Chloridising-roasting followed by aqua leaching has been used to extract potassium from glauconitic sandstone. The investigation includes study of the kinetic aspects of roasting and effects of major process variables. The variables studied are time, temperature, particle size of glauconitic sandstone, and ratio of mixing of calcium chloride and glauconitic sandstone. An attempt has been made to express the reaction rate as a function of process variables through the use of the following empirical correlations: (a) tau(alpha=0.3-0.8)=5.43x10(-8)(alpha(2.15). d(1.541)2 . r(-2.03). e(12321/T)) (b) tau(alpha=0.9)=2.6x10(-8)(r(-2.105). e(20377.7/T)) These correlations express the combined effect of different process variables on degree of conversion.