A method for efficient defluorination of tail gas in wet-process phosphoric acid production

Abstract

The invention relates to a method for efficient defluorination of tail gas in wet process phosphoric acid production. The method includes the steps of: conducting anticorrosion treatment on a sulfuricacid adding pipe in traditional wet process phosphoric acid production, lengthening the sulfuric acid adding pipe according to need, and inserting the sulfuric acid adding pipe below liquid level ofa reaction tank slurry, while adding sulfuric acid, adding a fluorine absorbent by a pump to the slurry surface above the sulfuric acid adding point, wherein the fluorine absorbent comprises the following components by mass percentage: 50-70% of sodium diethylhexyl sulfosuccinate, 10-20% of ethanol and 20-30% of isooctyl alcohol. The method provided by the invention converts the original violent reaction caused by adding of sulfuric acid to the slurry surface to the internal reaction of slurry, part of the fluorine-containing gas generated by the reaction is absorbed by the slurry, and at thesame time, the fluorine absorbent is added above the sulfuric acid adding point to effectively absorb the fluorine-containing gas overflowing from the slurry. The method provided by the invention canreduce the total fluoride content of tail gas in wet process phosphoric acid production to 9mg / m<3> or below.

Description

technical field [0001] The invention belongs to the technical field of phosphoric acid production and relates to a method for removing fluorine from tail gas in the phosphoric acid production process. Background technique [0002] In the production process of wet-process phosphoric acid, because phosphate rock contains fluorine, a large amount of fluorine-containing compounds will be produced during the reaction, and some of them will enter the tail gas scrubbing system in the form of gas. Due to limited conditions, the wet phosphoric acid tail gas scrubbing system at this stage cannot absorb and treat the fluorine-containing gas in the tail gas well, thereby reducing the comprehensive utilization rate of fluorine, and the fluorine in the tail gas will also pollute the environment. Our country pays more and more attention to environmental protection issues. In recent years, a series of environmental protection policies and standards have been issued successively, requiring w...

AI Technical Summary

Problems solved by technology

Due to limited conditions, the current wet phosphoric acid tail gas scrubbing system cannot absorb and treat the fluorine-containing gas in the tail gas well, thereby reducing the comprehensive utilization rate of fluorine, and the fluorine in the tail gas will also pollute the environment

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