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Mar 01, 2019 1. Introduction. At the current time, China is the largest coal producing and coal consuming country in the world (Hu et al., 2015).Coal gangue is a solid waste material generated during the coal excavation processes of coal mining (Cao et al., 2016), and accounts for approximately 10–15% of total coal production (Liu and Liu, 2010).Due to its inherent low heat and utilization value, coal ...
Feb 18, 2015 Coal gangue is a problematic by-product generated from the process of mining and beneficiation of coal. It approximately accounts for 10–15 mass % of coal production [].Huge quantities of coal gangue has been stockpiled during decades of coal production and cause severe environmental impacts, such as acid drainage, heavy metals leaching as well as atmospheric pollution [2–4].
Oct 20, 2020 Acid mine drainage (AMD) is a hazardous by-product of coal mining, which may intensify the creep deformation of cemented gangue backfill (CGB) in solid backfill mining. In this study, the long-term stability and creep property of CGB soaked in AMD were quantitatively measured by experimental and theoretical analysis. The uniaxial compressive strength, elastic modulus, and mass of CGB …
1. Introduction. The key layer of roof rock is that which has the most influence on the collapse of the roof behind the longwall and the magnitude of the surface subsidence (Hou 1999, Xu et al 2009).Typical shallow coal seams are found in West of China where the main overburden strata structure is a single key layer, which is shown in figure 2.The leading factor of overburden strata movement ...
Feb 15, 2021 The content of Al 2 O 3 is 44.79%, which is higher than its content in most potential secondary resources of Al 2 O 3, such as fly ash (the average content of Al 2 O 3 is 35%) (Yao et al., 2014) and coal gangue (the average content of Al 2 O 3 is 30−40%) (Asuha et al., 2018). The ratio of aluminium to silicon in tailings is only 1.19, which ...
Coal will continue to be the main energy source in China for the immediate future, although the environmental pollution and ecological impacts of each stage in the full life cycle of coal mining, transportation, and combustion generate large quantities of external costs. The Late Permian coals in southwestern (SW) China usually contain high amounts of fluorine (F), arsenic (As), and ash, which ...
Gob-side entry retaining by roof cutting (GERRC) employed in a deep inclined thick coal seam (DITCS) can not only increase economic benefits and coal recovery, but also optimize surrounding rock structure. In accordance with the principles of GERRC, the technology of GERRC in DITCS is introduced and a roof-cutting mechanical model of GERRC is proposed to determine the key parameters of the ...
May 11, 2021 Self-ignition coal gangue (SCG) used as one of precursors to fabricate autoclaved aerated concrete (AAC). Aiming at studying water absorptivity and frost resistance performance of SCG-based AAC (SCGAAC), three-period water absorption tests and freeze-thaw tests were carried out and the corresponding results were recorded and analyzed. In order to modify the water absorptivity of …
Dec 22, 2012 Coal is a black or brownish-black sedimentary rock that can be burned for fuel and used to generate electricity.It is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning). Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.
Aug 01, 2020 A 40 mm coal cube was cut from a raw coal specimen in the lab, and the initial scan was carried out without impact loads at the X-ray imaging facility, Zhejiang University, China.A dynamic impact load experiment with an impact velocity of 2.5 m/s (and corresponding strain rate of 41.5 s −1) was carried out using the SHPB experimental system.. Finally, the second scanning of the damaged coal ...
Mar 08, 2021 Water inrush at floor area is a natural hazard during coal mining. Especially in the northern coalfield of China, more than 55% of coal mines are threatened by water inrush at floor area. The hazard of water inrush is becoming more serious with increasing mining depth. In this paper, the deformation and failure behavior at floor area in deep longwall mining site were analyzed.
In this study, the roof-cutting-type gob-side entry retaining is introduced, and its application in medium-thickness coal seams is studied. Based on the analysis of the construction procedure and principle, the mechanical model of the retained roadway structure and cantilever beam formed by roof cutting was established, and the support resistance and roof deformation were obtained.
The waste of coal energy has attracted attention due to the general increase in the degree of mining mechanization [1 – 3].To ensure the safety of underground work, the traditional longwall mining method balances the roof pressure in the remaining coal pillars, but the waste of coal resources is more serious [4, 5].Therefore, the traditional gob-side entry retaining (GSER) technology has ...
Feb 23, 2021 Cemented coal gangue paste backfill (CCGPB) containing coal gangue and fly ash is a backfilling technique newly developed in coal mines in China that allows environmentally hazardous products, such as gangue and fly ash, to be reused in underground stopes. CCGPB materials provide efficient ground support for the caving of strata and reduce surface subsidence.
Dec 07, 2020 Coal gangue (CG) is generated during coal mining activities. About 15–20% of CG by weight of the total coal output is discharged during its production. CG has become a primary environmental concern around the world (Zhang & Ling 2020). It was reported that 175 million tons of coal waste have been stocked in dumps for decades in Europe.
Jul 05, 2019 During the transport of raw coal, the presence of coal dust makes it difficult to extract position coordinates without edge contour information, or recognize coals and gangues. To separate gangues from raw coal, the key lies in identifying the edges of gangues and finding the feature difference between gangues and coals.
Jan 23, 2021 When coal gangue particles impact on the tail beam, according to equations ()–(), the normal force between them is among whichThe contact surface of the tail beam can be equivalent to a sphere with an infinite radius, i.e., , so the equivalent contact radius between coal gangue particles and the tail beam is The tangential force when coal gangue impacts the tail beam is
Using gangue backfilling in underground coal mining not only controls the roof deformation in the gob area but also reduces the amount of mining waste rock. However, due to the limitations of the complicated engineering conditions, backfilling mining in the steep coal seam is not widely applied. In this study, a long-distance backfilling technology with a scraper winch for a steep coal seam ...
May 20, 2016 I. INTRODUCTION Coal gangue (CG) produced from coal mining and coal processing is one of the largest amounts of industrial solid wastes in China (Liu and Liu, Reference Liu and Liu 2010).More than 700 million tons of CG is generated annually in China and its resource utilization attracts many researchers’ attention (Bian et al., Reference Bian, Dong, Lei, Leng, Mu and Wang 2009; …
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