Particle collection and heavy metals migration during high-temperature electrostatic precipitation in copper smelting: A pilot-scale study

Recently, large amounts of particulate matter (PM) and heavy metals (HMs) have been generated in the processes of non-ferrous metal smelting (NFMS). High-temperature electrostatic precipitator (HT-ESP) was the key method to capturing PM while extensive HMs enriched. In this work, the PM collection and migration of HMs in the HTESP process of copper smelting were investigated through an established pilot-scale platform. The excellent performance of the pilot-scale HT-ESP could achieve a particle collection efficiency of 99.5 %. The distribution patterns of HMs in various particle sizes revealed that the volatile heavy metals, arsenic (As) and selenium (Se) were predominantly distributed in PM1.0 and PM1-2.5 with a moderately dispersed distribution, whereas copper (Cu) and lead (Pb) were densely concentrated on particles. When the temperature difference between the inlet and the outlet of the HT-ESP narrowed to 23 K, the original As and Se enriched in hopper particles partially volatilized and migrated into the gas phase and adhered to tiny size particles. The enrichment ratio in the gas phase (ERG) of As and Se increased by 2.7 % and 18.5 %, respectively. The results were beneficial to reducing the enrichment of volatile HMs in copper smelting ash and provided guidance for resource utilization of the copper smelting industry.