Study on the thixotropic characteristics of the unclassified-tailing mortar in different shear modes

In order to explore the thixotropic characteristics of the cementing filling slurry with tailings, the rheological parameters of an unclassified-tailing are tested under the conditions of constant shear mode, annular shear mode and terraced shear mode.The results show that the shear stress and apparent viscosity in a constant shear mode decrease gradually with the increase of time until they tend to be stable, while the yield stress of slurry increases gradually with the increase of shear rate and the plastic viscosity decreases gradually.In cyclic shear mode, no matter the shear rate increases or decreases, the shear stress generally presents a downward trend, while the change of apparent viscosity is opposite to the change of shear rate.In the step shear mode, with the sudden increase of shear rate, the tailings slurry will enter the elastic change stage again, and the shear stress and apparent viscosity will increase slightly, and then enter the stress relaxation stage, the shear stress and apparent viscosity will gradually decrease.The thixotropic law of tailing slurry are explained, which is of certain guiding significance to the field pipeline transportation of mine.