Abstract: A method of wet granulation of fertilizer and other materials into granules. The method involves formation of the granule directly on the pan from the feedstock without intermediate steps or the use of seed materials. The result is a product having a completely uniform cross section. The feedstock is initially in the size distribution of -150 mesh with 90% or greater in the size range of 200 mesh. Moisture is maintained to facilitate a steady process without cycling. The method has the advantage of allowing granulation of materials either known to be hazardous or inherently difficult to granulate in a safe and expedient manner.

Abstract: Process for removing mercury from a gas contaminated with mercury vapor, comprising the steps of cooling the contaminated gas, removing water vapor from the cooled gas and filtering the dehydrated gas through a medium comprised of pure elemental sulfur. The mercury bound to the medium may be removed by heating liquid carbon disulfide to form a carbon disulfide vapor, cooling the carbon disulfide vapor so that liquid carbon disulfide is formed, spraying the liquid carbon disulfide over the medium containing the bound mercury, so as to remove the mercury from the medium and allowing elemental sulfur to dissolve into the liquid carbon disulfide and allowing said elemental mercury to separate away from the elemental sulfur/carbon disulfide solution.

Abstract: A process for the extraction of precious metals from a copper sulphide ore or concentrate, by treating a leach residue of the ore or concentrate, includes the steps of removing elemental sulphur from the leach residue to obtain a low sulphur residue and subjecting the low sulphur residue to an oxidative leach at elevated temperature and pressure to oxidize sulphur and precious metal compounds present in the low sulphur residue to produce a residue for the extraction of the precious metals therefrom.

Abstract: A process for the recovery of sulfur from a hydrogen sulfide containing gas, comprising oxidizing hydrogen sulfide with oxygen, and then reacting the product gas of this oxidation further by using at least two catalytic stages. The H.sub.2 S concentration in the gas leaving the last catalytic stage is controlled to have a value ranging between 0.8 and 3% by volume by reducing the quantity of combustion or oxidation air passed to the oxidation stage and/or causing a portion of the hydrogen sulfide-containing feedstock gas to bypass the oxidation stage and to be added to the gas flowing to a catalytic stage. The gas leaving the last catalytic stage is introduced into a heat exchanger having a wall temperature below the solidification point of sulfur and above the dew point of water, wherein the sulfur deposits on the heat exchanger wall and is removed with the aid of gravity.

Abstract: A process for the extraction of a metal from an ore or concentrate comprises subjecting the ore or concentrate to pressure oxidation in the presence of oxygen and an acidic solution containing halogen ions and a source of bisulphate or sulphate ions, such as H.sub.2 SO.sub.4. The metals which can be extracted by the process comprises copper, as well as non-cuprous metals, such as zinc, and precious metals, such as gold and silver.

Abstract: A process for the extraction of zinc from a sulphide ore or concentrate containing copper and zinc includes subjecting the concentrate to pressure oxidation in the presence of oxygen and an acidic halide solution to obtain a resulting pressure oxidation slurry and subjecting the slurry to a liquid/solid separation step to produce a liquor containing copper and zinc in solution. The liquor containing the copper and zinc is subjected to a first solvent extraction with a copper extractant to remove copper from the solution and to produce a copper depleted raffinate. The copper depleted raffinate is subjected to a second solid extraction with a zinc extractant to produce a zinc depleted raffinate and the zinc depleted raffinate is recycled to the pressure oxidation step.

Abstract: The invention relates to a process for removing elemental sulfur which is present in a gas in the form of vapor and/or entrained particles, in which process the gas to be treated is cooled. The gas to be treated is introduced into a heat exchanger at the lower end thereof and with the aid of the temperature and/or the flow velocity of the cooling medium it is ensured that the wall of the heat exchanger has a temperature below the solidification point of sulfur and above the dew point of water, if any, present in the gas. The deposited sulfur is removed under the influence of gravity countercurrent to the gas to be treated.

Abstract: A sulfur-based, chemical soil-corrective or conditioner for agricultural use in the form of pellets, said product containing fly sulfur powder, at least 3% by weight of an inert compound selected from the group consisting of clay, bentonite, kaolin and mixtures thereof, and at least 0.5% by weight of a wetting agent; said components are mixed with one another, then subjected to wet extrusion and next to drying, so as to obtain mechanically strong pellets which are porous and suitable to be very easily disgregated when they are in contact with soil moisture.

