Recovery of high surface area alumina from aluminium dross tailings

Aluminium dress tailings (ADT), a chemical waste from a factory producing a luminium in Egypt, was used for the recovery of the aluminium content in th e form of alumina (Al2O3). Extraction of the aluminium was carried out via atmospheric- and high-pressure leaching with caustic soda. Then, it was sep arated from the sodium aluminate solutions thus obtained, using six differe nt precipitation methods. The precipitates were filtered, washed, dried and calcined at 600 degrees C to produce the test aluminas. The precipitates a nd the calcination products were analysed for their chemical and crystallin e phase compositions. The calcination products (aluminas) were subjected to sorpometry for surface area determination, and to particle sizing. The res ults indicated that highly pure (SiO2 < 0.53% and Na2O<0.1-14%), well-defin ed crystalline gamma-aluminas of high surface areas (>200m(2)g(-1)) and uni form small crystallite sizes (60-70 Angstrom) could be efficiently recovere d from ADT. Optimal recovery conditions were examined and determined. (C) 2 000 Society of Chemical Industry.