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US3843540A Expired / Lapsed US ⏱️ 0.0 years remaining

Production of magnetic fluids by peptization techniques

Assignee: United States Department of the Interior
•
Filing: 1972-07-26
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Granted: 1974-10-22
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Expires: 1992-07-26
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Abstract

Abstract 1. A PROCESS FOR PRODUCING MAGNETIC FLUIDS FROM AQUEOUS INDUSTRIAL WASTE STREAMS CONTAINING FERROUS IRON SALTS WHICH COMSPRISES: OXIDIZING A PORTION OF THE FERROUS IRON CONTAINED IN THE WASTE STREAM TO THE FERRIC STATE; REACTING THE WASTE STREAM, NOW CONTAINING FERROUS AND FERRIC IRON SALTS, WITH AN EXCESS OF AMMONIUM HYDROXIDE TO PRECIPITATE A SLURRY OF COLLOIDAL SIZE FERROSO-FERRIC IRON OXIDE PARTICLES; ADDING A LONG CHAIN FATTY ACID HAVING ABOUT 18 CARBON ATOMS TO THE IRON OXIDE PARTICLE SLURRY WHEREBY THE FATTY ACID REACTS WITH AMMONIUM HYDROXIDE TO FORM AN AMMONIUM SALT OF THE FATTY ACID AND TO THEREAFTER COAT IRON OXIDE PARTICLES CONTAINED IN TH SLURRY WITH AN ADSORBED LAYER OF AMMONIATED FATTY ACID TO HEATING THE SLURRY TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF THE AMMONIATED FATTY ACID TO CONVERT THE ADSORBED LAYER OF AMMONIATED FATTY ACID TO THE ACID FORM AND TO EXPEL AMMONIA FROM THE SLURRY, AND RECOVERING FROM THE SLURRY A PRODUCT FRACTION COMPRISING FERRIMAGNETIC IRON OXIDE PARTICLES OF COLLOIDAL SIZE COATED WITH AN ADBSORBED LAYER OF FATTY ACID.

Inventors

  • 👤 G Reimers
  • 👤 S Khalafalla

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 17:34
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/44; H01F1/445

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 174 words
A PROCESS FOR PRODUCING MAGNETIC FLUIDS FROM AQUEOUS INDUSTRIAL WASTE STREAMS CONTAINING FERROUS IRON SALTS WHICH COMSPRISES: OXIDIZING A PORTION OF THE FERROUS IRON CONTAINED IN THE WASTE STREAM TO THE FERRIC STATE; REACTING THE WASTE STREAM, NOW CONTAINING FERROUS AND FERRIC IRON SALTS, WITH AN EXCESS OF AMMONIUM HYDROXIDE TO PRECIPITATE A SLURRY OF COLLOIDAL SIZE FERROSO-FERRIC IRON OXIDE PARTICLES; ADDING A LONG CHAIN FATTY ACID HAVING ABOUT 18 CARBON ATOMS TO THE IRON OXIDE PARTICLE SLURRY WHEREBY THE FATTY ACID REACTS WITH AMMONIUM HYDROXIDE TO FORM AN AMMONIUM SALT OF THE FATTY ACID AND TO THEREAFTER COAT IRON OXIDE PARTICLES CONTAINED IN TH SLURRY WITH AN ADSORBED LAYER OF AMMONIATED FATTY ACID TO HEATING THE SLURRY TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF THE AMMONIATED FATTY ACID TO CONVERT THE ADSORBED LAYER OF AMMONIATED FATTY ACID TO THE ACID FORM AND TO EXPEL AMMONIA FROM THE SLURRY, AND RECOVERING FROM THE SLURRY A PRODUCT FRACTION COMPRISING FERRIMAGNETIC IRON OXIDE PARTICLES OF COLLOIDAL SIZE COATED WITH AN ADBSORBED LAYER OF FATTY ACID.
Claim 2
Dependent Claim 174 words
A PROCESS FOR PRODUCING MAGNETIC FLUIDS FROM AQUEOUS INDUSTRIAL WASTE STREAMS CONTAINING FERROUS IRON SALTS WHICH COMSPRISES: OXIDIZING A PORTION OF THE FERROUS IRON CONTAINED IN THE WASTE STREAM TO THE FERRIC STATE; REACTING THE WASTE STREAM, NOW CONTAINING FERROUS AND FERRIC IRON SALTS, WITH AN EXCESS OF AMMONIUM HYDROXIDE TO PRECIPITATE A SLURRY OF COLLOIDAL SIZE FERROSO-FERRIC IRON OXIDE PARTICLES; ADDING A LONG CHAIN FATTY ACID HAVING ABOUT 18 CARBON ATOMS TO THE IRON OXIDE PARTICLE SLURRY WHEREBY THE FATTY ACID REACTS WITH AMMONIUM HYDROXIDE TO FORM AN AMMONIUM SALT OF THE FATTY ACID AND TO THEREAFTER COAT IRON OXIDE PARTICLES CONTAINED IN TH SLURRY WITH AN ADSORBED LAYER OF AMMONIATED FATTY ACID TO HEATING THE SLURRY TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF THE AMMONIATED FATTY ACID TO CONVERT THE ADSORBED LAYER OF AMMONIATED FATTY ACID TO THE ACID FORM AND TO EXPEL AMMONIA FROM THE SLURRY, AND RECOVERING FROM THE SLURRY A PRODUCT FRACTION COMPRISING FERRIMAGNETIC IRON OXIDE PARTICLES OF COLLOIDAL SIZE COATED WITH AN ADBSORBED LAYER OF FATTY ACID.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-10-21 1978-04-22 1978-10-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-10-21 1982-04-22 1982-10-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-10-21 1986-04-22 1986-10-22 $7700.00 Window Closed / Lapsed

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