Abstract: A process for recovering elemental sulfur from volcanic and non-volcanic ores is disclosed. Ore is processed by crushing the ore to a coarse particle size autoclaving to separate the sulfur from the ore, mild grinding to selectively reduce the size of the liberated sulfur particles, flotation and sulfur separation/filtration steps to produce a sulfur of at least 99% purity. The process recovers at least 90% of the elemental sulfur contained in the ore. The particular crushing of the ore and selective grinding techniques for reducing sulfur particles for reducing sulfur particles size are important factors in the efficiency of the process since the grinding techniques inhibit the formation of fine gangue which is difficult to separate from the liberated sulfur.

Abstract: A process for the recovery of an organic phase and an aqueous phase from three phase emulsions such as those formed during the extraction of uranium from wet phosphoric acid is described. Such emulsions contain a light-density liquid phase and a heavy-density liquid phase and are stabilized by a solid phase of intermediate density. The emulsion is first heated and then separated into its three components using a centrifugal filter with an appropriate filter aid. At high filter feed rates the dense liquid phase passes freely through the filter media while the light phase liquid begins to accumulate in the centrifuge and is withdrawn from the centrifuge via a properly positioned skimmer tube. The apparatus containing the skimmer tube is also described.