矿渣-石灰混合粉碎过程的机械力化学活化效应

Effect of mechanochemical activation inmixed pulverizing process of slag and lime

为揭示机械力化学效应对矿渣水化活性的影响、提高矿渣水化活性,利用混合粉碎过程对矿渣进行机械力活化,考察化学激发剂种类、掺量及混磨时间对矿渣微观结构及水化活性的影响规律,分析混合粉碎过程中的机械力化学活化效应及其作用机制。结果表明:以氢氧化钙为化学助剂且粉碎时间一定的情况下,随氢氧化钙质量分数的增加,产物矿粉的28 d龄期活性指数先增大后减小,当氢氧化钙质量分数为3%时矿粉的活性指数达到126%,明显优于单独粉碎样品的;当氢氧化钙质量分数一定时,随着混合粉碎过程的延续,矿粉的活性指数呈增大趋势,增大速度先快后慢,并逐渐趋于稳定;微观结构表征,尤其是X射线衍射分析显示,混合物中氢氧化钙质量分数随混合粉碎过程的进行而减小;采用氧化钙取代氢氧化钙作为化学助剂,混合粉碎过程中表现出的机械力化学活化效果比氢氧化钙的明显降低。

In order to explore the contribution of mechanochemical effect to the hydration activity of slag and enhance the activity index of slag,a process of mixed pulverization was carried out to realize the mechanochemical activation of slag-containing powder.The effects of the kind and content of the chemical aid,as well as the processing time,were investigated in details by testing the activity index and microstructural characteristics of slag products,which were subsequently used to analyze and discuss the working mechanism of mechanlchemical activation in the process of mixed pulverization.The results show that once Ca(OH)_(2) is employed as the chemical aid and the pulverizing time is fixed,the 28 d activity index of slag-containing powder is found to increase evidently with the increasing of Ca(OH)_(2) content up to 3%,and thus arrive a maximum activity index of 126%,but further increase of Ca(OH)_(2) content gives rise of a relative low value of the 28 d activity index.The maximum activity index is obtained with a Ca(OH)_(2) content of 3%,which is evidently superior to that of the reference sample.In the cases of a fixed Ca(OH)_(2) content of 3%,the activity index of slag-containing powder behaves a tendency of increasing with the continuous processing of mixed pulverization,although the increasing rate slow down gradually with the time.Microstructural characterization especially X-ray diffraction indicate the expenditure of Ca(OH)_(2) with the processing of the mixed pulverization.As a comparison,the employment of CaO as the chemical aid do not arrive an equivalent effect of mechanochemical activation in the process of mixed pulverization.