Kinetics and thermodynamic parameters of Cr6+ Separation by fly ash from aqueous solution has been evaluated. It was found that the separation process is partly diffusion controlled and endothermic in nature. The mass transfer coefficient increases with an increase in temperature, The activation energy and change of enthalpy were also evaluated and found to be 17.5 kJ/mol and 14.47 kcal/mol, respectively. The free energy of the process was small but positive, and it decreases with an increase of temperature. The change of entropy was found to be small and remains unchanged over the 30 to 50 degrees C temperature range. This process follows the Langmuir isotherm model where Q(0) and b were also determined at different temperatures.