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US4287069A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the improved working up of effluent

Assignee: Bayer AG
•
Filing: 1980-05-05
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Granted: 1981-09-01
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Expires: 2000-05-05
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Abstract

Abstract The instant invention is directed to a process for the separation of aqueous sludges in the purification of effluents in purification plants, comprising: (a) mixing organic and/or inorganic aqueous sludges with ground monomer-free tolylene diisocyanate (TDI) distillation residues having a mean particle size of less than 2 mm; (b) removing the water from the resulting purified sludges; and (c) disposing of the purified sludges.

Inventors

  • 👤 Artur Reischl
  • 👤 Kurt Mack
  • 👤 Friedhelm Sahlmen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 04:31
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C02F11/00; C02F11/12; Y; Y10; Y10S; Y10S210/00; Y10S210/918; Y10S210/919

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 58 words
A process for the separation of aqueous sludges in the purification of effluents in purification plants, comprising: (a) mixing organic and/or inorganic aqueous sludges with ground monomer-free tolylene diisocyanate (TDI) distillation residues having a mean particle size of less than 2 mm; (b) removing the water from the resulting purified sludges; and (c) disposing of the purified sludges.
Claim 2
Dependent Claim 58 words
A process for the separation of aqueous sludges in the purification of effluents in purification plants, comprising: (a) mixing organic and/or inorganic aqueous sludges with ground monomer-free tolylene diisocyanate (TDI) distillation residues having a mean particle size of less than 2 mm; (b) removing the water from the resulting purified sludges; and (c) disposing of the purified sludges.
Claim 3
Dependent Claim 16 words
The process of claim 1, wherein said TDI distillation residues have been prereacted with isocyanate-reactive compounds.
Claim 4
Dependent Claim 21 words
The process of claim 1, wherein said ground TDI distillation residues have a mean particle size of 1 mm or less.
Claim 5
Dependent Claim 21 words
The process of claim 3, wherein said ground TDI distillation residues have a mean particle size of 0.03 to 0.8 mm.
Claim 6
Dependent Claim 22 words
The process of claim 1, wherein said TDI distillation residues are denatured by adding to water with a temperature above 130° C.
Claim 7
Dependent Claim 22 words
The process of claim 1, wherein the isocyanate groups of said TDI distillation residues are completely reacted with water and/or isocyanate-reactive compounds.
Claim 8
Dependent Claim 15 words
The process of claim 1, wherein said TDI distillation residues contain cationic and/or anionic groups.
Claim 9
Dependent Claim 27 words
The process of claim 1, wherein said TDI distillation residues are added in a quantity of from 10 to 80% by weight, based on the total solids.
Claim 10
Dependent Claim 21 words
The process of claim 1, wherein said TDI distillation residues are mixed with said aqueous sludges in an activated sludge tank.

References Cited (Backward Citations)

US3942970A Cited
JPS4957663A Cited
DE2437367A1 Cited
US3893916A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-08-31 1985-03-02 1985-09-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-08-31 1989-03-02 1989-09-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-08-31 1993-03-02 1993-09-01 $7700.00 Window Closed / Lapsed

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