Experimental Model Study of Liquid–Liquid and Liquid–Gas Interfaces during Blast Furnace Hearth Drainage

Weiqiang Liu,Henrik Saxén,Lei Shao

doi:10.3390/met10040496

Abstract

The smooth drainage of produced iron and slag is a prerequisite for stable and efficient blast furnace operation. For this it is essential to understand the drainage behavior and the evolution of the liquid levels in the hearth. A two-dimensional Hele–Shaw model was used to study the liquid–liquid and liquid–gas interfaces experimentally and to clarify the effect of the initial amount of iron and slag, slag viscosity, and blast pressure on the drainage behavior. In accordance with the findings of other investigators, the gas breakthrough time increased and residual ratios for both liquids decreased with an increase of the initial levels of iron and slag, a decrease in blast pressure, and an increase in slag viscosity. The conditions under which the slag–iron interface in the end state was at the taphole and not below it were finally studied and reported.

Highlights

The ironmaking blast furnace (BF), which will likely remain the dominant process in supplying hot metal for the production of crude steel in the near future, has undergone remarkable developments in both operating efficiency and working volume
Smooth drainage is of crucial importance to the hearth integrity that is today commonly recognized as the main factor limiting BF campaign life
It is seen that bending the l–g interface bends more than the l–l interface, which is due to differences in viscosity and density the l–g interface bends more than the l–l interface, which thetwo twoliquid liquidphases

Summary

Introduction

The ironmaking blast furnace (BF), which will likely remain the dominant process in supplying hot metal for the production of crude steel in the near future, has undergone remarkable developments in both operating efficiency and working volume. Incomplete drainage may occur, often caused by problems in extracting slag of high viscosity or at high draining rates. In such situations, the resulting l–g interface in the hearth may rise excessively, which has an adverse effect on the BF operation, resulting in, e.g., unstable burden descent. In the most extreme situation, the l–g interface can even rise up to the level of the tuyeres, causing serious problems in the blast supply, or in the worst case explosion due to water leakage, which can endanger the safety of the casthouse personnel [2]

Methods

Results

Discussion

Conclusion