Mechanism of mercury vapor release from flue gas desulfurization gypsum

Zhu, Zhenwu; Zhuo, Yuqun; Fan, Yaming; Wang, Zhipeng

doi:10.1016/j.fuproc.2016.10.015

Cited by 25 publications

(2 citation statements)

References 33 publications

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“…The thermal treatment involved in gypsum production can lead to the release of mercury into the atmosphere, resulting in pollution and posing potential risks to human health. Therefore, it is imperative to investigate the migration behavior of heavy metals within desulfurization gypsum [4][5][6][7][8]. In a study on the heavy metal stability in desulfurization gypsum, Zhao et al [9] investigated the thermal stability, chemical speciation, and leaching characteristics of seven heavy metals (Hg, As, Cr, Cd, Ba, Mn, and Pb) in the desulfurization gypsum from three coal-fired power plants in China.…”

Section: Introductionmentioning

confidence: 99%

Solidification and Release Characteristics of Heavy Metals in Gypsum from Coal-Fired Power Plants

Wang,

Wei,

Zhao

et al. 2024

Energies

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Heavy metals in flue gas desulfurization (FGD) gypsum from coal-fired power plants are at risk of releaching during the processes of stockpiling and resource utilization. In this study, the effects of organosulfur chelators dithiocarbamate (DTC) and trisodium trithiocyanate-15 (TMT-15) on the solidification characteristics of heavy metals in desulphurized gypsum under different mass fractions, pH values, water contents and reaction times were investigated. The chemical composition and morphology were analyzed by inductively coupled plasma atomic emission spectrometer (ICP-AES) and scanning electron microscope (SEM). The experiments showed that both DTC and TMT-15 were effective at stabilizing the heavy metals in the FGD gypsum, with more than a 50% curing effect for all the heavy metals except Pb. DTC showed a better stabilization for Pb, Hg, Cu, Zn, and Cr, and TMT-15 showed a better curing effect for Cd. The solidified gypsum had good heavy metal stability in low-water-content environments. Increasing the mass fraction, reaction time, and pH decreased the heavy metal leaching, and the mass fraction had the greatest effect on the total heavy metal leaching concentration, followed by the reaction time and pH value.

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Section: Introductionmentioning

confidence: 99%

Solidification and Release Characteristics of Heavy Metals in Gypsum from Coal-Fired Power Plants

Wang,

Wei,

Zhao

et al. 2024

Energies

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“…The relatively low recovery ratio means that the technique cannot accurately be used to determine the release characteristic of mercury in each form. Many scholars have determined that the Hg 0 will be released when the FGD gypsum is exposed to air or water. − Therefore, it is possible that the exposure of gypsum to the air, the addition of aqueous solution, and heating the solution in a water bath all lead to the loss of mercury and cause the low recovery ratio. In this study, gas phase evolution experiments were set up first to prove that elemental mercury was escaping during the extraction process.…”

Section: Introductionmentioning

confidence: 99%

Increasing Recovery Ratios with an Improved European Community Bureau of Reference Method for Mercury Analysis in Flue Gas Desulfurization Gypsum

Bian

Zhang

et al. 2018

Energy Fuels

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Coal-fired power plants produce flue gas desulfurization (FGD) gypsum as a byproduct of the sulfur removal process. This gypsum is contaminated with trace elements. Knowing the occurrence and release characteristics of trace elements from the FGD gypsum is very important if the gypsum is to be safely used in different applications. The sequential extraction procedure proposed by the European Community Bureau of Reference (BCR) can be used to provide mercury speciation information for FGD gypsum samples. Many researchers have used the BCR sequential extraction method to analyze the occurrence of mercury in FGD gypsum. Unfortunately, the recovery ratio is low, around 50–60%. The recovery is low because the BCR method does not include the portion of elemental mercury (Hg0) lost during each leaching step. In this work, modifications to the BCR method were made to more accurately determine the amount of mercury lost during the extraction. Using this “improved BCR method”, the Lumex RA-915+/PYRO-915 mercury analyzer measures the mercury content in the residues at each extraction step. The difference between the sample and residue concentrations is equal to the amount of Hg released. This indirect measurement method was used to overcome the shortcomings of the traditional BCR sequential extraction process. The results show that the “improved BCR method” has a recovery ratio of about 99%, which can more accurately evaluate the environmental stability of mercury in gypsum. Thus, an improved five-step sequential extraction procedure for analysis of mercury was successfully applied to FGD gypsum samples in this study.

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Combustion Emissions

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Mechanism of mercury vapor release from flue gas desulfurization gypsum

Cited by 25 publications

References 33 publications

Solidification and Release Characteristics of Heavy Metals in Gypsum from Coal-Fired Power Plants

Solidification and Release Characteristics of Heavy Metals in Gypsum from Coal-Fired Power Plants

Increasing Recovery Ratios with an Improved European Community Bureau of Reference Method for Mercury Analysis in Flue Gas Desulfurization Gypsum

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