Abstract: Tibet has abundant lithium brine resources.Through many years′research，the author developed a new technology：deep carbonization method for processing and purifying the carbonate-type lithium concentrate from the brine in the Zhabuye salt lake，Tibet.Under a certain CO2 pressure and reaction temperature，solid lithium concentrate could be transformed into the water soluble lithium bicarbonate，so that it could be separated from the insoluble impurities.Then through resin exchange impurity removing，heating decomposition，refining & washing，drying，and crashing，the battery-grade lithium carbonate could be obtained.This new technology had such advantages as simple process，short flow，small material circulation，high metal recovery，less pollution，low cost，and less investment，comparing with the current causticizing process.It′s the most promising process route at present and it has already got China Invention Patent（CN，102502720）.

Key words: deep carbonization method, pressure carbonization, resin exchange, battery-grade lithium carbonate