Engineering tests were applied in coal roadway 5107 of coal seam 5# of the Baidong Coal Mine of the Datong Coal Mine Group Given the site conditions a reasonable fracturing length of m was
In recent years an increasing number of CBM wells have been excavated in the process of coal mining and hydraulic fractures have been exposed With in situ observations the geometry and filling characteristics of fractures can be directly described by the naked eye This provides a particular approach to further understanding fracture
The problems preventing the use of mine hydraulic fracturing for stimulating the preliminary degassing in coal seams are considered The solutions are presented for sealing the borehole interval by solidifying composition with initiator for transverse fracture of rocks An original system for transportation of equipment along the holes and a robotized device for
Solving the problem of gas extraction from low permeability coal seams is an urgent issue in the global coal industry and exploring green and efficient mining methods has potential applications
Contour strip mining Contour mining is commonly practiced where a coal seam outcrops in rolling or hilly terrain Basically the method consists of removing the overburden above the coal seam and then starting at the outcrop and proceeding along the hillside creating a bench around the hill In the past the blasted overburden spoil was simply shoved down the
In coal mining machinery hydraulic cylinders are mainly used to control the movement and positioning of various mechanical components such as tunneling machines coal mining machines transfer machines conveyors and other equipment Due to its strong pushing and pulling force good wear resistance safety and reliability hydraulic
Solid backfill coal mining a crucial element of green mining technology presents substantial advantages over the caving method in terms of controlling rock strata damage and surface subsidence [1] [2] This method not only addresses environmental concerns associated with coal mining and gangue accumulation but also facilitates the recovery of coal
Yan et al 2022 set a hydraulic curtain in a coal mine to prevent radioactive contaminants from flowing into the mine Babu and Mishra 2022 examined the hydraulic property of a liner under the influence of the mimetic leachate and the hydraulic conductivity of the liner can achieve × 10−8 cm/s Sun et al 2019 predicted the
Method Hydraulic Mining and sub level caving method were applied in some Indian geo mining conditions with limited success Successful experiences of recent high capacity underground coal mining mechanisation is the failure of some of the capital intensive power supported longwall and at thesame time gigantic growth ofopencast
A hydraulic support is one of the key pieces of equipment in a fully mechanized coal mining face The shaft is seriously worn due to repeated support shifting in coal mining operations and the hydraulic support bears a large amount of impact load in the support process leading to a threat to its dynamic stability In order to study the impact load on the posture and
As a special energy rock containing methane coal mining often entails the fatal risk of gas outbursts due to the differential enrichment of methane However the current key preventative techniques such as mining a protective layer and pre drainage of gas are not applicable to conventional soft coal seams Based on a field study of the Xinyuan Coal Mine in
With the increase of coal mining depth hydraulic supports with large mining height and high working resistance are widely used and the length of working face and the number of supports are
Thick coal seam with complex structures and thick hard roof in the initial mining phase pose various challenges including a long weighting interval strong rock pressure poor top coal caving
The identification of water sources and hydraulic connectivity in different aquifers within coal mines is crucial for effective groundwater management and has important implications for mine safety water resource conservation and regional ecological protection The Dongming opencast coal mine in Hailar City Inner Mongolia China is threatened by groundwater
Duncan G J Hydraulic coal mining developments in New Zealand Solid Energy 1998 Whittall P Pike River Coal—Hydraulic Mine Design on New Zealand s West Coast Pike River Coal Limited
In a reliability assessment of hydraulic fracturing the efficacy of hydraulic fracturing must be evaluated and the source properties and magnitude of micro earthquakes induced by hydraulic fracturing in a coal mine need to be quantified Firstly the changing trends of the number and energy of micro seismic events induced by hydraulic fracturing with high
The Caojiatan coal mine situated in the core of Phase I planning in the Yushen mining area of northern Shaanxi China As shown in the Supplementary martial Fig 11 when there is no direct hydraulic connection between coal seams and water bearing aquifers traditional simulation approaches often fail to capture the true impact of mining
Hydraulic fracturing of coal seam is considered as a process of development of discontinuities in rock mass elements due to change in hydrogeomechanical situation on filtration of fluid under pressure Failure is associated with excess of the effective stresses over the rock tension strength The problem on filtration and failure of massif is solved by the finite element method
The method of mining coal entails the use of crude petroleum under high pressure together with elevated temperatures in hydraulic fashion to produce a hybrid oil coal fuel A powerful stream of oil is aimed at sections of coal strata to disintegrate the coal The resultant slurry can be recycled for reuse in the mining operation with provisions being made for screening out the larger coal
