Abstract: Ammonia-containing sour gas is combusted at high flame temperature with at least 90 percent purity oxygen in an externally cooled combustor, the ammonia-free product is cooled, then, in conjunction with additional acid gas which does not contain ammonia, is passed to a Claus furnace wherein less than one-third of the hydrogen sulfide is combusted with oxygen enriched air enabling boosting sulfur recovery in a Claus plant without detrimental effects on catalyst life, furnace refractories and pressure drops.

Abstract: A sulfur recovery process wherein a minor fraction of a hydrogen sulfide-containing gas is precombusted with oxygen in an externally cooled combustion zone while extracting the major fraction of the heat released in the substantially complete combustion of hydrogen sulfide to sulfur dioxide in that zone, the gas is further cooled and is then passed to a Claus reaction furnace together with the major fraction of the gas, enabling using oxygen for a substantial productivity increase within the temperature and flow rate limitations of a Claus plant without need for a temperature moderator introduced into the precombustor.

Abstract: Method and apparatus for adding solids to molten metal by continuously feeding both the solids and the metal into a vortex forming chamber from which the mixture is discharged at the core of the vortex as a free-falling, hollow-centered stream.