钠盐球磨协同活化铜尾矿及胶凝水化性能研究

Study on the synergistic activation and cementing and hydration properties of copper tailings by sodium salt ball milling

为提高铜尾矿活性,制备全尾矿胶凝材料,本文进行了机械球磨、无水Na_(2)CO_(3)、Na_(2)SO_(4)与铜尾矿共磨提高铜尾矿反应活性实验研究。通过调整钠盐掺量、球磨时间,分析了机械化学球磨过程中粒度分布和矿物相变化;采用球磨活化铜尾矿胶凝材料28 d抗压强度表征活化效果,利用XRD、TG-DTG、FT-IR、SEM-EDS等表征方法,阐明了铜尾矿水化反应机理。研究结果表明:在Na_(2)CO_(3)、Na_(2)SO_(4)掺量分别为50%、25%,球磨时间分别为40 min、60 min时,铜尾矿活性激发效果最佳;进行钠盐球磨后,铜尾矿粒径减小,颗粒均质化,石英、白云母、叶绿石、钙硅氧化物等主要结晶矿物非晶化,钠盐球磨活性铜尾矿基胶凝材料(CCT样品和SCT样品)28 d抗压强度分别达到了55.4 MPa、30.7 MPa,相比机械球磨铜尾矿(CT),抗压强度分别提高了13倍、7倍;钠盐的掺加对铜尾矿水化反应产物种类无影响,活性铜尾矿经水化反应主要生成C—S—H凝胶、N—A—S—H凝胶及短棒状钙矾石等水化产物,使活性铜尾矿基胶凝材料显示出良好的力学性能。

In order to improve the activity of copper tailings and prepare the gel material of whole tailings,the mechanical ball mill,anhydrous Na_(2)CO_(3),Na_(2)SO_(4)and copper tailings improved the reactivity of copper tailings.By adjusting the amount of sodium salt and milling time,the particle size distribution and mineral phase change during mechanochemical milling are analyzed.The 28 days compressive strength of the ball milling activated copper tailings cementitious material is used to characterize the activation effect.The hydration reaction mechanism of copper tailings is clarified by XRD,TG-DTG,FT-IR,SEM-EDS and other characterization methods.The research results show that the activation effect of copper tailings is the best when the content of Na_(2)CO_(3)and Na_(2)SO_(4)is 50%and 25%respectively,and the milling time is 40 min and 60 min respectively.After sodium salt ball milling,the particle size of copper tailings is reduced,the particles are homogenized,and the main crystalline minerals such as quartz,muscovite,phyllite,calcium silicon oxide are amorphous.The 28 days compressive strength of sodium salt ball milling activated copper tail-based cementitious material(CCT and SCT)reaches 55.4 MPa and 30.7 MPa,respectively.Compared with mechanical ball milling copper tailings(CT),the compressive strength is increased by 13 times and 7 times respectively.The addition of sodium salt has no effect on the type of copper tailings hydration reaction products.The active copper tailings mainly generate C—S—H gel,N—A—S—H gel,short rod ettringite and other hydration products through hydration reaction,so that the active copper tailings based cementitious material show good mechanical properties.