Method and assembly for recovering magnesium ammonium phosphate

A method for recovering magnesium ammonium phosphate from sludge supplied to a reaction tank in which an aerobic environment prevails, and in which the sludge is guided in a cycle supported by aeration, with cationic magnesium being added to the sludge, and magnesium ammonium phosphate crystals precipitated from the sludge being removed via an extraction device provided in a floor area of the reaction tank,

• wherein substances collected in the extraction device, and containing the magnesium ammonium phosphate crystals, are loosened up, and/or flushed, and
• wherein gas and liquid are introduced into the extraction device alternatingly, and substances exiting the extraction device on a side of the tank by means of a guide are passed through a funnel-shaped, or conically designed lower section of the reaction tank, and subjected in an adjoining cylindrical upper section to a flow in the cylindrical upper section.