氨法脱硫工艺超低排放改造后氯离子的富集及危害研究

Enrichment and Hazard Research of Chloride Ions After Ammonia Desulfurization Process

脱硫浆液中氯离子主要来源于烟气、工艺水和脱硫剂。工艺水一般是普通的工业水,水中含有一定量的氯离子;烟气中的HCl气体和灰尘中的氯化物,特别是灰尘颗粒中的氯化物的比例很大,烟气中氯离子主要受煤中含氯量的影响,氯离子对不锈钢造成腐蚀,破坏钝化膜;并且试验发现,氯离子浓度越高,结晶速度越快,所得晶体越多,晶粒越小。证明在实际生产中若氯离子含量不断富集,附着在硫酸铵晶体的表面,抑制了晶体的生长,对结晶有较大影响,因此测定浆液中氯离子是很有必要的。针对某煤化工燃煤锅炉超低排放改造后出现的氯离子腐蚀的原因分析的简要探讨,并提出建议性措施。

Chlorine ions in the desulfurization slurry mainly come from flue gas,process water and desulfurization agent.Process water is generally ordinary industrial water,which contains a certain amount of chloride ions.HCl gas in smoke and chloride in dust,especially the proportion of chloride in dust particles is very large,the chloride ion in the flue gas is mainly affected by the chlorine content in coal,chloride ion causes corrosion to stainless steel,damages the passivation film.And the test found that the higher the chloride concentration,the crystallization speed is faster,the more crystals are obtained,and the grains are smaller.It is proved that if the chloride ion content is constantly enriched in the actual production,attached to the surface of the ammonium sulfate crystal,inhibit the growth of the crystal,has a great impact on the crystallization,so it is necessary to determine the chloride ion in slurry.This paper briefly discusses the causes of chloride ion corrosion after ultra-low emission transformation of coal-fired boiler in a coal chemical industry,and puts forward some suggestions.