contents, presented the highest burnout and average temperature values. Coaxial oxygen enrichment showed a negative effect on coal combustibility in the cases with 26.9% of O2. This is explained by the large amount of gas being injected by the coaxial lance, resulting in a cooling effect and particle concentration. Also, blending coal A with coal B resulted in an improvement of burnout for both coals, because of the synergetic effect caused by their combustion.

KEYWORDS:

• Blast furnace
• coaxial
• burnout
• pulverized coal injection
• mathematical modelling
• PCI
• CFD
• computational fluid dynamics‌
• raceway
• combustibility‌
• combustion‌
• coal blends

Acknowledgements

The authors are grateful to the Metallurgical, Materials and Mining Engineering Postgraduate Program and the Laboratory of Simulations (LaSim), both located in UFMG. The authors would also like to acknowledge the financial support provided by CAPES (‘Coordenação de Aperfeiçoamento de Pessoal de Nível Superior’).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by CAPES through the Program for Academic Excellence - PROEX.