城市污泥灰分矿物质组分演变与热重实验分析

Mineral components evolution and thermogravimetric analysis of municipal sludge ash

中文关键词: 城市污水污泥  灰分  灰化温度  热重

英文关键词: Municipal sludge  Ash content  Ash temperature  Thermogravimetic analysis

中文摘要:

      运用XRD、EDX以及TGA等实验方法对大连不同污水处理厂不同灰化温度下的污泥灰分进行分析。研究表明在实验温度范围内，灰分中矿物质组分变化较大，温度较低时灰分中矿物质以方解石、石英以及焦磷酸盐为主，另外存在硅线石，磁铁矿和赤铁矿等。随灰化温度的升高，除石英稳定外，灰分中长石类、硬石膏以及磷酸正盐和磷酸铝钙、磷酸铁钙成为主要成分。由于灰分中碱性氧化物较多，温度超过900 °C出现了部分熔融现象。TGA实验表明同一种物质不同温度的灰分失重明显不同，灰化温度越高，失重越小。不同灰化温度下灰分反映出污泥在焚烧过程中反应进程，随受热温度升高，都出现了矿物质失去吸附水，矿物质析出结晶水，污泥中有机物燃烧，方解石分解，以及随后的硬石膏分解等失重阶段。

英文摘要:

      Four kinds of municipal sludge ash were studied by energy dispersive X-ray spectroscopy (EDX)，X-ray diffractometer (XRD) and thermogravimetric analysis (TGA) methods. The result showed that the mineral components in ashes varied significantly in the range of experiment temperature. Calcite, quartz, and pyrophosphate were mainly present in the ashes with lower temperature, in addition to sillimanite, magnetite, hematite, etc. With the temperature increase, feldspathic, anhydrite and phosphate, stanfieldite as well as quartz became the main components. Due to the high proportion of alkaline oxide, partial melting phenomenon occurred when the temperature exceeding 900 °C. TGA experiment showed that the weightlessness of the same sludge in different temperature ash was different. The higher temperature ash had, the smaller weightlessness was. Different sludge ash temperatures reflected the reaction progress through combustion. With the temperature increase, four kinds of sludge follow the stages of loss of the adsorbed water, dehydroxylation of mineral crystal, residual organics combustion, calcite and dolomite decomposition and volatilization of SO2 weightlessness.