利用低活性钒尾矿制备地聚合物的研究

Research on Utilizing Low-reactive Vanadium Tailing as Source Material for Geopolymer Synthesis

以钒尾矿为主要硅铝原料制备地聚合物,以实现二次资源回收利用的目的。首先对原钒尾矿进行预处理,以提高其活性;再将预处理后的钒尾矿与碱激发剂溶液、铝酸钠混合,通过压制成型工艺制得地聚合物样品。实验结果表明:使用KOH与活性硅胶粉复合作为碱激发剂时,样品3 d后抗压强度最高,即为36.2 MPa;XRD和SEM分析表明:通过预处理,钒尾矿中主要结晶相石英被分解,而且其颗粒变小、粒度分布更均匀,其活性得以提高;通过FTIR和SEM对具有代表性的地聚合物样品分析表明:在由钒尾矿生成地聚合物的过程中,发生了对地聚合物强度性能起重要作用的结构转变。

In order to realize the recycling of the secondary resources,this paper presents the investigation of utilizing vanadium tailing as the main Si-Al source material for geopolymer synthesis.Firstly,the as-received vanadium tailing was pre-processed,so as to enhance its reactivity.Then the pre-processed vanadium tailing was blended with alkaline activator solution and sodium aluminate.Geopolymer samples were prepared by compressed-casting technology.As the results showed,the highest 3-day compressive strength of 36.2MPa could be obtained when using the mixture of KOH and active silica powder as alkaline activator.XRD and SEM analysis of vanadium tailing indicated that,by means of pre-processing,the main crystalline phase in vanadium tailing viz.,quartz was decomposed,and the grain size of vanadium tailing became smaller and more homogeneous,suggesting that the reactivity of vanadium tailing was enhanced;FTIR and SEM analysis of the representative geopolymer sample revealed that the structure conversion of vanadium tailing to geopolymeric product which significantly affected the strength of geopolymer had taken place.