Effect of sintering raw materials with municipal sludge on sintering process and sinter quality

Firstly, the main chemical compositions and combustion characteristics of municipal sludge were analyzed by chemical analysis and thermo gravimetric analysis. The effects of sintering raw materials with different contents of municipal sludge (0 mass%, 3 mass%, 6 mass% and 9 mass%) on the main technical and economic indexes, sintering phase composition and mechanical strength were studied. The results show that burning calorific value of the sludge is 5 325. 66 kJ/kg, that is, 1 kg of sludge is equivalent to 0. 182 kg of standard coal. The addition of sludge is beneficial to reduce the use of sintered fuel. With the increase of the amount of sludge in the sintering raw material, the content of calcium ferrite in the sinter increases firstly and then decreases. When the addition of sludge is 6 mass%, the content of calcium ferrite in the sinter reaches the maximum. When the addition of sludge is less than 3 mass %, the firing rate, yield, utilization coefficient, dropping intensity and drum strength of the sinter increase gradually and then slowly decrease. With the increase of sludge content, the vertical sintering speed decreases at first and then increases, and reaches the minimum when the amount of sludge is 3mass%.