(General session) Mineral processing / Environment / Recycling

[2K0401-14-06] [Student presentation: Master’s course] Investigation of the shape effect of the agitator in attritor on selective grinding of silicon-based photovoltaic panel

○Chenzuo Ye¹, Yutaro Takaya^2,3, Yuki Tsunazawa⁴, Kazuhiro Mochidzuki^2,5, Chiharu Tokoro^2,3 (1. Graduate School of Waseda University, 2. Waseda University, 3. The University of Tokyo, 4. National Institute of Advanced Industrial Science and Technology, 5. Retoca Laboratory LLC)

司会：古屋仲茂樹（産業技術総合研究所）

Keywords:Photovoltaic panel, Selective grinding, DEM simulation

In recent years, with the popularization of solar energy technology, more and more waste photovoltaic (PV) panels have been produced. To recover available materials, such as silicon, silver, and copper, from silicon-based photovoltaic panels, grinding technology for the liberation should be established. An attritor is one of the grinders having the potential to achieve selective grinding for PV panels. However, few studies have reported on the optimum design and conditions for the attritor. Therefore, we investigated the agitator shape in the attritor from the viewpoint of experiments, kinetic analysis, and simulation to improve grinding efficiency in the attritor. In the experiment, to compare two different agitator shapes, we conduct a series of experiments with the same amount of PV panel and grinding media. After grinding experiments, ground products are sieved, and chemical compositions of each particle size group are analyzed by an X-ray Fluorescence analyzer (XRF). Components containing Si and Ag are easily ground and relatively become small pieces, and this tendency is especially remarkable in the attritor with a sharp agitator. To evaluate the grinding performance in the attritor, experimental data on particle size distribution is used to grinding kinetic constants for each element using kinetic analysis theory. Besides, we apply the discrete element method (DEM) to investigate the influence of the agitator shape. Although the DEM simulation cannot directly simulate the breakage of PV panels, collision energy can be calculated. From the visualization of the grinding media motion in the attritor, comparison of the collision energy, it is demonstrated that the attritor with a sharp agitator has higher grinding efficiency. Therefore, the kinetic analysis and simulation results can support experimental results and contribute to optimizing selective grinding for PV panels.