Formation of CaCO_(3) hollow microspheres in carbonated distiller waste from Solvay soda ash plants  

作　　者：Wenjiao Xu Huaigang Cheng Enze Li Zihe Pan Fangqin Cheng 

机构地区：[1]Institute of Resources and Environmental Engineering,Engineering Research Center of CO_(2)Emission Reduction and Resource Utilization,Ministry of Education of the People’s Republic of China,Shanxi University,Taiyuan 030006,China

出　　处：《Frontiers of Chemical Science and Engineering》2022年第11期1659-1671,共13页化学科学与工程前沿（英文版）

基　　金：This work is supported by the National Natural Science Foundation of China(Grant Nos.U20A20149,21878180 and 21908137);the Graduate Education Project of Shanxi Province(NO.2021Y139).

摘　　要：For decades,distiller waste and CO_(2) were not the first choice for production of high valued products.Here,CaCO_(3) hollow microspheres,a high-value product was synthesized from such a reaction system.The synthetic methods,the formation mechanism and operational cost were discussed.When 2.5 L·min^(–1)·L^(–1) CO_(2) was flowed into distiller waste(pH=11.4),spheres with 4–13μm diameters and about 2μm shell thickness were obtained.It is found that there is a transformation of CaCO_(3) particles from solid-cubic nuclei to hollow spheres.Firstly,the Ca(OH)_(2) in the distiller waste stimulated the nucleation of calcite with a non-template effect and further maintained the calcite form and prevented the formation of vaterite.Therefore,in absence of auxiliaries,the formation of hollow structures mainly depended on the growth and aging of CaCO_(3).Studies on the crystal morphology and its changes during the growth process point to the inside–out Ostwald effect in the formation of hollow spheres.Change in chemical properties of the bulk solution caused changes in interfacial tension and interfacial energy,which promoted the morphological transformation of CaCO_(3) particles from cubic calcite to spherical clusters.Finally,the flow process for absorption of CO_(2) by distiller waste was designed and found profitable.

关 键 词：distiller waste CO_(2) hollow microsphere CaCO_(3) Ca(OH)_(2) inside−out Ostwald effect 

分 类 号：X703[环境科学与工程—环境工程]