Abstract: This invention is a process for detecting low concentration levels of sulfur oxides (SO.sub.2) in a flowing gas stream (typically a combustion exhaust gas stream) and a catalytic SO.sub.2 sensor system which may be used in that process.

Abstract: An organic solvent alone or together with a rubber process oil is added to a powder of .mu.-sulfur, the mixture is granulated, and the granulation product is heated at a temperature lower than 120.degree. C. to evaporate the organic solvent, whereby granular .mu.-sulfur having an improved flowability is obtained. This granular .mu.-sulfur is valuable as a rubber-vulcanizing agent.

Abstract: A catalytic polyvalent metal redox solution can be recovered and re-used in a catalytic polyvalent metal redox solution H.sub.2 S-removal, sulfur production process by interposing a closed loop evaporator/condenser process and apparatus in the sulfur washing/filtering/recovery process and apparatus so that wash water used to purify the sulfur, and any polyvalent metal redox solution recovered from the sulfur melter are fed to an evaporator to concentrate the redox solution to a concentration capable of effective absorption of H.sub.2 S, and the water evaporated in the evaporator is condensed as pure water for use in washing and/or filtering the recovered sulfur.

Abstract: An H.sub.2 S-containing gas is combusted with oxygen in at least one burner, which discharges into a combustion chamber. The resulting mixed gases contain H.sub.2 S, SO.sub.2, free hydrogen and elementary sulfur and are at temperatures of about 900.degree. to 2000.degree. C. At temperatures of about 900.degree. to 2000.degree. C. at least part of the free hydrogen is removed from said mixed gases. The free hydrogen may be removed from the mixed gases, e.g., through membranes.

Abstract: Sulphur is obtained to the desired granulation and at the same time cooled by means of a directed hollow cylindrical jet of melted sulfur, on either side of which, i.e., both inside and outside the cylinder of molten sulfur, there are two jets of cold water, the jets being directed onto a disk which is able to turn freely. The jets of water and sulfur strike the disk between the middle of the disk and its outer edge and make it turn, while at the same time the sulfur hardens into granules. The turning spins the granules off the disk. The fact that there are two jets of water leads to a better particle size of the sulfur and, because there is a better contact between the water and the sulfur, prevents any hardening of the sulfur upon the disk.

Abstract: To improve the handling characteristics and dispersibility of a sulfur containing froth, especially a froth obtained from the regeneration step in a process for scrubbing out and oxidizing H.sub.2 S, there is added to the scrubbing liquor an ionic or non-ionic surfactant, e.g., dioctyl or dodecyl sulfosucciniate in sufficient concentrations, e.g., 3-16 ppm, to substantially prevent the sulfur particles from becoming crusty and stiff, this technique being particularly applicable to the replacement of diethanolamine.

Abstract: A cake containing sulfur and other materials in a base solvent, such as that resulting from a liquid redox hydrogen sulfide removal process, is purified to obtain elemental sulfur by preferential solubilization of the sulfur, employing a selected solvent immiscible with the base solvent at an elevated temperature less than that required to produce a phase change. The base and selected solvents are then separated, and the temperature of the sulfur solvent is lowered to recrystalize elemental sulfur.

Abstract: Moist particulate sulfur is subject to microbial oxidation during extended storage, resulting in an undesirable accumulation of sulfuric acid in the sulfur. Treatment of the sulfur with an antimicrobial agent reduces or prevents the formation of the acid.

Abstract: This invention provides a process for removing H.sub.2 S from the gaseous stream by contacting the stream with an aqueous solution of a water soluble oxidized polyvalent metal chelate catalyst in the presence of oxygen whereby the metal chelate catalyst oxidizes the hydrogen sulfide to produce elemental sulfur and the oxygen present oxidizes the reduced metal chelate catalyst to its oxidized form. This process is performed in a single reaction vessel and forms a suspension or slurry of the precipitated elemental sulfur which is maintained in suspension by the use of a dispersing agent. The process is continued until the sulfur content reaches a level of 5 percent by weight or 10 percent or more by weight of the solution, then the entire solution is discarded and replaced with a fresh solution and the process repeated. This invention also provides a composition for H.sub.2 S removal comprising a polyvalent metal chelate catalyst, a buffer and a dispersing agent.

