Pollutant emission and attrition performance of low calorific blended coals during co-combustion in fluidized bed

•Attrition and emission of low calorific blended coals are studied in fluidized bed.•The quantitative fragmentation indexes of blends during combustion are presented.•Low SO2 and NO release are achieved when adding coal slime into the mixture.•The main reason for the attrition of coal particles is the primary fragmentation.