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.

The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.

The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.

A process and associated system for the improved reclamation of disturbed lands (e.g., mined lands) is disclosed. In particular, the system including a dewatering cyclone, a screw classifier, and a dewatering apparatus (e.g. a dewatering belt) arranged in series to enable rapid and cost effective dewatering of slurries containing dilute clay and sand tailings to create an improved engineered reclamation material (ERM). The ERM formed by the controlled combining of dewatered sand tailings with dilute clay slurry and with a flocculant and overburden. The ratio of clay:sand:overburden of the ERM may be achieved by balancing the solid content (Cw) and water content (1-Cw) materials of the clay slurry, sand tailings and overburden. In some embodiments, the system may include at least one additional component, such as, for example, static screen(s), centrifuge(s), vibrating screens, drum screens, belt screens, belt filters, and/or other liquid-solid separation devices.

A process and associated system for the improved reclamation of disturbed lands (e.g., mined lands) is disclosed. In particular, the system including a dewatering cyclone, a screw classifier, and a dewatering apparatus (e.g. a dewatering belt) arranged in series to enable rapid and cost effective dewatering of slurries containing dilute clay and sand tailings to create an improved engineered reclamation material (ERM). The ERM formed by the controlled combining of dewatered sand tailings with dilute clay slurry and with a flocculant and overburden. The ratio of clay:sand:overburden of the ERM may be achieved by balancing the solid content (Cw) and water content (1-Cw) materials of the clay slurry, sand tailings and overburden. In some embodiments, the system may include at least one additional component, such as, for example, static screen(s), centrifuge(s), vibrating screens, drum screens, belt screens, belt filters, and/or other liquid-solid separation devices.

The invention is directed to a method of strip mining that involves dividing the pit into blocks in a diamond shape arrangement with an angular advancing strike face and removing waste material from each diagonally adjacent block so as to minimize the amount of waste material pushed by dozers and maintain the incline of ramps to gradients of 10% or less so that trucks can take mined ore from the pit.

The present invention provides a mining method. The method includes: dividing a mining region into a plurality of federated mining regions; performing an open-pit mining operation in each of the federated mining regions and forming a pit in each of the federated mining regions; performing an underground mining operation on a slope of the pit and forming a plurality of excavated tunnels; and backfilling a pit of a previous federated mining region with a spoil of a subsequent federated mining region.

The present invention provides a mining method. The method includes: dividing a mining region into a plurality of federated mining regions; performing an open-pit mining operation in each of the federated mining regions and forming a pit in each of the federated mining regions; performing an underground mining operation on a slope of the pit and forming a plurality of excavated tunnels; and backfilling a pit of a previous federated mining region with a spoil of a subsequent federated mining region.

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.

The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.