Based on a supercritical 600 MW CFB unit

the effects of blending coal slime with large proportion on boiler performance and pollutant emission were studied in a 1 MW CFB combustion test-bed. The test results show that

the blending ratio of the coal slime could reach up to 70%

and the co-combustion was stable at this ratio. The proportion of fly ash increased with the coal slime's blending ratio

it was 77.84%

82.32% and 83.78% respectively when the blending ratio was 35%

55% and 70%.The large proportion of slime could reduce the amount of circulating materials in the furnace

which was not conducive to the uniform temperature distribution in the whole furnace. The combustion efficiency was 99.29%～99.41%

and the blending ratio of slime did not affect the combustion efficiency obviously. Blending slime had no obvious influence on the slagging characteristics of coal. When increasing the blending ratio of coal slime

the SO_2 emission decreased at first and then increased

while the NOx emission gradually decreased.