铜尾矿粉对复合胶凝体系强度和微结构的影响

Influence of Copper Tailing Powder on the Compressive Strength and Microscopic Structure of Complex Binder

为阐明铜尾矿粉在水泥铜尾矿粉复合胶凝体系中的作用机理,制备了铜尾矿粉掺量分别为15%,30%和45%的水泥铜尾矿粉净浆试样,并采用抗压强度活性指数和水化活性贡献率等指标,定量分析了铜尾矿粉研磨时间和养护温度等活性激发方式对净浆试样抗压强度的影响;用X射线衍射(XRD)和扫描电镜(SEM)观察了净浆试样水化产物的微观结构.结果表明:常温养护条件下,增加铜尾矿粉掺量将降低净浆试样的抗压强度,但对其后期强度增长有利;当铜尾矿粉掺量为45%时,铜尾矿粉的水化活性很低,浆体中存在大量孔隙;铜尾矿粉在水泥浆体中没有形成新的晶相,直到28 d龄期时铜尾矿粉的活性才被激发;增加研磨时间可显著提高铜尾矿粉的水化活性;在增加养护温度的同时增加铜尾矿粉的研磨时间,可进一步提高净浆试样的抗压强度,但对其后期强度增长不利.

In order to investigate the action mechanisms of copper tailing powder in the complex binders pastes,the samples of complex binder with copper tailing powder content up to 15%,30%and 45%were prepared.Influence of different grinding time and curing temperature of copper tailing powder on the compressive strength of complex binder paste were investigated by compressive strength activity index and hydration activity contribution rate.The hydrated product of complex binders pastes were studied by using XRD and SEM.The results show that the compressive strength of complex binder paste decreases with the increasing copper tailing powder content,but the later strength will increase.The hydration activity of copper tailing powder is very low when the content is 45%,and there are many pores in the slurry.Copper tailings do not form new crystal phase in cement slurry until 28 d when the activity of copper tailings is activated.The complex binders pastes strength will increase and the later strength growth rate will decrease when the curing temperature and grinding time increased.