New article about green liquor dregs from LTU Print
Written by Andreas Drott   
Wednesday, 10 October 2012 09:46

Green liquor dregs (GLD) are the largest waste fraction retrieved at the sulphate pulp mill. GLD has a low hydraulic conductivity and is alkaline which opens the possibility of using it for construction of sealing layers. Two sites have been sampled where the GLD age is known. The effect of aging on the material properties specifically the ability to function as a barrier against oxygen and its capacity to buffer in the long term was studied. The mechanical strength has also been evaluated to asses if it can withstand the pressures from the cover layer. Suction tests showed that the capillarity forces in GLD bind water strongly to the particles preventing it from drying. The high water content in GLD and the strength of the water bounding are major advantages for the use in sealing layers to create a water saturated layer preventing oxygen penetration. GLD is therefore believed to be an excellent barrier material in the sealing layer. The GLD’s buffering capacity is high and the results indicate that it will last for a long time which is consistent with its large reservoir of lime. The shear strength increased when the GLD is placed in field conditions.

Assessment of the effect of aging on green liquor dregs cover for tailings deposits: Field investigation

Mäkitalo, M. , Lu, J. , Stahre, N. , Maurice, C.&Öhlander, B.2012 in: Proceedings of the 8th International Conference on the Environmental and Technical Implications of Construction with Alternative Materials . Arm, M., Vandecasteele, C., Heynen, J., Suer, P. & Lind, B. (red.). ISCOWA, page 5.

Last Updated on Wednesday, 10 October 2012 09:48