	US 12,291,472 B2
	Decomposition of struvite
Yariv Cohen, Uppsala (SE); Patrik Enfält, Uppsala (SE); John Svärd, Gothenburg (SE); Carl-Johan Högberg, Uppsala (SE); and Emilie Nordström, Uppsala (SE)
Assigned to Easy Mining Sweden AB, Sollentuna (SE)
Appl. No. 17/619,786
Filed by EasyMining Sweden AB, Sollentuna (SE)
PCT Filed Jun. 11, 2020, PCT No. PCT/SE2020/050605 § 371(c)(1), (2) Date Dec. 16, 2021, PCT Pub. No. WO2020/256622, PCT Pub. Date Dec. 24, 2020.
Claims priority of application No. 1950734-2 (SE), filed on Jun. 17, 2019.
Prior Publication US 2022/0315460 A1, Oct. 6, 2022
Int. Cl. C02F 1/66 (2023.01); C02F 1/52 (2023.01); C02F 101/16 (2006.01); C05B 7/00 (2006.01); C05B 11/00 (2006.01)

CPC C02F 1/66 (2013.01) [C02F 1/5254 (2013.01); C02F 2101/16 (2013.01); C05B 7/00 (2013.01); C05B 11/00 (2013.01)]

17 Claims

1. A method for decomposing struvite, comprising the steps of:

dissolving a feed material comprising struvite in a mineral acid, thereby forming a solution comprising phosphate ions, magnesium ions and ammonium ions originating from dissolved struvite, wherein said solution includes said dissolved struvite and has an acid pH;

first separating any insoluble components from said solution;

removing magnesium from said solution after said first separating;

said step of removing magnesium comprises the part steps of:

increasing a pH of said solution to a pH in the range of 4.5 to 6;

precipitating magnesium compounds that do not comprise ammonium; and

second separating said precipitated magnesium compounds from said solution;

whereby said solution after said step of removing magnesium comprises an ammonium salt of said mineral acid.