废弃脱硝催化剂附着飞灰的特性分析与钒砷浸出研究  

Characteristics analysis and the leaching research about vanadium and arsenic of fly ash attached with waste denitration catalyst

作　　者：刘向辉[1] 杨巧文[1] LIU Xianghui;YANG Qiaowen(School of Chemical and Environment Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《煤炭学报》2021年第S01期441-447,共7页Journal of China Coal Society

基　　金：中央高校基本业务费资助项目(2010Y14)。

摘　　要：为考察燃煤电厂失活脱硝催化剂附着飞灰的主要成分和毒性,对飞灰进行收集,以收集的飞灰为研究对象,对飞灰进行XRF,XRD和SEM表征分析,并采用硫酸硝酸浸出方法分析飞灰重金属浸出毒性。结果表明飞灰中主要成分是二氧化硅、硅铝酸盐和硫酸钙,还含有一定量二氧化钛及重金属(铜、锌、铬、铅、钡和镍),其中镍、砷和钒含量较高,分别为66.96,252.33和432.85 mg/kg。毒性浸出试验中,发现飞灰中元素铜、锌、铬、铅、钡和镍均被浸出,浸出量分别为0.042,0.038,0.011,0.006,0.004和0.034 mg/L,同时发现该飞灰中砷浸出量为9.33 mg/L,高于标准中的规定值5 mg/L,且浸出液中钒含量高达27.27 mg/L,表明飞灰具有一定的浸出毒性。为了降低飞灰钒和砷的浸出毒性,采用氢氧化钠溶液对飞灰中钒和砷进行浸出,考察碱液质量分数、温度和碱浸时间对飞灰中钒和砷浸出的影响,研究表明碱液浸出最佳条件为:碱液质量分数11%,浸出温度70℃,浸出时间60 min;此时钒和砷的浸出率分别可以达到99.24%和92.33%,浸出渣中钒和砷的毒性浸出量为0,其余的元素浸出量也大幅降低,浸出液中钒和砷可以后续资源化利用。In order to investigate the main components and toxicity of fly ash attached with deactivated denitrification catalysts in coal-fired power plants,fly ash sample was collected,and a series of characterization analysis(XRF,XRD and SEM)was carried out on the fly ash.Meanwhile,the leaching toxicity of heavy metals in fly ash was investigated with sulfuric acid and nitric acid leaching method.The results showed that the main components of fly ash were silicon dioxide,aluminosilicate and calcium sulfate.And a certain amount of titanium dioxide was in fly ash.Some heavy metals(copper,zinc,chromium,lead,barium and nickel)were detected,and the content of nickel,arsenic and vanadium were 66.96,252.33 and 432.85 mg/kg respectively,which were higher than other metals.The leaching toxicity of heavy metals in fly ash was conducted with the sulfuric acid and nitric acid leaching method.The elements copper,zinc,chromium,lead,barium and nickel in the fly ash were considered,and the leaching amounts were 0.042,0.038,0.011,0.006,0.004 and 0.034 mg/L respectively.At the same time,it was found that the leaching amount of arsenic in the fly ash was 9.33 mg/L,which was higher than the standard 5 mg/L,and the vanadium content in the leaching solution was as high as 27.27 mg/L.It showed that fly ash has certain leaching toxicity.In order to reduce the leaching toxicity of vanadium and arsenic in fly ash,sodium hydroxide solution was used to leach vanadium and arsenic in fly ash.The influence of alkali concentration,temperature and alkaline leaching time on the leaching efficiency of vanadium and arsenic in fly ash was investigated.The leaching rates of vanadium and arsenic can reach 99.24%and 92.33%respectively at the best conditions(sodium hydroxide concentration 11%,leaching temperature 70℃,and leaching time 60 min).The leaching toxicity of vanadium and arsenic from the leaching residue was also conducted.The leaching amount of vanadium and arsenic decreased to 0 with the sulfuric acid nitric acid leaching method,meanwhile,the leach

关 键 词：飞灰 浸出 脱硝催化剂 钒 砷 

分 类 号：TQ536.4[化学工程—煤化学工程]