Utilization of green liquor dreg in lightweight aggregates: Effect of texture on physical properties

Green liquor dreg (GLD) is a side stream generated by pulp industry. Due to its complex physicochemical nature, it has been reported to be difficult material to utilize. Here, a novel approach towards utilization of moist and dry green liquor dreg as binder and filler in alkali-activated lightweight artificial aggregates was developed. Dried GLD and moist GLD were granulated with blast furnace slag (BFS) and Bioash in different mixtures using alkali activation. The effect of the GLD nature (dried and moist) on strength, microstructure and durability of the lightweight granules were determined and compared. Results show that the method used in homogenizing the moist GLD and other powders was efficient and improved the frost resistance. The reaction product identified in the granule's includes calcium silicate hydrate, Mg-Al layered double hydroxides, and ettringite. These results demonstrate the potential of GLD as a binder and fillers in cementitious applications.