脱硫废水处理前后喷射Cl析出特性

脱硫废水中含有高浓度的氯盐，影响脱硫系统的安全运行。采用Factsage热力学计算软件来模拟单一氯盐溶液和处理前后脱硫废水经过尾部烟道喷射后Cl析出特性。结果表明：CaCl₂，MgCl₂和NH₄Cl溶液喷射过程析出Cl主要以含Cl气体形式析出；喷射NaCl溶液时，Cl全部以NaCl（s）形式析出，而无气体析出。未处理的脱硫废水烟道喷射蒸发过程，75%以上的Cl以NaCl（s）的形式析出。除去Ca²⁺，Mg²⁺、NH₄⁺等离子后，脱硫废水烟道喷射蒸发过程不会析出HCl气体，产物NaCl（s）会被电除尘除去。因此脱硫废水的预处理减少了含Cl气体的析出，减轻了对尾部烟道的腐蚀。

Precipitation Characteristics of Chlorine in the Process of Desulfurization Wastewater Spray Before and After Treatment

Desulfurization wastewater contains high concentrations of chloride salts, which affects the safe operation of the desulfurization system. The Factsage thermodynamic calculation software was used to simulate the precipitation characteristics of chlorine in a single chloride solution and the desulfurization wastewater before and after treatment through the tail flue spray. The results showed that the precipitates were observed in the form of chlorine-contained gas if CaCl₂, MgCl₂ and NH₄Cl solutions were sprayed. While if NaCl solution was sprayed, all of the chlorine content were precipitated as NaCl(s) without any gas evolution. In the process of spray evaporation with untreated desulfurization wastewater, more than 75% of chlorine were precipitated as NaCl(s). After the removal of Ca²⁺, Mg²⁺, NH₄⁺, etc., no HCl gas was formed in the flue gas spray evaporation process of the desulfurization wastewater, and the product NaCl(s) would be removed by electric dust removal device. Therefore, the pretreatment of the desulfurization wastewater has effectively reduced the precipitation of chlorine-contained gas and therefore the corrosion of the tail flue is mitigated.