Recycling of waste cell phones

Abstract

Recycling provides environmental benefits, including energy savings, reduced waste volumes, and reduced emissions associated with energy use. Cell (mobile) phones are widely used throughout much of the world. However, less than one percent of the millions of cell phones retired and discarded annually are recycled. Almost all materials used in cell phone manufacturing - metals, plastics, batteries, and packaging - can be recovered and recycled into new products. This study summarizes recycling technologies for waste cell phones and, as a case study, examines the potential for recovering valuable metals from waste cell phones using acidic leaching. The process steps include dismantling waste mobile phones, preprocessing to separate materials, and directing them to final treatment processes. In the leaching experiments, sulfuric, nitric, and hydrochloric acids were used. In the sulfuric acid leaching experiment, the effects of acid concentration, temperature, peroxide addition, and leaching time on metal dissolution efficiencies were investigated. Leaching efficiencies achieved were 97.9 % Fe in 8 mol H2SO4, 88 % Pb, 100 % Ni, 90.4 % Co, and 4.1 % Cu in 1 mol HNO3 solutions, 100 % Pb, and 100 % Al in 4 mol HCl, all within one hour. Therefore, for effective leaching of all metals, a sequential leaching process using different acids is recommended.