利用高硅铁尾矿制备蒸压加气混凝土

Autoclaved aerated concrete prepared with high-silicon iron tailing

利用高硅铁尾矿(HIT)制备高硅铁尾矿蒸压加气混凝土(HIT-AAC),研究了HIT细度、钙硅比对HIT-AAC料浆性能和试块物理力学性能的影响;结合XRD、FTIR和SEM对HIT-AAC进行微观分析。结果表明:随着HIT细度的增大,料浆扩散度、发气速率、发气高度均有所降低,最终发气时间缩短,试块的干密度和抗压强度均有所提高;随着钙硅比的增大,料浆扩散度减小和试块干密度先下降后上升,发气速率和发气高度增加,最终发气时间缩短,抗压强度先提高后降低,当钙硅比为0.65时抗压强度最高,为4.29 MPa。水化产物主要为石英和托贝莫来石,随着钙硅比的增大,托贝莫来石由针棒状结构转为片状结构。

High-silicon iron tailing autoclaved aerated concrete(HIT-AAC)was prepared by using high-silicon iron tailing(HIT),and the influence of HIT fineness and calcium-silicon molar ratio(Ca/Si)on the slurry properties of HIT-AAC and the basic physical and mechanical properties of the products were investigated.Combined with XRD,FTIR and SEM,the microscopic analysis of HIT-AAC products was performed.The tested results showed that with the increase of HIT fineness,the diffusion,gas generation rate and gas generation height of the slurry decrease,and the final gas generation time becomes shorter,while the dry density and compressive strength of products increase.With the increase of the Ca/Si,the diffusion of HIT-AAC slurry and the dry density of the product showed a fluctuating downtrend,the gas generation rate and gas generation height increased,the final gas generation time becames shorter,and the compressive strength showed a trend of first increasing and then decreasing.When the calcium silicon ratio is 0.65,the compressive strength is the highest,which is 4.29 MPa.Microscopic analysis showed that the hydration products were mainly quartz and tobemullite,and the morphology of the hydration products gradually changed from a needle-like structure to a sheet-like structure with the increase of the Ca/Si.