The kinetic description and mechanism of the solid-state reactions between metal basic carbonate (M=Co2+, Cu2+ and Zn2+) and aliphatic carboxylic acids (oxalic, tartaric, succinic and citric acids) were studied using non-isothermal analysis (TG, DTA) and capillary techniques. The reactions were found to proceed in all cases (except citric acid) by one mole of metal carbonate and two moles of metal carbonate and two moles of organic acid. The kinetic analyses of non-isothermal data were best described by each of the dimensional phase boundary R2 and two-dimensional diffusion controlled reactions D2. While the capillary technique showed that the initial reaction occurs at the phase boundary of the reactants and kinetically of the reacting controlled by diffusion mechanism in which the diffusion species through the product layers are the organic acids. |
