Five-factor Response Surface Optimisation of Hydrochloric acid
Dissolution of Alumina from a Nigerian Clay
Abstract
Abstract Certain process variables usually affect the yield of ores from
clays in acid dissolution processes. Varying these variables has been
identified to affect the yield of ores from clays. In order to increase
the process efficiency and evaluate the interactive effects of the
process variables, optimization is usually performed for the dissolution
process. In this study the interactive effects of calcination
temperature, leaching temperature, acid concentration, liquid-solid
weight ratio and stirring speed on the yield of alumina from the local
clay was investigated using the Response Surface Methodology based on
the central composite rotatable design. The second order polynomial
regression equation was appropriate for fitting the experimental data
and 0.9209 was obtained as the correlation between the predicted and
experimental responses. Calcinations temperature of 677.27oC; leaching
temperature of 65.18oC; acid concentration of 1.9mol/cm3; liquid-solid
weight ratio of 10.36 and stirring speed of 442.92rpm were the values of
the process variables which gave the optimum alumina yield of 80.07%.