A comparative study of the super cooling and carbonization processes of the gibbsitic Ghanaian Bauxite

Abstract

A comparative study of the super cooling and carbonization processes of the gibbsitic Ghanaian Bauxite was investigated. Carbonization of the sodium aluminate solution (NaAl(OH)4 was carried out by introducing CO2 at atmospheric pressure into the solution to obtain aluminate trihydrate gel precipitate which was calcined at a temperature of 550 °C to produce gamma-alumina why in the super-cooling process, fresh alumina seed was used to precipitate the pregnant solution(NaAl(OH)4. The effect of Lime in desiliconisation, precipitating time, lime addition and alumina yield were determined. The percentage yield of aluminum obtained at the end of experiment for carbonization and super cooling were 92% and 62% at 6 hours and 100 hours respectively. The desiliconisation of 0.0008-0.001g/l of SiO2 was effectively achieved by the addition of varied concentration of lime. The average particle size of 0.105 and 0.193 mm for both super cooling and carbonization process were obtained from the products respectively