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 3d and 7d, 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.