By breaking down the ferroalloy with sodium peroxide, leaching the melt with water and adding nitric acid and potassium permanganate, all the phosphorus is oxidized to phosphoric acid. Phosphorus is precipitated in the state of ammonium phosphomolybdate, the phosphomolybdate is dissolved and phosphorus is then precipitated in the state of ammonium-magnesium phosphate, which is then transformed by calcination into magnesium pyrophosphate. Finally, the magnesium pyrophosphate is weighed. Solutions and reagents. Method. Try it blank. Calculation.
UNI 3308-1953 history
1953UNI 3308-1953 Procedures for chemical analysis of metals. Determination of the phosphorus in ferrophosphorus. Gravimetric method.