通过将市政污泥与煤混配制成污泥煤浆,可利用气流床气化技术实现污泥资源化、无害化、减量化处置。目前,有关市政污泥对气化煤灰黏温特性影响与机理研究较少,限制了污泥煤浆在气化领域的应用。选用一种典型气化用煤煤灰(YLA),配入不同比例市政污泥灰(SSA)以模拟污泥与煤共气化灰,测定原料灰样与混合灰样的灰熔融性与黏温特性。利用XRD分析与相图理论,研究熔渣降温过程中结晶趋势,并利用FTIR表征熔渣硅氧单元结构分布,阐明市政污泥灰含量对熔渣黏度的影响机理。结果表明:最理想的SSA添加比例为10%,且SSA质量分数超过30%会导致样品排渣性能急剧降低。SSA质量分数为10%时,流动温度已较低,且具有168℃可操作温度范围。SSA质量分数超过30%后,因灰中铁、磷含量显著增加,流动温度上升,可操作温度范围收窄,且因结晶趋势增强,临界黏度温度接近操作温度下限,易造成熔渣黏度剧烈变化。FTIR分析及峰值拟合结果表明,硅氧结构聚合度降低是熔渣黏度随SSA含量增加而不断降低的主要原因。

By blending municipal sewage sludge with coal to prepare sludge slurry, it is expected to achieve resourceful, harmless, and re⁃ducing disposal of sludge by using entrained-flow gasification technology. At present, there are few studies on the influence and mecha⁃nism of municipal sludge on the viscosity-temperature characteristics of gasification coal ash, which limits the application of sludge-coalwater slurry in gasification. Ash of typical coal (YLA) for gasification was selected and mixed with different proportions of sewage sludgeash (SSA) to simulate the co-gasification ash of sludge and coal, and the ash fusion temperatures and viscosity-temperature curves of theraw and mixed ash samples were measured. XRD analysis and phase diagram theory were used to investigate the variation of crystallizationtendency in slag during the cooling process, and FTIR was used to characterize the structural distribution of slag silica-oxygen units and toelucidate the mechanism by which municipal sludge ash content changed slag viscosity. The results show that 10% is the ideal SSA addi⁃tion ratio and the slag discharge performance will be deteriorated if SSA content is above 30%. When SSA content is 10%, the flow tem⁃perature is sufficiently reduced and has an operable temperature range of 168 ℃ . When the SSA content exceeds 30%, the flow tempera⁃ture increases due to the significant increase in iron and phosphorus content in the ash, and the operable temperature range is narrowed.And the critical viscosity temperature is close to the lower limit of the operating temperature due to the increased crystallization tendency,which easily causes drastic changes in slag viscosity. FTIR analysis and peak fitting results show that the reduced polymerization of the sili⁃ca-oxygen structure is the main reason for the decreasing viscosity of the slag with increasing SSA content.

0 引言

1 试验

   1.1 试验样品

   1.2 灰熔融温度测定

   1.3 黏温特性测定

   1.4 激冷渣制备与分析

   1.5 热力学平衡计算

2 结果与讨论

   2.1 样品灰熔融温度及矿相组成

   2.2 污泥灰含量对灰渣黏温特性的影响

   2.3 污泥灰含量对熔渣结晶趋势的影响

   2.4 污泥灰含量对熔渣网络结构的影响

3 结论