High-concentration polyaluminum chloride: Preparation and effects of the Al concentration on the distribution and transformation of Al species

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2009-12, Vol.155 (1), p.528-533
• Main Authors: Zhao, Hua-Zhang, Liu, Chuan, Xu, Yi, Ni, Jin-Ren
• Format: Article
• Language: English
• Subjects: Al species; Applied sciences; Chemical engineering; Concentration; Exact sciences and technology; Polyaluminum chloride; Preparation; Transformation
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2009.08.007

Using an instantaneous base-feeding method and a batch-feeding method, high-concentration polyaluminum chloride (PACl) products were prepared employing CaO as the basification reagent. The distribution and transformation of the Al species of PACl was explored for the first time over a broad total Al concentration (Al T) range. There is always an optimal basicity ( B value) at which the product has the highest Al b content, whether Al T is high or low. The optimal B value and the highest Al b content obtained both decrease with increasing Al T. When the B value is lower than optimal, the overall reaction mainly leads to the production of Al b; when the B value is higher, the reaction leads to the production of Al c. During the dilution process, high B value PACl has a tendency towards Al b formation, while low B value PACl favors Al c formation. The transformation behaviors of Al species are influenced by Al T in the preparation or dilution process.