Microwave-Based Approach to Recovering Zinc from Electric Arc Furnace Dust Using Silicon Powder as a Non-carbonaceous Reductant

In the recycling of zinc from electric arc furnace dust using microwave-based furnaces, the use of graphite powder as a reductant results in significant greenhouse gas emissions. In this study, graphite was replaced by a non-carbonaceous reductant in the form of silicon powder. The sample is heated in a microwave-based furnace under 7.5 kW maximum power irradiation at 2.45 GHz. The results clearly indicate that the reaction proceeded between zinc ferrite and silicon powder. The maximum removal rate of zinc obtained was 80% in cases where more than 10 times the stoichiometric amount of silicon powder was used for a heating time of more than 20 min. The apparent activation energy of microwave-based heating was 115.39 kJ/mol lower than that when heating with a conventional furnace.

Automated summary

In this study, graphite was replaced by silicon powder as the reductant in the recycling of zinc from electric arc furnace dust using microwave-based furnaces. The reaction between zinc ferrite and silicon powder yielded a maximum removal rate of 80% of zinc when more than 10 times the stoichiometric amount of silicon powder was used for a heating time of over 20 minutes. The apparent activation energy of microwave-based heating was 115.39 kJ/mol lower than that of conventional furnace heating.