Influence of waste brake oil on the rheological properties of coal sludge slurry

Abstract

In this work, the effect of waste brake oil (WBO) on the dispersion property of coal oil-sludge slurry (COSS) was investigated and comprehensively analyzed. Apparent viscosity of COSS decreases from 997mPa.s to 276mPa.s with the increasing of SS content from zero to 12% under the CV of 17.70 MJ/kg and O/S of 2.0. The combination of sewage sludge (SS) and WBO could decrease the apparent viscosity of COSS, and SS content and O/S are two important parameters to affect the apparent viscosity. WBO mainly contains the hydrocarbon compound and a lot of oxygenated functional groups according to its GC/MS results. WBO could cover on the surface of SS and coal particle, and reduce their hydrophobic character and the adsorbance amount of dispersant based on the FTIR, XPS and adsorption performance results. In addition, the mechanism of WBO on slurry characteristics of COSS was investigated. With the low content of WBO, the liquid bridges from WBO force the solid particles to adhere together and form a stable network structure, thus reducing the flow ability of the suspension. With the increasing of WBO, the network structures could be broken into cells by stirring it, resulting in a dramatic decrease in viscosity. This research provides a potential way to dispose the SS and waste industry oil.