Europe’s drive to secure supplies of critical minerals is increasingly turning toward materials already generated by existing mining and metallurgical operations. One such opportunity is being pursued by Metallon Clean Extractions, a subsidiary of Zinc of Ireland, which is developing the ARGO hydrometallurgical process to recover valuable metals from zinc-leach residues.
Recovering Critical Metals From Zinc Residues
The programme has received a €734,000 VLAIO grant as part of a €1.22 million development programme. Zinc of Ireland is contributing approximately €489,000 over 24 months. Development is being conducted with KU Leuven’s SOLVOMET platform, while Nyrstar is participating through feedstock supply and industrial testing.
A pilot stage is targeted for early 2027. ARGO is designed to recover zinc, lead and silver, alongside smaller quantities of gallium, germanium and indium. These minor metals have strategic importance because European domestic supply remains limited, while several are used in semiconductors, optics and advanced industrial applications.
Existing Waste Becomes a Mineral Resource
The feedstock gives the project a different starting point from conventional mining developments. Zinc-leach residue has already passed through mining and part of the processing chain. It is also located at industrial sites that can provide existing infrastructure, potentially avoiding the need to develop a new mine, waste facility and haulage infrastructure.
That could create a different economic and development model from traditional mineral projects. Instead of extracting additional ore, the process seeks to recover additional value from material that has already been generated by the metallurgical industry.
Chemistry Determines Commercial Viability
The principal challenge is processing chemistry. Industrial residues can contain complex combinations of valuable metals and impurities. The commercial performance of the process will therefore depend on factors including metal recovery rates, reagent consumption and final product purity. A process can demonstrate technical recovery while still failing to achieve the economics required for commercial-scale production.
ARGO is consequently testing a broader proposition for Europe’s critical-minerals supply chain. If valuable minor metals can be recovered economically from zinc-processing residues, Europe could increase supplies of strategically important materials without waiting for entirely new mines to be developed. The approach could also change how metallurgical waste is viewed. Materials previously treated primarily as waste or environmental liabilities could become secondary mineral inventories, creating an additional source of gallium, germanium, indium and other critical metals from infrastructure that already exists.
