基于响应面法的碳酸钠活化铜尾矿胶凝性能机制研究

为了有效激发铜尾矿活性制备性能良好的胶凝材料,以铜尾矿为主要原材料,水玻璃和NaOH为碱激发剂,采用响应面优化法开展胶凝材料配比优化实验,并通过方差分析以及三维曲图研究自变量及其交互作用对28d抗压强度的影响；利用XRD、SEM、FT-IR、TG-DTG等对试样的矿相成分、微观形貌等特征进行分析。结果表明：通过优化实验获得最优配比为碳酸钠掺量50%、氢氧化钠掺量1%、水玻璃掺量22g/100g,此参数下铜尾矿胶凝材料28d抗压强度为30.41MPa。经过机械球磨40min后,碳酸钠在适当的碱性环境下使铜尾矿的活性激发到较佳状态,铜尾矿经水化反应生成了大量结晶度较高的C-S-H凝胶与棱柱状钙钒石等水化产物,彼此相互连接构成网状结构,使胶凝材料保持较高的强度性能。

Study on the mechanism of gelling performance of sodium carbonate-activated copper tailings based on response surface method

In order to effectively stimulate the activity of copper tailings to prepare cementitious materials with good performance, copper tailings were used as the main raw materials, water glass and NaOH were used as alkali initiators, and the response surface optimization method was used to carry out the optimization experiment of cementitious material ratio, and the influence of independent variables and their interaction on the compressive strength of 28d was studied by analysis of variance and three-dimensional curved plot. XRD, SEM, FT-IR, TG-DTG, etc. were used to analyze the mineral composition, micromorphology and other characteristics of the sample. The results show that the optimal ratio obtained by optimization experiment is 50% sodium carbonate content, 1% sodium hydroxide content and 22g/100g water glass content, and the compressive strength of copper tailings cementitious material in 28d is 30.41MPa. After 40min of mechanical ball milling, sodium carbonate excites the activity of copper tailings to a better state under an appropriate alkaline environment, and a large number of C-S-H gels with high crystallinity and prismatic calcium vanadium and other hydration products are generated by hydration of copper tailings, which are connected with each other to form a network structure, so that the cementitious material maintains high strength performance.