The electrochemical production of highly effective polyaluminum chloride

This paper presents a new electrolytic method for the synthesis of PAC (polyaluminum chloride). The ECR (electrochemical reactor) used aluminum sheets as anode and AlCl3 aqueous solution as electrolyte. This method adopted low voltage and high electric current intensity during electrolysis. Some factors of the electrochemistry and the chemistry of the aqueous solution, affecting the formation of the most effective species of PAC, were also studied. The liquid product of PAC, in which the most effective species, Alb (The polymeric Al component estimated by the ferron method), was above 70% by weight of the total aluminum with a basicity, B (OH/Al molar ratios)=2.4, was successfully generated. The results measured by the ferron method and 27Al NMR method showed that the Alb or Al13 content of the E-PAC (PAC prepared by electrolysis) were obviously higher than that of the general PAC and other coagulants.