Research On Characteristics Of Sintered Body Mixed With Sewage Sludge

With the development of socialization and the increase of population, the wastewaterdischarged from the wastewater treatment plants increased sharply which results in moreproduction of sewage sludge. How to dispose the sewage sludge effectively becomes aglobal issue. The current consensus of resolving this issue is to utilise the sludge asresource, which can change the waste into treasure.This work focused on the treatment of the sewage sludge by the methed ofdesiccating, grinding and incinerating; Sintered body of sewage sludge incineration ashdeveloped by extrusion and baking preparation; Based on the purpose of meeting thenational standard of GB5101—2003, we discussed the influence of the sludgeincineration ash content and sintering temperature on the sintered body to the mainphysical and mechanical properties (Volume density, compressive strength and linearshrinkage) and the weather resistance properties (water absorption, saturation coefficientand frost resistance) of the sinter body.The results showed that the sludge incineration ash sintered body was better than thedry sludge sintered body in the aspect of surface appearance and the emission of odourgas; Under the sintering temperature of 1050℃, sludge incineration ash sintered kept agood surface appearance, and with the increase of sludge incineration ash content, thebulk density of sintered body decreased, the compressive strength and linear shrinkagereduced, the water absorption increased, the saturation coefficient kept stable, and theappearance of the thawed green body remained well. The SEM analysis showed that theamount and volume of open pores in the interior of the the sludge incineration ashsintered body went up. When the sludge incineration ash content is 40%, the sinteredbody with the sintering temperature of 990℃showed the phenomenon of under-fired, thesurface appearance of the sintered body with the sintering temperature of 1080℃waspoor and showed the phenomenon of over-fired. As the increase of the sinteringtemperature, the bulk density of the sintered body and compressive strength increased, thedrying linear shrinkage kept constant, the total linear shrinkage rate decreased, the waterabsorption and saturation coefficient reduced, the surface appearance of the green bodykept unchanged. The SEM analysis shows that the amount and volume of open pores inthe interior of the the sludge incineration ash sintered body went down. Considering themechanical properties and the weather resistance properties, we concluded that at themaximum calcination temperature of 1050℃, the sludge incineration ash sintered bodyadded 40% sludge incineration ash quantity utilized most sludge incineration ash and coalgangue which reached 80%, and the sintered body can meet the first-class brick with compressive strength MU10 in the national standard GB5101—2003.