烧结烟气湿法脱硫废水处理及资源化利用探讨

Discussion on Treatment and Resource Utilization of Wet Flue Gas Desulfurization Wastewater in Sintering Plant

脱硫废水呈弱酸性,Cl-和盐含量较高,并含有COD、氨氮、多种重金属等污染物,腐蚀性强,对环境危害大,深度净化处理和综合利用难度大。通过分析脱硫废水传统处理工艺和零排放工艺应用中存在的问题,结合烧结矿喷洒氯化钙溶液的特点,提出将脱硫废水蒸氨去除氨氮并采用晶种法强制循环工艺浓缩减量,将浓缩液替代氯化钙溶液喷洒烧结矿,蒸氨制取的氨水作为烧结烟气脱硝还原剂,蒸发冷凝水作为烧结生石灰消化用水,实现脱硫废水综合利用和零排放。

The desulfurization wastewater has weak acidity,high content of Cl-and salt,and contains COD,ammonia nitrogen,a variety of heavy metals and other pollutants,with strong corrosiveness,and harmful to the environment,so its deep purification treatment and comprehensive utilization is difficult.In this paper,based on the analysis of the problems existing in the application of traditional treatment process and zero discharge process of desulfurization wastewater,and combined with the characteristics of spraying calcium chloride solution in sintering,it is proposed that ammonia nitrogen is removed firstly by evaporation,then be concentrated by crystal seed forced circulation process,the concentrated solution is used to spray sinter instead of calcium chloride solution,the ammonia produced by evaporation is used as the denitrification reductant of sintering flue gas,and the evaporated condensed water is used as the digestion water of quicklime,to realize the comprehensive utilization and zero discharge of desulphurization wastewater.