城市生活垃圾焚烧飞灰的水化产热研究

Study on hydration heat generation of municipal solid waste incineration fly ash

为探究城市生活垃圾焚烧飞灰的水化产热规律,研究了其化学成分、矿物相组成,采用室内水化热测定试验测得其水化温度变化情况。根据水化温度曲线计算产热量分析了初始含水率对飞灰水化产热的影响程度,最后依据水化产热速率曲线对飞灰水化阶段进行了划分。结果表明:城市生活垃圾焚烧飞灰的主要化学成分为CaO、Cl、K_(2)O等,矿物相组成主要是含钙矿物Ca(OH)_(2)、CaSO_(4)、Ca_(3)SiO_(5)和含氯矿物NaCl、KCl以及金属氧化物MgO等。初始含水率为15%、20%、25%、30%的试样,24 h累积单位产热量分别为48.73、60.04、60.89、61.20 J/g。飞灰水化产热可划分为初始产热阶段、加速产热阶段、产热衰减阶段、产热稳定阶段4个阶段。

In order to explore the hydration heat generation law of municipal solid waste incineration fly ash,its chemical composition and mineral phase composition were studied,and its hydration temperature change was measured by indoor hydration heat measurement test.According to the hydration temperature curve,the influence of initial water content on the hydration heat generation of fly ash is analyzed.Finally,the hydration stages of fly ash are divided according to the hydration heat generation rate curve.The results show that the main chemical composition of MSW incineration fly ash is CaO,Cl,K_(2)O,etc.The mineral phase composition is mainly composed of calcium minerals Ca(OH)_(2),CaSO_(4),Ca_(3)SiO_(5),chlorine minerals NaCl,KCl,and metal oxide MgO.The cumulative unit heat production of samples with 15%,20%,25%and 30%initial water content in 24 h is 48.73,60.04,60.89 and 61.20 J/g respectively.The hydration heat generation of fly ash can be divided into four stages:initial heat generation stage,accelerated heat generation stage,heat generation attenuation stage,stable stage of heat generation.