Anti-sintering calcium-based absorbent as well as preparation method and application thereof

The invention provides an anti-sintering calcium-based absorbent as well as a preparation method and application thereof. The preparation method comprises the following steps: step 1, mixing carbide slag and pyroligneous liquor and reacting; 2, carrying out solid-liquid separation on a reaction mixture in the step 1; step 3, uniformly mixing the liquid phase obtained in the step 2 with an aluminum source, and then performing evaporative crystallization; and 4, pyrolyzing and calcining the crystallized solid in the step 3 in an inert atmosphere to obtain the anti-sintering calcium-based absorbent. The anti-sintering calcium-based absorbent can be applied to direct dechlorination and desulfurization of high-temperature flue gas, CO2 capture and the like, has the advantages of high specific surface area, rich pore structure, high temperature resistance and sintering resistance, and has the dechlorination efficiency 25% or above higher than that of a traditional CaO absorbent at the high temperature (650-750 DEG