Laterite leaching pilot confirmed the promising laboratory results

Outotec and VTT have developed together a novel process concept for nickel laterites, which enables high metal recoveries with significantly lower acid consumption compared to the conventional methods. The pilot was designed and modelled using the results from various batch reactor leaching experiments. The pilot system was operated in continuous mode for 2 weeks at Outotec’s research center in Pori, Finland, in March 2019. The recovery of nickel was approximately 85% including so called neutralization leach. Pilot run for Ni precipitation from the Pregnant Leach Solution was performed after the leaching pilot. The entire process will be assessed from the technical, economical and environmental views.

Eero Kolehmainen, WP6 leader at Outotec, was delighted of the results of the pilot run: “The leaching and precipitation circuits were operated continuously with very good results. The pilot run demonstrated the good operability of the circuits and generated useful information for further process evaluation”.

Ville Miettinen, senior scientist in hydrometallurgy at VTT, highlighted the excellent collaboration between VTT and Outotec in the technology development: “The co-operation between VTT and Outotec was very good during the whole project. The hydrometallurgical pilot was designed together with Outotec and VTT based on the results from VTT´s batch tests. The co-operation continued during the pilot when VTT researchers and technicians were present in the Outotec Research centre and were involved in the piloting work. This project was also an excellent opportunity for the information exchange and learning between VTT and Outotec. ”

Professor Anthimos Xenidis, a member of the Advisory Board of METGROW+, visited the pilot plant during its operation. Prof. Xenidis said that it is an excellent, real professional work of a group of partners with long experience on hydrometallurgical process development. It takes advantage of the inherent characteristics of the laterites under investigation in order to develop a cost-effective treatment scheme resulting in high nickel extraction rates at low sulphuric acid consumption, thus providing a dynamic perspective to the sector for the exploitation of low grades laterites.