Abstract: A process and apparatus for removing hydrogen sulfide from high pressure gas and recovering liquid sulfur, which includes reacting the H.sub.2 S with sulfite ions and an acetic acid-acid salt buffering system in an aqueous stream whereby liquid sulfur is formed, producing an effluent gas stream containing residual H.sub.2 S and an effluent aqueous stream containing the liquid sulfur, extracting the residual H.sub.2 S from the gaseous effluent stream, and using the extracted H.sub.2 S as well as H.sub.2 S recovered from the effluent aqueous stream as a source of sulfite ions for circulation to the reaction step, and as a source for additional liquid and solid sulfur. Apparatus and methods are also disclosed for recovering solid sulfur from a gaseous stream containing gaseous sulfur by contacting the gaseous stream with sulfur particles in a fluidized bed.

Abstract: Sulphur is obtained to the desired granulation and at the same time cooled by means of a directed hollow cylindrical jet of melted sulfur, on either side of which, i.e., both inside and outside the cylinder of molten sulfur, there are jets of cold water, the three jets directed onto a disk which disk is able to turn freely. The jets of water and sulfur strike the disk between the middle of the disk and its outer edge and make it turn, while at the same time the sulfur hardens into granules. The turning spins the granules off the disk. The fact that there are two jets of water leads to a better particle size of the sulfur and, because there is a better contact between the water and the sulfur, prevents any hardening of the sulfur upon the disk.

Abstract: An apparatus and process are described for the cooling and condensing of sulfur and water vapors from a Claus gas below the sulfur freezing point (248.degree. F.) at low pressure (<30 psia), so that solid sulfur and condensed water are simultaneously removed from the Claus gas without solid sulfur plugging of the separation equipment and with efficient separation of the sulfur from water.

Abstract: For the separation of sulfur from a sulfur/alkaline solution suspension, the suspension is heated to a temperature above the melting temperature of the sulfur and is introduced under pressure into a separating tank 1, containing a separating chamber 8, alkaline solution chamber, and sulfur chamber 12. From the separating tank, settled liquid sulfur is continuously withdrawn, on the one hand, via conduit 16 and alkaline solution is continuously withdrawn, on the other hand, via conduit 9. In order to provide a system having little susceptibility to trouble, the separating chamber and alkaline solution chamber are operated in the flooded mode, thereby avoiding the necessity for a steam blanket therein.

Abstract: Method and apparatus for recovering sulfur from an aqueous slurry. The slurry is passed downwardly through a shell-and-tube heat exchanger having vertically arranged tubes, wherein it is heated sufficiently to melt the sulfur. The liquid mixture leaving the heat exchanger is discharged into a first separation zone, in which a phase separation between the lighter aqueous phase and the denser liquid sulfur occurs. The upper aqueous phase is then transported to an intermediate point in the height of a vertically elongated second separation zone, while the molten sulfur is transported from the lower end of the first separation zone to a point adjacent the lower end of said second separation zone, in which an interface between the phases is maintained at a point below the entry point of the aqueous liquid phase into the second separation zone. The aqueous liquid is discharged from the top of the second separation zone, while molten sulfur is discharged from the bottom of said zone.

Abstract: A process for the recovery of sulfur from sulfur-bearing ores employing an aqueous leaching solution containing calcium monosulfide, calcium hydrosulfide or mixtures of such calcium sulfide species. The sulfur ore is contacted in an extraction zone with the aqueous leaching solution under conditions to solubilize sulfur from the ore in the form of calcium polysulfide. Preferably, the extraction step is carried out at an elevated temperature. The loaded leaching solution is recovered from the extraction zone and applied to a sulfur-production zone. Here the loaded solution is contacted with hydrogen sulfide under conditions to react the hydrogen sulfide with the calcium polysulfide to produce calcium hydrosulfide and elemental sulfur. The calcium hydrosulfide solution is recycled for use as leaching solution in the sulfur extraction zone.

Abstract: A sour gas obtained from an enhanced oil recovery is converted to sulfur slurry which is concentrated for easy filtration, or for direct disposal, by the addition of substantially small amounts of a solid flocculating agent e.g. clay, optionally in combination with selected suitable conventional liquid polymer flocculants. For this purpose, bentonite has been shown to be a particularly effective solid flocculating agent.

Abstract: There is disclosed a process for the removal of sulfur from an aqueous sulfur-containing suspension through sulfur coalescence. Sulfur coalescence is initiated by passing the aqueous sulfur-containing suspension through a multi-passage filtering media. In one embodiment of the present invention, the aqueous sulfur-containing suspension is passed through a filtering media comprised of randomly oriented fibrous filter material. In another embodiment of the present invention, the aqueous sulfur containing suspension is passed through sintered metal filters. Optionally, downstream polishing, or filtration, steps using either the above enumerated filters or combinations of the above filters can also be used.

