How to control the pulp concentration of thickener underflow

It is required to measure and control its instantaneous concentration, rather than the average concentration in a certain period of time, so that its underflow concentration changes within a set range. Ensure that the thickener can run stably for a long time without harrowing. The particle size of positive flotation pulp is very fine, and the surface electronegativity is strong, which leads to large electrostatic repulsion between particles and difficult pulp treatment. It is necessary to neutralize the surface of pulp particles with electricity. The selection of treatment agent for tailings sedimentation and dehydration was studied, and a new process of electric neutralization and adsorption bridging was adopted to treat bauxite tailings sedimentation and dehydration. The test shows that this process can reduce the overflow plankton to below 1g/l, and greatly increase the underflow concentration of tailings thickener. The results showed that the best dosing schemes were W 1+P3, W3+P3 and W 15+P3, among which W 15+P3 was the best. The initial concentration of pulp should not be too high, and it is better to control it below 12%. In water treatment, the PH value of tailings slurry should be adjusted to 6.7 ~ 7.7 by adding electric neutralizer first, and then adding adsorption bridging agent to ensure the settlement effect. The tailings settling equipment was studied, and the tailings dewatering process of deep cone high-efficiency settling tank without driving and maintenance was adopted to further settle and dewater the tailings slurry of positive flotation of soil ore. The test shows that the concentration of tailings slurry can be increased to 45 ~ 50% by this process, and the overflow floater is less than1g/L. All the overflow water is returned to the production process for mineral processing and Bayer washing, and there is no obvious harmful effect. At the same time, the labor intensity of workers is low, and the workload of maintenance is very small. Through the industrial operation of the new technology of dewatering tailings by direct flotation of soil ore, the operating conditions are gradually improved and the process indexes are continuously optimized, thus realizing the full utilization of tailings water. The improvement measures of technology and equipment are put forward: improving the conveying capacity of tailings pump; Improve the configuration and adding method of flocculant; Select high-precision mud layer detection and control equipment.