The Influence Of Different Dispersant On Slurring Characteristics And Combustibility Of The Sludge Coal Water Slurry

With increasing of sewage treatment, the amount of sewage sludge will increase rapidly and its disposal has been a global concern. Coal-water slurry (CWS) prepared with high moisture sewage sludge, which utilized the sludge calorific value, reduced the sludge processing cost and pollutant discharging, has the positive economy and environment benefits. This research mainly focused on the slurryability of CWS mixed with sewage sludge and the combustion characteristics of their blends.With dispersants such as NDF, MC, NC, MF, it is feasible mixing the sludge with CWS, with ratio of 5%,10% sludge, the slurry sample could be good product, while the sludge dosage of 15%,20%,the slurry can not flow easily. The appropriate of dispersant can improve the dispersion properties of coal water slurry.The sludge coal water slurry combustion characteristics are complex, the nature of the sludge and coal has a great impact on their combustion characteristics. Due to small proportion of sludge, the performance is close to the combustion characteristics of coal-water slurry. The combustion characteristics of sludge(CWS and S-CWS) were studied through the thermal analysis (TA).The results indicated that the ignition temperature of S-CWS was about 10～20℃lower than ordinary CWS, becase of volatile decomposed and burned more quickly which improved the burning performance of S-CWS. The comprehensive burning index S increased with the proportion of sludge combined. According to flammability index C and comprehensive burning index S, the combustion characteristics of S-CWS with 10% sludge was better than S-CWS with 5% sludge.Taken together, the proportion of municipal sewage sludge mixed system of 5% to 10%, corresponding to the amount of 1% of the additives under the conditions of slurry, the sludge mixed with coal-water slurry system is feasible. According to the results of combustion analysis, under the condition of proportion of 10% sludge mixed with coal-water slurry, which can be achieved better combustion characteristics. This would proposed a new way for resource utilization of sewage sludge.