球磨液对机械化学半干法改性飞灰脱汞性能的影响  

Effect of ball milling solution on mercury removal of mechanochemical semi-dry modified fly ash

作　　者：朱明 段钰锋[1] 耿新泽 金启航 张军[1] ZHU Ming;DUAN Yufeng;GENG Xinze;JIN Qihang;ZHANG Jun(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,School of Energy and Environment,Southeast University,Nanjing 210096,China)

机构地区：[1]能源热转换及其过程测控教育部重点实验室,东南大学能源与环境学院,江苏南京210096

出　　处：《中南大学学报（自然科学版）》2023年第10期3840-3851,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51876039)。

摘　　要：采用全方位行星式球磨机对燃煤飞灰进行机械化学半干法改性,分别探究球磨辅助液对改性飞灰脱汞性能的影响及反应前后飞灰中的汞形态,并结合飞灰改性前后的理化特性对其脱汞机理进行分析。研究结果表明:球磨液的加入可使飞灰粒度变小,比表面积增大,孔隙结构更发育,含氧官能团更丰富,有利于Hg^(0)的脱除;添加不同球磨液时,脱汞效率从高到低为乙酸、乙醇、水,这是由于乙酸可使飞灰表面的COOH/C(O)—O—C官能团含量从11.25%增加至23.56%,从而促进Hg^(0)的氧化脱除;添加改性剂S后,可使飞灰表面负载S单质,非氧化态的硫含有较多未配对电子,使Hg^(0)更易以HgS的形式被氧化吸附,进而提升飞灰的脱汞性能;在飞灰对汞的脱除中,以氧化脱除为主,其占比大于80%,吸附脱除占比较小。The coal-fired fly ash was modified by mechanochemical semi-dry method through omnidirectional planetary ball mill.The effect of ball mill auxiliary liquid on mercury removal performance of the modified fly ash was investigated,and the mercury morphology before and after the adsorption was explored.The mechanism of mercury removal was analyzed based on the physicochemical properties before and after modification.The results show that the addition of ball milling solutions makes the fly ash sizes smaller,specific surface area larger,pore structure more developed,and oxygen-containing functional groups enriched,which is conducive to removing Hg^(0).When different ball milling solutions are added,the efficiencies of mercury removal rank from high to low as follows:acetic acid,ethanol and water,which is attributed to that the acetic acid can increase the content of COOH/C(O)-O-C functional groups on surface of fly ash from 11.25%to 23.56%,promoting the oxidative removal of Hg^(0).The addition of modifier S allows the S monomers to be loaded on the fly ash surface.The non oxidized state of sulfur contains more unpaired electrons,making it easier for Hg^(0)to be oxidatively adsorbed in the form of HgS,which improves the efficiency of mercury removal.The removal of mercury from fly ash is dominated by oxidation,accounting for more than 80%,while the absorption removal accounts for less.

关 键 词：机械化学法 球磨液 半干法 飞灰 脱汞 

分 类 号：X511[环境科学与工程—环境工程]