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Process and apparatus for re-cycling engine coolant

  • US 4,946,595 A
  • Filed: 09/09/1988
  • Issued: 08/07/1990
  • Est. Priority Date: 09/09/1988
  • Status: Expired due to Term
First Claim
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1. A process for physically and chemically treating a used coolant composition of the type used within an internal combustion engine cooling system, after removal from said system, to remove unwanted impurities and degradation by-products including dissolved metals, dirt, silt, salts and other unwanted suspended particulate matter contained therein, said coolant composition containing one or more glycol and/or alcohol-based antifreeze components, said process comprising:

  • contacting said coolant composition with one or more known oxidizing agents in an amount sufficient to form metallic oxides from any unwanted dissolved metals present in said composition thereby forming particulate metallic oxide precipitates;

    contacting said coolant composition with one or more known salt forming agents in an amount sufficient to react with any unwanted organic acids present in said composition thereby forming particulate salt precipitates;

    filtering said coolant composition through any suitable filtration membrane or other separation means capable of removing particulate precipitates therefrom;

    adding to said coolant composition one or more suitable corrosion inhibiting agents selected from the group consisting of phosphates, phosphonates, silicates, borates, nitrites, nitrates, azols, modified acrylates and molybdates; and

    introducing into said coolant composition one or more known buffering agents in an amount sufficient to adjust the pH of the final solution to between about 9.5 and 10.5 thereby providing a recycled coolant composition having corrosion capabilities equal or superior to that of the original coolant composition prior to removal.

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