Abstract: A process for pelletizing a mixture of elemental sulphur and bentonite clay to produce a water degradable prill includes adding dry clay dust to molten sulphur at an elevated temperature to provide a molten sulphur-clay mixture, forming droplets of the mixture, providing a liquid fertilizer coolant at a temperature lower than the freezing temperature of the sulphur-bentonite mixture, feeding the droplets into the coolant, passing the droplets through the coolant for a time sufficient to anneal the droplets into pellets, and removing the annealed pellets from the coolant.