Abstract: A waste water treatment system includes a preliminary first stage separator for separating an aqueous phase from other materials. A pressure vessel sedimentation follows for removing most of the remaining solids from the waste material. The liquid and a minor fraction of the solids then pass on to an evaporation vessel where the water vapor is removed, compressed and passed through a condenser inside the evaporator vessel to recycle heat in the evaporator. The condenser is a stacked plate heat exchanger of unique design with the plates separated by steam gaskets and water gaskets to provide a very high heat transfer surface area to volume ratio. The condensate from the condenser passes through a second heat exchanger that heats the liquid flowing into the evaporator. The effluent water is purified by the evaporation. The residual solids may be heat treated to evaporate residual moisture and to sterilize the solids using a steam-jacketed auger. The resultant solids may be used as fertilizer.

Abstract: An apparatus for converting molten elemental sulphur into solid pellets is described. Droplets of molten sulphur are passed through a liquid cooling medium, preferably water, the medium being maintained at a temperature range wherein annealing of the sulphur will occur. The pellets thereby obtained are hard surfaced, resistant to crushing and have low water retention in storage. In one embodiment semi-molten droplets are flattened during passage through the cooling medium by engaging deflection plates so that less flowable and more economically storable pellets are obtained.

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.