A kinetic study of the leaching of Abu Rusheid ferrocolumbite concentrate sample in sulfuric acid
media under atmospheric pressure has been investigated. The effects of reaction temperature, sulfuric
acid concentration, stirring speed, particle size and solid/liquid mass ratio on the dissolution rate of
ferrocolumbite were examined. It is found that the dissolution rate of ferrocolumbite significantly increases
with increasing acid concentration, temperature, stirring speed and decreasing the particle size. By using 3M
H2SO4 solution, about 89% of ferrocolumbite was dissolved within 140 minutes using < 0.053 mm particle
size at a temperature of 75 0C and a stirring speed of 360 rpm. The experimental data were well interpreted
with a shrinking core model under diffusion control through the product layer, where the following rate
equation was established:
1+2 (1- X) – 3 (1- X) 2/3= = k2t
The result of the study indicated that the leaching data fitted a diffusion model. Values of 0.7993, 23.64
kJmol-1 and 1.24 X 10-3 min-1 were calculated as reaction order, activation energy and Arrhenius constant,
respectively for the dissolution process.