Kinetics of sulfuric acid leaching of low-grade zinc silicate ore

Dissolution kinetics of ulexite in acetic acid solutions

“…Therefore, the value of activation energy of a dissolution reaction may be used to predict the rate-controlling step. The activation energy of a diffusion-controlled process is typically from 4 to 12 kJ/mol, while for a chemically controlled process is usually greater than 40 kJ/mol (Abdel-Aal, 2000;Ashraf et al, 2005). The value of the activation energy obtained in the dissolution process confirms that this leaching process is controlled by chemical reaction.…”

Kinetic study of the manganese mine tailings leaching by organic reductant in sulfuric acid solution

“…The activation energy of a diffusion controlled process is usually 21 kJ/mole or less, when the chemical reaction is the rate controlling step the activation energy is usually in the range 40-100 kJ/mole [21,22]. The value of the activation energy obtained in the dissolution process confirms that this leaching process is controlled by the chemical reaction.…”

Dissolution kinetics of natural magnesite in lactic acid solutions

“…The activation energy of a diffusion controlled process is characterized to be from 4.18 to 12.55 kJ/ mol, while for a chemically controlled process it is usually greater than 41.84 kJ/mol (Abdel-Aal, 2000). Such a value for the activation energy indicates that the leaching of magnesite with lactic acid solutions is controlled by surface chemical reaction.…”