Decomposition of Packaging Materials and Recycling GaAs from Waste ICs by Hydrothermal Treatment

Integrated circuits (ICs) are widely used in all the electrical and electronic equipment, and the recycling technology of ICs has been poorly developed. This study proposes a promising process to decompose packaging materials and recycle GaAs from waste ICs via hydrothermal technology. Critical influencing factors were investigated, such as reaction temperature, holding time, rotating speed, and H₂O₂ adding amount. The results indicated that packaging materials of waste ICs were effectively decomposed by hydrothermal treatment, and the mechanism was possibly free radical reaction. After hydrothermal treatment, GaAs was easily liberated and recovered by physical disaggregation methods. The recovery efficiencies of gallium and arsenic were 99.76% and 79.27%, respectively, and the removal ratio of packaging materials reached 95.44% under optimal parameters of 275 °C, 120 min, 300 r/min, H₂O₂ 15 mL. In addition, copper and silica powder in waste ICs were also recycled availably. Recovery efficiency of copper was above 98.5%, the purity could reach 95.18%, and the recycled silica powder has potential as an inorganic filler. This work provides an efficient and environmentally friendly process for recycling GaAs from waste ICs, which is significant for resource regeneration and environmental conservation.