Abstract: A method of melting sulphur, in block form, uses a heating device having lower heating surfaces and means for withdrawing sulphur. The device is positioned on a block of sulphur so that the heating surface(s) are inclined downardly to a collection location spaced inwardly from sides of the sulphur block. The heat is supplied to the heating surfaces to melt sulphur, and molten sulphur is withdrawn by the means for withdrawing it. As sulphur is melted, the heating device is progressively lowered through the block of sulphur. A corresponding apparatus having inclined heating surfaces is provided. As the sulphur is melted so that molten sulphur runs down towards the collection location, the device can be used right up against the edge of a block of sulphur.

Abstract: A process and apparatus for preparing a porous, particulate sulfur by combining a coherent molten sulfur stream with a coherent water stream to provide an aqueous slurry of a porous, particulate sulfur having a uniform particle size distribution. In the process of this invention, a molten sulfur stream is passed through a substantially downwardly oriented, rectangular slot to provide a sheet of molten sulfur, and said sheet of molten sulfur is sheared by directing at least one sheet of water thereat, at a velocity and flow rate sufficient to disrupt said sheet of molten sulfur and provide solid sulfur particles having a substantially uniform size. The solid sulfur particles are recovered, as an aqueous slurry thereof, and separated from said slurry by substantially removing the water therefrom.

Abstract: An improved solid-liquid separation step for use in connection with the Stretford process introduces a small amount of an additive which is then emulsified and mechanically treated in a colloid mill or processed through an air dissolver before introduction into a flotation cell. The process uses dissolved air and/or dispersed air to float the elemental sulfur while simultaneously regenerating the Stretford solution for recirculation.

Abstract: A cyclic process and composition for the removal of hydrogen sulfide from a variety of gas streams is disclosed. The gas stream containing the sour gases is contacted with a specified reactant solution and a combination crystal modifier of phosphate and thiosulfate ions. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process includes sulfur removal and regeneration of the reactant.

Abstract: A cyclic process and composition for the removal of hydrogen sulfide from a variety of gas streams is disclosed. The gas stream containing the sour gases is contacted with a specified reactant solution and a combination crystal modifier of phosphate and thiosulfate ions. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process includes sulfur removal and regeneration of the reactant.

Abstract: A method is provided for removing elemental sulfur particles from a hydrogen sulfide removal process which employs a regenerable, aqueous washing solution capable of absorbing hydrogen sulfide from an industrial gas stream and converting that hydrogen sulfide to elemental sulfur. The washing solution of such a process is contacted with bubbles of an oxygen-containing gas while in the presence of controlled concentrations of a selected hydrocarbon and a selected surfactant.

Abstract: A device for automatically shutting off a sulfur melter when its supply of sulfur is exhausted or when sulfur bridging has occurred is disclosed. The shutoff uses a temperature value sensed at the top of the melter's sloping melter bottom and shuts the heat off when the sensed temperature exceeds a preset value related to sulfur's melting temperature. The device avoids jamming and maintenance problems inherent in the use of mechanical level controls in a powdered/molten sulfur environment.

Abstract: A suspension of sulfur in a scrubbing liquid is preheated with steam to a temperature above the melting point of the sulfur so that the latter spontaneously melts in the suspension which is introduced into a separating chamber in a sealed vessel. The scrubbing liquid is decanted over a weir into a second chamber while the molten sulfur is drawn out at the bottom into a third chamber. The separating chamber is maintained at a pressure and temperature, by a vapor cushion above the liquid, such that evaporation of the incoming liquid does not occur, i.e. the separation pressure is the saturation pressure of the cushion. To prevent vapor condensation on the molten sulfur, the latter is maintained at a temperature higher than that of the liquid in the adjacent separating chamber.

Abstract: A method for the removal of moisture associated with sulfur and for the melting of solid sulfur. A flow of molten sulfur is circulated through a mixing device in a substantially spiral flow wherein the circulating molten sulfur forms a continuous vortex of molten sulfur. Particulate solid sulfur with or without associated moisture, either as such or in the form of an aqueous slurry or moisture-containing liquid sulfur is fed into the vortex of circulating molten sulfur. Sulfur is discharged from the mixing device and any associated moisture is evaporated and separates from the sulfur. Molten sulfur substantially free of moisture is recovered.

