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Treatment of Coal Industry Effluents
Published in Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang, Treatment of Industrial Effluents, 2019
Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang
Coal slurry or sludge is a waste fluid produced by washing of coal with water and chemicals before distributing them to market. When coal is mined underground or by high wall or auger miners, a significant amount of rocks and clays gets mixed within it. These materials must be removed before the coal can be sold to power plants or steel mills. In a wet washing plant, or coal preparation plant, the raw coal is crushed and mixed with a large amount of water, magnetite, and organic chemicals. The huge volume of wastewater left is coal slurry. Rock, clay, and coal too small to float or sink as well as all the chemicals used to wash the coal are present in the slurry, which makes it highly toxic. Chronic exposure to the metals found in coal slurry can virtually damage every part of the body. Health problems associated with such metals include intestinal lesions, neuropathy, kidney and liver failure, cancer, high blood pressure, brittle bones, miscarriages, and birth defects among others. Studies of the effects of coal slurry on human cell tissues have found evidence that coal slurry causes cancerous proliferation, cell death, and damage to kidney cells.
Mining and Drilling
Published in Cameron La Follette , Chris Maser, Sustainability and the Rights of Nature, 2017
Cameron La Follette , Chris Maser
Mountaintop-removal mining for coal in Appalachia has destroyed at least 470 mountains, burying something like 2,000 miles of streams under the rubble, and destroyed 800,000 acres of biologically rich forest. Coal slurry, which remains after the coal is washed, contains impurities, coal dust, and chemical agents. It is injected into abandoned underground mines or held in vast slurry ponds near the mine sites. There are hundreds of these slurry impoundments throughout Appalachia. Ash from the combustion of coal is dumped in rural areas, despite the fact that it contains arsenic, mercury, cadmium, and similar heavy metals, which are extremely toxic. But Congress exempted coal ash from hazardous waste rules in 1980, and state laws are often lax and inconsistent.15
Coal
Published in Peter M. Schwarz, Energy Economics, 2023
Barges are an alternative when the supplier is near a waterway, and trucks are viable for short distances. These modes of transportation also emit coal dust during loading and unloading, as well as emissions from their combustion of fuel. Pipelines are a possible form of transportation for coal slurry. Water use can be an issue in dry regions. Exported coal uses ships, with larger capacity ships for longer distances.
Measurement method and experimental study on the intrusion resistance of coal slurry/wet pulverized coal
Published in International Journal of Coal Preparation and Utilization, 2023
Xiaolei Ma, Daolong Yang, Haichao Duan, Jinjing Tang, Kehong Zheng
Coal slurry is formed by coal dust particles and water in the process of coal dust reduction, which belongs to wet particulate matter with certain cohesion and viscosity. Many research scholars have done a lot of research on the physical properties of granular media with cohesion and viscosity, including the relationship between the resistance of intruding objects in granular media and the shape and size of the intruding objects in the dry case (Albert et al. 2000) (Bergmann et al. 2017) (Costantino et al. 2011) (François, Yoël, and Olivier 2013) (Hosoi and Goldman 2015) (James et al. 2017) (Gravish, Umbanhowar, and Goldman 2010) (Pacheco-V and Ruiz-Suárez 2010) (Reddy, Forterre, and Pouliquen 2011) (Takada and Hayakawa 2019) (Wieghardt 1975; Yang, Nick, and Goldman 2011), the resistance law of probing rods moving in granular media at specific depths and velocities (Hilton and Tordesillas 2013) (Lauga and Powers 2009) (Takada and Hayakawa 2016) (Yuka and Ko 2014)), the study of the resistance in pipeline conveying in the case of water content protocol the resistance characteristics of coal slurry (Gao et al. 2016), the effect of resistance, lubrication and pore pressure on the dynamic or static characteristics of granular systems (Andreea, Xavier, and Arshad 2017) (Delannay et al. 2017) (Nucci, Armanini, and Larcher 2019) (Rausan, Andreea, and Arshad 2018) (Stevens and Hrenya 2005)), the relationship between the motion of the probe rod in a wet granular medium and the size of the probe rod (Hossain and Rognon 2020), so it is crucial to analyze the determinants of the resistance of a moving object in dry versus wet particles (Coppin et al. 2022).
Study of particle size distribution of pulverized coals in utility boilers
Published in Particulate Science and Technology, 2018
Utility boilers are basically designed for specific PSD to enhance the combustion characteristics for maximum efficiency and particulate emissions control (Chang et al. 2015). Incorrect coal PSD may lead to lower boiler output, friction in the boiler, greater carbon content in ash, and lower efficiency (Chang et al. 2015). An alternative fuel technology, growing massively, is coal slurry fuels. Coal slurry fuels consist of pulverized or micro-ionized coal particles suspended or dispersed in liquids like water, oil, and methanol (Lee, James, and Sudarshan 2015). Coal slurry fuels have the advantages of possessing high energy density and being convenient to handle as a liquid fuel (Lee, James, and Sudarshan 2015).
Drying Characteristics and Kinetics Behavior of Indian Coal Slurries Using Natural Draft Tray Dryer
Published in International Journal of Coal Preparation and Utilization, 2023
Deepak Kumar Paswan, Amrit Anand, Barun Kumar Nandi, Shalini Gautam
Coal slurry is a by-product of coal washery and because of its higher moisture content, cannot be employed on a large basis, high ash content, and low GCVs. Because of the fast expansion in the quantity of coal washing in India in current years, the amount of coal slurry has increased rapidly in recent years, ultimately leading to massive energy loss and environmental damage. At the moment, the preferred way for using coal slurry is to burn it as fuel for power generation (Cheng and He 2012). The larger moisture level, on the other hand, presents serious issues in preventing its widespread use and perhaps affecting the boiler’s steady functioning. As a result, coal slurry must be dried prior to burning to minimize moisture content and boost the gross calorific values so that the coal slurry may be used more widely for economic, social, and environmental reasons. Currently, there are two different kinds of coal slurry drying techniques: mechanical drying and heat drying. Mechanical drying comprises shifting, centrifugation, and filter press drying; nonetheless, the moisture content remains high (about 20%)(Xiaomin 2004) after mechanical drying and does not suit the demands of the vast majority of industrial applications. To reduce the moisture level even more, thermal drying is necessary. Direct or indirect contact between wet coal sand and a heated medium, such as hot air, is now used to dry it, (Hu et al. 2013; Man et al. 2015; Park et al. 2014; Pawlak-Kruczek, Plutecki, and Michalski 2014), high-temperature gas, or a combination of the two (Vorres 1994), as well as superheated steam (Aziz, Oda, and Kashiwagi 2014; Gao 2010; Pakowski, Adamski, and Kwapisz 2012; J. Zhu et al. 2015). Similarly, low rank coals will remain the primary energy sources through 2100 (Horio 2010). According to US Department of Energy demographics, availability of known coal across the world will be remain more than 150 years at present consumption rates (Jangam, Karthikeyan, and Mujumdar 2011).