Influence of acoustic wave on thickening sedimentation of unclassified tailings

The high-concentration filling of unclassified tailings is the main development trend of current back-fill mining. How to accelerate the rapid precipitation and dewatering of fine grains in sand silos to obtain high concentration tailings mortar is the key technology. In order to improve the effect of thickening sedimentation of unclassified tailings slurry(UTS) and reduce the expense of dewatering, the acoustic wave was introduced into the thickening sedimentation experiment of UTS. The effect of acoustic wave on the thickening sedimentation of UTS was explored. The acoustic wave frequency and power were pre-selected by comparing the sound pressure distribution laws between clear water and the UTS. Then, the acoustic wave parameters were optimised by the control variable method. Furthermore, the variation laws of sedimentation velocity and mass fraction of underflow of UTS were analysed under different conditions and their acoustic wave mechanism was discussed. The results show that the sound pressure in UTS is equivalent to 70% of the sound pressure value in clean water at the same point. Thickening sedimentation has the best effect when the acoustic wave frequency is 100 Hz, the power is 8 W, and the application time is 15 min. Compared with free sedimentation and flocculation sedimentation (flocculant unit consumption 20 g/t, flocculant solution concentration 0.2%), the sedimentation velocity is increased by 56.759% and 0.801%, respectively, and the underflow concentration is increased by 2.54% and 6.302%, respectively. Therefore, an acoustic wave is capable of improving the sedimentation velocity and mass fraction of underflow under the condition of a suitable sound field.
The high-concentration filling of unclassified tailings is the main development trend of current back-fill mining. How to accelerate the rapid precipitation and dewatering of fine grains in sand silos to obtain high concentration tailings mortar is the key technology. In order to improve the effect of thickening sedimentation of unclassified tailings slurry(UTS) and reduce the expense of dewatering, the acoustic wave was introduced into the thickening sedimentation experiment of UTS. The effect of acoustic wave on the thickening sedimentation of UTS was explored. The acoustic wave frequency and power were pre-selected by comparing the sound pressure distribution laws between clear water and the UTS. Then, the acoustic wave parameters were optimised by the control variable method. Furthermore, the variation laws of sedimentation velocity and mass fraction of underflow of UTS were analysed under different conditions and their acoustic wave mechanism was discussed. The results show that the sound pressure in UTS is equivalent to 70% of the sound pressure value in clean water at the same point. Thickening sedimentation has the best effect when the acoustic wave frequency is 100 Hz, the power is 8 W, and the application time is 15 min. Compared with free sedimentation and flocculation sedimentation (flocculant unit consumption 20 g/t, flocculant solution concentration 0.2%), the sedimentation velocity is increased by 56.759% and 0.801%, respectively, and the underflow concentration is increased by 2.54% and 6.302%, respectively. Therefore, an acoustic wave is capable of improving the sedimentation velocity and mass fraction of underflow under the condition of a suitable sound field.