Chemical leaching of nickel from the seeds of the metal hyperaccumulator plant Alyssum murale

Ultramafic rocks contain Ni at high concentrations that cannot be mined by traditional technologies. The Ni hyperaccumulator Alyssum murale widely present in ultramafic regions could be used to extract the metal from the soil. This study presents a process to recover Ni from the seeds of A. murale by chemical leaching. Experimental assays demonstrated that the leaching of crushed A. murale seeds in a 0.5 M H2SO4 solution at a 90 °C with a 15% solids concentration, for a 120 min duration will extract 97.0 ± 6.8% of the Ni. The use of a three-step counter-current extraction process removes almost completely (99.0 ± 0.3%) the Ni from the A. murale seeds. Further Ni recovery will be performed by using a separation route and electrochemical deposition process in order to produce Ni cathodes.