On January 4th, the research team led by Academician Xie Pinghua published a research paper titled "Carbon negative backfill mining in coal mines for carbon neutralization: Chemical carbon fixation performances with mineralized gangue" in the top international mining journal "International Journal of Rock Mechanics and Mining Sciences", with the State Key Laboratory of Intelligent Construction and Health Operation and Maintenance of Deep Ground Engineering as the first affiliated institution. This paper signifies significant progress in carbon-negative backfill mining technology, notably enhancing the global influence of Chinese researchers in the field of coal development. It holds great importance for promoting the achievement of the "dual carbon" goals.
Coal mine backfill mining technology is an approach we must take to secure energy supply and green, low-carbon development in China. Currently, the existing principles and technological equipment systems for backfill mining struggle to overcome technical bottlenecks associated with high-efficiency, high-yield, and low-carbon extraction. Reforming backfill materials and methods has become imperative. In response to the strategic goals of "developing resources from kilometer-deep mines and filling materials for mines with a capacity of tens of millions of tons (two 'one thousands')" and "achieving near-zero ecological damage and near-zero rockburst risk (two 'near zeros')" in coal's green and low-carbon extraction, Academician Xie Pinghua proposed a novel concept and technical framework for carbon-negative backfill mining. He constructed a carbon-negative high-porosity backfill material structure CGIF (CO2 Gangue Inorganic Framework) composed of CO2, gangue, and rapid-setting binders. Additionally, he introduced efficient carbon-negative backfill mining technologies and processes for multi-face concurrent mining, designing an efficient carbon-negative backfill process that combines post-support material dropping with joint injection of CO2 and cementitious materials. Based on an annual raw coal output of 4 to 4.5 billion metric tons, it is further estimated that the annual carbon-negative quantity of CGIF mixture filling bodies in mined-out areas would be 1.36 to 2.16 billion metric tons. This would also reduce the annual usage of gangue as backfill material by 2.68 to 4.19 billion metric tons.
Since Academician Xie Pinghua introduced the new concept and technical vision of carbon-negative backfill mining at the 22nd National Scientific Coal Mining and Mine Pressure Theory Conference (June 2023, Xinjiang), he has consistently adhered to the national energy development strategy focusing on low-carbon coal mining and clean utilization. To ensure the scientific rigor and forward-thinking nature of research on carbon-negative backfill mining, he led his research team to continuously promote in-depth research and summarized achievements in the theory and technology of carbon-negative backfill mining. In a special issue celebrating the 60th anniversary of the founding of the Journal of China Coal Society, he published a research paper titled "Theoretical and Technical Vision for Efficient Carbon-Negative Backfill Mining in Coal Mines," comprehensively outlining the theoretical framework, technical research, and development plan for carbon-negative backfill mining. Regarding methods, processes, and equipment for carbon-negative backfill mining. His team has filed 19 invention patent applications, with 3 already granted. Moreover, research on carbon-negative backfill mining technology has received support from the Major National Science and Technology Project for Deep Earth, with expectations to complete a demonstration project for carbon-negative backfill mining within three years. This initiative aims to promote the transformation of research outcomes into practical applications, advancing the adoption and implementation of carbon-negative backfill mining technology.
Full Text:
https://doi.org/10.1016/j.ijrmms.2024.106016
Figure 1: Principles and process of carbon-negative backfill technology
Figure 2: Sealed carbon-fixation stirring reactor
Figure 3: Relationship between carbon sequestration capacity,
carbonation degree, and variables
