关键词: 脱硫废水, 低温多效闪蒸, 烟气余热, 深度处理技术, 自结晶, 防结垢, 零排放

Abstract: Zero liquid discharge（ZLD）of flue gas desulfurization（FGD）wastewater from coal-fired power plants has
attracted lots of public attentions. A low-temperature flue gas waste heat flash evaporation technology for FGD wastewater
advanced treatment was proposed ，and has been applied in a pilot project who can process the wastewater at 15 m3/h. The
results show that the process system is of simple structure，stable and reliable operation，high recovery rate of
condensation water ，and zero desulfurization wastewater discharge.The system achieves the goal of ZLD. The process needs
no dosing pretreatment，and takes gypsum as crystal seed to realize divalent salt crystal separation during the wastewater
concentration. The direct desulfurization treatment cost of the system is low which is about 19.42 yuan per cubic meter.
Comparing the water quality indexes of raw water and condensation water，except for the ammonia nitrogen removal rate，
the removal rates of SS，COD，Ca2+，Mg2+，SO42-，Cl- are higher than 96%. They have basically reached the water quality
standard for boiler makeup water according to The reuse of urban recycling water—Water quality standard for urban
miscellaneous water consumption（GB/T 19923—2005）

Key words: desulfurization wastewater, low-temperature multiple-effect flash evaporation, flue gas waste heat, advanced
treatment technology, spontaneous crystallization, anti-scaling, zero discharge