关键词: 尾砂充填, 正交试验, 抗压强度

Abstract: Taking the total tailings of a metal mine in China as the base material, 16 groups of speci⁃ mens were prepared by selecting the cement-sand ratio, slurry concentration and curing age as the main factors, and each factor had 4 levels. The orthogonal test was carried out to determine the uniaxial compres⁃ sive strength and reveal the influence of various factors on the strength. The results show that each factor of the test on the compressive strength of the filling body follows the order of influence is curing age > ce⁃ ment-sand ratio > slurry concentration, in which cement-sand ratio plays a decisive role in the ultimate strength of specimens. At a fixed concentration and age, the greater the cement-sand ratio, the more obvi⁃ ous the strength increase ; prolonging the age or increasing the slurry concentration also contributes to strength growth. The optimal ratio selected by the orthogonal test is the slurry concentration of 74%, the ce⁃ ment-sand ratio of 1:4, the age of 28 d, and the corresponding compressive strength of 2.697 MPa, which is the maximum value of all combinations. It should be noted that the high cement-sand ratio will increase the cost of materials, the increase of concentration will generally deteriorate the fluidity, and the energy con⁃ sumption of transportation will increase. The economy should be further weighed in the construction of fill⁃ ing system.

Key words: tailings backfilling, orthogonal testing, comprehensive strength