— Thermodynamic analysis using the C-R method shows that the activation energy of the reaction between ASA and coal dust mixture is 91.371 % higher than the activation energy of the coal dust reaction during the rapid reaction phase, and the ASA makes the coal dust pyrolysis reaction require more energy and increase the difficulty of …

 — Apart from the presence of pollutants like PAHs in coal, the simple presence of coal dust has been shown to cause ecological harm. In South Africa, for example, a 2004 study found that coal dust from the Richards Bay Coal Terminal harms local mangrove trees and related ecosystems by impairing the ability of the trees to photosynthesize. The ...

 — Instead, it might be a fraction for a fractal medium reaction. This is because coal combustion is so complex that it cannot be described as a basic reaction or a mixture of several basic reactions. Coal combustion is therefore influenced by many factors. 7.2.4.2.3 Restriction Effects of Surface Structure and Ash Layer

 — A two–step parallel coal dust oxidation reaction mechanism is used to study the self–ignition and combustion characteristics of coal dust under inclination conditions. The consumption and ...

 — Coal is the basic energy and important industrial raw material in China, and the energy system dominated by coal has supported the rapid development of the national economy (Chen et al., 2008; Wang et al., 2021).In the process of coal mining, because coal dust and gas often coexist in coal mines, when the gas is ignited and under the action of …

 — When the ratio of Fe to Ca is 2:8, the formation of 2CaO·Fe 2 O 3 at 800–900 °C decreases the rate and efficiency of combustion. 32 Avoiding these disadvantages can significantly improve the catalytic effect of the dust. 34 To date, the carbon–oxygen reaction mechanism of the catalytic reaction mainly includes the electron transfer theory ...

1.5.2 Combustion. Coal combustion is an age-old practice for the generation of electricity but the quality requirements for various types of combustion systems are different. There …

 — The reaction front of CH 4 /coal dust mixture is captured by a high-speed camera equipped with an image intensifier and a bandwidth filter. The turbulence parameters of flow fields are recorded by Particle Image Velocimetry. ... Effect of fuel ratio of coal on the turbulent flame speed of ammonia/coal particle cloud co-combustion at …

The production of coal dust is a common side effect of almost all mining activities (Shahan et al. 2019) Considering the global extent of coal mining and its potential for a large burden of ...

 — A two–step parallel coal dust oxidation reaction mechanism is used to study the self–ignition and combustion characteristics of coal dust under inclination conditions. The consumption and transfer of multiple substances are considered. ... [13] was conducted in a static environment with an average wind speed of less than 0.01 m/s (measured ...

Wet dedusting is the main coal dust suppression technique in coal mines, and coal wettability is the main factor affecting dust suppression efficiency. To investigate the main factors affecting the coal wettability and improve it, the coal–water contact angle was used as an index to characterize the coal wettability, and the wettability of six coal samples …

 — At present, fossil fuel is used to meet 80% of the world's energy demands [1,2,3].Coal combustion accounts for over 27% of the energy output [2,4], resulting in the emissions of the oxides of sulfur (up to 55% of all the world's SO 2) and nitrogen (up to 25%), carbon dioxide (up to 45%) and fine ash particles (PM x) (up to 20%) [5,6].A high …

 — To this end, a review of coal dust combustion as reported in the literature is presented, and a mathematical model of flame propagation through coal dust-air mixtures is developed in detail. The model is basically used to predict burning velocities and to study the structure of coal dust-air flames.

 — The sulfur, in coal, oxidizes upon combustion and pollutes the air, water, and land by releasing SOx (SO 2, SO 3, SO 3 2− and H 2 SO 4).The formation of the poisonous SO 2 gas, a major pollutant in air, may accelerate the rate of diseases and decrease life expectancy around power plants (Bascom et al., 1996, Kelsall et al., 1997, Health …

 — From Figure 12, it can be seen that at 4–8 ms, the coal dust gradually accelerates to move to the right, and with the increase of the coal dust concentration, the coal dust movement speed gradually decreases, …

 — It was found that the addition of low-concentration coal dust increased the pressure and flame propagation speed of the explosions, and the volatile content and gas content in the coal dust played ...

 — The production rate of R i species by the chemical reaction is ... Computational fluid dynamics were used to analyze the dust emission according to the wind direction and speed when coal dust was generated in a coal storage shed. When the wind speed is 2.0 m/s, the dust behavior according to the wind direction during coal storage in …

Coal dust explosion is a process of rapid oxidation reaction between oxygen in air and coal dust under the action of high temperature or heat source with certain ignition energy, …

However, different coal dust concentrations will lead to contrasting influence degrees on the result. Liu et al. [8] found that coal dust can accelerate the flame propagation speed of methane ...

 — Regarding the heterogeneous reactions of raw coal dust particles, the decreasing combustion reaction rate, and heat generation rate had a negative impact on the devolatilization and combustion of coal dust. Therefore, the combustion reactions and consumption of coal char, fixed carbon, and active structures were insufficient and …

However, different coal dust concentrations will lead to contrasting influence degrees on the result. Liu et al. [8] found that coal dust can accelerate the flame propagation speed of methane ...

 — The flame propagation behaviors of methane-air/coal dust mixtures showed that the coal dust after low-temperature oxidation displayed a lower flame propagation speed in the stage of gas phase ...

 — Coal dust flame suppression experiments were carried out in a coal dust explosibility identification and analysis system, as shown in Fig. 2. First, 1.0 g pulverized coal was placed in the sample tube together with different mass fractions of the suppressor sample. The sample tube was securely fixed in case it would be blown away by air …

 — The explosion risk of hybrid CH4/coal dust is much higher than that of pure coal dust in all dust concentrations, but it is only higher than that of pure coal dust explosion at high CH4 ...

 — The Global Carbon Cycle. Figure 15.6.3 15.6. 3 illustrates the global carbon cycle, the distribution and flow of carbon on Earth. Normally, the fate of atmospheric CO …

various concentrations of coal mine dust. Figure 4. Predicted prevalence of PMF among British coal miners after a 35-year working lifetime by mean concentration of respirable coal mine dust. Figure 5. Prevalence of simple CWP category 1 or greater among U.S. coal miners by estimated cumulative dust exposure and coal rank. Figure 6.

 — Burning of the coal dust is mainly from carbon char that mixes with air by relative velocity between the gas and solid phases. Reactions of volatized methane are …

The coal dust explosibility data are compared to those of other hydrocarbons, such as polyethylene dust and methane gas, in an attempt to understand better the basics of coal ... speed personal computer (PC)-based data acquisition system. It can sample data from 16 channels at a maximum rate of 9 kHz if all channels are used or at ...

 — Autoignition and smoldering of coal dust have gained great safety concern in both industry and mining due to their high susceptibility to heating. To better understand their controlling mechanism, autoignition and smoldering of bituminous coal particles (1-mm diameter) and coal powders (0.1-mm diameter) in the form of bulk layer heated by 4–45 …

 — Despite international efforts to limit worker exposure to coal dust, it continues to impact the health of thousands of miners across Europe. Airborne coal dust has been studied to improve risk models and its control to protect workers. Particle size distribution analyses shows that using spraying systems to suppress airborne dusts can …