降膜结晶法在高纯硫酸制备中的应用  

Application of falling film crystallization process in preparation of high-purity sulfuric acid

作　　者：朱静[1] 丁雪峰[1] 李天祥[1,2] 刘飞 

机构地区：[1]贵州大学化学与化工学院,贵州贵阳550003 [2]瓮福(集团)有限责任公司技术开发中心

出　　处：《无机盐工业》2014年第6期38-41,共4页Inorganic Chemicals Industry

基　　金：贵州省科学技术基金项目(黔科合J字[2012]2155号)

摘　　要：现行高纯硫酸生产工艺复杂、能耗大且成本高。降膜结晶法具有绿色环保、节能和工艺简单的优势。采用减压蒸馏、降膜结晶工艺对工业硫酸进行净化提纯,可以制备出达到BV-Ⅲ级的高纯硫酸。最佳工艺条件:1)通过减压蒸馏将工业硫酸中的大部分杂质除去;2)通过降膜结晶获得粗晶体,结晶条件为初始结晶温度-5℃、降温步长每10 min降温0.6℃、结晶时间80 min、料液流量20 mL/min;3)对粗晶体进行发汗提纯,发汗条件为发汗终温6℃、升温速度3℃/h、升温方式每10 min升温0.5℃。该工艺在高纯硫酸的制备方面有着广阔的应用前景。The existing production processes of highly pure sulfuric acid are complicated, high energy wasting, and high cost. Falling film crystallization process has advantages of environmentally friendly, energy-saving, and simple flow.Vacuum distil- lation and repeated falling film crystallization processes were applied to purify industrial sulfuric acid, and then the highly pure sulfuric acid reaching BV-Ⅲ level was achieved.The optimal process conditions were acquired ： 1 ） most of the impuri- ties in industrial sulfuric acid were moved off by vacuum distillation ;2） to obtain coarse crystals by falling film crystalliza- tion, crystallization conditions were the initial crystallization temperature of-5 ℃, the cooling step of 0.6℃ per 10 min, crys- tallization time of 80 min, and feed flow rate of 20 mL/min ; 3 ） to purify the crude crystals, sweating conditions were the final sweating temperature of 6 ℃, the heating rate of 3℃/h, and heating temperature of 0.5℃ per 10 rain.Therefore, falling film crystallization process has a wide application prospect to produce high purity sulfuric acid.

关 键 词：减压蒸馏 降膜结晶 高纯硫酸 

分 类 号：TQ125.14[化学工程—无机化工]