Decomposition of struvite

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.