Abstract: Firstly，it pointed out the lime-flue gas brine purification technology had an significant defect that there was a lot of calcium and magnesium mud and light calcium carbonate（PCC） ‘waste-slurry’ having been buried in abandoned wells.It then proposed a new technology of lime-flue gas brine purification with waste-slurry zero discharge.This new technology used a professional digestion machine instead of emulsifying barrel，so as to achieve continuous production of lime milk and lime slag automatic elimination.Also by adding sodium polyacrylate as a crystallization additive，standing，and maturing etc.to make magnesium hydroxide float on the surface of saturated salt water，so as to realize the separation from dehydrate-gypsum settled in the bottom.Finally the all recycling of magnesium hydroxide，dehydrate-gypsum，PCC，and brine almost was realized. With a refined salt enterprise with annual output of 1×106 t as an example，4 000 t magnesium hydroxide，1.39×105 t dehy- drate-gypsum，26 000 t PCC，and 6.25×105 t brine could be recycled，with remarkable economic and social benefits.

Key words: lime flue gas brine purification process, waste-slurry, magnesium hydroxide, dehydrate-gypsum, PCC