Feasibilities for silicon recovery from solar cells waste by treatment with nitric acid

Abstract

3 Research Group ‘Waste Resources Management’, Institute of Environmental Technology and Energy Economics, Hamburg University of Technology, 40 Eissendorfer Street, Hamburg, Germany The feasibilities of silicon recovering from solar cell waste (SCW) by treatment with nitric acid at its concentrations of 1, 2, 3 and 4M were investigated. The research results have shown that complete leaching of aluminum from the silicon matrix is not possible. It can be explained by formation of aluminum compounds with oxygen and silicon on the aluminum particles. Total silver leaching is achieved at maximal 4M concentrations of nitric acid. The influence of nitric acid concentrations on the leaching efficiency of these metals is significantly reduced at higher temperatures (up to 50°C). Higher metal leaching efficiency is characteristic of larger SCA particles under more favourable spatial conditions for penetration of nitric acid ions.