Provided is a novel method for producing phosphoric acid. A production method for producing phosphoric acid in accordance with the present disclosure includes: a step (a) of obtaining an acid extract by treating bone tissue with an acid; a step (b) of obtaining a calcium phosphate precipitate by adding a base to the acid extract which has been obtained; a step (c) of obtaining a calcium phosphate solution by adding an acid to the calcium phosphate precipitate which has been obtained; and a step (d) of removing precipitated calcium by adding, to the calcium phosphate solution which has been obtained, at least one selected from the group consisting of sulfate, carbonate, and hydrogen carbonate.

Provided is a novel method for producing phosphoric acid. A production method for producing phosphoric acid in accordance with the present disclosure includes: a step (a) of obtaining an acid extract by treating bone tissue with an acid; a step (b) of obtaining a calcium phosphate precipitate by adding a base to the acid extract which has been obtained; a step (c) of obtaining a calcium phosphate solution by adding an acid to the calcium phosphate precipitate which has been obtained; and a step (d) of removing precipitated calcium by adding, to the calcium phosphate solution which has been obtained, at least one selected from the group consisting of sulfate, carbonate, and hydrogen carbonate.

Provided is a production method for producing a novel fertilizer (e.g., liquid fertilizer) containing a bone tissue degradation product. A production method for producing a fertilizer containing phosphoric acid in accordance with the present disclosure includes at least one of: a step 1 (S7) of producing a fertilizer from a bone solubilization liquid A which has been obtained by treating bone tissue with a solution containing both an acid and a protease; a step 2 (S2) of producing a fertilizer from an acid extract which has been obtained by treating bone tissue with an acid; and a step 3 (S5) of producing a fertilizer from a protease treatment liquid which has been obtained by treating, with a protease, bone tissue which has been treated with an acid.

Provided is a production method for producing a novel fertilizer (e.g., liquid fertilizer) containing a bone tissue degradation product. A production method for producing a fertilizer containing phosphoric acid in accordance with the present disclosure includes at least one of: a step 1 (S7) of producing a fertilizer from a bone solubilization liquid A which has been obtained by treating bone tissue with a solution containing both an acid and a protease; a step 2 (S2) of producing a fertilizer from an acid extract which has been obtained by treating bone tissue with an acid; and a step 3 (S5) of producing a fertilizer from a protease treatment liquid which has been obtained by treating, with a protease, bone tissue which has been treated with an acid.

The present application provides a method for separating and purifying phosphoric acid and phosphogypsum from a wet-process phosphoric acid slurry, and phosphoric acid and phosphogypsum prepared thereby. The method is beneficial for the dissociation, precipitation and separation of colloidal silicon and carbon impurities, such that the aim of in-situ removal and rapid separation of colloidal impurities to obtain the ore slurry, from which impurities have been removed, during a reaction process for outputting phosphogypsum is realized, and a low-impurity phosphoric acid product and phosphogypsum product can be obtained after the ore slurry, from which impurities have been removed, has been further treated.