Elemental Mercury Capture from Flue Gas by Magnetic Mn鈥揊e Spinel: Effect of Chemical Heterogeneity

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• 作者：Shijian Yang ; Yongfu Guo ; Naiqiang Yan ; Daqing Wu ; Hongping He ; Zan Qu ; Jinping Jia
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2011
• 出版时间：August 17, 2011
• 年：2011
• 卷：50
• 期：16
• 页码：9650-9656
• 全文大小：908K
• 年卷期：v.50,no.16(August 17, 2011)
• ISSN：1520-5045

文摘

A stoichiometric nanosized Mn鈥揊e spinel (Fe_2.2Mn_0.8O₄) was synthesized using a coprecipitation method. After the thermal treatment at 400 掳C under air, chemical heterogeneity deriving from the oxidation kinetic difference between Fe²⁺ and Mn²⁺/Mn³⁺ was observed in (Fe_2.2Mn_0.8)_1-未O₄. XPS and TEM analyses both pointed a Mn enrichment (especially Mn⁴⁺ cation) on the particle鈥檚 surface. Furthermore, the percent of cation vacancy on the surface increased obviously due to the enrichment of Mn⁴⁺ cation on the surface. As a result, the capacity of (Fe_2.2Mn_0.8)_1-未O₄-400 for elemental mercury capture was generally much better than those of MnO_x/纬-Fe₂O₃, (Fe_2.2Mn_0.8)_1-未O₄-200 and Fe_2.2Mn_0.8O₄. Furthermore, the saturation magnetization of (Fe_2.2Mn_0.8)_1-未O₄ obviously increased after the thermal treatment under air at 400 掳C, which made it easier to separate the sorbent and adsorbed mercury from the fly ash for recycling, regeneration, and safe disposal of the adsorbed mercury. Therefore, (Fe_2.2Mn_0.8)_1-未O₄-400 may be a promising sorbent for elemental mercury capture.