工程渣土烧制轻质陶粒的实验研究

Experimental study on the preparation of lightweight ceramsite with engineering muck

以宁波工程渣土为原料烧制轻质陶粒,研究结果表明,工程渣土在预烧温度为420℃、预烧时间为15 min、焙烧温度为1260℃、焙烧时间为50 min条件下可制得表观密度为1.23 g/cm^(3)、24 h吸水率为1.82%、单颗粒抗压强度为5.6 MPa的高性能陶粒。陶粒内部结构疏松多孔,外部结构致密,具有较低的表观密度,同时吸水率较低、强度较高。通过TG-DSC分析、高温显微镜分析、XRD分析发现,影响工程渣土陶粒性能的主要因素是焙烧温度及焙烧时间,这主要是由于二者对陶粒的热膨胀行为有较明显的影响。不同焙烧制度下陶粒晶相变化主要为石英与莫来石之间的转化。预烧阶段对陶粒性能的影响不大。

Lightweight ceramsite was prepared by Ningbo engineering muck as the raw material. The results show that the high performance ceramisite was prepared with appropriate sintering process(calcination temperature 1260 ℃,calcination time 50 min,baking temperature 420 ℃,baking time 15 min). The ceramsite’s properties were as following:apparent density of 1.23 g/cm^(3),the 24 h water absorption rate of 1.82%,and the single particle strength of 5.6 MPa. The performance of low water absorption and apparent density,high strength is achieved by the porous internal structure and dense external structure of the ceramsite. The TG/DSC,high temperature microscope and XRD analysis results show that the main factors affecting the engineering muck ceramsite are the temperature and time of calcination,which is due to their significant effect on the thermal expansion behavior of ceramsite.The transformation between quartz and aluminum silicate is the main change of the ceramsite crystal phase of different sintering process. The pre-firing stage has little effect on the ceramsite performance.