EDTA disodium salt → Ethylenediaminetetraacetic Acid

HRID 1737127Notes

Reaction equation

HRID 1737127 reaction equation
[CH2:1]([N:12]([CH2:17][C:18]([O-:20])=[O:19])[CH2:13][C:14]([OH:16])=[O:15])[CH2:2][N:3]([CH2:8][C:9]([O-:11])=[O:10])[CH2:4][C:5]([OH:7])=[O:6].[Na+].[Na+].C(=O)([O-])[O-].[Na+].[Na+]>[Ag]>[CH2:2]([N:3]([CH2:8][C:9]([OH:11])=[O:10])[CH2:4][C:5]([OH:7])=[O:6])[CH2:1][N:12]([CH2:17][C:18]([OH:20])=[O:19])[CH2:13][C:14]([OH:16])=[O:15]

Participants

4

Reactant 2

HCID 8759EDTA disodium saltHCID 10340Sodium Carbonate

Product 1

HCID 6049Ethylenediaminetetraacetic Acid

Reagents, catalysts & solvents 1

HCID 23954SilverCatalyst3×

Procedure

An EA-5 fixer solution is treated in the silver recovery unit 200 shown in FIG. 2 which also incorporates a silver precipitating unit 80, according to U.S. Pat. No. 5,437,792 and described above. Silver precipitating unit 80 comprises a vessel 81 which receives untreated EA-5 fixer via line 250 at inlet 49 and is drawn via line 220 at outlet 39 to form a continuous stream of untreated EA-5 fixer flowing at a rate of 100 mls/minute. A solution of 15 g/l disodium EDTA dihydrate and 45 g/l sodium carbonate in storage vessel 210 is drawn off by line 211 by pump 212. The solution is then pumped to line 220 via line 213 and injected at a rate of 100 mls per minute through injection tee 215 into a seasoned and untreated EA-5 fixer solution with a pH of about 4.1, in line 220, flowing at a rate of 100 mls per minute. The resulting solution is then mixed within a tubular reactor 216. The solution is then returned to a silver precipitation unit 80 which employs TMT as a silver precipitating agent, and a flocculant to agglomerate the TMT-silver precipitate, as described above.

Workup

  1. customis drawn via line 220 at outlet
  2. custom39 to form a continuous stream of untreated EA-5
  3. additionThe resulting solution is then mixed within a tubular reactor 216
  4. customThe solution is then returned to a silver precipitation unit 80 which

Sources & evidence

ORD record
ord-1c8cf7be2da9485a8a1b62ef6a3848e5
Source dataset
uspto-grants-1999_10
Patent number
US05961939

Reaction notes

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