摘要
利用自行设计的0.2MW旋风熔融炉研究了不同氧化物（CaO、SiO2和MgO）对焚烧飞灰熔融过程中重金属迁移行为的影响。结果表明：CaO掺杂量为5%时可抑制熔融过程中重金属的排放；SiO2和MgO的掺杂有利于重金属向熔渣中迁移。烟气中As、Cd、Zn、Pb的比例随SiO2掺杂量的增加而减少,而Cu、Co、Mn的在熔渣中的比例显著提高。烟气中重金属含量随着MgO掺杂量的增加呈先减小后增加的趋势,在10%左右达到最低。当MgO掺杂量为10%时,As、Zn、Cd、Pb、Hg大部分迁移至熔融飞灰或烟气中,由高到低顺序为：Hg〉As〉Zn〉 Pb〉Cd。对于Cu、Co和Mn,迁移至熔渣中范围约在45.5 %~59.4 %之间,而在烟气中的比例在23.8%~26.3%之间。XRD分析表明,飞灰中掺杂5%的CaO后,熔渣中为：CaSiO3、CaAl2Si2O8、Ca2Al2SiO7、Fe2SiO4。随着SiO2掺杂量的增加,熔渣中Ca2Al2SiO7、CaSiO3等晶体的份额下降,有利于熔渣中形成玻璃态无定形物质,可显著提高重金属迁移到熔渣的比例。当试样中MgO掺杂量为10%时,熔渣中的主要晶相为：（MgFe）2SiO4、Fe3Al2Si3O12、Ca2MgSi2O7,其熔渣玻璃化程度较好。
The effects of different oxide （CaO, SiO2 and MgO） on heavy metals migration behavior of municipal solid waste incinerator （MSWI） fly ash were investigated in a self-designed 0.2MW swirling furnace during melting process. The results show that the emission of heavy metals could be inhibited when CaO doping amount is 5%. Doping SiO2 and MgO in fly ash is advantageous to migration heavy metals in slag. With the doping amount of SiO2 increasing, the percentages of As, Cd, Zn and Pb were reduced in the flue gas. And the rate of Cu, Co, Mn in the slag is significantly increasing. The percentage of heavy metals content in the flue gas is decreased at first and then increased with the increase in MgO doping, at about 10% to a minimum. When the doping amount of MgO is 10%, most of As, Zn, Cd, Pb and Hg are migrated to the molten fly ash or flue gas, descending order, Hg〉As〉Zn〉Pb〉Cd. The percentage migration of Cu, Co and Mn in the slag is the range of approximately 45.5%-59.4%, while the proportion in the flue gas is 23.8%-26.3%. XRD analysis show that with the fly ash doping 5% CaO, the slag contains CaSiO3, CaAl2Si2O8, Ca2Al2SiO7, and Fe2SiO4. With the increase in doping SiO2, slag Ca2Al2SiO7, CaSiO3 declining share of such crystals. It is conductive to the formation of slag glassy amorphous substance. Increase in the proportion of SiO2 adding fly ash could significantly improve the proportion of heavy metals transfer to the slag. When the MgO content in the samples dope is 10%, the main crystalline phases in slag are （MgFe）2SiO4, Fe3Al2Si3O12, and Ca2MgSi2O7, the slag is in preferably vitrification.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2014年第17期2754-2760,共7页
Proceedings of the CSEE
基金
国家自然科学基金项目(50806020)
河南省科技创新人才计划(杰出青年)(114100510010)~~
关键词
城市生活垃圾焚烧飞灰
旋风炉
熔融
重金属
迁移
municipal solid waste incinerator （MSWI） flyash
swirling furnace
melting
heavy metals
migration
