Jadar ...RIO have spent over 200m on it so far and put another $200m on the table to get it through feasibility study...also fwiw its actually lithium sodium borosilicate generated out of the mineral Jatarite...its pretty much the only place where this mineral is found; The project will also require what would be the only lithium / boron separation plant on the planet.
The project was discovered back in 2004, RIOs latest resource upgrade figures is at 139mt...its a very slow expensive burn 2004 and still not through feasibility .....you reckon we need to worry about Jadar ...probably only minable 1/2 the year too being in sibera