# Melting Behavior of Direct Reduced Iron Pellets with Different Carbon Content in Molten Steel and Molten Slag

## TL;DR

This study shows that higher carbon content in iron pellets speeds up their melting in molten environments due to improved heat transfer from gas reactions.

## Contribution

A validated computational model reveals how carbon content affects DRI pellet melting via gas evolution and heat transfer.

## Key findings

- Higher carbon content increases the melting rate of DRI pellets despite higher enthalpy demands.
- Gas evolution from FeO and carbon reactions enhances heat transfer within the pellets.
- The computational model aligns well with experimental data on temperature and gas generation.

## Abstract

This study investigates the melting behavior of direct reduced iron (DRI) pellets in molten slag and steel baths, focusing on how the carbon content influences the melting rate through the stirring effects of gas evolution on heat transfer. A computational model using COMSOL Multiphysics 6.1 is developed to simulate the temperature profile at the pellet’s core and the gas evolution resulting from the reaction between FeO and carbon within the pellet. The model is validated using experimental data from this study as well as literature on the DRI pellet–molten slag system. Results indicate that, despite the increased enthalpy demand associated with the gas-generating reactions, higher carbon content enhances heat transfer within the pellet, leading to an increased melting rate. The computational model accurately predicts gas generation and temperature profiles, aligning well with experimental observations. Overall, the findings demonstrate that increasing the carbon content in DRI pellets accelerates the melting process.