Comprehensive Performance and Microscopic Hydration Mechanism of Phosphogypsum-Cement Based Composite Filling Material
In order to improve the performance and environmental benefits of mine filling paste,the cemented filling paste was prepared by using phosphogypsum-cement composite gelling agent.The influences of gelling agent ratio and aggregate properties on slump,drying shrinkage,permeability coefficient and strength were analyzed.The microscopic hydration mechanism of filling paste was analyzed.The results show that the phosphogypsum-cement gelling agent has an improved effect on the fluidity,shrinkage and strength of the filling paste.The content of phosphogypsum is an important factor affecting the performance of the paste.When the content of phosphogypsum is 20％,the compressive strength and flexural strength of the filling paste are the highest,the permeability and shrinkage are the lowest,and the durability is the best.A certain proportion of coarse aggregate containing steel slag can increase the strength of phosphogypsum-cement based filling paste.Phosphogypsum has a good chemical activity,which promotes the formation of flocculated gelling products during the reaction process,improves the density of paste at the meso level,and enhances the comprehensive performance of mine filling paste.Using phosphogypsum-cement based filling paste to implement gravity filling mining technology is not only conducive to saving mining costs,but also realizes the resource utilization of phosphogypsum,which has broad application prospects in the construction of green mines.
万方数据
维普
