摘要
硫酸法钛白粉生产过程中会产生钛白废酸(H_(2)SO_(4)约20%),其为危险废弃物,具有极大的环境风险。本文探究采用冷冻结晶对废酸的提纯效果,以实现废酸的资源化处理。根据硫酸亚铁溶解度随温度降低而减小的特性,通过废酸的冷冻结晶,使硫酸亚铁过饱和并以七水硫酸亚铁的形式析出,达到废酸提纯的目的。提纯的废酸可回用于钛白粉厂的生产。获得的七水硫酸亚铁具有一定的经济价值,可应用在新能源等领域。与传统的废酸直接中和得到红石膏相比,提纯的废酸经中和法处理后得到白石膏,表明杂质铁得到有效去除。因此从源头上减少红石膏的产生,这也扩大了其应用场景。此外,根据废酸的高温特点(50~65℃),在实际应用中设计能量回收工艺,以实现节能降耗。
Titanium dioxide waste acid(H_(2)SO_(4)about 20%)is produced in the production of sulfuric acid titanium dioxide,which is hazardous waste and has great environmental risks.In this paper,aiming at the recycle treatment of the titanium white waste acid,the freeze crystallization process is adopted.Given the fact that the solubility of the ferrous sulfate decreases with the decreasing temperature,the waste acid is purified via the freezing crystallization,during which the FeSO 4 is supersusaturated and then precipitated in the form of FeSO 4·7H 2O.The purified waste acid can be reused in the titanium dioxide plant and FeSO 4·7H 2O has certain economic value and can be used in the new energy fields.Compared with the traditional direct waste acid neutralization and obtaining red gypsum,the purified waste acid is neutralized and then obtain the white plaster,showing the impurity iron is effectively removed.As a result,the production of the red gypsum is reduced and can expand its application range.In addition,since the waste acid has high temperature characteristic(50~65℃),the energy recovery is also designed in practical application to save the energy and reduce the consumption.
作者
张威
韩颖
薛文波
刘孟博
Zhang Wei;Han Ying;Xue Wenbo;Liu Mengbo(WELLE Environmental Group Co.,Ltd.,Changzhou 213000,China)
出处
《山东化工》
CAS
2023年第21期260-263,共4页
Shandong Chemical Industry
关键词
钛白废酸
冷冻结晶
资源化处理
节能降耗
titanium white waste acid
freeze crystallization
resourceful treatment
energy-saving and cost-reducing
