Effect of Particle Gradation on Properties of Phosphogypsum–based Cement Paste Backfill

Abstract

Particle size of phosphogypsum (PG) is very small and uniform, which is poor in gradation. This feature can affect the quality of cement paste backfill (CPB) and may even lead to incomplete condensation. Given the problems mentioned, the main objective of this paper is to optimize the PG gradation. By mixing PG and quartz sand with different ratios, backfill samples were prepared based on the ideal gradation theory (Fuller grading curve). The results show that the optimization of PG gradation and the increase in the maximum particle size was beneficial to improve the quality of PG-based CPB.