实现绿色低碳是推动煤炭产业高质量发展的必然选择。为了实现这一目标，提出一种采用超临界CO₂相变发泡技术制备泡沫混凝土的方法，制备了一种兼具高孔隙结构和固碳能力的硅酸盐水泥基超临界CO₂发泡混凝土。研究了超临界CO₂对材料干密度、孔隙结构和固碳能力的影响规律及作用机制。结果表明：超临界CO₂相变发泡混凝土制备过程是考虑硅酸盐水泥特性及其与CO₂矿化反应特性的温压动态协调过程。利用超临界CO₂相变发泡技术制备硅酸盐水泥基泡沫混凝土机理可分为CO₂−水泥浆液共存、CO₂−水泥浆液共溶、超临界CO₂−水泥浆液共溶、卸压发泡4个阶段。提高实验压力可以增大超临界CO₂−混凝土体系中的CO₂浓度，降低超临界CO₂发泡混凝土的干密度，超临界CO₂发泡混凝土干密度为787.14～993.52 kg/m³，变化范围为8.28%～19.20%。超临界CO₂发泡混凝土孔隙率的发展受CO₂在超临界CO₂−混凝土体系中的扩散—溶解—反应行为影响，其孔隙率为47.87%～89.79%，增大实验压力，优化保压时间是制备高孔隙率超临界CO₂发泡混凝土的发展方向。超临界CO₂发泡混凝土泡孔总体呈均匀、规则、独立的圆孔，其孔径大致相同，约为0.2 mm。增大实验压力可以促进CO₂矿化反应程度，有效优化泡孔结构及分布密度。每吨超临界CO₂发泡混凝土骨架固碳率为6.32%～10.36%，泡孔储碳量为0.98～2.27 kg，具有明显的固碳潜力，但其制备工艺及参数仍需进一步改善。超临界CO₂发泡混凝土有望发展为一种近零碳矿用功能性材料，对实现煤电一体化基地源头减碳意义重大。

Realizing green and low-carbon development will be a new requirement facing the coal industry. In order to address this problem, this paper proposed a method of preparing foam concrete using a supercritical CO₂ phase change foaming technology, and a Portland cement-based supercritical CO₂ foamed concrete with both high pore structure and carbon sequestration capacity was prepared. The effects of supercritical CO₂ on the dry density, pore structure and carbon sequestration capacity of the material and its mechanism were investigated. The experimental results revealed that the supercritical CO₂ phase change foamed concrete preparation process is a temperature-pressure dynamic coordination process considering Portland cement properties and its reaction properties with CO₂ mineralization. The mechanism of Portland cement-based foamed concrete prepared by the supercritical CO₂ phase change foaming technology may be divided into four stages: CO₂-cement slurry coexistence, CO₂-cement slurry co-solution, supercritical CO₂-cement slurry co-solution, and unpressurized foaming. Increasing the experimental pressure can increase the CO₂ concentration in the supercritical CO₂-concrete system and reduce the dry density of supercritical CO₂-foamed concrete, which varies from 787.14 to 993.52 kg/m³ with a range of 8.28% to 19.20%. The development of porosity of supercritical CO₂ foamed concrete was affected by the diffusion-dissolution behavior of CO₂ in the supercritical CO₂-concrete system, and its porosity was 47.87%-89.79%. Increasing the experimental pressure and optimizing the holding time are the development direction for preparing supercritical CO₂ foamed concrete with high porosity. The supercritical CO₂ foamed concrete has uniform, regular and independent circular pores with approximately the same pore diameter of 0.2 mm. Increasing the experimental pressure can promote the degree of CO₂ mineralization reaction and effectively optimize the structure and distribution density of the pores. Each tonne of supercritical CO₂ foamed concrete has a carbon sequestration capacity of 6.32%-10.36% in the skeleton and 0.98-2.27 kg in the pore, which has obvious carbon sequestration potential, but the preparation process and parameters still need to be further improved. The results show that the supercritical CO₂ foamed concrete is expected to be developed into a functional material with near-zero-carbon for mining, which is of great significance for realizing the carbon reduction at the source of coal power integration base.