Greener reactants, renewable energies and environmental impact mitigation strategies in pyrometallurgical processes: A review | SpringerLink

Plasma torch technologies

Thermal plasma is created from the contact of plasma forming gas between two conducting electrodes. Plasma torches apply this principle to generate a continuous high temperature plasma jet. Plasma torches are advantageous due to their high energy density, maximum temperatures and heat transfer rates.266 From an operational perspective, plasma torches are interesting due to their small installation sizes, rapid start-up and shutdown features and use of electrical energy.219 This technology is associated with waste management applications but has found use in the metallurgical industry. Plasma torches are used in plasma atomization techniques to produce spherical metallic powders intended as feed stock for additive manufacturing notably for titanium.267 Plasma atomization generates powders with sizes of 25–250 μμm and with a higher yield of particles with lower than 45 μμm in diameter than conventional gas atomization.268 An interesting application of plasma torches is the production of sustainable turquoise hydrogen and carbon for use in the metallurgical industry. The electricity consumption of plasma torches is however a potential obstacle.269

Clean energy in electrometallurgy: Replacing chemical reactants by green electrical work is a promising way to eliminate or reduce CO22 emissions related to metal making. The electrowinning of Cu, Ni, Co, Zn, Pb and other precious metals is widely done in an aqueous electrolyte while a molten salt electrolyte is used for reactive metals such as Al, Ca, Mg and Na. New electrochemical technologies are also being explored as an alternative way to extract Al, Fe and other metals.

Inert anodes for Al production