铁尾矿烧结多孔保温材料气孔形成的机理研究

Study on bubble formation mechanism for thermal insulation porous materials of iron tailings

介绍以铁尾矿为主要原料，添加发泡剂和粘结剂，烧结制备高孔隙率保温材料的工艺。该材料可通过控制发泡剂的加入量和烧成温度来调节多孔保温材料的体积密度和孔径大小。X射线衍射分析材料相结构及扫描电镜观测微观结构的结果表明，该保温材料的主相为非晶相，材料的孔径大小及分布均匀。通过实验，对不同烧成温度下的材料研究分析其气孔形成机理，气孔的形成过程包括液相生成、气孔形成、气孔长大和气孔上浮4个过程；气孔形成的重要工艺参数为烧成温度在1000～1200℃，在发泡温度附近温度升降速率必须缓慢，以2～5℃／min为宜。

In this paper, the sintering process of high porous insulation material was introduced,taking iron-tailings as the main raw material and the foaming agent and binding agent as additives. Both the volume density and the hole diameter of the porous insulation material could be changed by adjusting the amount of the foaming agent and the sintering temperature. The anal- ysis results of X-ray diffraction and scanning electron microscope indicated that the main phase of this insulation material was amorphous phase,and the holes were evenly distributed with uniform diameter. The formation mechanism of porous was obtained from the research and analysis of samples of this material under different temperature. The bubble formation process consists of four stages,including liquid phase formation, bubble formation,bubble growth and bubble rising. The important process parameter of the bubble formation is the sintering temperature,which is 1000-1200 ℃. The temperature increase or decrease speed near the foaming temperature should be slow, preferred at the rate of 2-5 ℃/min.