Patents
A process is disclosed where treatment of waste aluminium dross, comprising alumina, Aluminium, silica, Fe2O3, NaCI, KCI, etc., with Sulfuric acid has been performed to take out preferentially alumina value into the solution as Aluminium Sulfate. More than 90% alumina recovery efficiency is found. Washing of aluminium dross is essential to achieve higher recovery. The Aluminium Sulfate solution obtained after Sulfuric acid dissolution of dross is hydrolysed to obtain amorphous Aluminium Hydroxide. In this case ammonia has been taken as the hydrolyzing precipitant. Amorphous aluminium hydroxide is further dehydrated at 900°C to obtain -alumina, which is considered as good activated alumina.