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This work addresses the carbonation of an aqueous solution that simulates leach liquor with sulphuric acid, a chemical system that is seldom studied, and the subsequent precipitation of Li 2 CO 3 via evaporation of the diluent water. New details were revealed on the automatic control of pH and temperature to optimizes the carbonation operation conditions and the quality of the products. Among the relevant findings are: a) the carbonation stage was optimized at pH 12 and 35°C because, under these conditions, the redox potential (100-200 mV) promotes the carbonates stability, b) the carbonation reaction in sulphated solutions has zero order and its activation energy is 6.81 kJ/mol, suggesting that the reaction is controlled by diffusion, and c) At pH 8 and 20°C the maximum purity (99.9 % Li 2 CO 3 ) was precipitated. Additionally, other carbonate based secondary phases were precipitated together with Li 2 CO 3 . The chemical stability of these secondary phases is pH dependent and are discussed in detail.[a

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