Selectivity evaluation on nickel recovery from electric arc furnace dust by amino acid-alkaline leaching

Abstract

In this research, it is confirmed that monosodium glutamate effectively extracted nickel (Ni) from electric arc furnace dust (EAFD) in alkaline conditions. The condition favorably recovered Ni, while other elements, especially Al and Fe, were enriched in solid residue. The optimum condition to recover Ni was at pH 8-9, MSG concentration 1 M, and pulp density 15-20 L/kg. However, selectivity factor (parameter comparing the concentration of Ni and another element in pregnant leach solution) suggested different optimum conditions for selective Ni recovery (i.e., at pH 10, MSG concentration 0.5 M, and pulp density 5 L/kg). In this case the concentration ratios of [Ni]/[Al], [Ni]/[Fe], [Ni]/[Mg] and [Ni]/[Ca] in pregnant leach solution were 25000, 380, 5 and 9, respectively. Kinetic modeling indicates the leaching process rate was controlled by the diffusion process. The low value of energy activation (23.9 kJ/mol) arbitrarily means the leaching process was controlled by the mass transport process.