Lithium Recovery from Challenging Deposits: Zinnwaldite and Magnesium-Rich Salt Lake Brines

Lithium can be found in bound form in silicatic rocks and dissolved in salt lake brines. Both types of lithium resources, whose amounts exceed the expected demand for lithium by several times, are used for lithium recovery. The known lithium resources with their geochemical characteristics are reviewed together with the presently applied recovery processes which are still very similar to the historically early techniques. New processes for direct carbonisation of zinnwaldite, hydrochloric and oxalic acid leaching as well as a new method for recovery of lithium from magnesium-rich brines are presented.