石灰石-石膏法废水对氨法脱硫硫酸铵结晶影响

Effect of Limestone-Gypsum Wastewater on Crystallization of Ammonium Sulfate in Ammonia Desulfurization

为充分发挥氨法脱硫系统自身优势,避免石灰石-石膏法废水外排造成污染环境,文中采用一期氨法脱硫预洗塔母液和料液槽母液作为溶剂,二期石灰石-石膏法各类脱硫废水作为溶质,深入研究添加各类废水对硫酸铵结晶及其晶体影响。研究表明:向一期预洗塔、料液槽硫酸铵母液中添加二期各类石灰石-石膏法废水,均可使硫酸铵结晶量明显增加,尤其添加脱硫塔浆液;添加各类废水后预洗塔母液结晶的硫酸铵晶体平均粒径均比未添加废水的晶体大,添加各类废水40.0 mL之后料液槽母液的硫酸铵结晶量增加缓慢;晶体形貌主要受不同废水元素所致。100.0 mL预洗塔硫酸铵母液较优的脱硫塔浆液添加体积为40.0 mL,100.0 mL料液槽硫酸铵母液较优的脱硫塔浆液添加体积为50.0 mL。相关研究成果可为烧结烟气石灰石-石膏法废水循环利用提供新思路。

In order to give full play to the advantages of the ammonia desulfurization system and avoid the pollution of the environment caused by the discharge of limestone-gypsum wastewater,this paper adopted the mother liquor of the first-stage ammonia desulfurization prewash tower and the mother liquor of the feed tank as the solvent,and the second-phase limestone-gypsum desulfurization wastewater was used as the solute,deeply studied the effect of adding various types of wastewater on the crystallization of ammonium sulfate and its crystals.The following conclusions were obtained.Added various types of second-stage limestone-gypsum wastewater to the first-stage prewash tower and the ammonium sulfate mother liquor in the feed tank could significantly increase the amount of ammonium sulfate crystals,especially adding desulfurization tower slurry.The average particle size of ammonium sulfate crystals crystallized from the mother liquor of the prewash tower after adding various types of waste water was larger than that of the crystals without adding waste water.After adding 40.0 mL of various types of waste water,the crystallization amount of ammonium sulfate in the mother liquor of the feed tank increased slowly.The crystal morphology was mainly caused by different wastewater elements.100.0 mL pre-wash tower ammonium sulfate mother liquor was preferably added in a volume of 40.0 mL of desulfurization tower slurry,and 100.0 mL feed tank ammonium sulfate mother liquor was preferably added in a volume of 50.0 mL of desulfurization tower slurry.Relevant research results can provide new ideas for recycling of sintered flue gas limestone-gypsum wastewater.