Study on properties of coal-sludge-slurry prepared by sludge from coal chemical industry

• Published in: Powder technology 2020-04, Vol.366, p.552-559
• Main Authors: Zhang, Yuxing, Xu, Zhiqiang, Tu, Yanan, Wang, Jinyu, Li, Jie
• Format: Article
• Language: English
• Subjects: Chemical industry; Chemical sludge; Coal; Coal industry; Coal-water-slurry; Coking; EDLVO; Gasification; Lignite; Pseudoplasticity; Rheology; Sludge; Slurries; Stability; Turbiscan LAB; Viscosity
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2020.03.005

Sludge from coal chemical industry is hazardous and difficult to disposal. In this study, a coal chemical sludge was mixed with lignite, coking coal and lean coal to prepare coal-sludge-slurry(CSS) for gasification and combustion. The results showed that the addition of sludge changed CSS from the dilatant fluid to the yield pseudo-plastic fluid. The stability of CSS was observed increasing, while the preparation concentration was decreased at the same viscosity requirement. A combination of BET analysis and EDLVO theory calculation was carried out to study the behavior among particles and water in CSS. Sludge could attract considerable water, increasing the viscosity of slurry. Besides, sludge might connect with coal particles to structure a three-dimensional network which would be destroyed by agitation and then released trapped water, resulting in the pseudo-plasticity of CSS. The network could also prevent the aggregation of particles and improve the stability of slurry. [Display omitted] •Coal-sludge-slurry were prepared by three coals and sludge from coal liquefaction.•The addition of sludge made slurry more stable as TSImax decreased from 0.93 to 0.24.•Sludge made slurry more pseudo-plastic as fluidity index n reduced from 1.11 to 0.63.•Sludge connected with coal particles to form a network according to EDLVO calculation.