*Article* **Numerical Study of Binary Trickle Flow of Liquid Iron and Molten Slag in Coke Bed by Smoothed Particle Hydrodynamics**

**Shungo Natsui 1,\*, Kazui Tonya 2, Hiroshi Nogami 1, Tatsuya Kikuchi 2, Ryosuke O. Suzuki 2, Ko-ichiro Ohno 3, Sohei Sukenaga 1, Tatsuya Kon 4, Shingo Ishihara <sup>1</sup> and Shigeru Ueda <sup>1</sup>**


Received: 16 January 2020; Accepted: 12 February 2020; Published: 14 February 2020

**Abstract:** In the bottom region of blast furnaces during the ironmaking process, the liquid iron and molten slag drip into the coke bed by the action of gravity. In this study, a practical multi-interfacial smoothed particle hydrodynamics (SPH) simulation is carried out to track the complex liquid transient dripping behavior involving two immiscible phases in the coke bed. Numerical simulations were performed for different conditions corresponding to different values of wettability force between molten slag and cokes. The predicted dripping velocity changes and interfacial shape were investigated. The relaxation of the surface force of liquid iron plays a significant role in the dripping rate; i.e., the molten slag on the cokes acts as a lubricant against liquid iron flow. If the attractive force between the coke and slag is smaller than the gravitational force, the slag then drops together with the liquid iron. When the attractive force between the coke and slag becomes dominant, the iron-slag interface will be preferentially detached. These results indicate that transient interface morphology is formed by the balance between the momentum of the melt and the force acting on each interface.

**Keywords:** ironmaking blast furnace; coke bed; trickle flow; molten slag; liquid iron; SPH
