Creating a Value Chain for CSMs: Valorization of Secondary Minerals and By-Products

The production of multiple commodities in a mining project is popular, whether to ease social acceptability or to improve the economic outlook. However, these rarely come to fruition. There are many reasons why co-productions get derailed, including strategic decisions, technical challenges, or financial constraints. This talk aims to outline solutions and prerequisites in order to ensure the successful outcome of such an endeavour.

This presentation aims to demonstrate the importance of recovering and valorizing secondary minerals, such as tantalum, for the Crevier project in Saguenay–Lac-Saint-Jean. Separation techniques and the various R&D partnerships involved will be presented.

The recovery of secondary substances extracted from asbestos-contaminated mining residues represents a strategic opportunity for Exterra, but poses significant technical and economic challenges.

On the technical side, the destruction of asbestos fibers, the production of magnesium oxide, the extraction of nickel and cobalt present in low concentrations, and the purification of amorphous silica require innovative processes (specific technologies, acid recycling, etc.), since conventional ore processing methods are not designed to be circular. In addition, extensive metallurgical testing is required to validate the feasibility of the process.

Economically, the recovery of secondary substances entails additional costs that can exceed the market value of nickel/cobalt concentrate and silica, especially in a context of high price volatility. Added to this is a lack of local processing infrastructure, making commercialization more complex.

For Exterra, the recovery of secondary substances can enhance the overall profitability of the project, reduce the volume of tailings, and enhance the contribution of the site’s remediation—a differentiating feature for investors. It therefore represents a venture in technological development with multiple upside opportunities in the medium term.

The Matawinie natural graphite deposit, located in the Lanaudière region of Québec, stands out for its exceptional potential in the supply chain of critical and strategic minerals. In addition to graphite, the deposit contains a variety of secondary minerals, including sulphides and metal oxides.

This presentation will highlight the potential for recovering these secondary minerals through metallurgical tests as well as technical and economic studies. The most promising mineral phases and the main challenges associated with their development will be analyzed and put into perspective.

ArcelorMittal Long Products Canada is collaborating with various research and engineering groups to identify new ways of upgrading its industrial by-products. In Contrecoeur, the company’s two steel plants generate approximately 32,000 metric tons of steelmaking dust per year. Approximately 1.4 Mt of these residues are currently stored on-site in engineered cells. With a view to improving long-term management, work was carried out to characterize the material, evaluate stabilization options, and explore new avenues for the recovery of metals of interest such as zinc, lead, iron, silver and germanium. Test results demonstrated that carbonation could contribute to the chemical stabilization of dust, by decreasing the mobility of metals and the pH of leachate. In addition, results related to the selective recovery of certain metals through alternative metallurgical pathways will also be presented.