Comprehensive utilization method of phosphogypsum

Abstract

The invention discloses a comprehensive utilization method of phosphogypsum and belongs to the field of phosphogypsum utilization. The method comprises the following steps: 1, doping bauxite powder and coal powder into phosphogypsum, and uniformly stirring, 2, processing the stirred mixture into balls, 3, putting the agglomerated ardealite into a calcining device, 4, feeding the calcining device into a tunnel kiln, 5, electrifying and igniting the calcining furnace, 6, collecting flue gas generated in calcination and feeding into sulfuric acid preparation equipment for sulfuric acid preparation, and 7, applying the calcined spheres as ceramsite. The method has the characteristic that the ardealite can be efficiently and comprehensively utilized to produce sulfuric acid and ceramsite.

Description

technical field [0001] The invention belongs to the field of phosphogypsum, in particular to an efficient comprehensive utilization method of phosphogypsum. Background technique [0002] Phosphogypsum is a by-product of phosphorus chemical enterprises. Since it cannot be directly reused, it causes secondary pollution and becomes a difficult problem for phosphorus chemical enterprises to solve. Since the content of phosphogypsum is calcium sulfate, in addition to the existing reprocessing of phosphogypsum Calcination, the main component of phosphogypsum, dihydrate gypsum, is converted into hemihydrate gypsum, and the harmful impurities inside the phosphogypsum are removed and used as building gypsum. The composition and ratio of the sulfate ion in the phosphogypsum are similar, so people use phosphogypsum to calcine to produce sulfuric acid, and use the calcium oxide left over from calcination to produce cement; The cement made of calcium oxide produced by gypsum calcination...

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Problems solved by technology

[0002] Phosphogypsum is a by-product of phosphorus chemical enterprises. Since it cannot be directly reused, it causes secondary pollution and becomes a difficult problem for phosphorus chemical enterprises to solve. Since the content of phosphogypsum is calcium sulfate, in addition to the existing reprocessing of phosphogypsum Calcination, the main component of phosphogypsum, dihydrate gypsum, is converted into hemihydrate gypsum, and the harmful impurities inside the phosphogypsum are removed and used as building gypsum. The composition and ratio of the sulfate ion in the phosphogypsum are similar, so people use phosphogypsum to calcine to produce sulfuric acid, and use the calcium oxide left over from calcination to produce cement; The cement made of calcium oxide produced by gypsum calcination is inactive and can only be used in small-scale application scenarios such as plugging, resulting in excess calcined calcium oxide; A large amount of air is blown in the calcination chamber to dilute the sulfur dioxide flue gas after calcination, so that the sulfur dioxide content in the flue gas collected during calcination is lower than 9%. In this way, the acid content of the collected flue gas is not enough, and the flue gas needs to be further concentrated. The production cost of sulfuric acid is too high

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