Plasma-driven Zinc Fuming from Industrial Process Residue
A very hot plasma gas is bubbled through a bath with molten fayalite slag to recover the zinc and lead of the slag via “deep fuming”, leading to a pure fayalite slag that can be further valorised as a building material. Plasma gas submerged in the liquid bath is studied to find the effect of plasma on the thermodynamics and kinetics of metal-fuming processes. The reaction rates and equilibria for the zinc-fuming reaction in a plasma reactor are investigated. This model is then validated in the world’s first large-scale operational plasma fumer. Process parameters are determined to achieve metal extraction at the lowest economic and ecological cost.