The present invention discloses a phosphate rock single stage closed-circuit grinding method, the phosphate rock into a ball mill, the slurry discharged from the pump into the mortar classifier classifying; coarse pulp mill returned after classification regrinding, The fine-grain slurry enters the thickener, and after being thickened, the desired slurry is obtained. The method has the advantages of simple process and easy manipulation, and effectively solves the problems of over-grinding and under-grinding of the slurry, and the implementation thereof can significantly improve the phosphorus yield of the wet-process phosphoric acid production, delay the service life of the equipment and the pipeline, and reduce the production cost of the wet-process phosphoric acid. Has a good application prospect.

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