Role of low molecular weight additives on the early-stages of magnesium carbonate mineralization

The early stages of MgCO3 formation remain highly unexplored as compared to CaCO3. Recent studies have shown that MgCO3 precipitation is non-classic and involves the formation of amorphous magnesium carbonate (AMC) prior to the stable carbonate phase. Here, the synthesis of AMC was carried out at constant alkaline pH using a potentiometric titration setup. We investigated the influence of sodium citrate and acetate, low molecular weight additives, on the nucleation, growth, and stability of AMC and its recrystallization, enabling tailored control over its formation for both environmental and engineering applications. These additives delay AMC nucleation and significantly impact its stability, and their presence in solution result in its recrystallization into less hydrated crystalline MgCO3 phases