The effect of inorganic salt in wastewater on the viscosity of coal water slurry

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

In this work, the effect of waste brake oil (WBO) on the dispersion property of coal-sludge oil slurry (CSOS) was investigated and comprehensively analyzed. Apparent viscosity of CSOS decreases from 997 to 276 mPa.s with the increasing of SS content from 0 to 12% under the calorific value (CV) of 17.70 MJ/kg and oil/sludge ratio (O/S) of 2.0. The combination of sewage sludge (SS) and WBO could decrease the apparent viscosity of CSOS, 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 CSOS 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, resulting in a dramatic decrease in viscosity. This research provides a potential way to dispose the SS and waste industry oil.

An effective recycle way of waste coke ash and coking wastewater for preparing coke ash coking wastewater slurry

The carbon riched coke ash (CA) and organic components riched coking wastewater (CW) recovered from coking plants wastes were utilized for the preparation of coke ash coking wastewater slurry (CACWS), aiming for the fuel and waste reduction and recovery. The effects induced by the properties of CA and compositions of CW on the performances of CACWS, such as slurryability, rheology, stability and dispersant adsorption were investigated and discussed. Characterizations like zeta potentials and contact angles on the surface of CA were also conducted to draw a comprehensive formation mechanism of CACWS. Results showed that the CA was suitable for preparing slurry due to the lack of micropore structures and hydrophobicity in the surface. The maximum content of CA in the as-prepared CACWS could reach 66% and CACWS exhibited non-Newtonian pseudoplastic fluid behaviour. By reducing the particle size distribution, the slurryability of CA could be effectively improved. Although the components in CW enhance the wettability of CA surface, compared with cations in CW, the organic components had more influence on CACWS, which also obviously increased the viscosity of CACWS. The maximum CA content in CACWS (ω = 66 wt%) reduced by 9% comparing to CA water slurry (ω = 75 wt%) which improved the storage stability about 10%. In addition, results show that the dispersant Triton X-405 reduced viscosity and improved stability while in comparison with the anionic polycarboxylate dispersant. Overall, this study may provide an innovative and effective utilization of CA and CW from the coke plants wastes.