EDTA disodium salt → Ethylenediaminetetraacetic Acid

HRID 1737128Notes

Reaction equation

HRID 1737128 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 23954SilverCatalyst4×

Procedure

A seasoned Kodak 885 hardened fixer was treated in the silver recovery unit 300 shown in FIG. 3, which incorporates a silver precipitating unit 80 according to U.S. Pat. No. 5,437,492 and described above. A continuous stream of untreated Kodak 855 hardened fixer at a flow rate of 100 mls/minute is provided in line 320. A solution of 7.5 g/l disodium EDTA dihydrate and 35 g/l sodium carbonate in storage vessel 310 is drawn off via line 311 by pump 312. The solution is then pumped to line 320 via line 313 and injected at a rate of 100 mls per minute through tee 315 into a seasoned Kodak 885 hardened fixer solution with a pH of about 4.8, flowing at a rate of 100 mls per minute in line 320. The resulting solution is then mixed within a tubular reactor 316. The solution is then returned to silver recovery unit 80 according to U.S. Pat. No. 5,437,792, which employs TMT as a silver precipitating agent and a flocculant to agglomerate the TMT-silver precipitate, as described above.

Workup

  1. customis provided in line 320
  2. additionThe resulting solution is then mixed within a tubular reactor 316

Sources & evidence

ORD record
ord-9f25ba1a487943059b248d1ea9d2e6a2
Source dataset
uspto-grants-1999_10
Patent number
US05961939

Reaction notes

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