Experimental Study on Dense Settlement of Full-Tail Mortar under Mechanical Vibration

Abstract

There are some problems in the application of slurry preparation technology, such as wide fluctuation range of underflow concentration, long settling time and low efficiency of solid–liquid separation. This is an important basis for researching the thick settling law of tailings slurry under the action of mechanical vibration and its influencing factors to solve these problems. To this end, a small vibration thickening testing machine and vibrating rod were designed and developed. Physical simulation experiments were conducted to analyze the settling characteristics of tailings slurry under different vibration duration, start time, vibration frequency, and vibration inertia single factors. The results show that: (1) Mechanical vibration can effectively accelerate the settling speed of tailings particles, but the relationship between them is a non-positive correlation, and mechanical vibration time control with in 5 mins is the best. With the delay of starting the vibration time, the final mass concentration first increases and then decreases. (2) As the vibration frequency increases, the final mass concentration of tailings settlement first increases and then decreases. When the eccentric vibrator speed is 6000 r/min, the best slurry settlement effect is achieved. (3) When the vibration inertia of the eccentric oscillator is 0.158 g·cm2 and the final mass concentration reaches 70.1%, the settling time only takes 210 min. (4) The lower the slurry concentration, the faster the settling speed. As the initial concentration increases, the final thickening time is also gradually prolonged. The research results provide some insights for the rapid thickening technology of rake-free paste thickeners.