Dust formation in electric arc furnace : birth of the particles

TL;DR

This study investigates the mechanisms of dust formation in electric arc furnaces, identifying bubble burst events as the main source, and suggests that reducing bubble size could significantly decrease dust emissions.

Contribution

Developed an experimental setup to study bubble burst phenomena in EAF dust formation, highlighting the role of film drops and proposing bubble size reduction as a mitigation strategy.

Findings

Film drops are the main source of dust particles.

Reducing bubble size below 4.5 mm prevents film drop formation.

Smaller bubbles significantly decrease dust emission in EAF.

Abstract

The characterization of Electric Arc Furnace (EAF) dust shows that bubble burst at the liquid steel surface is the principal source of dust emission. We have therefore developed an experimental device for studying this phenomenon. As in the case of the air-water system, the bubble-burst gives birth to two types of droplets: film drops and jet drops. The jet drop formation is observed with high-speed video. The film drop aerosol is collected on filters and then characterized by means of SEM, granulometric and gravimetric analyses. Results are presented and discussed. The quantification of both types of projections leads to the conclusion that the film drop projections represent the major source of dust. The amount of film drops greatly decreases with the parent bubble size. Under 4.5 mm in bubble diameter, no film drops are formed. Decreasing enough the bubble size would therefore represent an effective solution for reducing drastically the EAF dust emission.