Additive for coal water slurry made from weak slurryability coal

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:45143

Zang, Zi-xiu; Zhang, Lin; Fu, Xino-an; Jiang, Long ^[1]

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1. Institute of Photographic Chemistry, Beijing (China)

Surface treatment of weak slurryability coal and preparation of highly concentrated coal water slurry (CWS) have been investigated using wettability and rheology measurements. By adding 0.5{approximately}10 wt.% (based on coal) pitch during dry milling coal surface became more hydrophobic and the coal could be easily prepared for CWS which had much lower viscosity compared with CWS of the untreated coal. The reasons of this result is high degree of hydrophobic surface of coal particles made surfactant adsorption easier compared with high degree of hydrophilic surface of coal particles. Another important reason in hydrophobic surface impeded the penetration of water into the inner pores of coal particles which resulted in decreasing swelling ability of coal and enhancing the fluidity of CWS. Four different additives have been investigated including three nonionic ethoxylated surfactants and one mixture of anionic surfactants (sodium humate derivative and naphthalenesulfonic acid-HCHO condensate). Both rheological and thixotropic properties showed that nonionic surfactant G2 was the most efficient additive for preparation of highly concentrated CWS. The results of dynamic experiment illustrated that the slurry had good dynamic stability, in other words, the viscosity of the slurry decreased very slowly at constant stir. The pitch treated coal powders were beneficiated coal had much lower viscosity compared with CWS of the unbeneficiated coal.

• OSTI ID: 45143
• Report Number(s): CONF-930413--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ADDITIVES
COAL FINES
FUEL SLURRIES
PRODUCTION
RHEOLOGY
STABILITY
SURFACE TREATMENTS
VISCOSITY
WATER
WETTABILITY