Al_2O_3对污泥和河道底泥制取陶粒的性能影响

Effect of Al_2O_3 on Characteristics of Lightweight Aggregates Made from Sewage Sludge and River Sediment

对以污水污泥和河道底泥为主要原料制取轻质陶粒过程中，不同Al2O3含量下陶粒物理性能、抗压强度、表面形态和晶体构成进行分析。结果表明，Al2O3含量为11％～19％时，可制得松散密度和表观密度较高、吸水率较小的陶粒，Al2O3含量过低或过高时，陶粒的抗压强度都有所降低。其中，Al2O3含量为14％时，陶粒表面致密、呈现玻璃化现象且具有较为规则的圆孔。陶粒中主要晶体为石英、钠长石、蓝晶石和赤铁矿，内部以稳定的硅酸盐晶体为主。

During production of lightweight aggregates from sewage sludge and fiver sediment, the effect of Al2O3 content on the characteristics of lightweight aggregates, including physical characteristics, compressive strength, morphological structures and crystalline phases, were investigated. The results showed that lightweight aggregates with high bulk density, high apparent density and lower water absorption could be obtained when the Al2O3 content was between 11% and 19%. When the content of Al203 was too high or too low, the compressive strength of lightweight aggregates decreased. When the Al2O3 content was 14%, the surface of lightweight aggregates was dense, showing vitrification phenomenon and well distributed holes. The main crystals in lightweight aggregates were quartz, albite, kyanite and hematite. Stable silicate crystals were dominant in the interior.