Coal water slurries (CWSs) are considered to be a new form of fuel that can alleviate the environmental and safety issues

associated with use of bulk solid fuel. However, CWSs does not always fi t into existing solid fuel supply and storage chain.

In this study, a novel method to control CWSs viscosity using pH-responsive thickener was proposed, off ering the advantages

of improved storage stability and on-demand viscosity control, thus allowing CWSs to be used as a c for a variety of applications.

This study investigates the eff ects of additives and pH on the viscosity and storage stability of CWSs. Poloxamer 407,

polynaphthalene sulfonate formaldehyde (PNSF), and a copolymer containing pigment-affi nic (PA) groups were used as

dispersants to lower CWSs viscosity. Xanthan gum, a modifi ed acrylic polymer (MAP), and carbomer were used as thickeners

for assessing the storage stability and fl uidity of CWSs based on viscosity changes. Optimal viscosity reduction was achieved

by the addition of PA. A viscosity of 7000 cP was achieved by the use of carbomer, with small amount comparable to 27.3

wt% of MAP and 22.7 wt% of Xanthan gum. Moreover, the carbomer-containing CWSs exhibited high storage stability in

a 360-h stability test, retaining 84.3% of the original baseline coal content. pH-dependent viscosity changes were observed

only in carbomer-containing samples.

Coal water slurry · Storage stability · Fluidity · Dispersant · Thickener

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