The present invention discloses a zero-gangue-discharge short-wall face pillar-free mining method, which is applicable to zero-gangue-discharge disposal in the mining operation in a mine shaft. A short-wall face is arranged in a selected area near a mine shaft according to the actual conditions of the mine shaft, the short-wall face is mined in a fully mining and fully back-filling mode, the gangues produced at other mining faces of the mine shaft are filled into the short-wall face, the short-wall face is supported with anchor rods along the edge of the filling face and the solid coal side to form an entry, and the entry is utilized to mine an adjacent working face. The method in the present invention mainly displaces the coal mass with gangues and thereby maximizes the utilization of the resources; in addition, the method can fully control the roof and realize mining without damage to the rock formation. Therefore, the method is of great value for wide application.

A mine exploitation method based on stoping, separation and filling control is disclosed herein. The method includes deploying a gangue-less coal mining system; choosing a suitable coal and gangue separation method according to a separation requirement; choosing a suitable filling method according to mine geology, production conditions and rock stratum control requirement; reversely calculating a filling rate according to gangue discharge requirement and control indexes by utilizing theoretical calculation, simulation and experiment; determining a filling process and a separation process according to the filling rate; and feeding back and adjusting the filling process and separation process parameters by monitoring filling and control effect indexes.

A mine exploitation method based on stoping, separation and filling control is disclosed herein. The method includes deploying a gangue-less coal mining system; choosing a suitable coal and gangue separation method according to a separation requirement; choosing a suitable filling method according to mine geology, production conditions and rock stratum control requirement; reversely calculating a filling rate according to gangue discharge requirement and control indexes by utilizing theoretical calculation, simulation and experiment; determining a filling process and a separation process according to the filling rate; and feeding back and adjusting the filling process and separation process parameters by monitoring filling and control effect indexes.

Polyamide foams which do not propagate fire are obtained by mixing (i) a liquid isocyanate component which comprises at least one polyisocyanate and in which the molar ratio of aromatic isocyanate groups to the sum of aromatic and aliphatic isocyanate groups is at least 60 mol %, with (ii) at least one liquid isocyanatereactive component which comprises a reactive diluent, and the reactive diluent 10 comprises (a) a chain-extending and/or crosslinking reactive diluent selected from among aliphatic branched C.sub.24-66-polycarboxylic acids, alicyclic C.sub.24-66-polycarboxylic acids and partial esters of polycarboxylic acids having at least two unesterified carboxyl groups and/or (b) a chain-terminating reactive diluent selected from among aliphatic branched C.sub.24-66-monocarboxylic acids, alicyclic C.sub.24-66-monocarboxylic acids and partial esters of polycarboxylic acids having one unesterified carboxyl group, wherein the liquid isocyanate-reactive component comprises an aromatic C.sub.8-18-polycarboxylic acid and/or an anhydride thereof.

A method and an apparatus for creating a void, low-density fill or combination of void and low-density fill for underground mining having at least one module of formwork to be positioned in an open slope of an underground mine prior to carrying out a backfilling operation.

Provided are a system and a method for monitoring bearing compression rate of a filler in a coal mine gob area. An ground information processing system, a vibration source control system, and a monitoring system are arranged on the ground according to a buried depth of the filler in the gob area. The vibration source control system generates vibration, and transmits a signal to the filler. The monitoring system on the ground receives different reflected waves according to different elasticities of the fillers under different compaction degrees. Final data is transmitted to the ground information processing system for data processing. The monitoring of the filler starts when the filler is filled in the gob area; the filler is gradually compacted. The filler is monitored until the thickness of the filler does not change. Finally, a bearing compression rate formula is utilized to calculate the bearing compression rate of the filler.

A method for controlling a subsidence area caused by underground mining in an adjoining open-pit mine, applied in an open-pit and underground coordinated mining process. In the method, a ground subsidence area caused by underground mining and production is directly filled and covered with overburden materials such as soil and rock discharged from an adjoining open-pit mine; small and medium fracture zones and large fracture zones caused by mining are timely backfilled, tamped, and levelled according to areas before the ground subsidence area appears, the thickness of the levelled soil layer is kept above 1 m, and the area slope is controlled within 7°. By fully using overburden materials from an adjoining open-pit mine, the method controls a subsidence area caused by underground mining and greatly shortens the discharge distance of the overburden materials from the adjoining open-pit mine, also solves the safety problems such as air leakage and spontaneous combustion of coal caused by fractures in mine subsidence, and brings significant economic and social benefits.

A method for controlling a subsidence area caused by underground mining in an adjoining open-pit mine, applied in an open-pit and underground coordinated mining process. In the method, a ground subsidence area caused by underground mining and production is directly filled and covered with overburden materials such as soil and rock discharged from an adjoining open-pit mine; small and medium fracture zones and large fracture zones caused by mining are timely backfilled, tamped, and levelled according to areas before the ground subsidence area appears, the thickness of the levelled soil layer is kept above 1 m, and the area slope is controlled within 7°. By fully using overburden materials from an adjoining open-pit mine, the method controls a subsidence area caused by underground mining and greatly shortens the discharge distance of the overburden materials from the adjoining open-pit mine, also solves the safety problems such as air leakage and spontaneous combustion of coal caused by fractures in mine subsidence, and brings significant economic and social benefits.

Methods of treating leachates in rock piles. Exemplary leachates include neutral aqueous leachates containing selenates and nitrates, said leachates being found in waste rock piles from coal mining operations. In certain embodiments, the method includes introducing an inert gas to the lower section of the rock pile, and allowing bacteria indigenous to the mining site to reduce the selenates and nitrates to selenium and nitrogen, respectively.

The present invention relates to a clean and efficient coal mining method, which is applicable to the field of solid waste treatment in mines. The method is characterized in: the width of short-segment working faces is designed according to the discharge volume of solid wastes produced in a mine, including downhole gangue and surface coal ash; first, two adjacent short-segment working faces are mined and backfilled, and the edges of the filling face and the solid coal side are supported with anchor rods while roadways are retained; the roadways retained at the two short-segment working faces and the coal mass in the middle constitute a long-segment working face mining system; the long-segment working face is mined, the short-segment backfilled working faces at the two sides are mined and backfilled at the same time, and the gangue produced at the long-segment working face is transported to the short-segment working faces to fill, so that a continuous mining system that consists of backfill mining at short-segment working faces and efficient stopping at long-segment working faces is realized. The method provided in the present invention can deal with all surface and downhole solid wastes in a mine, reduces the cost of gangue treatment, and mitigates damages to the ecological environment; besides, the method utilizes solid wastes to fill the gobs to form roadways, eliminates coal pillars and improve resource recovery rate.