Research Of Cyclonic Mineralization Features Based On High-speed Dynamic Microscopic Test

The microscopic mechanism research of the cyclonic mineralization is basically based on qualitative theory, because the cyclonic flow field is complex and variable, which leads to the difficulty of observing the microscopic process. The research of the motion features of a single bubble and particle in the cyclonic flow field is meaningful to analyze the characteristics of cyclonic mineralization.The high-speed dynamic microscopic test system is composed of a cyclonic flotation experimental platform and two high-speed dynamic cameras placed vertically, which is used to take the motion process shootings of a single bubble and particle. With the ProAnalyst software, three dimensional coordinate system of flotation column is defined. Three-dimensional coordinates have been obtained after the respective trace of videos from two high-speed dynamic cameras, in order to research the motion features of a single bubble and particle and the bubble-particle interaction in the cyclonic flow field.With the research of the motion features of a single bubble and particle in the cyclonic flow field, stable three-dimensional traces of a single bubble and particle under different conditions have been obtained. The results show that: The bubbles are close to the central axis of the column, whereas the particles are close to the inside wall when moving. With increasing of the circular-flow, the axial velocity of a single bubble decreases, whereas the total velocity and the maximum radius of a single bubble both increase. With increasing of the bubble diameter, the axial velocity and the total velocity of a single bubble both decrease, whereas the maximum radius of a single bubble increases. With increasing of the circular-flow and decreasing of the particle diameter and density,the maximum axial height,axial velocity and the residence time of a single particle all increase.Based on the motion features of a single bubble and particle in the cyclonic flow field of flotation column, bubble mineralization features are mainly analyzed in the view of particle residence time. The results show that: The cyclonic flow field of large circular-flow, the particle of small diameter and low density, and the bubble of small diameter contribute to bubble-particle mineralization under the cyclonic flow field. Adding the sieve plate to the upper part of cone section of the flotation column, disperse the bubbles on the cross section of the flotation column from the central axis to the inside wall, and increases the probability of bubble mineralization greatly.The collision and adhesion process between a bubble and a particle in the cyclonic flotation is recorded by the high-speed dynamic microscopic test system, and the bubble mineralization process can be observed visually. The results show that: When approaching the bubble, the solid particle tends to move as how the bubble moves, then breakthroughs of hydration shell of the bubble, finally collides with and adheres to the bubble. The bubble and particle, which mineralize when testing, moves in the similar direction, meets and finally collides tangentially, which is the shearing mineralization. After adhering to the bubble, the solid particle moves on the surface of bubble, to seek for the real end of the bubble for stability.