Open Access

ARTICLE

Numerical Simulation of the Atomization Process for Blast Furnace Slag Granulation

Li-Li Wang^*, Hong-Xing Qin, Nan Dong

Hebei Key of Laboratory of Intelligence Equipment Digitalize Design and Process Simulation, Tangshan University, Tangshan, 063000, China

* Corresponding Author: Li-Li Wang. Email:

Fluid Dynamics & Materials Processing 2025, 21(6), 1489-1503. https://doi.org/10.32604/fdmp.2025.061154

Received 18 November 2024; Accepted 28 February 2025; Issue published 30 June 2025

Abstract

The so-called close-coupled gas atomization process involves melting a metal and using a high-pressure gas jet positioned close to the melt stream to rapidly break it into fine, spherical powder particles. This technique, adapted for blast furnace slag granulation using a circular seam nozzle, typically aims to produce solid slag particles sized 30–140 µm, thereby allowing the utilization of slag as a resource. This study explores the atomization dynamics of liquid blast furnace slag, focusing on the effects of atomization pressure. Primary atomization is simulated using a combination of the Volume of Fluid (VOF) method and the Shear Stress Transport k-ω turbulence model, while secondary atomization is analyzed through the Discrete Phase Model (DPM). The results reveal that primary atomization progresses in three stages: the slag column transforms into an umbrella-shaped liquid film, whose leading edge fragments into particles while forming a cavity-like structure, which is eventually torn into ligaments. This primary deformation is driven by the interplay of airflow velocity in the recirculation zone and the guide tube outlet pressure (Fp). Increasing the atomization pressure amplifies airflow velocity, recirculation zone size, expansion and shock waves, though the guide tube outlet pressure variations remain irregular. Notably, at 4.5 MPa, the primary deformation is most pronounced. Secondary atomization yields finer slag particles as a result of more vigorous primary atomization. For this pressure, the smallest average particle size and the highest yield of particles within the target range (30–140 µm) are achieved.

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