The application of alkaline pellets can increase the proportion of pellets into the furnace,effectively reduce the slag ratio and energy consumption,improve the utilization coefficient of the blast furnace,and reduce carbon emissions. The effect of alkalinity on the preparation of high silica concentrate pellets is studied,and the optimal process parameters for the production of high silica concentrate alkaline pellets by chain grate-kiln method are clarified. The results show that the spherical index of limestone is higher than that of iron concentrate. The limestone is evenly distributed in the fresh pellet without obvious segregation. After the alkalinity of the pellets is increased,there is not much change in performance of the fresh pellet. Increasing the preheating temperature can increase the compressive strength of the pellets. With the increase of roasting temperature,the compressive strength of the roasted pellets with different alkalinity increases,and the higher the alkalinity,the greater the compressive strength of the pellets at each roasting temperature point. When the roasting temperature is 1 230 ℃ and the roasting time is 10 min,the compressive strength of each alkalinity roasted pellets can reach 3 000 N/P. In low-alkalinity pellets,the flux reacts with iron ore concentrate to form silicate or calcium-iron silicate minerals;In high-alkalinity pellets,the binder phase minerals are converted to calcium ferrite. The reductive expansion rate of pellets increases first and then decreases with the increase of alkalinity. When the alkalinity is 0.8,the reduction expansion rate of pellets is the largest,exceeding 20%. When the alkalinity is greater than 1.0,the reductive expansion rate of pellets is less than 10%.