Obtaining alumina from Agbaja clay was seriously hindered due to small surface area and presence of negative surface charges. The research was targeted towards the modification of the local clay by thermal treatment and investigation of the kinetic models. The clay was characterized using FTIR, XRD and SEM. The effects of temperature and time on the calcinations process was studied in the temperature range of 400-900 oC and at the time range of 30-180 minutes. Effects of particle size, concentration of the acid, acid-clay weight ratio, stirring speed and leaching temperature on alumina yield were studied. Results obtained revealed that with the exception of particle size, increasing all the process parameters increased the yield of alumina. The optimum calcinations conditions were found to be 700 oC for a period of 1hr. rnThe dissolution process followed the liquid-film diffusion controlled model and the kinetic equation was obtained asrn1-(1-x)2/3 =0.0075C0.552[HCl] (dp)-0.482 (l/s)0.491(sp)0.6388exp(-34/RT)trnActivation energy was calculated to be 34KJ/mol.
Udeigwe Uchenna, Okechukwu Dominic Onukwuli, Ajemba Regina, Ude Callistus Nonso. Kinetics studies of hydrochloric acid leaching of alumina from Agbaja clay. International Journal of Research in Advanced Engineering and Technology, Volume 1, Issue 1, 2015, Pages 64-72