A method for catalytically improving the defluorination efficiency of wet-process phosphoric acid stripping

Abstract

The invention discloses a method for catalytically improving wet-process phosphoric acid steam stripping defluorination efficiency, and relates to the technical field of wet-process phosphoric acid defluorination processes. By carrying out arsenic removal and heavy metal removal purification procedures on raw material phosphoric acid, clear purified concentrated phosphoric acid with low impurity content can be obtained; after a defluorination catalyst is added into the purified concentrated phosphoric acid, the defluorination catalyst and a defluorination agent are mixed and heated, and then steam stripping defluorination is performed, so that the defluorination resistance can be effectively reduced, the defluorination efficiency is improved, the consumption of the defluorination agent, steam and electricity in the defluorination process is reduced, and the defluorination cost is reduced; in the defluorination process, a steam stripping defluorination process is adopted, and an indirect steam heating mode is adopted; the defluorinated phosphoric acid production efficiency is high, the yield is high, the consumption is low, the phosphoric acid quality is good, the impurity content is low, the phosphorus-fluorine ratio (P2O5 / F) can reach 285 or above, and the defluorinated phosphoric acid can be directly used for producing feed-grade calcium phosphate.

Description

technical field

[0001] The invention relates to the technical field of wet-process phosphoric acid defluorination technology, in particular to a method for catalytically improving the stripping defluorination efficiency of wet-process phosphoric acid. Background technique

[0002] Since the 1950s, countries around the world have used wet-process phosphoric acid as a raw material to produce calcium phosphate as a feed additive, of which calcium hydrogen phosphate is the main one. The key technology of using wet-process phosphoric acid to produce feed phosphate is the purification of wet-process phosphoric acid, that is, the content of fluorine and other impurities in wet-process phosphoric acid can be purified to meet the requirements of producing feed-grade phosphate. The pros and cons of defluorination technology directly affect the yield and quality of the final product.

[0003] There are two main techniques for wet-process phosphoric acid defluorination: chemical precip...

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