Abstract: A process for the production of granular sulfur in a rotating drum in which molten sulfur at a temperature within the range of about 110.degree. to 160.degree. C. is sprayed in a contact zone onto a bed of moving sulfur particles and a continuous curtain of said particles and resulting particles are passed to a cooling zone prior to discharge. A countercurrent flow of substantially inert cooling gas at a temperature in the range of about 10.degree. to 50.degree. C. and containing not more than 8% by volume oxygen is introduced to the cooling zone and a portion or all of said cooling gas is passed through the contact zone. The contact and cooling zones can be formed in a single rotating drum and separated from each other by a retaining ring or formed in separate vessels.Discharge particles from the cooling zone are separated according to size and undersized particles are recycled as fines to the contact zone at a ratio of 4:1 to 2:1 of fines to product granules.

Abstract: This invention relates to a method and apparatus for the in situ melting and removal of liquid sulphur from a solid sulphur storage block. The method comprises supplying heat to the storage block sufficient to melt the sulphur of the storage block to produce liquid sulphur, collecting the liquid sulphur and removing the liquid sulphur. The apparatus comprises heating means for heating and melting the sulphur storage block to produce liquid sulphur, means for collecting the liquid sulphur and means for removing the liquid sulphur from the collecting means.

Abstract: Molten sulphur is cooled to as low as 5.degree. F above its solidification temperature without being in direct contact with the heat exchange liquid. Such liquid is recirculated and is initially cooled to a first temperature below the solidification temperature of the molten sulphur and then heated to a predetermined second temperature which is also below such solidification temperature.

Abstract: Movement of liquid sulphur requires a considerable heat source to maintain the sulphur in liquid form. The present application and method utilizes an outer steel pipe having a liquid sulphur inlet at one end and a liquid sulphur outlet at the other end and at least one heating fluid carrying conduit extending through the outer pipe. Liquid sulphur is pumped in at one end and the majority of this liquid sulphur is maintained in the molten state through out the length of the pipe line by the heating liquid carrying conduit. However an annular shell of solidified sulphur is allowed to form in contact with the inner surface of the wall of the outer pipe so that it acts as a thermal insulator and assists in maintaining the sulphur that is remaining in the liquid state.

Abstract: A system for reducing sulfur dioxide to elemental sulfur in which a reactor vessel is divided into a plurality of compartments, and coal is fed from a single source into each of the compartments. A sulfur dioxide rich gas is distributed to each of the compartments and is contacted with the coal to form substantially pure sulfur.

Abstract: A method of, and apparatus for, melting block sulfur to avoid contamination of the environment by sulfur dust employ a heating element having a plurality of flow passages formed by pipe sections in a generally planar array, with a steam inlet and a condensate outlet enabling steam to be flowed through the passages. The underside of the heating element has a flow surface adjacent one edge thereof, and a suspension is provided for lowering the heating element onto the sulfur block with the heating element downwardly inclined towards that edge and with the edge projecting beyond the sulfur block so that molten sulfur adhering by surface tension to the flow surface flows beyond the sulfur block and drops into a collecting trough.

Abstract: A liquid body of volatile inorganic chemical which reacts with water and evolves acidic vapor, such as liquid sulfur trioxide, is treated to suppress the evolution of said noxious vapors therefrom to the atmosphere by applying to the exposed surface of said liquid body a treating agent comprising glass microbubbles having on the surfaces thereof an adherent film resulting from the application to said surfaces of a fluoroaliphatic radical-containing material selected from the group consisting of fluorosilane or poly(fluorosiloxane).

Abstract: A continuous process of desulfurizing coal and other ores contaminated with sulfur and recovering the sulfur in relatively pure crystal form, the process for coal including the steps of crushing sulfur bearing coal ore, mixing the crushed ore in a solvent forming a solvent liquor in which the sulfur is dissolved, centrifuging the solvent liquor separating a coal slurry from the solvent liquor, centrifuging the coal slurry separating the coal from the tailings including rare metals for further refining to recover the rare metals, drying the coal slurry and recovering the solvent, filtering the remaining solvent liquor removing ash, crystallizing the sulfur in the filtered solvent, centrifugally separating the crystallized sulfur from the solvent and recovering the solvent, drying the crystallized sulfur and further recovering the solvent, heating the crystallized sulfur to form a sulfur liquid and casting the sulfur in preformed molds to produce building materials.