摘要
煤气化细渣是煤炭清洁高效利用的副产物之一,其资源化应用迫在眉睫。通过简单筛分得到固定碳含量高于60%的高炭组分,并以此为原料,采用超声酸浸法制备多孔材料。以核废水中放射性碘的吸附处理为应用背景,用碘吸附值表征多孔材料的吸附性能。结合SEM、BET、XRD和FT-IR等性质和结构分析方法,系统研究了超声时间、超声功率、酸浓度和温度对多孔材料碘吸附性能和组成结构的影响规律;并探讨了超声强化酸浸对残炭的组成结构的影响机制和灰成分的迁移转化规律,总结出超声强化酸浸作用机理。结果表明,煤气化细渣高炭组分在酸浓度为4 mol/L、酸浸温度为50℃、超声功率为210 W,超声时间1.5 h的条件下,所制备多孔材料的碘吸附性能最佳,为468.53 mg/g,比表面积达到474.97 m^(2)/g,且具有以介孔为主的丰富孔隙结构。各因素对多孔材料碘吸附性能影响的顺序为:超声时间>酸浓度>超声功率>酸浸温度。超声强化酸浸作用机理是超声空化和机械波作用一方面强化炭灰黏附颗粒的解离,使堵塞在气化细渣孔道内的灰颗粒脱附,增加孔隙结构的连通性;其次,会导致炭灰颗粒表面裂纹的产生,增强碳颗粒内部无机组分的可及性;第三,能够提高酸浸过程的传质速率,强化气化细渣中的无机组分的浸出效果。
Coal gasification fine slag is one of the by-products from clean and efficient utilization of coal,and its resource utilization is extremely urgent.In this work,a high carbon fraction with a fixed carbon content higher than 60%was obtained by simple sieving of gasification fine slag,from which a porous material was prepared by ultrasonic acid leaching method.The adsorption performance of porous materials,being used as treatment of radioactive iodine in nuclear wastewater,is characterized by iodine adsorption value.The effects of ultrasound time,ultrasound power,acid concentration,and temperature on the iodine adsorption performance and compositional structure of the porous materials were systematically investigated by combining the results of SEM,BET,XRD,and FTIR.The mechanisms of ultrasound-enhanced acid leaching on compositional structure of residual carbon and migration and transformation laws of the ash constituents were explored and summarized.The results show that the porous material prepared under conditions of acid concentration of 4 mol/L,acid immersion temperature of 50℃,ultrasonic power of 210 W,and ultrasonic time of 1.5 h has the best iodine adsorption performance of 468.53 mg/g,with a specific surface area of 474.97 m^(2)/g,and possesses a rich pore structure with predominant mesopores.The order of each factor on the iodine adsorption performance is:sonication time>acid concentration>sonication power>acid immersion temperature.The mechanism of ultrasonic enhanced acid leaching is that ultrasonic cavitation and mechanical wave action firstly enhance dissociation of carbon-ash adherent particles,thus making desorption of ash particles blocked in pore channels of the gasification slag to increase its connectivity;secondly,lead to generation of cracks on surface of the carbon and ash particles to enhance accessibility of inorganic components inside the carbon particles;and thirdly,enhance the acid leaching process by increasing mass transfer rate to strengthen leaching effect of inorganic components in the gasification slag.
作者
李翠翠
韩瑞
周安宁
张宁宁
郭凯强
陈恒
陈肖役
李振
王俊哲
LI Cuicui;HAN Rui;ZHOU Anning;ZHANG Ningning;GUO Kaiqiang;CHEN Heng;CHEN Xiaoyi;LI Zhen;WANG Junzhe(School of Chemistry and Chemical Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Coal Resources Exploration and Comprehensive Utilization,MNR,Xi’an 710054,China;Shaanxi Coal Chemical New Energy Co.Ltd,Xi’an 710000,China)
出处
《燃料化学学报（中英文）》
EI
CAS
CSCD
北大核心
2024年第5期630-646,共17页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(52374279)
陕西省重点研发计划(2023-YBGY-055)资助。
关键词
煤气化细渣
残碳
超声
酸浸
多孔材料
coal gasification fine slag
residue carbon
ultrasound
acid leaching
porous material
