富含有机质淤泥对保温粘土烧结砖导热系数的影响研究

Effect of Organic Abundant Sediments on Thermal Conductivity of Insulating Fired Clay Brick

以城市河道淤泥为主要原料,替代部分粘土,烧结制备了轻质保温粘土烧结砖,重点研究了环境温度、烧成温度、淤泥掺量对烧结砖导热系数的影响。结果表明:随着环境温度升高,烧结砖导热系数缓慢增长,增长速率在10-3数量级;随着烧成温度增加,导热系数先增大后减小;随着淤泥掺量增加,导热系数逐渐减小。从烧结砖矿物成分、孔隙率、孔隙结构特征三方面对导热系数变化机理进行了初步解释。掺入50%淤泥,烧结砖导热系数下降约41.5%,与一般有机成孔剂相比,城市河道淤泥具有较好的成孔效果。

Lightweight insulating fired clay brick was prepared by using urban river sediments as a primary raw material.The effects of environmental temperature,firing temperature,and sediments content on the thermal conductivity of the fired bricks were investigated.The results show that as the environmental temperature increases,the thermal conductivity of the fired brick increases slowly,and the growth rate is on the order of 10-3.As the firing temperature increases,the thermal conductivity increases first and then decreases.As the sediments content increases,the thermal conductivity decreases gradually.From the three aspects of mineral composition,porosity and pore structure characteristics of fired bricks,the mechanism of the change of thermal conductivity was preliminarily explained.When 50%sediments is added,the thermal conductivity of fired bricks decreases by 41.5%.Compared with general organic pore-forming agents,urban river sediments have a considerable pore-forming effect.