河道底泥陶粒烧制的工艺条件及性能研究

探讨以河道底泥、污水污泥、黏土为原料制作陶粒的最佳烧制工艺条件,利用单因素实验对陶粒性能进行比较分析,利用X射线衍射(XRD)、扫描电子显微镜(SEM)对微观结构进行表征分析。结果表明:以河道底泥烧制陶粒是可行的,预热温度和时间的控制将影响陶粒的轻质化,烧结温度应接近陶粒低共熔点,通过改变烧结时间可获得不同类型陶粒。烧制高强陶粒时,在陶粒体系低共熔点温度环境下延长烧结时间比单纯提高烧结温度更恰当。以预热温度400℃、预热时间20min、烧结温度1175℃、烧结时间25min为烧制条件制作的河道底泥陶粒具有良好的性能,堆积密度为620kg/m3,表观密度为1125kg/m3,筒压强度约为0.7MPa,吸水率达36.27%。

Study on calcination technological condition and characteristics of river sediment ceramsite

The main purpose of this study was to investigate the optimal calcination technique for making ceramsite from river sediment,using sewage sludge and clay as raw materials,the properties of ceramisite were compared by single factor test,and the microstructures were measured by XRD and SEM. The results showed that it was feasible to produce ceramsite with river sediment. Preheating temperature and time could affect the density of ceramsite. The calcination temperature should be close to the eutectic point of the ceramsite. Different types of ceramsite could be obtained by changing the calcination time. When making high- strength ceramsite,it was more appropriate to prolong the calcination time in the eutectic temperature environment of the ceramic system than to increase the calcination temperature. The river sediment ceramsite had good performance under 400 ℃ preheating temperature,20 min preheating time,1175 ℃ calcination temperature and25 min calcination time,bulk density and apparent density were 620 kg/m3and1125 kg/m3,compressive strength was about 0.7 MPa,water absorption rate was 36.27%.