NPK

• Compounds present in NPK fertilisers :

  • Nitrogen
  • Phosphorus
  • Potassium
• Why are fertilisers used?

  • Agricultural productivity
  • Plants grow bigger and more rapidly
• What particularly are NPK fertilisers?

  • formulations of various salts containing appropriate percentages of the elements.
• What can ammonia be used for to manufacture?

  • Ammonium salts e.g ammonium nitrate
  • Nitric acid
  • Via the Haber Process
• What particular compounds are mined?

  • Potassium chloride
  • Potassium sulfate
  • Phosphate rock
• Why can't phosphate rock be used directly as a fertiliser?

  • Insoluble
• How phosphate rock treated?

  • nitric acid or sulfuric acid to produce soluble salts that can be used as fertilisers.
• Phosphate rock + nitric acid = ?

  • Phosphoric acid + calcium nitrate
• What must happen with phosphoric acid?

  • Neutralised with ammonia
  • Produces ammonia phosphate, can be used as a NPK fertiliser
• Phosphate rock + sulfuric acid =?

  • Mixture of calcium phosphate + calcium sulfate
  • Single superphosphate
  • Can be used in NPK fertiliser
• Phosphate rock + phosphoric acid =?

  • Triple superphosphate
  • Can be found in NPK fertilisers