Method for reusing contaminant separated from naphthalenesulfonic acid neutralization wash waste liquor

Method for reusing contaminant separated from naphthalenesulfonic acid neutralization wash waste liquor

CN
  • CN 1,269,742 C
  • Filed: 07/10/2004
  • Issued: 08/16/2006
  • Est. Priority Date: 07/10/2004
  • Status: Active Grant
First Claim
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1. A method for recycling pollutants separated from naphthalene sulfonic acid neutralization washing waste liquid is characterized in that the pollutants separated from naphthalene sulfonic acid neutralization washing waste liquid are concentrated or added with naphthalene sulfonic acid or added with methyl naphthalene sulfonic acid or added with a mixture of naphthalene sulfonic acid and methyl naphthalene sulfonic acid until the material solid content is 40-70 weight percent of waste water concentrated liquid, and the recycling method of the waste water concentrated liquid is completed according to the following steps:

  • (a) adding sulfuric acid into the waste water concentrated solution to adjust the total acidity to 24% -32%, adding formaldehyde into the waste water concentrated solution, wherein the amount of the added formaldehyde is 0.6-1.0 time of the molar number of the sulfonate in the material, and carrying out condensation reaction for 2-6 hours at the temperature of 80-150 ℃

    ;

    (b) after the condensation reaction is finished, adding alkali to adjust the pH value to 7-9, carrying out neutralization reaction, separating solid sulfate, and using the obtained filtrate as a naphthalene water reducer;

    in the neutralization reaction (b), the base is;

    sodium hydroxide is used as the main ingredient, and calcium hydroxide or calcium oxide is used as the auxiliary ingredient.

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