Abstract
By-product gypsum, produced through the traditional neutralization precipitation method for treating industrial acidic wastewater, is difficult to recycle due to its high moisture content. In this study, we proposed a novel neutralization process i.e. the two-stage neutralization method. By-product gypsum was used as an alkaline neutralizer and recycled as seed crystals for the first time. The original by-product gypsum has the poor dehydration performance due to its small particle size and the presence of colloids on its surface. After adding the by-product gypsum to the acidic wastewater, the ratio of CaO/SO3 in the system descended and colloids were dissociated. On the one hand, the alkaline component of the incomplete reaction continues to play a neutralizing role. On the other hand, CaSO4·2H2O particles act as seed crystals, promoting rapid growth of new crystals along their surface, which effectively improved crystallization performance and dehydration performance of the neutralization slag (outward discharge of slag). Compared with the original method, the wet weight of the neutralization slag is decreased from 186.0 g/L to 88.8 g/L, and the water cut is declined from 64.5% to 34.1%. The utilization ratio of the carbide slag augmented from 63.0% to 99.47%.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Chemical Engineering and Processing - Process Intensification
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
