Method for recovering lithium with high efficiency from low-grade lithium minerals through process imporvement, and lithium carbonate prepared thereby

A method for recovering lithium with high efficiency from low-grade lithium minerals through process improvement, the method comprising:

• a step (S10) for acid-roasting a lithium-containing mineral to form an acid-roasted conversion product that is an oxide of constituent metal of the lithium-containing mineral;
• a step (S20) for heat-treating the acid-roasted conversion product;
• a step (S30) for water-leaching the heat-treated acid-roasted conversion product to prepare a lithium-containing water-leaching solution;
• a step (S40) for adding an alkali solvent to the lithium-containing water-leaching solution to precipitate and remove impurities, wherein the impurities includes Al, Mg, Fe, Mn, and Si, while excluding lithium;
• and
• a step (S50) for preparing at least one selected from a group consisting of lithium phosphate, lithium sulfate, and lithium carbonate, from the lithium-containing water-leaching solution removed of the impurities,
• wherein, in the step (S10), the acid-roasting is performed by mixing the lithium-containing mineral with an acid solution, drying a mixture of the lithium-containing mineral and the acid solution, and then heating the mixture.