The rotary viscometer was adopted to test the rheological behavior of coal slurry.Moreover

the relationship between coal slurry concentration and its viscosity

and the coal slurry shear rate and shear stress were obtained through the experiments.Thus

the frictional resistance loss of the pipeline transportation system can be calculated.The results showed that:when the coal slurry concentration was within the range from 60%to 70%

the pseudoplastic state coal slurry transformed to Binham fluid with an increase in the coal slurry concentration;the coal slurry viscosity changed with the slurry concentration;when the slurry concentration was 71.1%

as the flow rate increasing

the pressure drop in pipe with diameter of 75mm increased sharply while that in pipe with diameter of 100mm increased slower;when the slurry concentration was larger than 71.1%

the slurry viscosity and shear stress increased rapidly

while there existed the optimal working condition for coal slurry pipeline transportation.