添加城市污泥对烧结过程及烧结矿质量的影响

首先通过化学分析和热重分析等方法对城市污泥的主要化学成分及燃烧特性进行分析研究。并将城市污泥按照质量分数为0%、3%、6%和9%的比例分别添加入烧结原料中,研究添加城市污泥对烧结过程主要技术经济指标、烧结矿物相组成及机械强度的影响。结果表明:污泥的燃烧热值为5 325.66kJ/kg,即1kg污泥相当于0.182kg标准煤,污泥的添加有利于减少烧结燃料的使用。随着烧结原料中污泥添加量的增加,烧结矿中铁酸钙含量呈现先增大后减小的趋势。当添加污泥的质量分数为6%时,烧结矿中铁酸钙含量达到最大值。当添加污泥的质量分数小于3%时,随着污泥的加入,烧结矿的烧成率、成品率、利用系数、落下强度以及转鼓指数都逐渐提高,之后均开始缓慢降低;而垂直烧结速度随着污泥的添加量的增加,呈现先减小后增大趋势,在添加污泥的质量分数为3%时达到最小值。

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 3 mass％.