Ex-situ mineralization and carbonated materials projects are a carbon-removal project type within the engineered & geological segment of the carbon market. They are designed to convert CO2 into stable carbonates in materials, wastes, or engineered systems. In practice, CO2 is converted into stable mineral carbonates for long-term storage. Common project configurations include Carbonated concrete aggregate; mineralization of reactive wastes; ex-situ mineralization systems.

Mineralization can offer very strong permanence where stable carbonates are formed and retained in durable products or storage pathways. This segment is generally aimed at more durable carbon storage and is often attractive to buyers seeking high permanence, but lifecycle emissions, measurement precision, and storage durability remain the decisive quality questions. For buyers and program designers, the most important diligence questions are: Is the reacted CO2 measured accurately? Are feedstocks suitable and stable? How is long-term storage demonstrated in the end product or disposal pathway?