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

Abstract

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%.

Keywords

• low volatile coal water slurry
• slurryability
• rheology characteristics
• combustion characteristics
• thermal analysis