A review of processing methods for electric arc furnace dust

Abstract

The work presents an analytical review of processing methods for industrial waste from the ferrous industry, namely, electric arc furnace dust. The annual emissions of this dust and the source of each dust component are determined. Scientific works on the topic of processing electric arc furnace dust published over the past 20 years are compared and analysed. The major methods for dust processing to recover iron, zinc and other metals include pyro - and hydrometallurgical techniques and their combinations. To date, several high-temperature technologies have been developed that allow zinc-containing dust to be efficiently processed (in particular, the Waelz process and secondary processes). However, many of these technologies have remained at the development stage for various reasons (either requiring considerable capital investments, or being unreliable, energy-intensive and inefficient). It is shown that hydrometallurgical processes are environmentally safe and selective to valuable components and allow technological parameters to be controlled. By selecting a suitable solvent (acidic or alkaline), the required metal can be selectively extracted from dust. In addition, such a technology will be cost-effective even under low contents of the extracted component. Approaches to processing metallurgical dust with inorganic and organic acids and ammonia-based solutions are described. Both conventional processing of electric arc furnace dust on an industrial scale and the laboratory developments recently introduced at zinc production plants (their features, advantages and disadvantages) are discussed. Technologies that allow valuable components in the dust to be extracted and returned to the production cycle are identified.