Mineral Carbonation can significantly reduce GHG emissions and it is one of the most promising methods to sequester postcombustion CO₂ emissions. In this work, a novel pH-swing indirect mineral carbonation approach by cation complexation using 2,2′-bipyridine has been developed. A mining residue mainly composed of Fe (II)-rich olivine was used as a feedstock. The leaching of the mining residue was performed using NH₄HSO₄ as solvent (pH 2–3), at 61 °C with 250 rpm of stirring during 2 h of reaction time. A total of 28 and 41 wt% of iron and magnesium was leached respectively. Then, the iron leachate was stabilized as [Fe(bipy)₃]²⁺ complex using 2,2′-bipyridine avoiding iron hydroxide precipitation when the solution pH is raised using NaOH. Finally, the mineral carbonation reaction was performed, using a CO₂ gas stream into the solution at alkaline pH. Different parameters such as the temperature, the pH, the reaction time and the vol% CO₂ gas injected were optimized in batch mode reactions. This innovative approach allows the use of mild temperature and pressure conditions to obtain iron carbonates. The best results shows that 50 wt% of the CO₂ gas stream have been removed from the gas phase giving a ratio of 0.11 kg of CO₂ sequestered per kg of residues, which represent an important improvement regarding past studies on Fayalite.

矿物碳化可以显着减少温室气体排放，它是隔离燃烧后 CO ₂排放的最有前途的方法之一。在这项工作中，开发了一种通过使用 2,2'-联吡啶进行阳离子络合的新型 pH 波动间接矿物碳酸化方法。主要由富含铁 (II) 的橄榄石组成的采矿残渣用作原料。使用 NH ₄ HSO ₄作为溶剂（pH 2-3），在 61 °C 和 250 rpm 的搅拌下，在 2 小时的反应时间内对采矿残渣进行浸出。总共分别浸出 28 和 41 重量％的铁和镁。然后，铁浸出液稳定为[Fe(bipy) ₃ ] ²⁺当使用 NaOH 升高溶液 pH 值时，使用 2,2'-联吡啶避免氢氧化铁沉淀。最后，进行矿物碳酸化反应，在碱性 pH 值下使用 CO ₂气流进入溶液。在分批模式反应中优化了不同的参数，例如温度、pH、反应时间和注入的CO ₂体积百分比。这种创新方法允许使用温和的温度和压力条件来获得碳酸铁。最好的结果表明，50 wt% 的 CO ₂气流已从气相中去除，每千克残留物封存0.11 kg CO ₂的比率，这代表了对过去对铁橄榄石的研究的重要改进。