Clean production process for improving crystallinity and granularity of heavy ash

The invention discloses a clean production process for improving crystallinity and granularity of heavy ash in the technical field of heavy ash production. The common heavy ash production system and the high-quality heavy ash production system are connected in series, high-concentration and high-temperature mother liquor of high-quality heavy ash is used for producing common heavy ash, and efficient utilization of the high-quality heavy ash mother liquor is achieved; the returned alkali is fed into the heavy ash calcining furnace to be calcined together with the monohydrate alkali, so that the moisture of the wet monohydrate alkali can be reduced, the calcining furnace is prevented from scabbing, the common heavy ash monohydrate alkali is larger and more uniform in crystal granularity and lower in water content on the premise of ensuring the yield, the steam consumption of the calcining process is reduced, and economic benefits are generated; the crystallization protective agent prepared by the invention has