| Abstrakt: |
Based on the requirements of green, efficient and low-energy separation and recovery of rare and precious metals in E-waste, a gas-solid separation model of E-waste particles was established by using CPFD (Computational Particle Fluid Dynamics) and Barracuda gas-solid coupling simulation analysis software. Due to the poor separation effect of rare and precious metal particles in E-waste caused by primary air flow, the particle mixing degree is high, and the grade and recovery of rare and precious metal particles are low. On the basis of primary air flow, secondary air flow is introduced to realize the secondary gradient separation of E-waste particles in the vertical direction. The migration trajectory and migration law of different particle flows and the separation characteristics of rare and precious metal particles in electronic waste under the action of two airflows were simulated. The separation efficiency of rare and precious metal particles in electronic waste, including grade and recovery, was discussed under two airflow parameters, material falling flow rate and particle size. The results show that the multi-density dry separation model can effectively enrich the rare and precious metal particles in E-waste. The falling flow rate and particle size of E-waste particles have significant effects on the separation of rare and precious metals. When the airflow velocity of the primary air inlet is 3.8 m/s, the airflow velocity of the secondary air inlet is 4.6 m/s, the width of the feed opening is 4 mm, the width of the two airflow openings is 35 mm, and the particle size is 75-100 µm, the grade and recovery of Au can reach 87.1% and 99.1%. The grade of Cu is 70.8%, the recovery is 85.8 %, and the enrichment ratio is 35.4. It shows that under the combined action of primary air flow and secondary air flow, changing the inlet flow of E-waste particles and controlling the particle size of particles can effectively improve the grade and recovery of rare and precious metals in E-waste, and provide reference for multi-density multi-gradient and high-precision dry separation. [ABSTRACT FROM AUTHOR] |
