Abstract:Based on the current situation of cemented paste backfill technology and the field operation in a mine, mix proportions of backfill materials including extra-fine tailings, waste rock and cement were performed to investigate the sensitive degree of various factors on the properties of extra-fine paste using orthogonal method. The test results show that mass concentration has a dominant role in the slump of extra-fine tailings paste. For the initial compressive strength of 3 d and 7 d, the sensitive degree of various factors from high to low is mass concentration, cement-tailings ratio, tailings-waste rock ratio, while the corresponding degree is cement-tailings ratio, mass concentration, tailings-waste rock ratio. It was also concluded that the extra-fine tailings paste with the mass concentration of 78%, a tailings-waste ratio of 9︰2 and a cement-tailings ratio of 1︰25 was the optimal mix proportion, which can obtain the requirement of field production and the cost control. The results could provide theoretical basis and technical support for the backfilling technology among the same type mines.