Treatment technology directed to using mine waste as a raw material to manufacture a mine filling product for use as a suitable precursor product or mine filling product to be used as a backfill material to close a mine. The precursor product or mine filling product retains its metals and is not be able to generate acidity. According to the disclosure, the precursor product or mine filling product, when placed in a mine, may also remove metals from mine fluids in the mine it contacts, and still retain the metals it hosted when it was a mine waste prior to it being used as a raw material to manufacture the precursor stowing backfill product.

An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery, the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery, the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

The invention relates to a microwave-mechanical fluidization mining system and a mining method for metal mines. The microwave-mechanical fluidization mining system comprises a microwave pre-splitting mechanical mining system, a microwave separation system, a high-power microwave focused melting system and a goaf, wherein ore-waste rock mixtures mined by the microwave pre-splitting mechanical mining system are transported to the microwave separation system through a conveyor I and an elevator on the microwave pre-splitting mechanical mining system, separated ores are transported to the high-power microwave focused melting system, and separated waste rocks are transported through a conveyor V to the goaf for filling. Microwave pre-splitting mechanical mining is adopted instead of a traditional blasting mining method to increase an excavation speed and avoid the influence of blasting on the stability of surrounding rocks.

The invention relates to a microwave-mechanical fluidization mining system and a mining method for metal mines. The microwave-mechanical fluidization mining system comprises a microwave pre-splitting mechanical mining system, a microwave separation system, a high-power microwave focused melting system and a goaf, wherein ore-waste rock mixtures mined by the microwave pre-splitting mechanical mining system are transported to the microwave separation system through a conveyor I and an elevator on the microwave pre-splitting mechanical mining system, separated ores are transported to the high-power microwave focused melting system, and separated waste rocks are transported through a conveyor V to the goaf for filling. Microwave pre-splitting mechanical mining is adopted instead of a traditional blasting mining method to increase an excavation speed and avoid the influence of blasting on the stability of surrounding rocks.

A process for controlled in-situ coal gasification is disclosed. The process includes surveying one or more selected coal bearing sites for designing a plurality of panels; designing a plurality of sub-panels of a plurality of corresponding panels with a plurality of bi-directional boreholes and a plurality of vertical service boreholes; channelizing the plurality of bi-directional boreholes and vertical service boreholes to one or more layers of coal seams; constructing one or more coal slice areas of predefined dimensions within the one or more layers of the coal seams; combusting coal inside the one or more coal slice areas; extracting combusted coal from the one or more coal slice areas through the plurality of vertical service boreholes; monitoring physical condition of at least one cavity created by extraction of the combusted coal; controlling remote filling of a filling material simultaneously at the at least one cavity using the filling device.

Provided is a method for recovering room-type coal pillars by cemented filling of reserved roadways, which is especially suitable for safe and efficient recovery of left coal pillars in room-type mining faces in mining areas where the ecological system is fragile, such as in western China. In the method, by constructing reserved roadways in two adjacent rows of room-type goafs, excavating coal pillar roadways in room-type coal pillars, and finally interconnecting the reserved roadways with the coal pillar roadways to form a U-shaped working face, room-type left coal pillars are recovered. Thus, not only the workload of roadway excavation is reduced, but also the recovery ratio of the coal resources is maximized. The method provides a novel technical model for the recovery of room-type left coal pillars in mining areas, such as in western China.

A microwave-mechanical fluidization mining system and a mining method for metal mines. The microwave-mechanical fluidization mining system comprises a microwave pre-splitting mechanical mining system, a microwave separation system, a high-power microwave focused melting system and a goaf, wherein ore-waste rock mixtures mined by the microwave pre-splitting mechanical mining system are transported to the microwave separation system through a conveyor and an elevator on the microwave pre-splitting mechanical mining system, separated ores are transported to the high-power microwave focused melting system, and separated waste rocks are transported through a conveyor to the goaf for filling. Microwave pre-splitting mechanical mining is adopted instead of a traditional blasting mining method to increase an excavation speed and avoid the influence of blasting on the stability of surrounding rocks.

A microwave-mechanical fluidization mining system and a mining method for metal mines. The microwave-mechanical fluidization mining system comprises a microwave pre-splitting mechanical mining system, a microwave separation system, a high-power microwave focused melting system and a goaf, wherein ore-waste rock mixtures mined by the microwave pre-splitting mechanical mining system are transported to the microwave separation system through a conveyor and an elevator on the microwave pre-splitting mechanical mining system, separated ores are transported to the high-power microwave focused melting system, and separated waste rocks are transported through a conveyor to the goaf for filling. Microwave pre-splitting mechanical mining is adopted instead of a traditional blasting mining method to increase an excavation speed and avoid the influence of blasting on the stability of surrounding rocks.

A plug for a void in a mine to divert water having a rigid closed cell foam which fills the void. The rigid closed cell foam having a plurality of pipes disposed within the foam. The pipes distributed throughout the void. The pipes are positioned in the foam so the pipes are staggered in length vertically with respect to various heights in the void, and the pipes are positioned in the foam every 4′ to 6′ horizontally with respect to the void. Each pipe has a mixing stick. A method for diverting water from a void in a mine.