Cost-Effective Production of Pure Al₁₃ from AlCl₃ by Electrolysis

An integrated electrolysis system was built to synthesize polyaluminum chloride with ultra high-basicity and even pure Al₁₃. The system converts AlCl₃ solution from aluminum electrode foil industry waste to Al₁₃ chloride directly with reasonable cost, typically $1.09 per kilogram as Al₂(OH)₅Cl·2H₂O at 25 °C. Electrolyte temperature and current density were investigated to optimize the process. Ferron assay and ²⁷Al NMR results indicated that the purity of Al₁₃ is over 99% in product solutions. Ion chromatogram analysis confirmed that Cl^– ions accounted for about 96.5% in all counteranions. Our integrated system is the first instance to obtain pure Al₁₃ polycations directly. Similar high purity products are only available after tedious purification. This effective and economic synthesis procedure has potential for mass production of Al₁₃ for water treatment and catalyst as well as cosmetic industries