Abstract: In this paper,the leaching technology of high-alumina fly ash from the clinker obtained by low-calcium dry sintering of soda lime was studied. The effects of leaching time,leaching temperature,liquid-solid ratio and alkali concentration on the leaching rate of sodium aluminate in clinker were investigated. The optimum technological parameters for leaching sodium aluminate from alumina clinker were explored. The phase of clinker was characterized by XRD and SEM before and after leaching. The kinetics of NaAlO_2 in leached alumina clinker was discussed. The results show that the leaching rate of sodium aluminate reaches more than 94% under the conditions of leaching time 7 min,leaching temperature about 65 ℃,liquid-solid ratio 5,and alkali concentration 0. Compared with the traditional standard leaching of bauxite at the temperature of (85±1) ℃ for 15 min,the leaching process is simple,the consumption of alkali is low,the leaching time is short and the leaching efficiency of aluminum is high. The kinetic analysis of sodium aluminate (NaAlO_2) leaching process of alumina clinker was carried out by shrinking core model,and its apparent activation energy was 26. 585 kJ/mol. The reaction is under mixed control and the activation energy of leaching reaction is low. This study provides basic parameters for the industrial practice of fly ash preheating and precalciner-lime suspension precalciner-low calcium dry sintering. The new process can reduce the consumption of alkali,shorten the leaching time,improve the leaching efficiency of aluminum,and promote the industrialization process of extracting alumina from high aluminum fly ash.