关键词: 钛铁矿, 循环伏安, 电化学溶解, 活化能, 硫酸

Abstract: Electrochemical techniques have been used to investigate the dissolution behaviors of ilmenite fraction of beach sand of Bangladesh in sulfuric acid solutions at various temperatures. It is seen from the cyclic voltammetric studies indicated that the dissolution of ilmenite is was very difficult without the addition of carbon powder in ilmenite. The effects of ilmenite-carbon ratio, acid concentration and temperature on cyclic voltammograms have been investigated to understand the dissolution process of ilmenite. The investigated results showed that the dissolution rate of ilmenite (FeTiO₃) is was slow at low applied reduction potentials and temperatures. However, the dissolution rate was increases accelerated at more negatively applied reduction potentials and higher temperatures. The dissolution rate was also increases increased with theon increasing acid concentrations up to 1 mol•dm^-3; . and aAt more larger acid concentrations and higher reduction potentials, ithe dissolution rate was decreases decreased due to the starting of H₂ gas evolution which eventually decreases reduced the active surface area of pellet by adsorption. The activation energy (Ea) is was evaluated to be 50±10  kJ•mol^-1 in the higher temperature region, (htr) andwhile 15±5  kJ•mol^-1 in the lower temperature region (ltr)., The value of activation energy suggestsing the process to be diffusion controlled process at the lower temperature regionltr and chemically controlled process at the higher temperature regionhtr.

Key words: ilmenite, cyclic voltammetry, electrochemical dissolution, activation energy, sulphuric acid