Abstract: An underground mining method for unexploited coal in a boundary open-pit mine is provided. A shaft construction platform is arranged at one rock step to two rock steps above a coal seam. Intermediate bridges are built starting from a pit bottom. Mining area clay is laid on a working slope where no intermediate bridge is built and on a side slope with an outcrop of the coal seam as a sealing layer to seal the slopes. Auxiliary vertical shafts and main inclined shafts are dug. The pit bottom is dug downward to form a digging space on a side close to the working slope between two adjacent ones of the intermediate bridges, and clay is filled into the digging space to form an artificial water barrier layer. A roadway communicating the main inclined shafts and the auxiliary vertical shafts is constructed, and a coal seam stope face is arranged.

Abstract: The present invention discloses a method for constructing inner dump type strip mine pit bottom reservoirs section by section, specifically including the following steps: S1: processing end slopes: discarding clay at a lowest step of an inner waste dump of a strip mine; S2: discharging concrete to slope faces of lowest steps of the end slopes on two sides of a pit bottom; S3: sealing the bottom; S4: discarding gravel into a pit of the strip mine; S5: laying geotextile; S6: re-adopting clay on the lowest steps of the end slopes of the inner waste dump, so as to form a reservoir sealing isolation layer; S7: constructing a plurality of reservoirs step by step in an advancing direction of the strip mine; S8: storing water resources: completing installation of water storage wells; S9: completing installation of water fetching wells; S10: storing water resources.

Abstract: An underground mining method for unexploited coal in a boundary open-pit mine is provided. A shaft construction platform is arranged at one rock step to two rock steps above a coal seam. Intermediate bridges are built starting from a pit bottom. Mining area clay is laid on a working slope where no intermediate bridge is built and on a side slope with an outcrop of the coal seam as a sealing layer to seal the slopes. Auxiliary vertical shafts and main inclined shafts are dug. The pit bottom is dug downward to form a digging space on a side close to the working slope between two adjacent ones of the intermediate bridges, and clay is filled into the digging space to form an artificial water barrier layer. A roadway communicating the main inclined shafts and the auxiliary vertical shafts is constructed, and a coal seam stope face is arranged.

Abstract: A method for constructing a dam inside a dump of an inner-dump strip mine includes: taking an upper surface connection line of a primary water-resisting layer as upper filling reference datum boundary of an artificial water-resisting layer; arranging a dam foundation pit and a trapezoidal abutment on a midline of the dam foundation pit; building and reinforcing a step-shaped retaining dam core wall on the artificial water-resisting layer; laying a foundation impervious layer, waterproof geotextile, and an earth blanket on one side, close to the primary aquifer, of the retaining dam core wall; strengthening advance of a dumping working face on one side, away from the primary aquifer, of the retaining dam core wall, and dumping overburden of a strip mine to form a support; filling a space between the earth blanket and the primary aquifer to form a blocker; and proceeding with construction and forming a continuous retaining dam.

Abstract: Provided herein is a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

Abstract: A method for slope geological disaster treatment and mineral resource recovery includes the following steps: S1: dividing a mountain top into a plurality of treatment sections and treatment segments; S2, selecting an easy-to-slide area at the upper portion of a first treatment segment and blasting an easy-to-slide body to make the easy-to-slide body roll down to a bottom of the slope; S3, forming a regular initial slope bench; S4, mining coal at the coal seam in a grouped mining adit manner, and laying grouting pipelines in the primary mining adits; S5, forming closed mining adits; S6, excavating secondary mining adits at intervals of the primary mining adits in sequence; S7, continuing mining in an adjacent second treatment segment in the same manner; and S8, continuing mining the first treatment segment of the second treatment section in the same manner.

Abstract: The disclosure discloses a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

Abstract: A method for constructing a dam inside a dump of an inner-dump strip mine includes: taking an upper surface connection line of a primary water-resisting layer as upper filling reference datum boundary of an artificial water-resisting layer; arranging a dam foundation pit and a trapezoidal abutment on a midline of the dam foundation pit; building and reinforcing a step-shaped retaining dam core wall on the artificial water-resisting layer; laying a foundation impervious layer, waterproof geotextile, and an earth blanket on one side, close to the primary aquifer, of the retaining dam core wall; strengthening advance of a dumping working face on one side, away from the primary aquifer, of the retaining dam core wall, and dumping overburden of a strip mine to form a support; filling a space between the earth blanket and the primary aquifer to form a blocker; and proceeding with construction and forming a continuous retaining dam.

Abstract: The present invention discloses a method for constructing inner dump type strip mine pit bottom reservoirs section by section, specifically including the following steps: S1: processing end slopes: discarding clay at a lowest step of an inner waste dump of a strip mine; S2: discharging concrete to slope faces of lowest steps of the end slopes on two sides of a pit bottom; S3: sealing the bottom; S4: discarding gravel into a pit of the strip mine; S5: laying geotextile; S6: re-adopting clay on the lowest steps of the end slopes of the inner waste dump, so as to form a reservoir sealing isolation layer; S7: constructing a plurality of reservoirs step by step in an advancing direction of the strip mine; S8: storing water resources: completing installation of water storage wells; S9: completing installation of water fetching wells; S10: storing water resources.

Abstract: The present invention discloses a dendritic reverse underground mining method for a thin coal seam at an end slope of a strip mine. The method includes the following steps: step S1: using a continuous coal mining machine to excavate a main adit toward a boundary of the strip mine along a seam floor; step S2: excavating secondary adits on two sides of the main adit obliquely in a forward direction of the main adit; step S3: transporting the excavated coal out of the main adit by the self-moving belt conveyors; step S4: after the excavating of a secondary adit of the secondary adits is ended, withdrawing the continuous coal mining machine and the self-moving belt conveyor from the secondary adit, and then excavating subsequent secondary adits of the secondary adits in a similar way; step S5: filling the secondary adits, and filling a goaf of the main adit.