Variant Study of Dry Beneficiation Methods for PV Module Cell Fractions

The global demand for clean energy has increased the installation of solar Photovoltaic (PV), both for domestic and industrial use. With a limited lifespan of 20-30 years, PV waste generation is expected to raise environmental concerns in the absence of an end-of-life (EOL) management framework. Several countries opt for illegal exports due to low accumulation of PV waste, as the current thermal process is energy-intensive and the hydrometallurgical approach produces process effluents that need further treatment. This study investigates the development of a low-cost, energy-efficient, and simplified multi-stage dry beneficiation process for recovering silicon and precious metals from EOL crystalline silicon (c-Si) PV modules. The methodology combined size-control grinding and electrostatic separation using a Hamos Corona drum Separator (CDS). The rod mill was designed for surface abrasion of glass at 69 rpm, 400 revolutions, and 2/25mm feed size, secondary milling operation with a hammer mill at 1800 rpm and 10 mm grate and the electrostatic separation experiments were conducted using a 2^3 full-factorial design with applied voltage, drum speed, and electrode splitter position as the operating factors across 0.1/0.71 mm and 0.71/1.6 mm size classes. The size classification evaluates the best approach for processing the silicon-rich fines fraction and the coarser, metallic-rich fraction. To measure the separation efficiency of the combined operating parameters, each sample was subjected to dense medium separation and XRF analysis. The optimal operating condition for the 0.1/0.71 mm fraction was 30 kV, 58 rpm, and a 70° electrode splitter position, with over 80% recovery across the glass, silicon, and metallic fractions (Cu, Zn, and Ag), with a grade of about 53 % silicon. In contrast, the performance in the upper size class indicated the need for a separate electrostatic separation setup for optimization. This study highlights the adoption of properly integrated size-control comminution and electrostatic separation as an effective recycling approach for c-Si PV waste.