Efficient and safe disposition of arsenic by incorporation in smelting slag through copper flash smelting process

摘要

During copper (Cu) production, the concomitant arsenic (As) is generally dispersed into various As-bearing byproducts which need to be disposed separately. This work presents an integrated disposition method for the hazardous As by returning the As-bearing byproducts to the copper flash smelting process and solidifying As into smelting slag. After recovering the remnant Cu in smelting slag, the tailings slag become the only output of As in Cu production system. The statistics show that under this operation mode the As brought in and out of the copper production system can keep balance. Investigations reveal that the As species in copper slag include Cu-As intermetallics, Cu-As sulfides and the As incorporated in fayalite phase and glassy silicates matrix. The tailings slag produced from slag flotation process exhibits a leaching toxicity lower than the USEPA and SEPA regulatory thresholds. This work indicates the copper flash smelting process is promising for the efficient and safe disposition of As via recirculation processing of As-bearing byproducts.