Co-combustion of Shenmu coal and pickling sludge in a pilot scale drop-tube furnace: Pollutants emissions in flue gas and fly ash

Abstract Co-combustion of Shenmu coal and pickling sludge was carried out in a pilot scale drop-tube furnace. The effect of different pickling sludge amounts on the NO x , SO 2 , HCl, HF, PCDD/Fs and gaseous heavy metals emissions and fly ash behaviors was studied. The burnout section furnace temperature was 1250 °C, and the pickling sludge amount ranged from 0 to 20 wt%. The result indicates that the co-combustion of x and HCl emission concentrations were basically stable; however, those of SO 2 and HF increased obviously. The total TEQ of PCDD/Fs emission was basically positively correlated to the sludge amount in the blended fuels, and the gaseous heavy metals emissions also increased obviously with the addition of sludge. To meet the national standard (GB18484-2001) on heavy metals emissions, the pickling sludge amount used in co-combustion must be