Method for preparing chlorine-removal alkali residue mixture by utilizing alkali residues through ammonia-soda process and application of chlorine-removal alkali residue mixture

The invention discloses a method for preparing a chlorine-removal alkali residue mixture by utilizing alkali residues through an ammonia-soda process. The method comprises the following steps: step 1, crushing returned sand and returned stones, and grinding to obtain returned sand and returned stone powder; step 2, soaking the returned sand and returned stone powder in water for 0.5-14 days, digesting overburnt calcium oxide, mixing the digested returned sand and returned stone powder, alkali residues and water, wherein a ratio of dry mass of the digested returned sand and returned stone powder to the alkali residues is 2:8 to 5:5 based on the mass percentage of the materials, and the total mass of the water is 1.5 to 8 times that of total dry mass of the digested returned sand and returned stone powder and alkali residues; or mixing the returned sand and returned stone powder, the alkali residues and water, soaking the mixture for 0.5-14 days, and digesting the overburnt calcium oxide; and step 3, performing filter pressing treatment, thereby obtaining the chlorine-removal alkali residue mixture of which the chloride ion content is lower than 0.30 percent of the total mass of solids in the mixture. The invention also discloses application of the chlorine-removal alkali residue mixture. The method and application disclosed by the invention are good in chlorine removal effect, simple in process, energy-saving and environmentally friendly.