Study on recovery of valuable metals from waste mobile phone PCB particles using liquid-solid fluidization technique

In this paper, an effort was made to separate the valuable metals from waste mobile phone printed circuit board (PCB) particles using liquid-solid fluidization technique. Based on the mechanical liberation characteristics of waste mobile phone PCBs, four closely sieved particles having a granularity, respectively, of 0.075-0.106, 0.106-0.18, 0.18-0.25 and 0.25-0.35 mm were chemically analyzed and charged into the fluidized bed to study the fluidization separation behavior. The minimum fluidization velocities and terminal settling velocities of single components were served as an important tool for the evaluations of the experimental data. The results showed that, in the process configuration, the fluidization separation was effective within each limited range of particle size with proper control on water velocity. When the water velocity was in the appropriate range, higher metal yield and grade could be obtained. The calculated minimum fluidization velocities and terminal settling velocities of waste mobile phone PCB particles were in reasonable agreement with the actual operating water velocities. Additionally, the influence of the porosity of perforated plate distributor and the height of the fluidized bed on the metal grade and yield was also discussed. The application of liquid-solid fluidization technique in beneficiation of waste mobile phone PCB particles is expected to be one of the important developmental directions.