The Influence of Feed Concentration on Thickener in Tailings

The thickener is mainly used for solid-liquid separation, tailwater purification and dry tailings discharge after cyclone classification in the dry tailings discharge process. Compared with the traditional thickener, the high-efficiency thickener mainly increases the processing capacity and improves the underflow concentration. According to the process flow, the underflow concentration control of the thickener is affected by many factors, such as the feedstock slurry flow rate and concentration, which affect the underflow control.

The stable production of the thickener requires a stable underflow slurry flow, and the concentration control is achieved by changing the speed of the underflow variable frequency pump. When the concentration is greater than the set value, the underflow variable frequency pump needs to increase the frequency and increase the speed to reduce the underflow concentration, which will increase the flow rate and cause unstable production; vice versa.

The control of underflow concentration

Underflow concentration control is a relatively slow process. The slurry enters the underflow variable frequency pump from the thickener and passes through a section of the pipeline, where a certain amount of fixed slurry is stored. This causes that when the concentration is greater than a given value in the concentration adjustment process, the pump speed is increased by increasing the pump frequency. However, due to the lag of underflow slurry transportation, it is difficult to achieve the required concentration value, which affects the control effect. The thickener produced by LZZG is equipped with a large number of inclined plates in the middle of the sedimentation zone, which increases the sedimentation area of the thickener and prevents the floating of fine particles, thereby well controlling the underflow concentration and making the underflow concentration higher.

The concentration meter has a certain non-linearity and measurement error when detecting the concentration, which has a certain influence on the concentration control. The variable frequency pump is affected by its own working characteristics. During the adjustment process, the frequency of the pump should not be too low, so as not to cause the underflow pump to be submerged by the slurry. Therefore, new control methods and strategies must be adopted on the basis of conventional control to realize the special requirements for the underflow concentration control of the thickener and realize the safety of underflow concentration.