A study of low volatile coal water slurry-preparation and combustion

This exploratory work focused on the preparation of coal water slurry from low volatile coal and its combustion characteristics. Sample of raw coal and coal slime (Tunliu&Changcun, Luan Ltd, Shanxi, CN) were ground and prepared into highconcentration coal water slurry (CWS), which could be up to 72% and the apparent viscosity was less than 1 200 mPa·s, showing a good slurryability of the sample. Then thermo gravimetric analysis (TGA) and combustion test were conducted and the result showed that sample from Changcun had a comparatively higher ignition temperature, while a lower combined combustion characteristic index compared to the high volatile CWS. Under the same heating rate, a higher activation energy was required for low volatile CWS, while its ash deposition rate was well below that of high volatile CWS. When combusted continuously in a 10t/h industry boiler under the condition of national emission standards, the Changcun CWS was well distributed in the furnace with a uniform temperature, a bright, stable and sparkless flame, and the burn-out rate was high with a combustion thermal efficiency of 86.93%.