Coal
Coal is a nonrenewable fossil fuel that is combusted and used to generate electricity. Mining techniques and combustion are both dangerous to miners …
Formation mechanism and dynamic process of open-pit coal mine
The Xinjing Open-Pit Coal Mine landslide is situated in the southern region of Helan Mountain (Fig. 1a). This region under experienced aulacogen deposition from the middle-late Proterozoic and to early Paleozoic periods, with the reactivation of ancient faults and rift development in the late Paleozoic, and reverse thrusting and folding uplift since …
Hydraulic fracturing of hard top coal and roof for controlling …
Due to the poor cavability of top coal, the connection between the high-level gas drainage lane and the gob is not sufficient during the initial mining stage in a extra-thick coal seam with hard ...
Gas desorption characteristics in different stages for …
Finally, based on the research results in different stages for retained water infiltration gas-bearing coal, how to effectively apply CSWI were discussed. The research result provides some theoretical foundation for the rational application of CSWI to coal mine gas control. 2. Coal samples and methodology2.1. Parameter of coal sample
Coal Types, Formation and Methods of Mining
A third phase in this coal development is bituminous (soft coal) which is one of the two stages used as a fuel in generating electrical power. ... Miners in Nova Scotia actually mine coal beneath the ocean. A secondary byproduct of mining coal is the emission of greenhouse and other gasses which pollute the air. The most widely known type of ...
Research on coal mining intensity based on the DPSIR-SPA …
With the increasing demand for coal resources, the coal mining intensity (CMI) is becoming higher and higher, and high-intensity mining has become an important development direction for coal underground mining technology (Cui et al. 2021; Feng et al. 2023; Zhao et al. 2021).Research on high-intensity mining in coal mines is relatively …
A Scourge for Coal Miners Stages a Brutal Comeback
When it passed mine safety legislation in 1969, Congress made eliminating black lung a national goal. For two decades, the prevalence of black lung dropped continuously — from 6.5 percent in the 1970s, to 2.5 percent in the 1980s and 2.1 percent in the 1990s. But then the trend reversed, with rates climbing to 3.2 percent in the 2000s.
Determination on the hazard zone of spontaneous coal combustion in the
Twenty-five major coal mining provinces, with more than 130 large and medium-sized coal mines, are threatened by spontaneous coal combustion to varying degrees ... The calculation models in three mining stages of the 2202 working face, roadway driving along the gob, normal mining, and end mining were selected and …
Evolution Law of Mining-induced Fractures in Shallow Buried Close Coal
The fractures development of upper single coal seam mining can be divided into two stages: subcritical mining stage and critical mining stage. (1) In subcritical mining stage, the development height of fracture is positively related to the face advance distance, the relationship between the fracture development height and face advances is …
Coal mining | Definition, History, Types, & Facts
Prospecting and exploration. The fundamental objective of coal prospecting is to discover coal resources through a search. In areas where coal mining has not been previously …
Coal life-cycle analysis embedded with land–energy nexus of a coal …
The change of raw coal production affects other data, such as energy consumption in the coal mining stage, the amount of raw coal into washing, and the amount of coal washed. The second key parameter is the net coal consumption rate of fossil-fired power plant. One third of the coal washing in Huainan is used for power …
Research progress in coal and gas co-mining modes in China
In the process of coal mining, owing to strata movement and stress redistribution, a concentrated stress zone, original stress zone, and stress relief zone will be formed in the coal seam. ... and coal mining has entered the deep mining stage. At the same time, a large number of shallow mines have been abandoned due to resource …
Coal explained Coal and the environment
The U.S. Energy Information Administration estimates (as of October 2022) that in 2021, CO 2 emissions from burning coal for energy accounted for about 20% of total U.S. energy-related CO 2 emissions and for nearly 60% of total CO 2 emissions from the electric power sector. In the past, fly ash was released into the air through the smokestack ...
GEOLOGICAL EXPLORATION AS PER UNFC STAGES AND …
Mining Technology Processing technology ... Four stages of Geological Assessment Provide Four Resource ... Coal seams, lignite beds, iron ore formation and capping, manganese horizons in sedimentary and meta-sedimentary sequences, thick bauxite capping, regional chromite lodes in large ultramafics; ...
