利用脱硫装置处理对位芳纶稀硫酸生成副产品石膏的工艺控制研究

Study on process conditions of by-product gypsumin desulfurization equipmentof dilute sulfuric acid treatment which derivedfrom production of para aramid fiber

利用脱硫装置采用石灰石浆液中和法处理芳纶稀硫酸废水,研究了加料顺序、成核剂、pH值、温度、时间对生成的石膏的附着水含量、粒度、纯度、形貌的影响。结果表明:常温下,采用石灰石中和稀硫酸,质量分数3%稀石膏浆液作为晶种,pH为5.5,时间为20 h,可获得棒状晶粒尺寸为50μm、附着水含量低于10%、纯度达95%以上的高品质石膏,可实现对稀硫酸废水的高效低成本高附加值处理。

Sulfuric acid solution,which was used for preparing by-product gypsum via neutralization reaction in desulfurization equipment,was derived from production process of aramid fiber.However,the gypsum prepared by limestone particles and sulfuric acid solution has low added value.In this research,we prepared by-product gypsum by limestone slurry and sulfuric acid solution.Subsequently,different process conditions was studied for preparing by-product gypsum,such as feeding sequence,addition of nucleating agent,pH of reaction system,reaction temperature,reaction time,etc.Meanwhile,the effects of process condition on the attached water content,particle size,purity,morphology of gypsum were investigated.This result suggests that high-quality gypsum was prepared by adding 3%dilute gypsum slurry as the crystal seed,controlling reaction system pH at 5.5 and reaction time at 20 h,at room temperature.The purity of high-quality gypsum was over 95%,and the attached water content was less than 10%.The rod grain sizeof high-quality gypsum was up to 50μm.