Microwave-Intensified Reduction of Biochar-Containing Briquettes

The coal-based direct reduction process has gradually become the focus of research concerning direct reduced iron production due to its advantages, including high reduction rate, stable chemical composition, and good metallurgical properties of products. Based on coal-based reduction theory and briquetting technique, this paper reports the use of microwave energy for intensifying the reduction of carbon-containing briquettes mainly consisting of magnetite concentrate and biochar. The heating behaviors of the raw materials show that under the conditions of microwave power of 1250 W, N flow rate of 4 L min −1 and briquetting pressure of 400 N, the briquettes present the highest heating rate. The average heating rate reaches 35.16 °C min −1. When the briquettes are irradiated by microwaves at 1050 °C for 45 min, the metallization degree of the reduced briquettes reaches 93.58%.