Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
The dissolution kinetics of Ukpor clay in hydrochloric acid is studied. The study was done by varying the various process parameters viz; calcination temperature, reaction temperature, acid concentration, solid-to-liquid ratio, particle size, and stirring speed. The experimental results show that the dissolution reaction increases with increase in calcination temperature, reaction temperature, acid concentration, and stirring speed, while it decreases with increasing solid-to-liquid ratio and particle size. The experimental data were analyzed according to the kinetic models for heterogeneous reaction processes using graphical and statistical methods and it was found that the dissolution of Ukpor clay in hydrochloric acid solution is controlled by ash product layer diffusion. The kinetic equation is given by 1 + 2(1 - X) - 3(1 - X) 2/3 = 1.40 x 103 C[HCl]0.37 (dp)-0.89 (s/l)-0.63 (w)0.42 exp (-4677/T) t. The activation energy of the dissolution reaction was calculated to be 39.009kJ/mol. This study has shown that Ukpor clay can serve as an alternative raw material for the aluminium industry in Nigeria and the kinetic data can be used in the design of process equipments for large scale production.

Keywords: dissolution, alumina, kinetics, shrinking core, clay

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