Metal Chloride Reduction using Argon/Hydrogen Plasmas

The production of industrial metals is a crucial, worldwide industry. The current approaches to reducing a metal ore to its metal product typically involve multiple steps, long processing times, and substantial CO₂ emissions. Chlorination is often used as one of the first processing steps for metal ore reduction, and it can also be used to extract valuable metals from slag waste or other mining byproducts. Therefore, the development of a universal process to reduce varying types of metal chlorides may allow us to simplify processes and expand our ability to recover valuable metals from waste. Here, we propose hydrogen-containing plasma as a promising method to achieve this.

A nonthermal inductively coupled argon-hydrogen plasma is used to treat metal chloride powders. We show the ability to reduce several metal chlorides that are traditionally difficult to reduce, including alkali metal chlorides, and to obtain metal products. We propose that the use of hydrogen is key to the process, as it allows for improved reduction kinetics due to the atomic hydrogen and serves to scavenge excess chlorine. This process is easily adaptable to numerous metal chlorides, and it has the potential to improve or replace existing metal processing methods.