Leaching Kinetics of Stibnite in Sodium Hydroxide Solution

The leaching kinetics of stibnite in basic solution has been investigated. Spherical pellets of antimony sulphide were dissolved in 1 molar sodium hydroxide solutions at different temperatures. It was foundthat the shrinking core with ash layer model could satisfactorily explain the dissolution process. Usingthis model, it was found that initially the rate controlling step was a chemical reaction with activation energy of 10.2 kJ/mol. As the ash layer built up, diffusion through the ash layer became the rate controlling step. The activation energy for this step was found to be 33.4 kJ/mol. It was also observedthat smaller particle size, larger solid to liquid ratio, and higher NaOH solution concentrations resulted in higher concentrations of stibnite in the leach solution

Keywords:

Antimony Sulphide , Alkali Leaching , Dissolution Kinetics , Shrinking Core , Ash Layer