Abstract:The current process of lithium extraction from spodumene primarily employs high temperature transition - sulfation roasting method, which usually requires transformation roasting and sulfation roasting at about 1 100 ℃, which has issues such as high energy consumption and long process flow. One-step low temperature roasting method with CaO and Na2SO4 as mixed additives to extract lithium from α-spodumene was proposed, and the amount of additives and roasting temperature were further optimized. The results indicate that the leaching rate of lithium is 94.97% under the conditions including roasting temperature of 900 ℃, roasting time of two hours, and a mixture of 50% Na2SO4 and 6% CaO. Using XRD, FT-IR, SEM-EDS and other methods, the ore-phase regulation mechanism of the mixed additives on the one-step roasting process of lithium extraction from α-spodumene is clarified as follows: At low temperature, CaO can react with α-spodumene to form anorthite and quartz, which destroys the stable structure of spodumene and reduces the transition temperature of α-spodumene. Na2SO4 further reacts with quartz and spodumene to form albite and soluble NaLiSO4. The process significantly reduces the roasting temperature of spodumene, realizes the short-range and efficient extraction of lithium, and has significant application value.