The MoU was signed in Belgrade overnight by Rio Tinto Salt, Uranium and Borates division managing director Simon Trott and Serbian Minister of Mining and Energy Aleksandar Antić in a ceremony attended by Serbian Prime Minister Ana Brnabić.

The agreement will enable the formation of joint working groups between Rio and the government to progress Jadar through the study and permitting phases faster.

“Rio Tinto sees Serbia as an attractive investment destination and the Jadar project is an important part of Rio Tinto’s growth portfolio,” Rio Tinto Energy & Minerals chief executive Bold Baatar said.

“A project of this magnitude requires time and expertise to design and bring into operation. We can only do this with the support of the Serbian government and local community.”

Rio has invested US$90 million in Jadar since its discovery in 2004.

The deposit contains jadarite, a new mineral unique to Serbia, which has not been found anywhere else in the world.

Rio recently announced increased resources of 136 million tonnes grading 1.86% lithium oxide and 15.4% boron trioxide, including an initial indicated component of 52.4Mt at 1.79% lithium oxide and 19.2% boron trioxide.

The project is currently in the prefeasibility phase, which has included pilot processing tests in California and Victoria.

Rio is aiming to make a final investment decision and start construction in 2020 ahead of first production in 2023.

Rio has said the project could produce more than 10% of the world’s lithium.