某高铝型铁尾矿低碳免烧砖的制备及性能研究

Preparation and performance research of low-carbon and non-fired brick with a high alumina iron tailings

为了解决铁尾矿堆存带来的环境压力,实现资源综合利用,以河北省张家口市某高铝型铁尾矿和水泥为原材料,通过压制成型的方式制备了一种低碳免烧砖。测量了铁尾矿免烧砖的抗压、抗折强度及密度,探究了水泥掺量和铁尾矿颗粒级配对该免烧砖性能的影响,并通过X射线衍射分析(XRD)、傅里叶红外光谱(FTIR)以及扫描电子显微镜(SEM)等手段探究了铁尾矿免烧砖的微观机理,结果表明:铁尾矿免烧砖的强度随着水泥掺量的增加而增大,铁尾矿颗粒级配会对铁尾矿免烧砖的强度产生显著影响;通过微观表征手段揭示了水泥掺量影响铁尾矿免烧砖强度的内在机理,即水泥掺量增加,水泥水化产物增多,铁尾矿免烧砖的孔隙被填充,增强了铁尾矿颗粒之间的胶结能力,从而提高了免烧砖强度。本研究成果可为类似铁尾矿资源化利用提供借鉴。

In order to solve the environmental pressure caused by the storage of iron tailings and achieve comprehensive resource utilization,a low-carbon unburned brick was prepared by pressing and molding a high alumina iron tailings and cement from Zhangjiakou city,Hebei province as raw materials.The compressive strength,flexural strength,and density of iron tailings unburned bricks were measured,and the effects of cement content and iron tailings particle size distribution on the performance of unburned bricks were investigated.The micro mechanism of iron tailings unburned bricks was analyzed by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM).The results showed that the strength of iron tailings unburned bricks increased with the increase of cement content,and the particle size distribution of iron tailings had the significant impact on the strength of iron tailings unburned bricks;The inner mechanism of cement content affecting the strength of iron tailings unfired brick was revealed by microscopic characterization,that is,as the cement content increases,the hydration products of cement increase,the pores of iron tailings unburned bricks were filled,and the bonding ability between iron tailings particles was enhanced,thereby improving the strength of unburned bricks.The results of this study can provide reference for the resource utilization of similar iron tailings.