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US3749648A Expired / Lapsed US ⏱️ 0.0 years remaining

Recovery of spent sulfuric acid from chlorinated and nitrated benzoic acid derivatives

Assignee: EIDP Inc
•
Filing: 1971-05-19
•
Granted: 1973-07-31
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Expires: 1991-05-19
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Abstract

Abstract A WASTE SULFURIC ACID-WATER SOLUTION CONTAINING SMALL AMOUNT OF NITRIC ACID, NITROUS ACID, HYDROFLUORIC ACID AND CHLORINATED AND NITRATED ORGANICS OF THE BENZOIC AND BENZOTRIFLUORIDE TYPE CAN BE RECONSTITUTED BY A RECOVERY PROCESS. IN ONE EMBODIMENT THE FIRST STEP WILL BE SOLVENT EXTRACTION TO REMOVE THE ORGANICS FROM THE WASTE ACID. THE SECOND STEP WILL INVOLVE STEAM STRIPPING OF THE WASTE ACID TO REMOVE THE NITRIC ACID, NITROUS ACID, HYDROFLUORIC ACID, AND THE SMALL QUANTITY OF SOLVENT WHICH WAS DISSOLVED IN THE ACID IN THE FIRST STEP. AFTER THESE PROCESS STEPS, THE RECONSTITUTED ACID WILL BE SUITABLE FOR NORMAL INDUSTRIAL USE. IN ANOTHER EMBODIMENT, THE WASTE ACID IS FIRST STEAM DISTILLED TO REMOVE THE NITRIC ACID, NITROUS ACID, HYDROFLUORIC ACID AND THE CHLORINATED AND NITRATED BENZOTRIFLUORIDE COMPOUNDS. THE STILL BOTTOMS ARE THEN COOLED AND FILTERED TO REMOVE THE BENZOIC ACID COMPOUNDS. THE FILTRATE IS THE DESIRED RECONSTITUTED ACID.

Inventors

  • 👤 A Boettler
  • 👤 A Clarke
  • 👤 R Wheatley

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 18:50
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/04; B01D11/0488; C; C01; C01B; C01B17/00; C01B17/69; C01B17/90; C01B17/94; C07; C07C; C07C201/00; C07C201/06; C07C201/16; C07C51/00; C07C51/42; C07C51/43; C07C51/44; C07C51/47; C07C51/48

Claims Analysis

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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-07-30 1977-01-29 1977-07-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-07-30 1981-01-29 1981-07-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-07-30 1985-01-29 1985-07-31 $7700.00 Window Closed / Lapsed

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