Production of ammonium phosphates

An arrangement for production of pure ammonium phosphates, comprising:

• a solvent having a solubility in water of less than 2%;
• a feed liquid comprising phosphoric acid and essentially free from nitrate ions;
• an extraction section, configured for performing a liquid-liquid extraction of phosphate between the feed liquid comprising phosphoric acid and the solvent;
• said extraction section having a first extraction inlet for provision of said feed liquid, a second extraction inlet for provision of said solvent, a first extraction outlet for delivering said feed liquid at least partly depleted in phosphate and a second extraction outlet for delivering said solvent loaded with phosphate;
• an aqueous ammonium phosphate strip solution;
• a stripping section configured for performing a liquid-liquid extraction of phosphate between said solvent loaded with phosphate and the strip solution;
• said stripping section having a first stripping inlet, connected to said second extraction outlet, for provision of said solvent loaded with phosphate, a second stripping inlet for provision of input strip solution, a first stripping outlet for delivering said solvent at least partly depleted in phosphate and a second stripping outlet for delivering output strip solution;
• said first stripping outlet being connected to said second extraction inlet for recirculating said solvent at least partly depleted in phosphate for further extraction of phosphate;
• wherein at least one of:
• at least 80% of said ammonium phosphate in said input strip solution is monoammonium phosphate;
• and
• said solvent is a water-immiscible alcohol;
• a source of ammonia comprised in end treatment arrangements connected to said second stripping outlet;
• an adding arrangement connected to said source of ammonia;
• a cooling arrangement configured for cooling off heat generated when said ammonia from said source of ammonia is added into said at least a partial stream of said strip solution;
• a precipitate remover configured for separating crystals from said output strip solution;
• said adding arrangement being configured for adding ammonia from said source of ammonia into at least a partial stream of said strip solution before or after said precipitate remover;
• and
• a recirculating system connected between said outlet from said precipitate remover and said second stripping inlet of said stripping section, said recirculating system being configured for reusing strip solution from said precipitate remover as input strip solution.