Production of phosphates
AssigneeThe Nash Engineering Company
InventorStephen J. King
Life of this patent
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Abstract
Various stages of the process of producing phosphates are subject to a vacuum produced by a liquid ring pump in various materials of construction using relatively high concentrations of sulfuric acid as the compressant liquid.
Claims14
In a method of producing phosphoric acid which includes subjecting a phosphate bearing rock to attack by sulfuric acid to produce a slurry of phosphoric acid and by-products, cooling the slurry by evaporation, filtering the resultant cooled slurry, and concentrating the resultant filtrate by evaporation to obtain relatively pure phosphoric acid, the improvement comprising delivering filtrate from a vacuum filter to a filtrate receiving chamber, connecting said filtrate receiving chamber to the inlet of a liquid ring pump and delivering sulfuric acid to the pump to constitute the ring liquid therefor in concentrations such that corrosion of the pump is minimized and operating said pump to cause said filtrate receiving chamber to be subject to a low pressure.
In a method of producing phosphoric acid which includes subjecting a phosphate bearing rock to attack by sulfuric acid to produce a slurry of phosphoric acid and by-products, cooling the slurry by evaporation, filtering the resultant cooled slurry, and concentrating the resultant filtrate by evaporation to obtain relatively pure phosphoric acid, the improvement comprising delivering phosphoric acid solution to an evaporator, delivering vapor from the evaporator to a condensor, exposing said condensor to a vacuum produced by a liquid ring pump and delivering sulfuric acid to said liquid ring pump to constitute the ring liquid therefor, the acid being in concentration such that corrosion of said pump is minimized.
In a method of producing phosphoric acid which includes subjecting a phosphate bearing rock to attack by sulfuric acid to produce a slurry of phosphoric acid and by-products, cooling the slurry by evaporation, filtering the resultant cooled slurry, and concentrating the resultant filtrate bny evaporation to obtain relatively pure phosphoric acid, the improvement comprising delivering the resultant relatively pure phosphoric acid solution to a crystallizer, delivering gas produced in said crystallizer to a condensor, exposing said condensor to a vacuum produced by a liquid ring pump and delivering sulfuric acid to said liquid ring pump to constitute the ring liquid therefor, said acid being in a concentration such that corrosion of said pump is minimized.
Dependencies are inferred from the claim text.