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US3981252A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-polluting disposal of antifouling paint residues encountered in shipyard abrasive blasting operations

Assignee: Individual
•
Filing: 1975-12-03
•
Granted: 1976-09-21
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Expires: 1995-12-03
📄 Original PDF 🌐 Google Patents

Abstract

Abstract A process for neutralizing the toxic nature of organo-metallic antifouling (AF) paint particles, in intimate mixture with spent abrasive particles, derived from the abrasive blasting of ships' hulls. The spent abrasive containing the organo-metallic paint residue is collected and heated in a vapor-tight furnace which is fitted with a safety pressure release valve. When the ignition temperature of the organo-metallic paint is exceeded, the organo-metallic paint particles are oxidized to a harmless, non-toxic metal oxide, which may be safely disposed of. Volatile organo-metallic paint vapors are drawn through an after-burner so that exhaust residue consist only of non-polluting carbon dioxide and water vapor. Metallic elements of commercial value, such as tin, may be recovered from the processed abrasive, which may also be reusable. To ensure complete combustion, air is fed into the combustion furnace from a blower fan, compressor, or other external source.

Inventors

  • 👤 Arthur Ticker

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 19:18
CPC Classifications
F; F23; F23G; F23G7/00

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 122 words
A safe, non-polluting method of handling and neutralizing the toxic nature of organo-metallic antifouling paint residue removed from ships comprising the steps of: removing the organo-metallic antifouling paint from a ship's hull as by abrasive blasting or other mechanical means; collecting the residue of said organo-metallic antifouling paint and spent abrasive blasting material; placing said residue of organo-metallic paint and abrasive material in a vapor-tight muffle furnace; heating said residue in said furnace in the presence of air for a period of time above its ignition temperature and the ignition temperature of its vapors; whereby said organo-metallic material is destroyed to yield carbon dioxide, water vapor and a non-toxic, non-organic metal oxide; and unloading the detoxified material for recycling or safe disposal.
Claim 2
Dependent Claim 122 words
A safe, non-polluting method of handling and neutralizing the toxic nature of organo-metallic antifouling paint residue removed from ships comprising the steps of: removing the organo-metallic antifouling paint from a ship's hull as by abrasive blasting or other mechanical means; collecting the residue of said organo-metallic antifouling paint and spent abrasive blasting material; placing said residue of organo-metallic paint and abrasive material in a vapor-tight muffle furnace; heating said residue in said furnace in the presence of air for a period of time above its ignition temperature and the ignition temperature of its vapors; whereby said organo-metallic material is destroyed to yield carbon dioxide, water vapor and a non-toxic, non-organic metal oxide; and unloading the detoxified material for recycling or safe disposal.
Claim 3
Dependent Claim 29 words
The method of claim 1 wherein the step of heating is further defined as: heating said residue to a temperature of at least 640°C for at least 45 min.
Claim 4
Dependent Claim 37 words
The method of claim 2 further comprising the step of: adding air to the interior of said furnace to replace consumed oxygen, and to fluidize particulates and thus ensure complete combustion of said organo-metallic and its vapors.
Claim 5
Dependent Claim 33 words
The method of claim 3 further comprising the steps of: venting the vapors driven off during the combustion of the organo-metallic residue to an after-burner; and afterburning said vapors to non-toxic inert compounds.
Claim 6
Dependent Claim 26 words
The method of claim 4 wherein said organo-metallic residue is: an organo-tin compound. The method of claim 4 wherein said organo-metallic residue is: an organo-lead compound.
Claim 7
Dependent Claim 13 words
The method of claim 5 wherein said organo-metallic residue is: triphenyl lead acetate.
Claim 8
Dependent Claim 39 words
The method of claim 1 wherein said steps of collecting said residue is provided by a mobile on-site process comprising the initial step of: vacuuming up the residue from the drydock floor to street level directly into said furnace.

References Cited (Backward Citations)

US2474645A Cited
US2815267A Cited
US3686034A Cited
US3821026A Cited
US3802916A Cited
US3899322A Cited
US3847664A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-09-21 1980-03-22 1980-09-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-09-21 1984-03-22 1984-09-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-09-21 1988-03-22 1988-09-21 $7700.00 Window Closed / Lapsed

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