生物质飞灰超声波辅助滤洗试验  

Experimental study on ultrasonic-assisted leaching of biomass fly ash

作　　者：韩奎华[1,2] 刘文洋 宋传林 任科 滕召才 牛胜利[1,2] 王永征[1,2] 朱应泉 龙慎伟 HAN Kuihua;LIU Wenyang;SONG Chuanlin;REN Ke;TENG Zhaocai;NIU Shengli;WANG Yongzheng;ZHU Yingquan;LONG Shenwei(School of Energy and Power Engineering,Shandong University,Jinan 250061,China;Shandong Engineering Laboratory for High-efficiency Energy Conservation and Energy Storage Technology&Equipment,Shandong University,Jinan 250061,China;Shandong Fengyuan Biomass Power Generation Co.,Ltd.,Zaozhuang 277300,China)

机构地区：[1]山东大学能源与动力工程学院,山东济南250061 [2]山东大学高效节能及储能技术与装备山东省工程实验室,山东济南250061 [3]山东丰源生物质发电股份有限公司,山东枣庄277300

出　　处：《洁净煤技术》2022年第6期184-191,共8页Clean Coal Technology

基　　金：山东省重点研发计划资助项目(2016GGX104005)。

摘　　要：生物质发电锅炉产生的飞灰一般用作建筑原料和肥料生产的辅料,然而飞灰中的有害成分会降低建筑材料的稳定性,造成农田重金属富集。因此,飞灰原料的预处理和适用性改善成为关键。以生物质电厂飞灰为原料,筛分得到粒径<0.2 mm的细灰,将细灰与去离子水配制浆液,采用超声辅助浸出、过滤处理;考察超声时间、浆液温度、固液质量比对宏量金属元素K、Na、Zn、Ca以及4种微量重金属元素Co、Cr、Ni、Pb浸出的影响规律,并探索适宜的操作参数。结果表明,试验采用的细灰富含CaO、SiO_(2)和K_(2)O。对于宏量金属元素,超声时间1~30 min,随时间延长金属元素浸出质量浓度和浸出量增大且趋向恒定,而Ca^(2+)由于发生碳酸化反应而先增大后缓慢减小。浆液温度25~70℃时,浆液浸出生成Ca^(2+)离子和碳酸盐化受温度影响尤其显著,随浆液温度升高,Ca^(2+)浸出质量浓度先增大后减小,其他金属元素浸出质量浓度和浸出量均增大。固液质量比1∶3~1∶6时,随固液质量比减小,金属元素浸出质量浓度降低,而金属元素浸出率增大。超声时间20 min、浆液温度50℃、固液质量比1∶5时,钾元素浸出率达到47.22%。超声时间、浆液温度和固液质量比对于微量重金属元素的浸出过程存在一定影响,在试验参数范围内重金属浸出率和浸出量维持在很低水平。典型操作参数为:超声时间30 min、浆液温度25℃、固液质量比1∶5时,Co、Cr、Ni和Pb四种重金属元素浸出率分别低于0.10%、0.30%、0.05%和0.10%。综合考虑技术系统实施和运行成本,适宜的超声时间为15~20 min、浆液温度为40~50℃、固液质量比为1∶3~1∶5。通过对比超声处理的浸出液和残渣中关键碱金属元素、硫和氯元素,宏量可溶性元素大量迁移至滤液中,且微量重金属含量极低,浸出液用作肥料和土壤调节剂具有现实意义。由于可溶性碱金属盐以及氯�The fly ash produced from biomass power generation boilers is generally used as building materials and auxiliary materials for fertilizer production.However,the hazardous components in fly ash can reduce the stability of building materials and cause the enrichment of heavy metals in farmland.Therefore,the pretreatment of fly ash raw materials and the improvement of suitability are the key issues.In this study,fly ash from biomass power plant was used as raw material to obtain fine ash with particle size<0.2 mm by sieving.Fine ash and deionized water were prepared into slurry,which was treated by ultrasonic-assisted leaching and filtration.The effects of sonication time,slurry temperature,solid-liquid mass ratio on the leaching of macroscopic metal elements K,Na,Zn,Ca,and four trace heavy metal ele⁃ments Co,Cr,Ni,Pb were investigated.The appropriate operating parameters were explored.The results show that the fine ash used in the experiment is rich in CaO,SiO_(2) and K_(2)O.For macroscopic metal elements,the leaching concentration and leaching amount of metal ele⁃ments increase and tend to be constant with the time prolonging within 1-30 minutes of sonication.While Ca^(2+) increases first and then decreases slowly due to carbonation reaction.In the range of slurry temperature from 25℃to 70℃,Ca^(2+) generation and carbonation are sig⁃nificantly affected by temperature.With the increase of slurry temperature,the leaching mass concentration of Ca^(2+) increases firstly and then decreases,but the leaching mass concentration and leaching amount of other metal elements increase.In the range of solid/liq⁃uid mass ratio 1∶3 to 1∶6,the leaching concentration of metal elements decreases and the leaching rate of metal elements increases with the decrease of solid/liquid mass ratio.When sonication time is 20 min,the slurry temperature is 50℃,and the mass ratio of solid to liq⁃uid is 1∶5,the leaching rate of potassium reaches 47.22%.Sonication time,slurry temperature and solid-liquid mass ratio have certa

关 键 词：生物质飞灰 超声波 碱金属元素 重金属元素 超声波辅助滤洗 

分 类 号：X705[环境科学与工程—环境工程]