Water-blocking performance of laterite in weak deposition areas of Neogene Baode Formation and its significance of resource exploitation

The in-depth study on the water-blocking performance of laterite in the weak deposition areas of the key aquiclude is of significant importance for mine production safety and ecological water resource protection. Specifically, the borehole data were re-optimized based on the regional sedimentary characteristics, the thickness distribution pattern of laterite deposit in Yushen mining area was studied, and the micro-engineering characteristics and control factors related to the water-blocking performance of laterite were explored. The results show that the deposition thickness of laterite gradually increases from northwest to southeast, the distribution of laterite becomes extremely uneven with the evolution of rivers, and the area of laterite missing zone reaches 48.80%. The particle size analysis and permeability test show that the water-blocking performance of laterite increases vertically with the increase of laterite deposition depth. The microstructure and material composition analysis show that the water-blocking performance of laterite is not in a simple linear relationship with its deposition thickness in the horizontal direction, and the water-blocking performance of laterite weak area decreases sharply with the decrease of its deposition thickness. Based on the concept of stable Darcy flow rate, the critical thickness of laterite in the weak zone with non-complete water-blocking performance was calculated, and through multi-source data fusion to obtain the zoning of the water-blocking performance of laterite in Yushen mining area was classified. The systematic study of engineering characteristics and water-blocking performance of laterite in Yushen mining area could provide important theoretical basis for identifying the potential geological factors that may cause hacards in the mines within the laterite weak area, realizing the protection and reconstruction of key aquiclude and guiding the practice of coal-water dual-resource cooperative co-mining engineering.