Method for acquiring lithium carbonate in zinnwaldite

The invention discloses a method for acquiring lithium carbonate in zinnwaldite, which comprises the following steps: mixing zinnwaldite and a calcination agent, then roasting, using water for leaching to obtain a leachate, purifying the leachate and removing impurities, refrigerating and separating sodium out, concentrating, and adding sodium carbonate in a concentrate to obtain lithium carbonate precipitation and a solution containing potassium, rubidium and caesium. The method can increase the extraction rates of lithium, potassium, rubidium and caesium in zinnwaldite concentrate.