Abstract: The effect of additives and the weight fraction of sludge on the slurry-ability of sludge-char water slurry (SCWS) was investigated using slurry preparation experiments.The results indicate that the DCSA additive enhances the slurry-ability of blended sludge/char feedstock and improves the rheological property as well as the stability performance of the SCWS compared with NF under the same experimental conditions.The weight fraction of sludge has significant impact on the slurry-ability of blended sludge/char feedstock.The correlation between the weight fraction of sludge (x) and slurry concentration (φ) can be quantitatively.The increase in the weight fraction of sludge undermines the slurry-ability of the sludge/char feedstock.The SCWS exhibits a pseudo-plastic behavior.The shear thinning property of SCWS become more pronounced with the increasing weight fraction of sludge.