Russia-based Halmek Lithium has selected Metso Outotec’s patented lithium hydroxide process for production of battery-grade lithium hydroxide at its greenfield plant in the Tula region in Russia. The order value has not been disclosed.

Battery-grade lithium hydroxide

Metso Outotec’s scope of delivery consists of the engineering and key equipment supply for the lithium hydroxide process, the basis of which will be the Metso Outotec OKTOP Autoclave Plant.

The Outotec lithium hydroxide process concept is based on a two-stage alkaline leach process. Lithium is first extracted from the silicate mineral in a pressure leaching stage using soda ash. The reaction involves the formation of soluble lithium carbonate and mineral component analcime (NaAlSi₂O₆·H₂O) as the main components.

In the second stage lithium carbonate is solubilized in a conversion reaction, producing lithium hydroxide solution and solid calcium carbonate, which will report together with other mineral residues. Lithium carbonate formed in hydrothermal leaching can be converted to lithium hydroxide in a fast reaction with high yields. Overall, the yield from concentrate for lithium leaching extraction typically exceeds 90%.

The alkaline hydroxide and carbonate processing milieu ensure very low solubilities of all the main impurity elements and compounds including Fe, Al, Mg, Ca, B, and P.

One of the most important tasks in the project was the selection of technology. Instead of the more traditional sulfuric acid processing to produce lithium hydroxide, we decided to choose the Metso Outotec lithium hydroxide process as it is the most promising and environmentally sound process at the moment. The pilot tests conducted at the Metso Outotec Research Center in Pori, Finland, provided excellent results.

—Pavel Galchenko, VP, Halmek Lithium

Metso Outotec has developed lithium hard rock-related technologies for some 20 years now. It started with the battery-grade lithium carbonate process and, when the market changed to favor lithium hydroxide, the process flowsheet was converted to directly produce battery-grade lithium hydroxide monohydrate (LHM) from spodumene. Both of the processes are patented and will be significant assets in our battery chemicals business, meeting the need to produce high-end Li-ion battery chemistries for the growing market.

—Mikko Rantaharju, Vice President, Hydrometallurgy business line at Metso Outotec

Halmek Lithium’s new hydrometallurgical plant, which will complement their existing lithium hydroxide plant, is currently under construction. As raw material, the new plant will use spodumene concentrate; it will feature a capacity of 20,000 tons per year of battery-grade lithium hydroxide monohydrate, which is used in the production of batteries for electric vehicles. The first production line is planned to start up in 2023, and the second production line with a capacity of 20,000 tons is expected to start production in 2026.