Phosphoric Acid → Phosphorus oxide (P4O10)

HRID 261182Notes

Reaction equation

HRID 261182 reaction equation
[P:1](=[O:5])([OH:4])([OH:3])[OH:2].[O-][P:7]([O-:10])([O-:9])=[O:8].[O-][P:12]([O-:15])([O-])=[O:13].[O-:16][P:17]([O-])([O-])=O.[F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].S(=O)(=O)(O)O>>[O:5]=[P:1]12[O:4][P:7]3([O:10][P:12]([O:15][P:17]([O:9]3)([O:3]1)=[O:16])(=[O:13])[O:2]2)=[O:8]

Participants

4

Reactant 3

HCID 1004Phosphoric Acid2×HCID 1118Sulfuric AcidHCID 10207414Fluorapatite (Ca5F(PO4)3)

Product 1

HCID 14812Phosphorus oxide (P4O10)Yield 35%

Procedure

In conventional methods for the production of wet process phosphoric acid, finely ground phosphate rock is reacted with dilute phosphoric acid (10% P2O5 to 25% P2O5) and sulphuric acid which may or may not be diluted. The reaction product is leached (i.e., digested or reacted with the acid) to yield a crude aqueous phosphoric acid solution in which is suspended a substantial quantity of solid impurities. This slurry is filtered to separate most of the undissolved gypsum and other solid impurities to yield a crude (22% P2O5 to 35% P2O5) aqueous product sometimes known as the number one filtrate. This filtrate contains suspended, finely divided, impurities that were not removed during the solid-liquid separation step plus solids that have crystallized after filtration. The solution also contains dissolved impurities. Reference is made to Chapter 16 of Volume II, Phosphorus and its Compounds, Van Wazer, Interscience Publishers (1961).

Workup

  1. additionbe diluted
  2. customdigested or reacted with the acid)
  3. customto yield a crude aqueous phosphoric acid solution in which
  4. filtrationThis slurry is filtered
  5. customto separate most of the undissolved gypsum and other solid impurities

Sources & evidence

ORD record
ord-47efeba57a39404e93b19fa1c085da14
Source dataset
uspto-grants-1979_08
Patent number
US04164550

Reaction notes

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