Production of Portland clinker is inherently associated with CO₂ emissions originating from limestone decomposition, the irreplaceable large-scale source of calcium oxide needed. Besides carbon capture and storage, CO₂ mineralization is the only lever left to reduce these process emissions. CO₂ mineralization is a reversal reaction to clinker production—CO₂ is bound into stable carbonates in an exothermic process. It can be applied in several environmentally and economically favorable ways at different stages of clinker, cement and concrete life cycle. These possibilities are assessed and discussed in this contribution. The results demonstrate that when combined with concrete recycling, the complete circularity of all its constituents, including the process CO₂ emissions from the clinker, can be achieved and the overall related CO₂ intensity significantly reduced.