Reaction mechanism of reductive decomposition of FGD gypsum with anthracite

Zheng, Dafeng; Lu, Hailin; Sun, Xiaoxin; Liu, Xiaodong; Han, Weiqing; Wang, Lianjun

doi:10.1016/j.tca.2013.02.026

Cited by 67 publications

(31 citation statements)

References 14 publications

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“…As expected, the carbon of char had an obvious decline with the addition of CaSO 4 correspondingly. The results were consistent with the reactions between carbon and CaSO 4 [15,16], which indicated that the carbon of coal as a solid reductant might be responsible for CaSO 4 decomposition during coal pyrolysis.…”

Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysissupporting

confidence: 81%

“…According to the previous literatures [15,16], there were two possible mechanisms. One approach was solid-solid reaction mechanism:…”

Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysismentioning

confidence: 99%

“…Besides carbon reducing agent, the pyrolyzed gas as gaseous reductants also could lead to CaSO 4 reduction [14][15][16][17]. To investigate the influence of pyrolyzed gas and produced tar on CaSO 4 decomposition, the char obtained at 900°C for an hour was used, which contained almost no volatile matter.…”

Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysismentioning

confidence: 99%

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An experimental study of CaSO 4 decomposition during coal pyrolysis

Jia

Wang

Cen

et al. 2016

Fuel

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Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysissupporting

confidence: 81%

“…According to the previous literatures [15,16], there were two possible mechanisms. One approach was solid-solid reaction mechanism:…”

Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysismentioning

confidence: 99%

Section: Mechanism Of Caso 4 Decomposition During Coal Pyrolysismentioning

confidence: 99%

See 1 more Smart Citation

An experimental study of CaSO 4 decomposition during coal pyrolysis

Jia

Wang

Cen

et al. 2016

Fuel

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“…Several authors have studied the conversion of CaSO 4 into CaS through the carbothermal reaction (Zheng et al, 2013, Zheng et al, 2011, Nengovhela et al, 2007, Van der Merwe et al, 1999. Strydom et al (1997) confirmed the need to perform thermal reduction of CaSO 4 using carbon as a reducing agent in the absence of air, as air was observed to impact negatively on the conversion of CaSO 4 to CaS.…”

Section: Introductionmentioning

confidence: 95%

Thermochemical reduction of pelletized gypsum mixed with carbonaceous reductants

Motaung¹,

Zvimba²,

Maree

et al. 2015

WSA

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The recovery of better quality waste gypsum during acid mine drainage (AMD) neutralization is one step closer to achieving downstream waste gypsum beneficiation for recovery of valuable materials. This can facilitate recovery of treatment costs and prevention of environmental pollution from gypsum waste-dumps. Thermal reduction using rotary kilns to recover valuable materials from waste gypsum remains a critical and controversial process because of waste gypsum handling problems, environmental pollution due to dust and gaseous emissions and poor conversion yields. In order to mitigate these problems and improve waste gypsum conversion yields, pelletization of waste gypsum in the presence of binders (starch and cellulose) was investigated. A laboratory-scale disc pelletizer was used to produce pellets from a mixture of coal and commercial gypsum or waste gypsum, generated during AMD neutralization, with starch and micro-crystalline cellulose used as binders. The pellets were subjected to high-temperature thermal treatment in a tube furnace to generate calcium sulphide (CaS), an important intermediate for waste gypsum beneficiation. The kinetics of thermal conversion of pelletized waste gypsum to CaS were found to be highly dependent on furnace temperature. Results also showed that pelletization affords improved handling of waste gypsum while use of binders as additives significantly improved the CaS yield, with starch giving the better yield compared to cellulose.

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“…Therefore, the desulfurization system must be employed in coal-fired units, and more than two hundred kinds of flue gas desulfurization (FGD) technologies have been studied, of which dozens have already been in operation. The wet FGD (WFGD) technologies account for about 85% for control technology of SO 2 all over the world and desulfurization based on limestone accounts for 90% for the control technology of SO 2 in China [2,3]. However, the desulfurization basing on limestone results in the following questions in China.…”

Section: Introductionmentioning

confidence: 99%