Original Article

Dissolution characteristics of TiC_0.3N_0.7 in low-carbon and safe blast furnace hearth

¹ School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083 China
² State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing, 100083 China

^* e-mail: zhang.jianliang@hotmail.com

Received: 24 September 2023
Accepted: 19 January 2024

Abstract

Investigating the presence of a Ti(C,N) protective layer in molten iron is of great significance for achieving low carbon and safe production in blast furnaces. This study focuses on analyzing the high temperature dissolution experiment of TiC_0.3N_0.7 in molten iron to elucidate the kinetics and mechanisms involved, as well as strategies for regulating its dissolution. The results reveal that the dissolution reaction of TiC_0.3N_0.7 is predominantly influenced by the temperature and flow speed of the molten iron. The dissolution process can be categorized into two stages: dissolution reaction and physical penetration. Diffusion mass transfer is the dominant factor controlling the dissolution of TiC_0.3N_0.7, with an apparent activation energy of 60.15 kJ/mol. Upon contact with molten iron, dendritic penetration of TiC_0.3N_0.7 particles occurs, starting from the edges. To enhance the stable presence of TiC_0.3N_0.7, recommendations include reinforcing furnace cylinder cooling, reducing the heat transfer coefficient of the blast furnace hearth's resistant material, increasing the carbon content of the molten iron, and decreasing the sulfur content of the molten iron.