Research progress and prospect of coal based solid waste backfilling mining technology

Coal⁃based solid waste backfilling mining technology is in line with the main research direction and new de⁃ velopment concept requirements of green and intelligent coal mining and clean，efficient and low⁃carbon utilization. It is the research focus and hot spot to promote the development of high quality and quantitative coal mining，low environ⁃ mental damage，and green and low⁃carbon operation. On the basis of summarizing the research and development back⁃ ground and development history of coal⁃based solid waste backfill mining technology，the research status of coal⁃based solid waste backfill mining technology system is systematically presented. After more than 20 years of industry⁃univer⁃ sity⁃research⁃use joint research， it has successively experienced five generations of technology research and development innovation. The typical solid waste backfilling technologies，that have basically formed a system including comprehensive mechanized solid backfilling， paste backfilling， long⁃wall and roadway⁃by⁃roadway cemented backfilling，overlying rock isolation grouting backfilling，and “underground mining⁃separating⁃backfilling and X”，pro⁃ vide a more comprehensive solution for “coal mining under buildings，waters⁃bodies and railways”，strip coal recovery， and coal⁃based solid waste underground disposal. Significant progress has also been made in theoretical research on the constitutive model of backfill materials，key rock formation control and surface deformation control in coal⁃based solid waste backfill mining，and a theoretical system for backfill mining rock formation control has been basically construc⁃ ted. With the development trends of intelligent upgrading，large⁃scale disposal and resource utilization of coal⁃based solid waste，the main development directions of coal⁃based solid waste backfilling and mining technology include but are not limited to the efficient and intelligent backfilling of coal⁃based solid waste，underground grouting backfilling and disposal，deep backfilling heat mining，coal⁃based solid waste backfilling underground carbon sequestration，coal⁃ based solid waste green functional materials underground utilization，etc. The existing research status and development trend comprehensively show that the coal⁃based solid waste backfilling mining technology is an important representative way to realize a green，intelligent and efficient mining of coal resources.