Extraction of potassium from Glauconitic Sandstone by the Roast-Leach Route.

Laboratory studies have been conducted on the roast-leach method as a possible route of extraction of potassium from glauconitic sandstone. Roasting kinetics with calcium chloride has been investigated. The effect of roasting time, temperature, particle size and ratio of glauconitic sandstone/calcium chloride on roasting of potassium have been investigated. After roasting potassium has been recovered in the from of potassium chloride by leaching with distilled water. The dissolution rate at different temperatures has also been studied. The roasting reaction has been found to follow the well defined Ginstling-Brounshtein diffusion equatio\ud The diffusion through the product layer has been found to be the rate controlling step. The activation energy for roasting has been found to be 103.3 kJ/mole