No abstract

Electrostatic separation has been extensively used in mineral processing, and has the potential to separate gangue minerals from raw talcum ore. As for electrostatic separation, the particle charging status is one of important influence factors. To describe the talcum particle charging status in a parallel plate electrostatic separator accurately, this paper proposes a modern images processing method. Based on the actual trajectories obtained from sequence images of particle movement and the analysis of physical forces applied on a charged particle, a numerical model is built, which could calculate the charge-to-mass ratios represented as the charging status of particle and simulate the particle trajectories. The simulated trajectories agree well with the experimental results obtained by images processing. In addition, chemical composition analysis is employed to reveal the relationship between ferrum gangue mineral content and charge-tomass ratios. Research results show that the proposed method is effective for describing the particle charging status in electrostatic separation.

To clarify direct impact characteristics (pressure and position) of middle-grade magnesite fragmentation by pulsed discharge in water, this work uses pressure film to accomplish passive measurement through pulsed discharge experiment and obtain the pressure. The impact position is determined by image analysis of fragmentation product morphology, crack edge and discharge channel. Then, pressure load on magnesite surface is numerically analyzed based on the measured pressure obtained from the film. Results indicate that, at 10 mm discharge gap, the impact pressure increases with the discharge voltage, and the discharge voltage to disintegrate magnesite is −40 kV. The impact position is normally in the boundary among different mineral components. Simulation analysis indicates that, the pressure load applied directly on magnesite surface is approximately 142.5 MPa at −40 kV and greater than the compressive strength of magnesite, thus leading to the fragmentation.

Abstract-In the online-plate electrostatic precipitator(EPs), uses three-dimensional PIV technique and image processing technology to observe the fine particles of flow field under -45KV pulse high pressure, and analyzes the motion state of the particles. Comparing with the traditional 2D-PIV technology, 3D-PIV technology can be more accurate and comprehensive to observe flow velocity vector of fine particles in electrode voltage. Avoiding inaccurate observation due to particles overlap. The experimental results show that the method can provide data support for more accurate description of particle motion behavior, which is great significance to improve the electrostatic precipitator.