Green liquor dregs as an alternative neutralizing agent at a pulp mill
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Green liquor dregs is the biggest waste fraction at sulphate pulp mills. It is commonly landfilled. Here we demonstrate that the utilization of green liquor dregs as a neutralizing agent for acidic wastewaters is a potential alternative and an environmentally friendly method in contrast to its landfill disposal. The liming effect value of 39.6% for green liquor dregs, expressed as Ca equivalent, is similar to the liming effect value of 38% of a commercial limestone product. In addition, the pH value of 10.7 indicates a strong liming effect.
KeywordsGreen liquor dregs Causticizing Waste Pulp mill Neutralizing agent Metals
The authors wish to thank the technical staff of Suomen Ympäristöpalvelu Oy, especially M.Sc. Ilkka Välimäki, under whose supervision all the chemical analyses were performed.
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