Method for producing high-quality phosphoric acid and high-quality phosphogypsum by leaching rare earth-containing phosphate rock with regenerated phosphoric acid

Abstract

The invention discloses a method for preparing high-quality phosphoric acid and high-quality phosphogypsum by leaching rare-earth-containing phosphorite with reproducible phosphoric acid. The method comprises the following steps: metering the rear-earth-containing phosphorite and the reproducible phosphoric acid, putting the rear-earth-containing phosphorite and the reproducible phosphoric acid into a first-segment leaching groove to carry out a leaching reaction, adding a flocculating agent into a sizing agent, allowing clear liquid to overflow into a monocalcium phosphate storage groove, pumping slag slurry into a second-segment leaching groove, adding the reproducible phosphoric acid to leach continually; at the end of a second-segment leaching reaction, adding the flocculating agent into slurry, allowing clear liquid to overflow into the monocalcium phosphate storage groove, pumping the slag slurry into a second-segment filter press, and feeding filtrate into the monocalcium phosphate storage groove to form a rare-earth-containing monocalcium phosphate solution; adding strong sulfuric acid into the solution, and reacting to obtain phosphoric acid containing phosphogypsum and rare earth; lastly, performing filter pressing to obtain rare-earth-containing high-quality phosphoric acid and high-quality phosphogypsum. By adopting the method, the high-quality phosphoric acid and the high-quality phosphogypsum can be prepared at the same time, and meanwhile a condition is created for comprehensive recycling of associated rare-earth resources. The method is suitable for middle-low grade phosphorite associated with rare earth.

Description

technical field

[0001] The present invention relates to phosphorus compounds, especially phosphoric acid, phosphogypsum, and rare earths. Further, it relates to a method for preparing phosphoric acid by leaching phosphorous rock with phosphoric acid. Background technique

[0002] As we all know, traditional wet-process phosphoric acid is obtained by extracting phosphate rock with sulfuric acid, and a large amount of phosphogypsum produced in the production process cannot be well comprehensively utilized due to its low quality; if rare earth-containing phosphate rock is used, the associated phosphate rock A large amount of rare earth resources will enter phosphogypsum and be depleted. It is difficult to obtain high-quality phosphoric acid and high-quality phosphogypsum. Therefore, it is not easy to recycle rare earth resources in phosphate rocks, so it is not easy to utilize rare earth-containing phosphate rocks. Therefore, the traditional process cannot be used for rare eart...

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