Phosphoric acid production gypsum filtration flocculant pre-dilution (make down) with post-filtration phosphoric acid
View Patent ↗A method for minimizing the addition of water to a phosphoric acid production process is described. The method uses phosphoric acid to make down a flocculant that is added to the process in order to promote filtration or clarification of crude phosphoric acid. Preferably, the phosphoric acid is a crude, clarified phosphoric acid that is recycled from the phosphoric acid production process itself.
1. A method of adding flocculant to a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
creating a flocculant-acid substance by mixing phosphoric acid and a flocculant emulsion comprising 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer, thereby inverting the emulsion and causing a change in conformation of the copolymer;
introducing the flocculant-acid substance into the gypsum slurry of the phosphoric acid production process.
2. The method of claim 1 , wherein the phosphoric acid is crude phosphoric acid removed from the phosphoric acid production process.
3. The method of claim 1 , wherein the mixing is achieved via at least one of inline blending and mixing in a mixing vessel.
4. The method of claim 1 , wherein the copolymer is a quick inverting polymer.
5. A method of improving solids separation performance and minimizing the introduction of additional fresh water in a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
introducing a flocculant emulsion comprising a 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer directly into phosphoric acid;
mixing the flocculant emulsion and the phosphoric acid, thereby inverting the flocculant emulsion and causing a change in conformation of the copolymer and forming a flocculant-acid substance;
adding the flocculant-acid substance to a gypsum slurry of the phosphoric acid production process; and
separating flocculated gypsum from the gypsum slurry;
wherein the phosphoric acid is clarified crude phosphoric acid recycled from the phosphoric acid production process; and
wherein the mixing is achieved via inline blending.
6. The method of claim 5 , wherein the copolymer is a quick inverting polymer.
7. A method of adding flocculant to a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
creating a flocculant-acid substance by inverting a flocculant emulsion comprising a 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer with phosphoric acid;
flocculating gypsum in a gypsum slurry of the phosphoric acid production process by combining the flocculant-acid substance and the gypsum slurry of the phosphoric acid production process; and
separating at least a portion of the flocculated gypsum via a filtration operation.
8. The method of claim 7 , wherein the copolymer is a quick inverting polymer.
9. The method of claim 7 , wherein the phosphoric acid is crude phosphoric acid removed from the phosphoric acid production process.
10. The method of claim 7 , wherein the phosphoric acid is a clarified crude phosphoric acid, the clarified crude phosphoric acid being prepared using phosphoric acid recycled from the phosphoric acid production process.