铁尾矿制备轻质骨料的实验研究

Experimental study on preparation of lightweight aggregate from iron tailings

为了提高铁尾矿的利用率,以硅酸盐水泥和Ca(OH)_(2)为粘结剂,通过冷粘结造粒技术制备轻质骨料,并借助X射线衍射仪(XRD)和扫描电子显微镜(SEM)等手段,研究了粘结剂对铁尾矿轻质骨料物理性能和物相结构的影响。结果表明,随着水泥含量的增加,骨料的堆积密度和吸水率降低,筒压强度增加。随着Ca(OH)_(2)含量的增加,骨料的强度和吸水率增加,堆积密度降低。当水泥含量为15%和Ca(OH)_(2)含量为9%时,养护28 d后的堆积密度达到最小,分别为848.3和860.5 kg/m^(3),筒压强度达到最大,分别为6.2和5.6 MPa,吸水率最大,分别为9.4%和9.6%。

In order to improve the utilization rate of iron tailings,Portland cement and Ca(OH)_(2) were used as binders to prepare lightweight aggregates by cold-bonding granulation technology.X-ray diffractometer(XRD)and scanning electron The effect of binder on the physical properties and phase structure of iron tailings prepare lightweight aggregates was studied by means of microscopy(SEM).The results showed that with the increase of cement content,the bulk density and water absorption of aggregate decreased,and the cylinder compressive strength increased.With the increase of Ca(OH)_(2) content,the strength and water absorption of the aggregates increase,and the bulk density decreases.This is due to the pozzolanic reaction of the iron tailings particles,resulting in an increase of C-S-H gel and ettringite,and the cohesion of the tailings particles.and pores increase.When the cement content is 15% and the Ca(OH)_(2) content is 9%,the bulk density after curing for 28 days reaches the minimum,which are 848.3 and 860.5 kg/m^(3) respectively,and the cylinder compressive strength reaches the maximum,which are 6.2 and 5.6 MPa respectively,the water absorption rate is the largest,9.4%and 9.6%respectively.