Synthesis of boehmite powder from aluminum etching solution

Boehmite (AlOOH) powder was synthesized using waste aluminium etching solution. In waste solution, precipitated phase was gibbsite (), and boehmite (AlOOH) phase was obtained at pH of 7 and 8 controlled by addition of acid. Boehmite powder was obtained by washing process to remove the Na ion in precipitated solution. Mean particle size of obtained powder was 40 nm. Boehmite phase transformed to phase via , , and .