Impact of greenhouse gases on surface coal mining in Brazil
Coal ore extraction involves both surface (open-pit) and underground mining techniques. The method selected depends on a variety of factors, including the nature and location of the deposit, size, depth, and grade of the deposit (Norgate and Haque, 2010).Surface mining operates in two distinct stages, overburden removal and …
Using hydraulic fracturing to control caving of the hanging
Hanging roofs can occur on a very large scale (generally can reach 15,000 m2) during the initial mining stages in longwall coal mining operations and are often a result of hard roof at the active mining face. Besides, when it suddenly fractures and caves, some risks and disasters would occur such as shock loading, wind blasts, and sudden …
Coal: exploration, reserves, and utilization | ChemTexts
Coal exploration is a very demanding task, highly dependent on geological and economic factors and the utilization of coal. This lecture text includes information on a variety of geological techniques used in the exploration of coal and coal-bearing sequences, as well as on the calculation, assessment, classification, and reporting of …
Coal mining
Coal mining - Extraction, Processing, Pollution: In geologic terms, coal is a sedimentary rock containing a mixture of constituents, mostly of vegetal origin. Vegetal matter is composed mainly of carbon, hydrogen, oxygen, nitrogen, sulfur, and some inorganic mineral elements. When this material decays under water, in the absence of oxygen, the carbon …
Coal
Graphite is the final stage of the carbonization process. Graphite conducts electricity well, and is commonly used in lithium ion batteries. Graphite can also resist temperatures of up to 3,000°C (5,400°F). ... Coal Mining Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it …
Coal mining
In room-and-pillar mining, coal deposits are mined by cutting a network of 'rooms' into the coal seam and leaving behind 'pillars' of coal to support the roof of the mine. These pillars can be up to 40% of the total coal in the seam – although this coal can sometimes be recovered at a later stage. Longwall.
Fractal characteristics of mining-induced overburden …
It can be seen from Fig. 3 that when the working face reaches 25 m, the direct roof of the working face sinks and collapses, forming a small number of obvious separation cracks above the goaf. When mining reaches 30 m, the old roof is suspended to the limit span and breaks and contacts the floor. It is the first pressure stage of the …
Life cycle assessment of coal mines of diverse scales over …
1. Introduction. In the life cycle of a coal mine, there are many environmental impacts, from the exploration to production and eventually closure (Ardejani et al., 2022).The impact of coal mining on greenhouse efficiency and sustainable development has been widely concerned (Akinyemi et al., 2019; Dutta et al., 2020; …
Model of environmental life cycle assessment for coal mining operations
Abstract. This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the …
Coal mining
The cycle of cutting, drilling, blasting, loading, roof supporting, and conveyor shifting is repeated until the entire block is mined out. In modern mechanized longwall operations, the coal is cut and loaded onto a face …
A review of the history of coal exploration, discovery and production
In 2009 the Law on Mineral and Coal Mining 4/2009 was introduced, replacing the previous Mining Law 11/1967, and bringing stronger regulation of the mining industry. ... Coal exploration activities peaked with the coal boom, but then declined, with "greenfields" coal exploration (i.e. early stage exploration in new target areas) reducing ...
Life cycle assessment of opencast coal mine …
51 Citations. Explore all metrics. Abstract. China has the largest coal production in the world due to abundant resource requirements for economic …
Life cycle assessment of opencast coal mine production: a
Inventory. Life cycle inventory (LCI) is an important part of the LCA, and its precision and integrity affect the results of LCA. The inventory considered in the study is shown in Table 1.The data of environmental impact factors in each stage were from the environmental impact assessment report of Yimin opencast coal mine (HBMEP …
Coal and Coal Mining
A four foot coal bed is overlain by 75 feet of overburden: calculate overburden volume using an area of 1 yard long by 1 yard wide: 75 ft./3 ft. per yard = 25 yards depth volume = 25 yds. depth x 1 yd. wide x 1 yard long volume = 25 cubic yds. of overburden. calculate volume …
(PDF) COAL MINING METHODS
Surface mining techniques can be broadly cl assified into the following types: (1) contour strip mining, (2) area strip mining, (3) open-pit mining, and. (4) auger mining. 6.1 Contour strip mining ...
Coal mining projects – Coal 2020 – Analysis
Investments in export-oriented coal mining projects are under consideration in a number of countries. They are at various stages in the development process and here are classified as "more-advanced" and "less-advanced"1. More-advanced projects under development represent about 93 Mtpa of coal mining capacity, of which about 69% are for …