Potassium Nitrate → Tetrasodium Pyrophosphate

HRID 2351260Notes

Reaction equation

HRID 2351260 reaction equation
[O-:1][P:2]([O:5][P:6]([O:9][P:10]([O-:13])([O-:12])=[O:11])([O-:8])=[O:7])([O-:4])=[O:3].[Na+:14].[Na+].[Na+].[Na+].[Na+].C(=O)(O)O.[Na+].C(=O)([O-])[O-].C(=O)(O)O.[Na+].[N+]([O-])([O-])=O.[K+]>>[O-:3][P:2]([O:5][P:6]([O-:9])([O-:8])=[O:7])([O-:4])=[O:1].[Na+:14].[Na+:14].[Na+:14].[Na+:14].[O-:13][P:10]([O:9][P:6]([O:5][P:2]([O-:4])([O-:3])=[O:1])([O-:8])=[O:7])([O-:12])=[O:11].[Na+:14].[Na+:14].[Na+:14].[Na+:14].[Na+:14]

Participants

5

Reactant 3

HCID 24434Potassium NitrateHCID 24455Sodium Tripolyphosphate2×HCID 22936102HCID 22936102, compound2×

Product 2

HCID 24403Tetrasodium PyrophosphateYield 98.9%HCID 24455Sodium TripolyphosphateYield 80%

Procedure

A stock mixture was made by mechanically blending 366 grams of STPP with 73 grams of sodium sesquicarbonate and 4.50 grams of KNO3. Two samples were taken from the mixture; one was milled in a lab pulverizing mill to approximately 100%-150 μm sieve and the other was left "as is". Both samples were calcined in a lab muffle furnace for one hour at 650° C. Assay of the samples showed that all the STPP in the milled sampled reacted with the sodium sesquicarbonate ("sesqui") to yield a calcined product with 98.9% TSPP and 1.1% metaphosphate whereas only 80% of the STPP reacted in the unmilled sample to yield a calcined product with 1.4% orthophosphate, 79.7% TSPP and 18.9% STPP. This example illustrates the importance of using a solid alkali which can be easily mixed with the solid STPP and further homogenized by milling.

Workup

  1. customone was milled in a lab
  2. waitthe other was left "
  3. aliquotsampled

Sources & evidence

ORD record
ord-0293e38b4f204b90970ac3ea22abc155
Source dataset
uspto-grants-1989_10
Patent number
US04873068

Reaction notes

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