Green liquor dregs for the amendment of tailings

• Green liquor dregs (GLD) from the sulphate pulping process is one of the main wastes from the pulp industry still being landfilled in Sweden. GLD has similar hydro-geotechnical properties as tailings paste and may be used as an amendment to tailings to reduce the leachate generation, improve the leachate quality, and improve the geotechnical properties of the mixture. The addition of 10% GLD (dry weight basis) reduced the hydraulic conductivity of the tailings by a factor of two. Addition of a 30% mixture (on a dry weight basis) of GLD and fly ash (FA) to tailings reduced the hydraulic conductivity by more than one order of magnitude. Thanks to its alkaline properties and it negative zeta potential, GLD has a direct effect on the metal leaching from tailings. The alkaline capacity of the pulping wastes raised the pH in the stabilized tailings and reduced leaching of Cu, Co, Cd, and Ni. Addition of 10% pulping waste to tailings on a dry weight basis was sufficient to reduce copper leaching by a factor of 4 to 10.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geokemi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geochemistry (hsv//eng)

Keyword

Applied Geology

Tillämpad geologi

Publication and Content Type

ref (subject category)

kon (subject category)