Optimizing circularity for copper slags by facilitating utilization as supplementary cementitious materials

The proposed project aims to study the effect of processing parameters in the slag cleaning process enabling the use of copper slag as a supplementary cementitious material (SCM).

In Sweden, the potential amounts to the annual recycling of 650 000 tons of slag, which would reduce the carbon dioxide emissions from the cement industry by ca 306 000 tons while decreasing the mining of calcite by 696 000 tons.

Considering these benefits, incorporating copper slag as an SCM is the most attractive application of this material and recycling the slag generated in Sweden amounts to lowered carbon dioxide emissions corresponding to 0.6% of the nationally emitted carbon dioxide equivalents in 2021.

Currently, copper slags are either landfilled or used as, e.g., ballast in road construction or as abrasive blasting media.

Previous studies have shown that copper slags have pozzolanic activity, i.e., the potential for use as an SCM, but no systematic studies on the means required to generate an attractive SCM have been made.

Therefore, the knowledge gap consists of a lack of information regarding the demands on the slag cleaning process posed to generate a reactive SCM.

Based on the mitigation of the carbon dioxide emissions and potential for a more efficient use of natural resources, the project is timely.

Furthermore, the project group has multiple years of experience in slag research, both in general and directed towards the cement industry, which offers a basis for a successful outcome.