轻质/超轻粉煤灰陶粒的研制及陶粒膨胀机理的探讨和应用

Preparation of ultra-lightweight fly ash ceramic(ULFAC), investigation and application of the bloating mechanism

以煤灰和粘土为原料制备轻质/超轻粉煤灰陶粒;从原料化学成分的角度推理膨胀过程并推导出可以用于指导实际生产的成分比例。首先对两种原料进行化学成分分析(EDX)和热分析(DSC/TGA);之后对原料进行配比烧制试验,得到不同原料和配比所生产粉煤灰陶粒的物理性质;最后对产品进行微观结构分析(SEM)和矿物组成分析(XRD)。实验结果表明,粉煤灰中含有的成气成分和粘土中含有的助熔成分是引起粉煤灰陶粒高温膨胀的主要原因。产生膨胀现象的骨架成分∶成气成分∶助熔成分≈78.5∶4.0∶16.5。

Fly ash and clay were used in the preparation of ultra-lightweight fly ash ceramic（ULFAC） with no forming agent added. The chemical components and mineral phases of FA and clay were determined by EDX and XRD, respectively, and the thermal properties of FA were determined by DSC/TGA. Then FA and clay were mixed in different dosages and sintered into ceramic. The physical properties and microstructure properties were determined, respectively. The results shows that clay was not suitable for the preparation of ultra lightweight or lightweight ceramic with nothing added, but when the addition of FA was 10%-20%, it was suitable for the preparation of ultra lightweight ceramic. The SEM images indicate the ULFAC are porous. Abundance of Fe2O3 in FA and base metal in clay is the reason for the bloating properties of ULFAC. The bloating properties of ceramic happened when the glassy phases∶ gaseous components ∶flux was ≈78. 5∶4. 0∶16. 5.