锰铁复合磁性材料制备及其对零价汞吸附性能研究  

Study on the preparation of manganese-Fe composite magnetic materials and their capability for gaseous elemental mercury capture

作　　者：曹静 刘盛余[1] 杨杰 能子礼超 杨淑清 CAO Jing;LIU Shengyu;YANG Jie;NENGZI Lichao;YANG Shuqing(College of Resources and Environment,Chengdu University of Information Technology,Chengdu 610225;Academy of Resources and Environmental Sciences,Xichang University,Xichang 615013)

机构地区：[1]成都信息工程大学资源环境学院,成都610225 [2]西昌学院资源与环境学院,西昌615013

出　　处：《环境科学学报》2021年第9期3745-3752,共8页Acta Scientiae Circumstantiae

基　　金：四川省科技厅重点研发项目(No.2020YFS0342);成都信息工程大学人才启动基金(No.KYTZ202014);国家自然科学基金面上项目(No.21676032);四川省教育厅创新团队项目(No.14TD0020)。

摘　　要：燃煤工业是我国人为汞排放的主要来源,寻求合理有效的途径来控制汞排放至关重要.本文将氧化性强的过渡金属锰离子引入Mn/γ-Fe_(2)O_(3)晶格中,制备出锰铁复合磁性材料(Fe_(3-x)Mn_(x))1-δO_(4),以其来模拟Hg0在燃煤废气中的吸附过程,并通过比表面积和孔隙率、X衍射分析、SEM、磁性分析、氧化还原等材料表征方法研究(Fe_(3-x)Mn_(x))1-δO_(4)的吸附性能,同时重点研究(Fe_(3-x)Mn_(x))1-δO_(4)在不同掺杂量、温度、空速等操作条件下对Hg0的吸附能力.结果显示,制备所得的(Fe_(3-x)Mn_(x))1-δO_(4)的比表面积均在120 m^(2)·g^(-1)以上,较大的比表面积和孔体积可以为Hg0的吸附反应提供更多的活性区域,促进反应进行.SEM表征也显示(Fe_(3-x)Mn_(x))1-δO_(4)的微观特征呈现球状颗粒物,拥有较大的表面积,能够提供更多的吸附活性位.在磁性铁氧化物中引入过渡金属锰,其对汞的氧化能力明显增强;在100~200℃的反应温度窗口,此时温度大小与(Fe_(3-x)Mn_(x))1-δO_(4)对汞的吸附能力成正比,达到200℃时,500 min内平均穿透率可达到9%;空速对(Fe_(3-x)Mn_(x))1-δO_(4)吸附汞的能力影响较小.In China, coal-fired power plants is the main stationary sources of atmospheric Hg emissions. Thus, it is vital to find a reasonable and effective way to control Hg emissions. In this work, the ferromanganese composite magnetic material(Fe_(3-x)Mn_(x))1-δO_(4) was prepared with Mn/γ-Fe_(2)O_(3) and strong oxidized transition metal manganese ions. It has been applied to adsorb the Hg0 from simulated coal-fired flue gas. Various characterization methods including specific surface area test, X-ray diffraction(XRD), scanning electron microscopy(SEM), magnetic analysis was employed for the characterization of the composite materials. It also focuses on the adsorption capacity of(Fe_(3-x)Mn_(x))1-δO_(4) to Hg0 under operating conditions such as doping quantity, different temperature and space velocity. It has been found that the the specific surface area of prepared(Fe_(3-x)Mn_(x))1-δO_(4) is more than 120 m^(2)·g^(-1).The larger specific surface area and pore volume can provide more active areas for the adsorption reaction of Hg0 and promote the reaction. SEM characterization also showed the microscopic characteristics of(Fe_(3-x)Mn_(x))1-δO_(4) are spherical particles with large surface area and can provide more adsorption active sites. The removal efficiency of the mercury could be enhanced when the transition metal manganese was doped on the magnetic iron oxide. In the reaction temperature window of 100~200 ℃, the temperature is the same as(Fe_(3-x)Mn_(x))1-δO_(4) is directly proportional to the adsorption capacity of mercury. When it reaches 200 ℃, the average penetration rate can reach 9% within 500 minutes, and the space velocity has little effect on the energy of mercury adsorption by(Fe_(3-x)Mn_(x))1-δO_(4).

关 键 词：Fe_(2)O_(3) 锰离子 零价汞 脱汞 燃煤废气 

分 类 号：X701[环境科学与工程—环境工程]