A kinetic study on the carbothermic reduction of zinc oxide from electric arc furnace dusts Mohammad Sheikhshab Bafghi, Karimi, Mandana Adeli Abstract In the present study, the reduction of zinc oxide from pellets made from electric arc furnace dusts has been investigated. Effects of such parameters as the type of carbonaceous materials as well as time and temperature on the reduction reaction have been examined. The reduced (dimensionless) time method was applied to perform a kinetic analysis of the system. Graphite, coke, and charcoal were used as reducing agents. The results showed that increasing the temperature in the range of 925-1150°C results in a remarkable increase in the reduction rate. It was also shown that the reduction process is controlled by chemical reaction. The reduction rate showed a strong dependence on the reactivity of the carbonaceous material, and the whole reduction process was shown to be considerably affected by the Boudouard reaction. The differences in the activation energies calculated for reduction with graphite (24.75 kcal/mol), coke (18.13 kcal/mol) and charcoal (11.52 kcal/mol) indicate the importance of the reactivity of carbonaceous material. Pelletization proved to be a very effective method in increasing the reduction rate. Keywords: Electric arc furnace dust, carbothermic reduction, pelletizing, kinetics, mechanism, activation energy 1. Introduction Electric arc furnaces (EAF) are extensively used in the steelmaking industry. Process dust of steelmaking EAF contains considerable amounts of zinc, which makes the dust a valuable secondary source of this metal. Around 20 kg of dust are collected per tonne of steel produced in electric arc furnaces [1]. The filtered dust is categorized as hazardous waste in most countries as it contains heavy metals. Recovery of valuable metals through adequate processes is of importance from both economic and environmental points of view. The characterization, minimization, and precise utilization of EAF dust including recovery of the accompanying elements have been the subject of several studies [1-8]. Several techniques have been proposed for the recovery of zinc based on hydrometallurgical processes [9-15], selective reduction by solid iron [16, 17], selective chlorination [18], thermal treatment with PVC [19] and carbothermic reduction [20-23]. Among these, Kim et al. [22] have studied the effect of various additives such as Fe 2 O 3 , CaCO 3 , and mill scale on the kinetics of the reduction reaction of zinc oxide. They used mixtures of loose powders contained in a covered alumina crucible, and deduced that all three additives enhance the