Shenmu Zhangjiamao Mining Co. , Ltd. , Shaanxi Coal and Chemical Industry Group
Coal Mining and Designing Department, Tiandi Science and Technology Co. , Ltd.
College of Engineering, Huazhong Agricultural University
Shaanxi Hydrogen Research Institute Co. , Ltd.

为验证CO2矿化处理多源固废的技术可行性,选取陕北地区典型的工业固废粉煤灰和电石渣为研究对象,探究两者的CO2矿化特性和反应前后的理化特性,探讨了两者混合固碳的相互作用机制。结果表明,粉煤灰的CO2去除率(~50%)和固碳量(~5.0g/kg)极为有限。电石渣中CaO含量高达96.97%,相比粉煤灰表现出较高的CO2去除率(~90%)和固碳量(~320g/kg)。然而,在CO2矿化过程中,电石渣颗粒表面CO2矿化反应十分剧烈,导致快速生成的CaCO3将未反应电石渣颗粒包裹,从而降低了固碳量。采用粉煤灰-电石渣协同矿化CO2,粉煤灰颗粒不仅为方解石提供沉淀结晶位点,同时分散电石渣颗粒,避免新生方解石包裹未反应电石渣颗粒,促进电石渣中活性矿物相反应更为完全,进而提升粉煤灰-电石渣混合物的固碳量。采用煤炭开采产生的粉煤灰,与电石渣及矿井水配制成浆液,对烟气中CO2进行矿化封存,矿化后浆液通过管道回填矿井,不仅有助于降低CO2排放,还可降低浆液中颗粒团聚板结,对煤电联营模式下粉煤灰资源化利用、煤炭采空区空间利用、矿井水利用以及电厂碳排放降低具有重要意义。

To confirm the technical feasibility of CO mineralization for multi - source solid waste treatment, the typical industrial solid waste, coal fly ash and calcium carbide slag in northern Shaanxi were selected to explore their CO mineralization performance and physicochemical properties before and after reaction, as well as their interaction during CO mineralization. The results show that the CO removal efficiency (50%) and CO sequestration capacity 5. 0 g/ kg) of coal fly ash were very limited. Compared with coal fly ash, calcium carbide slag showed a higher CO removal efficiency (90%) and CO sequestration capacity (340 g/ kg). However, in the process of CO mineralization, the CO mineralization reaction on the surface of calcium carbide slag particles was very intense, resulting in the rapidly generated CaCO coating the unreacted calcium carbide slag particles, thus reducing the amount of CO sequestration capacity. When coal fly ash and calcium carbide slag was mixed for the synergic CO mineralization, coal fly ash particles not only provided the precipitation crystallization site for calcite, but also dispersed the calcium carbide slag particles, preventing the newly formed calcite from covering the unreacted calcium carbide slag particles, which promoted the reaction of calcium carbide slag, and increased the CO sequestration capacity of coal fly ash and calcium carbide slag mixture. The fly ash produced by coal mining is prepared into slurry with calcium carbide slag and mine water to mineralize and seal CO in the flue gas. After mineralization, the slurry is backfilled into the mine through pipes, which not only helps to reduce CO emission, but also reduces the agglomeration of particles in the slurry. It is of great significance to the utilization of fly ash resources, the utilization of coal goaf space, the utilization of mine water and the reduction of carbon emission of power plants under the coal-power joint operation mode.

中国煤炭科工集团有限公司科技创新创业资金专项(2022-2-ZD004)

胡俭,孙万明,范生军,等.粉煤灰电石渣协同CO2矿化及资源化利用研究[J].煤炭工程,2024,56(12):192-198.