Meitan kexue jishu (Mar 2023)
Research progress and prospect of coal gangue slurry backfilling technology in goaf
Abstract
Coal gangue slurry backfilling is an important technical means of harmless large-scale disposal of gangue under low disturbance conditions, and is one of the important ways to achieve green coal mining, in line with the national green development concept. But for the preparation, long-distance transportation, and goaf disposal of the slurry backfilling material and other aspects of the research is still imperfection, part of the problem of research is still blank, seriously restricting the development of slurry backfilling technology in the field of coal gangue solid waste disposal. Through recent years, coal gangue slurry backfilling in the basic theory and key technology has made a lot of results. The article systematically composes a variety of coal gangue backfilling solid waste disposal technology and its development history, summarizes its applicability and advantages and disadvantages, elaborates the technical background and scientific connotation of the birth of slurry backfilling, and clarifies the key technology and process principle of slurry backfilling. From the perspective of large-scale promotion and application, the three key scientific issues of precise preparation and rheological characteristics of slurry backfilling materials, long-distance pipeline transport characteristics of gangue slurry, spatial dynamic evolution of goaf and the law of slurry intervention have been summarized, and research on precise slurry production technology, pipeline transport technology, and multi-position backfilling technology of slurry has been focused around the above key scientific issues. The rheological characteristics of gangue slurry under multi-factor coupling conditions are analyzed, the mechanism of gangue slurry formation is revealed, the precise preparation model of gangue slurry is constructed, the determination method of key parameters of gangue slurry pipeline transportation is proposed, and the flow and diffusion laws of three forms of slurry-high, low and adjacent are summarized, which in turn to guide the slurry backfilling engineering practice. Based on the above research, the shortcomings and the focus of the future research of the current research on slurry backfilling technology are analyzed, and the development trend of coal gangue slurry backfilling technology under the background of Dual Carbon has prospected, and the following three directions are considered to be the focus of future research: ①mineralized CO2 preparation of carbon-negative slurry technology; ②slurry reconstruction rock layer technology based on MICP technology; ③slurry replacement fluidized mining technology for hard-to-mine coal bodies.
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